Skip to main content

Full text of "Insects injurious to staple crops"

See other formats 


For  Reference 


NOT  TO  BE  TAKEN  FROM  THIS  ROOM 


fmmmmmBmmmammmmaaioammtmaamatt 


m4Mlmn^j^04{t(iwuf^H 


Property  of 

N.  C.  EXPERiiMENT  STATION 
Department  of  Entomology 

No. 


INSECTS    INJURIOUS    TO 
STAPLE  CROPS. 


BY 

E.  DWIGHT  SANDERSON,  B  S.Agk., 

ENTOMOLOGIST,     UELAWAllE    COLLEGE    AGRICULTURAL 

EXPERIMKNT    STATION; 

ASSOCIATE    PROFESSOR   OF   ZOOLOGY, 

DELAWARE  COLLEGE. 


FIRST  EDITION-. 
FIRST    THOUSAND. 


NEW  YORK : 

JOHN  WILEY  &   SONS. 

I.ONDON-   CHAPMAN   &   HALL,    Limited. 


Copyriffht,  1902, 

BY 

E.  D.  SAISDERSON. 


ROBERT    DRUMVOND,   PRINTER,    NEW    YORK. 


PREFACE. 


The  sources  of  information  concerning  the  insects 
affecting  our  staple  crops  are  widely  scattered  throughout 
the  bulletins  of  the  State  Agricultural  Experiment  Stations 
and  of  the  United  States  Department  of  Agriculture,  a  few 
books  on  Economic  Entomology,  and  various  other  publica- 
tions. Few  men  but  the  entomologist  have  the  desire  or 
ability  to  glean  an  account  of  any  given  insect  from  tlie 
first-mentioned  publications,  if  they  know  of  the  existence 
of  others  than  those  published  by  their  own  State  station. 
The  few  books  which  have  been  written  upon  American 
Economic  Entomology  usually  give  but  a  brief  and  sum- 
mary account  of  any  given  insect,  too  brief — it  seems  to 
the  writer — to  give  a  very  clear  understanding  of  the 
matter. 

In  preparing  the  following  pages  the  author  has  been 
more  and  more  impressed  by  the  fact  that  for  the  control 
of  most  of  the  worst  insect  pests  of  our  staple  crops,  the 
farmer  must  depend  very  largely  upon  general  methods  of 
farm  practice.  This  being  the  case,  it  is  essential  that  he 
have  a  correct  knowledge  of  the  pest  to  be  combated  ;  such 
a  knowledge  of  its  life-history  as  will  make  plain  the  reason 
for  the  effect  of  any  given  ^jrocedure  against  it.  Thus  the 
better  class  of  farmers  may  find  a  work  in  which  each 


Yl  PEEFACE. 

insect  is  treated  somewhat  comjirehensively  as  to  life- 
history,  habits,  and  remedies,  yet  without  being  exhaustive 
or  technical,  to  be  of  considerable  service  to  them.  To 
furnish  such  a  guide  to  the  more  intelligent  class  of  prac- 
tical farmers  has  been  the  aim  of  the  writer,  w^io  trusts 
that  the  following  j^ages  will  be  read  as  such  and  not  as  in 
any  way  a  contribution  to  science. 

The  author  wishes  most  unreservedly  to  disclaim  any 
originality  for  the  contents  of  the  work,  and  to  state  that 
unless  otherwise  noted  all  the  facts  are  merely  compiled 
from  the  writings  of  others.  Free  use  has  been  made  of 
the  writings  of  all  the  most  prominent  American  ento- 
mologists. Where  the  treatment  of  a  group  of  insects  has 
been  largely  drawn  from  one  or  two  sources,  they  will  often 
be  indicated  by  quotations  in  the  text. 

Many  of  the  following  chajiters  or  parts  of  them  have 
previously  appeared  in  various  agricultural  journals  during 
the  past  three  or  four  years,  to  the  editors  of  which  the 
author  desires  to  express  his  thanks  for  their  courtesy  in 
allowing  him  to  here  republish  them:  namely.  The  Country 
Gentleman,  The  Farmers'  Eeview,  Farm  and  Fireside, 
Farm  Xews,  The  National  Rural,  Texas  Farm  and  Eanch, 
The  American  Agriculturist,  The  National  Stockman  and 
Farmer,  and  The  Practical  Farmer. 

The  author  is  jjarticularly  indebted  to  Prof.  M.  V. 
Slingerland,  of  Cornell  University,  for  kindly  reading 
23ortions  of  the  manuscrijot  and  for  several  suggestions  of 
value;  to  Dr.  L.  0.  Howard  for  assistance  in  part  of  Chap- 
ter X;  and  to  his  wife,  Anna  Cecilia  Sanderson,  for  a  large 
amount  of  clerical  assistance. 

K.  I) WIGHT  Saxdkksox. 
Newark,  Del.,  February,  1901. 


SOUKCES   OF   ILLUSTRATIONS. 


Electrotypes  of  the  following  figures  were  purchased, 
being  secured  through  the  tindness  of  the  parties  named : 
Fig.  9,  from  Houghton,  Mifflin  &  Co. ;  Fig.  102,  from  the 
Iowa  Ag.  Exp.  Sta.,  through  Prof.  H.  E.  Summers;  Figs. 
7,  136,  and  137,  from  Dr.  J.  B.  Smith;  Figs.  51,  52,  60, 
84,  and  85,  from  Cornell  Tniv.  Ag.  Exp.  Sta.,  through 
Prof.  M.  Y.  Slingerland:  Figs.  25  and  28,  from  The 
Farmers'  Keview,  Chicago;  Figs.  74,  75,  76,  77,  and  78, 
from  Dr.  S.  A.  Forbes;  Figs.  71  and  72,  from  The 
Country  Gentleman,  for  which  they  were  originally 
redrawn  by  the  author;  Fig.  53,  from  the  Xebr.  Agr.  Exp. 
Sta.,  through  Prof.  L.  Bruner;  and  Figs.  11,  24,  31,  50, 
59,  61,  62,^64,  66,  67,  68,  79,  80,  81,  82,  83,  88,  89,  90, 
91,  92,  93,  94,  97,  104,  105,  106,  107,  108,  109,  111,  112, 
113,  114,  116,  117,  118,  119,  120,  121,  122,  123,  124, 
126,  127,  128,  129,  131,  134,  135,  136,  143,  146,  154, 
155,  156,  157,  158,  159,  160,  161,  162,  from  the  United 
States  Department  of  Agriculture,  through  the  kindness 
of  Dr.  L.  0.  Howard  and  Mr.  F.  H.  Chittenden,  of  the 
Division  of  Entomology  and  the  Division  of  Publications, 
to  which  gentlemen  we  are  under  especial  obligation. 

The  following  figures  were  kindly  loaned  by  the  parties 
named:  Figs.   29,  30,   32,   33,  34,  35,  36,   37,  38,  39,   40, 

vii 


Vlll  SOURCES    OF    ILLUSTRATIONS, 

41,  42,  44,  45,  4G,  47,  48,  110,  and  150,  from  the  Md. 
Agr.  Exp.  Sta.,  through  Prof.  A.  L.  Qiiaintance,  these 
havmg  heen  first  used  by  the  author  iu  The  Farmers' 
Review;  Figs.  Go,  132,  and  133,  from  the  Ky.  Agr.  Exp. 
Sta.,  through  Prof.  H.  Carman;  Fig.  125,  from  the  Fhi. 
Agr.  Exp.  Sta.,  through  Prof.  H.  A.  Gossard;  Figs.  54, 
55,  56,  57,  58,  63,  70,  96,  98,  101,  and  103,  from  the 
Ohio  Agr.  Exp.  Sta.,  through  Prof,  F.  M.  Webster;  Fig. 
49,  from  the  Minn.  Agr.  Exp.  Sta.,  through  Director 
W.  M.  Liggett;  Figs.  12  and  95,  from  the  DeL  Coll,  Agr. 
Exp.  Sta.;  Fig.  151,  from  the  Peninsula  Horticultural 
Society,  through  Prof.  Wesley  Webb. 

Figs.  19,  20,  21,  6(j,  138,  139,  140,  141,  144,  and  147 
were  loaned  by  the  author.  Figs.  13,  14,  15,  16,  17,  18, 
23,  26,  27,  99,  115,  145,  149,  152,  and  153  were  copied 
from  prints.  Figs.  1,  4,  5,  6,  8,  and  10,  and  Figs.  2,  3, 
22,  86,  87,  and  100  and  frontispiece  are  original  from 
photos  by  the  author,  the  photos  of  the  latter  numbers 
being  loaned  by  the  Del.  Coll.  Agr.  Exp.  Sta. 


TABLE   OF   CONTENTS. 


PAGE 

Preface v 

Sources  of  Illustrations vii 

CHAPTER  I. 
Injury  done  Staple  Crops  by  Insect  Pests ..-..       1 

CHAPTER  II. 
Structure  and  Development  of  Insects « 6 

CHAPTER  III. 
General  Farm  Practice  against  Injurious  Insects 20 

CHAPTER  IV. 
Beneficial  Insects  30 

CHAPTER  V. 
Insects  Injurious  to  Grains  and  Grasses 44 

CHAPTER  VI. 
Insects  Injurious  to  Wheat 90 

CHAPTER  VII. 
Insects  Injurious  to  Indian  Corn 125 

CHAPTER  VIII. 

"  Weevil  "  in  Grain 155 

ix 


X  TABLE    OF    COXTEXTS. 

CHAPTER  IX. 

PAGE 

Insects  Injurious  to  Clover 172 

CHAPTER  X. 
Insects  Injurious  to  Cotton 188 

CHAPTER  XI. 
Insects  Injurious  to  Tobacco 214 

CHAPTER  XII. 
Insects  Injurious  to  the  Potato 239 

CHAPTER  XIII. 
Insects  Injurious  to  the  Sugar-beet 252 

CHAPTER  XIV. 
Insects  Injurious  to  the  Hop-plant  269 

CHAPTER  XV. 
Insecticides 284 


(TJ^,  .     /   -1^^       b> 


INSECTS  INJURIOUS  TO  STAPLE  CROPS. 


CHAPTEE   I. 

INJURY   DONE   STAPLE   CROPS   BY   INSECT   PESTS. 

Ever  since  the  plagne  of  locusts  in  the  time  of  the 
Pharaohs,  insects  have  maintained  a  continual  opposition 
to  agriculture.  History  is  replete  Avith  accounts  of  insect 
scourges  and  the  enormous  losses  occasioned  by  them. 
And  instead  of  diminishing  with  the  advancement  in  agri- 
cultural methods,  injurious  insects  have  undoubtedly  be- 
come both  more  numerous  and  more  destructive  in  modern 
times.  Every  now  and  then  we  hear  of  communities 
assembling  for  prayer  and  fasting  to  appease  the  Almighty, 
whose  wrath  has  hurled  a  new  insect  plague  against  them. 
But  a  little  reflection  will  show  that  the?e  scourges  are 
entirely  due  to  natural  causes.  In  fact  such  injuries  are 
very  largely  due  to  man  himself,  who,  in  trying  to  subdue 
Nature  by  the  clearing  and  cultivation  of  the  land,  has 
deprived  the  insects  of  their  natural  food.  Thus  they  must 
needs  feed  upon  that  which  is  substituted  by  him,  and  as 
it  is  less  abundant  than  the  former  wild  vegetation,  the 
number  of  insects  and  the  injuries  they  inflict  are  more 


2  INSECTS   INJURIOUS   TO   STAPLE   CROPS. 

upparent.  But  the  native  insects  are  by  no  means  entirely 
responsible  for  this  condition.  Foreign  insects  are  con- 
stantly being  imported  in  one  way  or  another,  sometimes 
already  being  established  pests  in  other  lands  and  some- 
times only  becoming  so  under  their  new  surroundings. 
These  are  even  more  injurious  than  those  native,  for 
whereas  many  of  our  native  birds,  insects,  and  diseases 
constantly  prey  upon  native  insects  and  thus  keep  their 
numbers  in  check,  the  enemies  of  imported  pests  rarely 
accompany  them,  and  they  thus  increase  at  an  alarming 
rate  and  do  enormous  damage  before  they  are  attacked  by 
the  natural  enemies  of  similar  native  pests. 

American  farmers  have  learned  from  sad  experience 
of  the  severe  losses  occasioned  by  insects,  but  few  realize 
their  enormity  when  considered  as  a  whole.  Several  cal- 
culations of  these  losses  have  been  made  by  competent 
authorities,  who  practically  agree  that  one-tenth  of  the 
total  agricultural  product  of  the  United  States,  or  $300,- 
000,000,  is  but  a  conservative  estimate  of  the  loss  annually 
sustained  by  this  country.  But  when  this  statement  has 
occasionally  been  made  by  the  author  it  has  been  met  with 
a  look  of  incredulity  which  very  plainly  indicated  that  he 
was  thought  to  have  a  very  elastic  imagination.  A  careful 
collection  of  such  data  as  may  be  confided  in  as  accurate 
shows  that  the  above  estimate  is  entirely  correct.  Con- 
siderably over  one-half  of  this  loss  is  upon  the  staple  crops, 
the  remainder  being  upon  truck  crops,  fruits,  domestic 
animals,  and  timber. 

Growing  Cereals. — Probably  no  other  insect  does  so 
wide-spread  damage  as  the  Hessian  Fly,  attacking  our  chief 
staple,  wheat,  as  well  as  rye  and  barley.  One-tenth  of 
the  whole  crop,  valued  at  140,000,000,  is  generally  con- 


INJURY    DONE   STAPLE    CROPS   BY   INSFCT   PESTS.  3 

ceded  to  he  destroyed  by  this  pest  every  year,  and  in 
certain  sections  the  loss  often  amounts  to  from  30  to  50 
per  cent.  If  the  loss  to  rye  and  barley  be  put  at  one- 
fourth  the  loss  of  wheat,  it  amounts  to  about  11,000,000. 
From  various  estimates  made  at  different  times  during 
that  period.  Prof.  F.  M.  Webster  states  that  1^330,000.000 
represents  the  loss  from  the  depredations  of  the  Chinch- 
bug  since  1850,  or  17,000,000  per  annum,  which  has  been 
largely  confined  to  the  States  of  the  Mississippi  Valley. 
Corn  has  a  host  of  insect  enemies.  Frequently  the  Corn 
Root-worm  has  damaged  the  crop  to  the  extent  of  10  to 
20  per  cent  in  many  of  the  largest  corn-growing  States. 
The  annual  loss  on  this  crop  due  to  insects  is  certainly 
not  under  5  per  cent,  or  $37,000,000.  Thus  with  only 
the  above  figures  we  see  an  annual  loss  of  185,000,000 
upon  growing  cereals. 

Stored  Grain. — But  stored  grain  has  its  insect  pests  also, 
which  are  especially  injurious  in  the  South.  Mr.  F.  H. 
Chittenden,  of  the  IT.  S.  Department  of  Agriculture,  places 
the  loss  on  stored  corn  in  the  seven  Gulf  States  at 
$20,000,000,  or  20  per  cent  of  their  crop.  If  only  one- 
fourth  of  this  amount,  or  5  per  cent,  of  the  rest  of  the 
country's  stored  corn  were  thus  lost,  it  would  amount  to 
$40,000,000.  Twenty  million  dollars,  or  3  per  cent  of  the 
value  of  all  other  stored  grain,  certainly  no  more  than 
cover  the  loss  sustained  upon  it  and  other  stored  products 
subject  to  insect  pests,  which  gives  an  approximate  total 
of  160,000,000  damage  to  stored  products. 

Grass  and  Hay. — A  host  of  grass  and  clover  insects 
damage  the  hay  crop.  Half  a  million  dollars  have  fre- 
quently been  given  as  the  loss  sustained  from  the  Army- 
worm  alone  in  individual  States.     Five  per  cent  of  the 


4  IITSECTS   INJURIOUS   TO    STAPLE   CROPS. 

hay  crop,  or  120,000,000,  fairly  represents  the  loss  upon 
this  crop  and  pasture-lands  due  to  insects. 

Cotton. — The  cotton-plant  has  a  number  of  serious 
enemies,  of  which  the  Cotton-worm,  Boll-worm,  and  Boll- 
weevil  are  the  worst.  In  1880  the  United  States  Ento- 
mologic^al  Commission  valued  the  annual  ravages  of  the 
Cotton-worm  at  130,000,000,  but,  thanks  to  their  careful 
study  of  the  pest,  the  damage  done  by  it  has  been  greatly 
lessened  in  recent  years.  But  the  Boll-weevil  has  now 
presented  itself  in  Texas.  In  1894  it  damaged  the  Texas 
crop  to  the  extent  of  18,000,000,  and  its  injuries  are  not 
reported  as  having  diminished.  Thus  ^15,000,000  must 
be  a  low  estimate  for  the  insect  depredations  upon  cotton. 

Tobacco. — The  tobacco  crop,  valued  at  $25,000,000,  has 
a  horde  of  insect  enemies  at  all  stages  of  its  existence, 
which  will  easily  consume  8  per  cent  of  it,  or  $2,000,000. 

Potatoes. — The  Colorado  Potato-beetle  does  not  do  that 
crop  so  serious  an  injury  as  formerly,  but  some  new 
enemies  to  it  have  appeared,  and  a  loss  of  $10,000,000, 
or  about  6  per  cent  of  the  value  of  that  crop,  is  un- 
doubtedly caused  by  our  six-legged  foes. 

Surely,  when  we  include  the  injury  done  to  fruits,  truck 
crops,  domestic  animals,  and  timber,  $300,000,000  is  a 
conservative  estimate  of  the  price  these  apparently  insig- 
nificant little  insects  are  annually  costing  this  country. 

Yet  there  is  another  aspect  to  the  matter.  ''  One  man's 
loss  is  another  man's  gain"  is  never  more  true  than  as 
regards  these  losses  occasioned  by  insects.  For,  through 
wide-spread  injury  by  them,  prices  rise;  while  if  these 
injuries  were  not  done  and  correspondingly  large  crops 
were  placed  upon  the  market,   prices  must  surely  fall. 


INJURY   DONE   STAPLE   CHOPS   BY    INSECT   PESTS.  5 

These  estimates  of  losses  due  to  insects  are  then  very 
largely  comparative.  Yet,  to  a  large  extent,  they  are  still 
real  losses,  the  same  as  are  those  occasioned  by  fire  and 
storm.  For  though  a  small  crop  may  bring  better  prices, 
it  is  usuall}'  at  the  expense  of  individuals  or  communities 
which  have  sustained  exceptionally  heavy  losses.  AVere 
these  losses  evenly  distributed  among  all  those  producing 
a  given  crop,  there  would  be  no  real  hardship  to  them; 
but  such  is  by  no  means  the  case. 

All  this,  then,  goes  to  emphasize  the  fact  that  the  suc- 
cessful farmer — as  the  successful  man  in  any  other  trade 
or  j)rofession — is  the  one  who  is  able  to  overcome  obstacles 
which,  though  possibly  ruining  his  neighbor,  are  making 
a  good  market  for  his  special  crop.  And  these  insect 
pests  can  be  largely  overcome.  The  millennium  will  doubt- 
less come  before  the  farmer  will  be  able  to  stop  fighting 
them,  but  a  large  part  of  the  damage  by  them  can  be  pre- 
vented at  a  cost  which  renders  it  profitable.  Rational 
methods  of  general  farm  practice  with  the  proper  use  of 
ap23aratus  and  insecticides,  even  such  as  are  now  known, 
and  in  which  improvements  are  being  constantly  made,  if 
intelligently  used  by  American  farmers,  would  save  to 
them  fully  two-thirds  of  this  enormous  loss. 


•^^ 


CHAPTER   II. 
STRUCTURE   AND   DEVELOPMENT   OF   INSECTS. 

The  more  experience  the  farmer  has  with  insect  pests, 
the  more  he  comes  to  realize  that  if  he  would  successfully 
combat  them,  he  must  have  a  certain  amount  of  necessary 
knowledge  concerning  their  structure  and  growth. 

In  general,  the  artificial  means  which  may  be  effectually 
used  to  combat  an  insect  pest  will  very  largely  depend 
upon  the  anatomical  structure  of  the  insect,  while  control 
by  general  methods  of  cidture  will  depend  upon  a  knowl- 
edge of  the  peculiarities  of  its  life-history. 

The  value  of  a  proper  understanding  of  these  important 
factors  in  insect  control  is  therefore  apparent. 

General  Structure  of  an  Insect. 

The  body  of  an  insect  is  composed  of  three  separate 
parts,  the  head,  thorax,  and  abdomen  (Fig.  1),  each  of 
which  is  composed  of  several  rings  or  segments.  To  the 
head  are  attached  the  jointed  antennae,  or  feelers,  the 
compound  eyes,  and  the  mouth-parts,  which  are  described 
below.  Each  of  the  three  segments  of  the  thorax  bears  a 
pair  of  legs,  and  adult  insects  usually  possess  one  or  two 
pairs  of  wings  upon  the  last  two  segments  of  the  thorax. 
The  abdomen  is  composed  of  nine  or  ten  segments,  but 

6 


STRUCTUKE    A^D    DEVELOPMENT   OF    INSECTS.  7 

bears  no  appendages  save  the  ovipositor  of  the  females  of 
certain  orders. 

Harvest-mites,  or  ^^  daddy-long-legs/^  sow-bugs,  thou- 
sand-legged worms,  and  similar  vermin  are  often  popularly 
called  insects,  but  all  of  them  can  readily  be  distinguished 
from  true  insects  by  their  possessing  more  than  six  legs. 


\ 

■^ 

i  ?^ 

abd^^ 

ff 

i 

r 

Fig.  1. — Honey-bee,  showing  three   principal  regions  of  the  body 
of  an  insect  : — Ji,  head;  tJi.,  thorax;  aJ/d.,  abdomen.     (Original.) 

the  harvest-mites  and  spiders  having  eight  and  the  others 
many  more. 


How  Insects  Grow. 

With  rare  exceptions  insects  hatch  from  eggs  laid  by 
the  adult  females.  Upon  hatching  they  are  but  little 
larger  than  the  eggs,  and  often  bear  but  little  resemblance 
to  their  parents.  Thus  the  young  caterpillar  would  never 
be  recognized  as  the  immature  stage  of  the  butterfly  by 
one  unfamiliar  with  its  transformations.  Grasshoppers 
and  some  other  insects,  however,  upon  hatching  from  the 
egg  bear  a  marked  resemblance  to  the  adult  form,  except 
that  they  lack  wings. 


8  INSECTS   INJURIOUS   TO    STAPLE    CROPS. 

Complete  Metamorphosis. — But  let  us  return  to  the  cater- 
pilLir  and  follow  it  through  its  short  hut  interesting  life. 
Upon  hatching  from  the  (igg  it  at  ouce  commences  to  feed 
and  grows  Tery  rapidly.  But  before  long  an  obstacle  to 
further  growth  arises.  Unlike  higher  animals,  insects 
possess  no  internal  skeleton  or  framework  for  the  organs 
of  the  bod}^,  but  the  outer  skin  becomes  hardened  and  to 
it  the  muscles  and  ligaments  are  attached.  This  harden- 
ing of  the  skin  is  best  seen  in  the  horny  wing-covers  of  the 
beetles  and  is  due  to  the  secretion  of  a  hard  substance 
called  chitin.  This  chitin  is  secreted  by  all  parts  of  the 
skin  in  greater  or  less  degree,  and  thus  forms  a  sort  of 
shell  for  the  whole  body.  Though  this  hardening  is  not 
so  apparent  in  larvae  as  in  adult  insects,  it  is  always 
present,  and  it  is  for  this  reason  that  when  the  young- 
caterpillar  has  made  a  certain  growth  it  is  forced  to  shed 
its  skin,  which  refuses  to  expand  further,  in  order  to 
develoj)  more  fully.  Thus  the  skins  of  insects  are  shed 
several  times  (see  Fig.  2,  h), — usually  five  or  six,  but 
sometimes  as  many  as  twenty, — this  process  being  known 
as  ^^  molting."  During  its  life  as  a  caterpillar,  which  is 
called  the  ''larval  stage,"  and  during  which  it  is  called  a 
^^arva,"  it  is  nn  elongate,  worm-like  creature,  with  six 
short,  jointed  legs  on  the  three  thoracic  segments,  a  pair 
of  fleshy  false  legs  or  pro-legs  on  the  last  abdominal  seg- 
ment, and  probably  several  pairs  of  pro-legs  between  these 
and  the  true  legs.  No  traces  of  wings  can  be  seen,  but  the 
body  is  often  covered  with  hairs,  spines,  or  warty  tubercles. 

But  with  the  next  molt  the  insect  changes  in  appearance 
most  radically,  becoming  a  joupa,  or  chrysalis  as  this  stage 
is  termed  for  butterflies.  During  the  pupal  stage  the 
insect  remains  dormant  either  in  a  small  cell  slightly  under 


STRUCTURE    AND    DKVELOl'MEXT   OF    INSECTS.  9 

the  surface  of  the  earth,  or  in  a  silken  cocoon  spun  by  the 
caterpillar,    or  merely   attached  to    the  food-plant    })y  a 


Fig.  2. — Complete  Metamorphosis,  The  different  stages  of  the 
Corn  Ear-worm  {HeliotMs  armiger  Hlibn.  \  a,  eggs  on  corn- 
silk;  h,  the  first  three  larval  stages;  c,  pupa  from  below;  d,  same 
from  above;  e,  adult  moth — all  enlarged;  h,  about  twice  natu- 
ral size.     (Original.) 

strand  of  silk  or  the  cast  larval  skin.  In  many  of  the 
Diptera, — the  order  including  flies,  mosquitoes,  gnats,  etc., 
— however,  the  last  larval  skin  is  not  shed,  but  hardens 
and  forms  a  case — called  a  puparium — within  which  the 
pupal  stage  is  passed. 


10  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

The  typical  jmpa  (Fig.  2,  c,  d)  of  a  butterfly  or  moth  is 
of  a  more  or  less  oval  shape,  rather  resembling  the  adult 
insect  than  the  larva,  with  the  wings  and  antennae  tightly 
folded  at  the  sides,  the  legs  drawn  up  snugly  together  under 
them,  and  the  head  and  mouth-parts  bent  upon  the  breast, 
or  sternum.  But  all  of  these  parts  are  not  always  recog- 
nizable, the  legs  and  mouth-parts  being  sometimes  lacking. 
Gradually  the  jidult  insect  develops,  and  at  last  the  pupal 
skin  is  broken  open  and  the  airy  butterfly  emerges  to  enjoy 
a  short  life  and  perpetuate  the  species.  Such  a  series  of 
transformations  is  that  commonly  found  among  butter- 
flies and  moths  (Lepidoj)tera),  beetles  (Coleoptera),  flies 
(Diptera),  and  bees  (Hymenoptera),  and  is  known  as  a 
complete  metamorphosis.  All  of  these  insects  normally  pass 
through  four  stages,  the  Qgg,  larva,  pupa,  and  adult. 

Incomplete  MetamorphosU. — In  contrast  to  this  mode  of 
development  is  that  of  the  grasshoppers  (Orthoptera),  bugs 
(Hemiptera),  and  some  other  insects.  As  already  stated 
these  are  much  like  the  adult  upon  emerging  from  the 
agg.  With  each  molt  they  become  larger  and  small  wing- 
like pads  gradually  appear  on  the  sides  of  the  thorax. 
There  is  no  dormant  or  pupal  stage,  the  adult  insect 
differing  from  the  previous  stages  in  having  fully  developed 
wings,  being  larger,  and  often  by  an  accompanying  change 
of  markings.  The  immature  stages  of  such  insects  are 
called  nymphs^  and  this  development  an  incomplete  meta- 
'inorpliosis,  having  but  three  stages,  the  Qgg,  nymph,  and 
adult  (Fig.  3). 

The  time  occupied  by  the  complete  life-cycle  of  an  insect 
varies  from  a  week  or  ten  days  for  the  plant-lice  to  thirteen 
or  seventeen  years  for  some  Cicadas,  and  is  entirely 
dependent  upon  the  habit  of  the  species  and  the  climate. 


STRUCTURE    AND    DEVELOPMENT    OF    INSECTS. 


11 


A  correct   knowledge   of  the   exact  time   and  conditions 
under  which  the  transformations  occur  for  each  individual 


Fig.  3. — Incomplete  jMetamorpliosis  of  a  Bug  [Brachymena  4-jmsiic- 
lata).  a,  eggs:  6,  adult  bug;  c,  different  stages  of  young  bugs 
or  nympLs.     (Original.) 

insect  pest  is  therefore  often  most  essential  when  seeking 
means  for  its  control. 


How  Insects  Feed. 

The   material  to  he  used   in  cumhating  a  given  insect  is 
almost  entirely  dependent  upon  the  structure  of  its  mouth- 


12 


IXSECTS    INJURIOUS   TO    STAPLE    CROPS. 


parts.     Much  Paris  green  is  wasted  upon  insects  unable 
to  eat  it  and  which  it  will,  therefore,  never  kill. 

Insects  may  be  roughly  divided  into  two  classes,  those 
which  bite  and  those  which  suck  their  food.  Among  the 
former  are  the  beetles,  grasshoppers,  the  larva3  of  butter- 
flies and  moths,  and  the  larvae  of  saw-flies;  and  among  the 


Ibr. 

MX.pA 


Kldh^ 


Fig.  4. — Front-view  Face  of  Grasshopper  {Schiziocerca  americnna). 
ant.,  anUnma;  oc,  ocellus;  ey.,  eye;  cl.,  clypeus;  Ibr.,  labrum,  or 
upper  lip;  mx.p.,  maxillary  palpus;  lab.  p.,  labial  palpus;  gal., 
galea,  lobe  of  maxilla;  lab.,  labium,  or  under  lip.     (Original.) 

latter  are  butterflies,  flies,  bees,  and  bugs,  while  the  larvae 
of  most  flies  and  bees  do  not  possess  mouth-parts  homol- 
ogous with  those  of  the  above. 

Biting  Mouth-imrts. — Mouth-parts  typical  of  those  of 
biting  insects  are  easily  seen  in  the  grasshopper  (Figs.  4,  5, 
and  6).  In  brief,  they  consist  of  an  upper  and  a  lower 
lip,  between  which  are  two  pairs  of  jaws  which  work  trans- 
versely. The  upper  pair  of  jaws,  or  mandihies  (md.),  are 
stout,    short,    and   horny,    usually   sharpened  at  the  tip, 


STRUCTURE    AND    DEVELOPMENT    OF   INSECTS. 


13 


slightly  serrated  at  the  margins,  and  flattened  at  the  base. 
The  lower  pair  of  jaws,  or  maxillcB  {mx.),  are  longer,  not 
so  strong,  and  to  each  of  them  is  attached  an  accessory 
lobe,  and  a  jointed  style  called  a  palpus  or  feeler.    At  each 


Fig.  5. — Mouth -parts  of  Grasshopper,  separated  to  show  position  and 
relation,  a,  from  above  the  mouth;  b,  looking  into  the  mouth; 
c.  from  below  the  mouth.  Ibr..  labrum,  or  upper  lip;  md.,  man- 
dible or  biting-iaw;  mx.,  maxilla,  or  second  jaw;  lab,  labium, 
or  und(n'  lip:  ^lyp.,  hypopharynx,  or  tongue;  mx.p.,  maxillary 
palpus.     (Original.) 

side  of  the  lower  lip  is  another  j^alpus,  these  palpi  being 
sensory  organs. 

Sucking  Moutli-parts. — In  the  sucking  insects  these 
mouth-parts  are  prolonged  into  a  tube  through  which  the 
juices  of  the  food  plant — or  animal — are  sucked.  In  the 
plant-lice  and  other  bugs  the  lower  lip  is  elongated  so  that 
it  forms  a  tube,  and  the  max  ill  a?  and  mandibles  consist  of 
long  hair-like  bristles,  or  seta?,  enclosed  within  this  tube 
(Fig.  7).  The  tip  of  this  beak  is  rested  upon  the  surface 
of  a  leaf  into  which  the  setae  are  thrust,  laceratino-  tlie 
tissue,  and  by  a  pumping  process  of  the  mouth  the  juices 
are  sucked  up  through  the  beak.  The  structure  of  the 
mouth-parts  of  the  various  orders  of  sucking  insects  varies 


14 


INSECTS   INJURIOUS   TO    STAPLE    CROPS. 


considerably,  but  all  agree  in  that  their  food  must    Ije 
sucked  up  in  a  liquid  state.     Any  application  of  a  poison - 


Fig.  6. — Cicada,  showing  Mouth-parts  of  a  Bug,  a  Sucking  Insect. 
a,  seen  from  below,  beak  or  rostrum  {ro.  G. )  reposing  between 
forelegs;  b,  head  removed;  e,  eye;  l})r.,  labrum;  md.,  man- 
dlble-setae ;  mx.,  maxillary  seta^ ;   lab.,  labium.     (Original.) 

ous  spray  to  the   surface  of  foliage  will   be  of  no   avail 
against  them,  though  sure  death  to  most  biting  insects 


STRUCTURE    AND    DEVELOPMENT   OF    INSECTS. 


15 


which  chew  the  leaves,  and  sucking  insects  must  therefore 
be  killed  by  other  means. 

How  Insects  Breathe. 

In  the  side  of  one  thoracic  segment  and  each  abdominal 
segment  except  the  last,  of  a  caterpillar  or  larva,  is  a  small 


Fig.  7. — Mouth  parts  of  a  Plant-louse;  a,  the  jointed  beak;  b,  the 
lancets,  much  enlarged;  c,  antenna;  d,  foot.  (After  J.  B. 
Smith. ) 

oval  spot,  in  the  centre  of  which  is  a  slit  closed  by  two 
membranous  lips.  These  apertures  are  called  sjjiracles  or 
stigmata  (Fig.  8,  st^-st^^),  and  are  the  openings  of  the 
respiratory  system.  Similar  openings  are  to  be  found  in 
all  insects,  though  not  so  easily  seen  in  the  adults.  Con- 
necting these  spiracles  is  a  pair  of  tubes  on  each  side  of 
the  body,  throughout  its  length,  from  which  branch  oil' 


16 


INSECTS   INJURIOUS   TO    STAPLE    CROPS. 


smaller  tubes  to  all  of  its  organs  and  tissues.  Fresh  air  is 
thus  inhaled  to  all  parts  of  the  body  through  these  tubes 
(Fig.  8,  tr). 


Fig  8. — Diagram  of  tracheal  or  breathing  system  of  an  Insect, 
.s-ij-s^jo,  the  ten  pairs  of  spiracles;  A,  head;  i?i_3,  the  three  seg- 
ments of  the  thorax;  Tr.,  the  two  main  tracheal  trunks;  trs., 
trachea  leading  from  the  main  trunk  to  the  spiracle;  tru.,  tra- 
chea connecting  the  two  main  trachea;  tri.,  visceral  trachea; 
tro.,  ventral  trachea;  tr.,  the  anterior  termination  of  the  tra- 
chea; g.-g.,  nerve-cord  with  ganglia  to  wiiich  go  branches  of 
the  visceral  trachea;  au.,  eyes;  a,  antennae;  p,  palpi;  m,  man- 
dibles; jPi-p^,  bases  of  the  legs.     (After  Kolbe.) 


The  blood  of  insects  does  not  circulate  through  any 
system  of  tubes  as  it  does  in  the  higher  animals.     Along 


STRUCTURE    AND    DEVELOPMENT    OF    INSECTS. 


17 


the  middle  of  the  back,  above  the  alimentary  canal,  is  a 
long  tube  popularly  called  the  heart  (Fig.  9,  ]i\  Fig.  10, 
dr).  This  heart  is  composed  of  a  number  of  chambers 
each  of  which  is  funished  with  side  valves  for  admitting 
blood  from  the  body-cavity.  The  blood  coming  into  the 
heart  from  the  body- cavity  is  propelled  forward  toward 
the  head,  where  it  again  flows  into  the  body-cavity.  Thus 
various  currents  of  blood  are  maintained  throusfhout  the 


Fig.  9. — Ideal  section  through  au  iu.sect.  a,  ahmentaiy  canal;  h, 
heart;  n,  nerve-cord;  s,  stigmata:  /,  tracheal  tubes;  I,  legs;  w, 
wings.     (From  Riverside  Nat.  History.) 

body,  but  other  than  the  heart  there  is  no  system  of  blood- 
vessels, the  blood  merely  filling  the  body- cavity  around 
and  through  the  various  organs  and  tissues.  Constantly 
flowing  around  the  respiratory  tubes  or  tracheae,  the  blood 
is  quickly  and  thoroughly  purified,  though  the  exact 
manner  in  which  this  is  done  is  not  definitely  known. 
The  respiratory  system  has  absolutely  no  connection  with 
the  mouth  or  pharynx  (Fig.  10,  ^j^),  as  have  the  lungs  of 
the  higher  animals,  and  if  an  insect  is  to  be  suffocated,  it 
must  be  done  by  closing  the  spiracles.     It  is  in  this  way 


18 


INSECTS   INJURIOUS   TO    STAPLE    CROPS. 


that  tobacco-dnst,  lime,  pj'Tethruin,  and  similar  insecti- 
cides kill  sucking  insects  by  ^penetrating  the  spiracles  and 
choking  the  tracheal  system.  Whale-oil  soap,  kerosene 
emulsion,  and  the  other  "contact"  insecticides,  or  ^' irri- 
tants," may  also  stop  up  the  spiracles  and  thus  cause 
death,  but  they  act  chiefly  as  "irritants,"  penetrating  the 


Fig.  10. — Internal  Anatomy  of  Silkworm.  A,  the  upper,  or  dorsal, 
body-wall  seen  from  within;  B,  the  back  of  the  silkworm  re- 
moved, showing  alimentary  canal:  C,  alimentary  canal  removed, 
showing  nervous  system  and  tracheal  trunks;  t?'.,  trachea;  d.v., 
dorsal  vessel  or  heart;  ph.,  pharynx  or  mouth;  sti.,  supra- 
oesophageal  ganglion;  sp.  sp.,  spiracles  or  breathing-pores;  n, 
nerve-cord;  ^r.^.,  tracheal  trunk;  oes.,  a^sophagus  or  throat;  c/'., 
crop;  s.g..  silk-gland;  pro.,  proventriculus  or  grinding-stomach ; 
St.,  stomach;  7i.i.,  hind-intestine.  (Photo,  by  author  from  Azoux 
model.) 

skin  and  thus  killing  the  insect.  When  insects  are  killed 
by  means  of  a  gas  such  as  carbon  bisulfide  or  hydrocyanic 
acid  gas,  they  are  truly  asphyxiated  by  a  substitution  of 
these  gases  for  air,  the  same  as  are  higher  animals  by  the 
use  of  anaesthetics, 


STRUCTUKE    AND    DEVELOPMENT    OF    INSECTS.  19 

Though  arsenical  poisons  are  generally  used  as  sprays 
for  biting  insects,  soft-bodied  caterpilhirs  and  similar  larv^ae 
are  often  killed  by  the  use  of  contact  insecticides,  which 
affect  them  the  same  as  sucking  insects. 

The  reader  will  observe  that,  almost  without  exception, 
the  remedies  advised  for  different  insect  pests  in  the  fol- 
lowing pages  are  determined  by  some  peculiarity,  either  of 
structure  or  develo^mient,  of  the  insect  to  be  combated. 


CHAPTER   III. 

GENERAL   FARM    METHODS   AGAINST    INSECT   PESTS. 

In"  the  following  pages  artificial  means  of  combating 
insect  pests,  such  as  spraying  with  insecticides,  are  not 
as  often  the  remedies  or  preventives  given  as  those  which 
consist  of  some  method  of  general  farm  practice.  That 
such  should  be  the  case  is  but  natural,  for  the  staple  crops, 
being  cultivated  in  large  areas,  can  hardly  be  treated  witli 
sprays  or  mechanical  devices,  in  many  instances,  with  any 
degree  of  profit.  The  best  methods  to  employ  against 
most  of  the  insects  affecting  the  staj^le  crops  are  what 
might  be  termed  cultural  methods,  consisting  of  some 
mode  of  culture  or  handling  the  crop  which  fatally  inter- 
feres with  the  development  of  a  given  insect  pest.  Such 
treatment  is  far  less  simple  in  many  instances,  however, 
than  the  use  of  a  spray-pump  or  powder-gun.  In  the 
latter  case  the  farmer  merely  waits  until  he  observes  a  crop 
being  injured  and  then  with  a  liberal  application  of  poison 
destroys  his  insect  enemies;  but  in  using  the  former 
method  he  must  have  a  more  or  less  accurate  knowledge 
of  the  life-history  of  the  insect  which  he  wishes  to  combat. 
It  will  also  be  necessary  for  him  to  observe  or  ascertain 
the  usual  dates  of  the  transformations  of  various  insects 
for  his  particular  locality,  as  they  vary  considerablv  for 
different  latitudes  and  altitudes,  and  to  make  due  allow- 

20 


GENERAL    FAUM    METHODS    AGAINST    INSECT   PESTS.      21 

auce  for  any  variation  of  these  dates  on  account  of  the 
peculiarities  of  the  individual  season. 

Looking  Ahead. — Few  farmers,  in  planning  the  manage- 
ment of  their  land  and  crops  for  tiie  coming  season,  con- 
sider the  effect  which  any  given  procedure  will  have  upon 
the  injurious  insects  with  which  they  may  have  to  contend. 
A  field  which  has  for  several  years  been  in  wheat,  corn,  or 
tobacco  may  be  sown  with  some  other  crop  for  the  sake 
of  soil  improvement,  or  may  even  be  favored  with  a  green- 
manuriug  of  rye,  crimson  clover,  or  cow-peas;  but  how 
often  is  it  considered  necessary  to  rotate  crops  in  order  to 
lessen  insect  pests  ?  In  most  cases  the  answer  would 
doubtless  be,  "  Xot  until  some  noticeable  loss  has  been 
suffered  from  their  injuries.''  That  this  is  a  mistake  may 
be  seen  from  a  brief  survey  of  the  best  methods  for  com- 
bating our  worst  insect  pests. 

For  this  purpose  let  us  take  the  list  of  sixty-three  insects 
given  in  the  Year  Book  of  the  United  States  Department 
of  Agriculture  for  1898  as  a  basis,  it  being  carefully  com- 
piled by  experienced  entomologists. 

But  in  passing,  though  foreign  to  our  theme,  it  may  be 
interesting  to  note  that  of  these  sixty-three  insects  twenty- 
seven  have  been  imported  from  foreign  climes,  thirty-one 
are  native,  and  four  are  of  doubtful  origin,  so  that  we  can 
correctly  say  that  fully  one-half  of  our  worst  insect  pests 
are  imported.  Among  those  native  to  the  United  States 
are  the  Chinch-bug,  Corn  Root-worm,  Cutworms,  Locusts, 
and  Colorado  Potato- beetle;  while  among  those  imported 
are  the  Angumois  Grain-moth,  Cypsy  Moth,  Codling- 
moth,  Cotton- worm.  Sugar-cane  Borer,  Grain  Weevils, 
Hessian  Fly,  and  San  Jose  Scale. 

Of  tliese  sixty-three  pests  eight  infest  stored  grains  and 


22  INSECTS    IX.TURIOUS   TO    STAPLE    CROPS. 

lionseliold  goods,  and  may  be  exterminated  by  the  fumes 
of  carbon  bisulfide;  and  five  are  insects  affecting  cattle, 
and  are  combated  with  various  washes. 

Thus  only  fifty  are  really  to  be  considered  insects  of  the 
farm  cro^is.  Of  these,  three  are  controlled  by  '-  ditching,'^ 
three  by  mechanical  means  or  devices,  and  for  two  of  them 
hydrocyanic  acid  gas  is  sure  death,  while  a  spray  of  whale- 
oil  soajD  is  advisable  for  two  others,  a  spray  of  kerosene 
emulsion  for  six,  and  of  Paris  green  or  London  purple  for 
fifteen,  these  sprays,  etc. ,  being  used  largely  for  orchard 
pests,  which  comprise  eighteen  of  the  fifty.  But  for  the 
control  of  many  of  the  insect  pests  affecting  the  staple 
crops,  and  which  are,  therefore,  of  the  greatest  economic 
im2:>ortance,  we  have  so  far  been  unable  to  devise  anything 
better  than  a  judicious  manipulation  of  purely  natural 
agents,  and  for  the  control  of  twenty-three  of  the  fifty 
farm  insects  listed,  or  nearly  one-half,  and  75  per  cent  of 
those  outside  the  orchard,  such  methods  must  be  mainly 
relied  upon. 

Clean  Farming. 

After  a  crop  has  been  harvested,  there  is  usually  some 
portion  of  it  which  is  allowed  to  remain  on  the  land.  In 
this  refuse  the  insects  peculiar  to  the  crop  often  go  on 
multiplying  until  winter,  and  greater  damage  to  the  crop 
in  the  following  year  is  therefore  probable.  Thus  the 
Wheat  Joint-worm  and  the  Corn  Stalk-borer  both  winter  in 
the  stubble  of  those  crops,  the  Potato  Stalk-borer  remains 
for  some  time  in  the  vines,  and  numerous  other  cases 
might  be  cited.  It  is  therefore  of  imj^ortance  in  our  war- 
fare against  insect  pests  that  the  remains  of  a  crop, 
stubble,  vines,  leaves,  or  stumps,  as  it  may  be,  should  be 


GENERAL  FARM  METHODS  AGAINST  INSECT  PESTS.   23 

removed  from  the  field  as  soon  after  it  is  harvested  as 
possible  Such  material  allowed  to  remain  in  the  field 
also  furnishes  the  adult  insects  an  excellent  place  in  which 
to  hibernate  over  winter.  Much  can  be  done  to  rid  a  field 
of  insects  by  cleaning  it  so  thoroughly  as  to  deprive  them 
of  shelter  during  the  winter,  during  which  time  they 
hibernate  under  all  sorts  of  rubbish,  grass,  and  weeds,  in 
fence-rails,  loose  bark  of  trees,  etc.  This  fact  may  also 
often  be  utilized  by  first  carefully  cleaning  a  field  and  then 
leaving  one  or  two  piles  of  rubbish  in  which  various  insects 
will  assemble  during  the  winter,  when  they  can  be  easily 
caught  by  burning  the  whole.  Such  a  trap  will  be  more 
effectual  in  catching  the  insects  affecting  truck  crops  than 
those  of  the  staple  crops. 

Weeds. 

But  even  when  all  the  piles  of  litter  and  rubbish  have 
been  carefully  cleared  up  many  of  our  native  insects  will 
merely  leave  them  for  some  common  weed  upon  Avhich 
they  will  feed  and  breed  during  the  season^  and,  if  it  should 
be  earlier  than  the  cultivated  crop,  will  continue  upon  it 
the  following  spring  until  the  cultivated  crop  is  to  be 
secured  for  food.  '•  Volunteer  *'  plants  should  be  included 
with  weeds  in  this  connection,  as  they  frequently  serve  the 
same  purpose.  Thus  the  Cotton  Boll-weevil  feeds  upon 
volunteer  cotton  during  the  spring,  and  the  Hessian  Fly 
on  the  volunteer  wheat  during  late  summer,  while  the 
Corn  Root-louse  lives  on  the  roots  of  the  smart-weed 
until  corn  is  out  of  the  ground.  Then,  too,  many  in- 
jurious insects  feed  in  the  larval  or  adult  stage  upon  some 
common  weed,  while  in  the  other  stage  they  are  injurious 
to  a  cultivated  crop.     The  flea-beetles  thus  feed  upon  the 


24  INSECTS   INJURIOUS   TO    STAPLE   CROPS. 

roots  of  Solonaceous  weeds  during  the  larval  stage,  and 
attack  all  sorts  of  garden  and  truck  crops  as  adults;  one  of 
the  Corn  Bill-bugs  lives  in  the  roots  of  a  wild  grass  as  a 
larva,  but  is  injurious  to  corn  as  a  beetle.  The  w^eeder 
(!an^  therefore,  be  occasionally  used  as  an  insecticide  as 
effectually  as  the  spray-pump. 

Burning. 

To  start  a  prairie  fire  in  order  to  destroy  all  the  insect 
life  of  the  j)lain  might  ^irove  to  be  poor  policy,  but  the 
careful  use  of  the  torch  has  a  distinct  place  upon  the  farm 
in  controlling  its  insect  foes.  The  burning  over  of  stubble 
and  grass  land  will  very  largely  aid  in  or  secure  the  entire 
extermination  of  Army-worms,  Chinch-bugs,  Locusts, 
and  Wheat  Joint-worms.  Raking  up  and  burning  the 
vines  will  be  excellent  practice  against  the  Squash-borer, 
Squash-bug,  Potato  Stalk-borer,  and  Hop  Plant-louse, 
while  the  removal  and  burning  of  all  wild  ^^l^mi-trees  in 
their  vicinity  will  greatly  lessen  the  damage  to  hops  by 
the  latter  pest. 

Deep  Fall  Plowing. 

Deep  fall  plowing  is  being  increasingly  recommended 
for  the  reduction  of  many  pests,  and  will  be  found  to  be 
of  advantage  for  the  Corn  Stalk-borer,  Corn  Ear-worm, 
Cutworms,  Locusts,  and  Wireworms.  In  both  burning 
and  fall  j^lowing  the  object  is  to  kill  that  stage  in  which 
the  insect  passes  the  winter. 

But  this  method  does  not  affect  all  of  these  insects  in 
the  same  manner.  Some  insects  will  be  destroyed  by 
having  the  cells  in  which  they  have  gone  to  pass  the  winter 
broken  up,  and  being  thrown  up  to  the  surface,  they  will 


GENERAL   FARM    METHODS    AOAIXST   INSECT    PESTS.      25 

be  killed  by  the  weather  before  they  again  provide  them- 
selves with  winter  quarters.     Among  these  are  those  which 
hibernate  over  winter  as  larvs,  and  those  which  pass  it  in 
the  pupal  stage.     Among  the  former  may  be  mentioned 
the    Cutworms  and  the  Corn  Stalks   or  Sngar-cane-borer 
Larvae.      Of  those  passing  the  winter  as  pnpge,   the  Corn 
Ear-worm  is  a  good  example.     It  goes  into  the  pupal  stage 
in  the  fall,  and  this  method  of  breaking  up  the  pupal  cells 
is  practically  the  only  way  of  combating  it  upon  corn  land. 
But   whereas   some   insects  are   destroyed  by  exposing 
them  on  the  surface,   others  may  be  literally  buried  alive 
and  thus  killed.     One  of  the  best  instances  of  the  value  of 
fall   plowing  in  this  way  is  in  the  destruction  of  grass- 
hoppers' eggs.      If  they  be  turned  under  to  the  depth  of 
five  or  six  inches  after  they  are  laid  in  the  fall,  the  young 
hatching  from  them  in  the  spring  will  be  utterly  unable 
to  regain  the  surface  and  will  thus  be  smothered  to  death. 
Other  insects  which  pass  the  winter  in  the  pupal  stage, 
but   whose  pup^e  are  encased  in  a  tough  cell  not  easily 
broken  open,  may  also  be  killed  by  being  turned  under  in 
this    manner.     In   fact,    even    adult    insects    may    be    so 
handled.    After  the  plants  are  all  thrown  out  of  the  ground 
in  Xovember  the  adults  of  the  Mexican  Cotton  Boll- weevil 
can  be  readily  caught  in  this  way  and  plowed  under  so 
deeply  that  they  can  never  regain  the  surface.     Young 
grasshoppers  are  also  destroyed  in  a  similar  manner  just 
after  they  have  emerged  from  the  eggs  in  the  spring. 

It  is  a  homely,  common-sense  method,  but  with  a  correct 
understanding  of  their  life-histories  it  may  be  used  to 
good  advantage  against  many  of  our  most  common  and 
injurious  insects. 


26  INSECTS   INJURIOUS   TO   STAPLE   CROPS. 

Drainage. 

The  Kice-weevil  can  be  largely  controlled  by  proper 
drainage,  and  the  Corn  Bill-bugs  are  usually  injurious 
only  on  land  adjacent  to  or  recently  reclaimed  from  swamp 
land,  and  disappear  with  the  introduction  of  proper 
drainage. 

Fertilizers. 

In  general,  land  covered  with  barnyard  manure  presents 
more  favorable  conditions  for  the  development  of  insects 
than  that  fertilized  with  luineral  fertilizers,  sometimes 
furnishing  them  food  and  always  affording  a  good  shelter 
for  the  cold  of  winter.  On  the  other  hand,  it  is  claimed 
that  kainit,  lime,  and  nitrate  of  soda  are  often  of  consider- 
able value  in  controlling,  driving  out,  or  preventing  the 
attacks  of  insects.  A  liberal  application  of  fertilizers  in 
any  form  will  always  be  of  great  value  in  preventing  loss 
from  root-feeding  insects  by  enabling  the  plant  to  outgrow 
the  injury  and  mature  fruit  in  spite  of  it. 

Poultry. 

A  flock  of  chickens  or  turkeys  following  the  plow  will 
pick  up  a  great  many  White  Grubs  and  Cutworms  and  can 
readily  be  trained  to  this — for  them — rather  pleasant  task. 
In  many  tobacco-growing  sections  large  flocks  of  turkeys 
are  raised  especially  for  destroying  the  Tobacco  Horn- 
worm  and  are  slowly  driven  through  the  tobacco-fields 
several  times  a  day. 

Trap  Crops. 

Doubtless  the  reason  that  trap  crops  are  not  more  in 
favor    Y/ith    the   farmer   is    because    their  successful    use 


GENERAL    FARM    METHODS   AGAINST   INSECT   PESTS.       27 

requires  more  or  less  of  a  knowledge  of  the  life-histor}^  and 
habits  of  the  pest  to  be  caught;  3^et  this  is  easily  acquired 
by  a  little  observation  and  reading,  and  the  men  who 
combat  these  pests  successfully  are  those  who  have  such  a 
knowledge  of  them.  Let  us  consider,  then,  one  or  two  of 
the  more  important  cases  where  this  principle  may  be  used 
to  advantage. 

The  Harlequin  Cabbage-bug  is  a  southern  insect,  but 
it  has  recejitly  been  found  in  southern  Pennsylvania  and 
seems  to  be  gradually  working  northward.  When  this 
insect  has  succeeded  in  reachiug  the  cabbage-field  it  is  an 
exceedingly  difficult  matter  to  prevent  serious  injury  by  it. 
If,  however,  a  crop  of  early  kale  is  planted  the  previous 
fall,  the  bugs  Avliich  hibernate  over  winter  will  attack  it  in 
the. spring,  aud  may  then  be  killed  by  spraying  them  with 
pure  kerosene,  and  the  danger  to  the  cabbage  crop  be  thus 
largely  averted. 

The  Corn  Ear-worm,  Tomato-worm,  Tobacco  Bud- 
worm,  or  Cotton  Boll-worm,  as  it  is  variously  known  in 
different  sections  of  the  country,  according  to  the  crop 
which  it  most  commonly  infests,  is  one  which  must  be 
treated  almost  entirely  by  means  of  a  trap  crop  of  corn. 
Unfortunately  for  that  plant,  however,  this  method  can- 
not, of  course,  be  of  use  in  protecting  the  corn-field,  where 
it  must  be  controlled  as  best  it  may  by  breaking  up  the 
cells  of  the  hibernating  pup^  by  late  fall  plowing.  But 
as  corn  is  the  favorite  food  of  the  worms,  and  the  moths 
will  invariably  deposit  their  eggs  in  its  silk,  tobacco, 
cotton,  and  possibly  tomatoes  may  be  largely  protected 
by  a  proper  handling  of  the  corn  crop.  By  planting  an 
early  crop  of  corn,  the  moths  will  deposit  their  eggs  in  the 
silk;    and  before  the  worms  have  become  full  grown  it 


28  INSECTS    INJURIOUS   TO    STAPLK    CROPS. 

should  be  cut  and  fed  to  stock.  Another  crop  should  have 
been  planted  near  by,  or  in  alternate  rows  with  the 
previous  one,  so  as  to  mature  a  little  later,  and  it  should 
be  handled  in  the  same  manner.  Even  a  third  will  prove 
to  be  of  considerable  value.  In  this  way  the  worms  will 
be  trapped  in  the  corn,  and  the  more  valuable  crop  pro- 
tected. Sweet  corn  is  the  best  to  use,  and  a  few  strips  will 
often  be  found  to  be  of  great  value  when  properly  used. 

Numerous  other  instances  of  the  successful  application 
of  this  principle  might  be  cited,  and  several  are  mentioned 
under  the  discussion  of  individual  insects.  AVith  a  correct 
knowledge  of  the  habits  of  a  given  pest,  the  ingenious 
farmer  will  often  find  the  method  one  of  great  value. 

Time  of  Planting. 

The  proper  time  of  planting  is  of  importance  in  the 
protection  of  many  crops  from  insect  attacks.  Late-sown 
wheat  is  usually  exempt  from  the  attack  of  the  Hessian 
Fly.  Late-planted  corn  is  much  less  affected  by  the 
Stalk-borer  than  that  planted  earlier  in  the  season. 

Rotation. 

A  very  important,  if  not  indeed  the  most  important, 
factor  in  insect  control  is  the  rotation  of  crops  in  such  a 
manner  that  no  single  crop  shall  be  continuously  grown 
on  the  same  land,  or  any  two  crops  nearly  related  botani- 
cally.  Allowing  land  to  remain  in  meadow  for  some  time 
forms  a  breeding-ground  for  White  Grubs,  Cutworms,  and 
Wireworms,  and  if  it  is  then  desirable  to  cultivate  the  land, 
it  should  be  planted  in  ^^otatoes  or  some  such  crop 
unrelated  to  the  grasses.  It  may  then  be  planted  with 
small  grains,  and  then  with  corn;  for  if  the  number  of 


GENERAL    FAini    METHODS    AGAINST    INSECT    PESTS.      29 

these  insects  iu  the  grass  land  be  at  once  concentrated 
upon  the  comparatively  few  corn  plants,  the  injury  will  be 
much  more  severe  than  if  the  change  be  a  gradual  one, 
with  first  a  crop  not  of  the  grass  family  which  would  be 
largely  immune  from  their  attacks,  and  then  a  small  grain. 
The  value  of  rotation  is  possibly  best  illustrated  in  the  case 
of  the  Western  Corn  Eoot-worm,  which  is  never  injurious 
to  corn  after  the  land  has  been  in  a  small  grain  or  clover. 
The  Hessian  Fly,  Wheat  Isosoma,  Wheat  Plant-louse, 
Wireworms,  and  many  other  of  our  worst  pests  may  be 
largely  controlled  by  a  rapid  rotation,  and  their  increase 
and  consequent  depredations  are  very  often  due  almost 
entirely  to  a  lack  of  such  practice,  which  is  also  of  the 
utmost  importance  in  preventing  soil  depletion. 

Thus  a  proper  understanding  of  the  pests  with  which 
he  has  to  deal  and  a  timely  consideration  and  application 
of  these  homely  methods  may  be  of  the  greatest  value, 
and  indeed  often  the  only  available  means  for  the  control 
of  the  larger  part  of  the  insect  enemies  of  the  general 
farmer. 


CHAPTER   IV. 
BENEFICIAL  INSECTS,  PREDACEOUS  AND  PARASITIC. 

Ladybird-beetles. 

After  his  strawberries  have  been  ruined  by  the  Straw- 
berry-weevil, the  garden  truck  by  Cutworms,  the  wheat 
despoiled  by  the  Hessian  Fly,  the  melon-patch  fallen  a 
prey  to  plant-lice,  and  the  fruit  crop  has  been  a  failure  on 
account  of  the  Codling-moth,  Plum  Curculio,  and  San 
Jose  Scale,  it  is  scarcely  surprising  that  the  farmer  does 
as  one  of  my  acquaintances  did  and  '^orders  the  hands  to 
kill  everything  that  crawls." 

But  such  would  be  entirely  too  heroic  a  measure,  and 
if  strictly  adhered  to  the  remedy  would  be  as  bad  as  the 
disease,  for  it  would  mean  not  only  useless  labor,  but  the 
destruction  of  the  most  effective  means  whereby  insect 
pests  are  held  in  check.  We  j^ride  ourselves — and  justly 
— that  with  our  Paris  green  and  kerosene  sj^rays  and  gas 
tent  most  of  the  crops  can  be  effectually  protected ;  but 
were  it  not  for  those  other  insects  which  feed  u23on  these 
injurious  forms,  what  an  enormous  and,  in  some  instances, 
almost  futile  task  it  would  bsl 

Among  these  beneficial  insects  the  little  Ladybird- 
beetles  of  the  family  CoccineUidce  are  entitled  to  be  in  the 
first  rank.      Almost  all  the  beetles  and  larvae   feed  upon 

30 


BENEFICIAL    INSECTS,    PREDACEOUS    AND    PARASITIC.       31 

plant-lice  and  scale  insects.  Of  such  value  are  those 
feeding  upon  scale  insects  that  not  many  years  ago  a  large 
number  of  Australian  species  were  imported  into  California 
that  they  might  prey  upon  the  San  Jose  and  other  scales. 
One  of  these  was  eminently  successful  and  almost  com- 
pletely destroyed  the  Cottony  Cushion-scale. 

Of  those  feeding  upon  plant-lice,  one  of  the  most 
common  is  the  Xine-spotted  Ladybird  (Coccinella  novem- 
notata).  This  beetle  is  about  one-fourth  of  an  inch  long, 
with  black  head  and  body.  The  wing-covers  are  orange- 
yellow  marked  with  nine  black  spots — four  on  each  side 
and  one  on  the  central  suture.  The  larva  has  been  fancied 
to  resemble  a  miniature  alligator;  it  is  nearly  twice  as 
long  as  wide,  almost  black,  marked  with  bluish  and  orange 
spots,  and  has  long  legs,  which  carry  it  around  quite 
rapidly.  The  beetles  hibernate  during  the  winter  and 
come  forth  in  the  scoring  and  lay  their  eggs  wherever  the 
young  will  be  able  to  find  food  when  they  hatch.  When 
the  larva  has  satisfied  its  ravenous  appetite  and  become 
full  grown  it  fastens  itself  to  the  food-plant — seemingly 
by  its  tail,  if  such  a  term  might  be  alloAved, — transforms 
to  the  pupa,  and  in  a  week  or  ten  days  the  adult  beetle 
emerges  from  the  pupal  skin.  This  life- cycle  is  repeated 
several  times  during  the  summer  season,  before  the  fall 
brood  turns  into  winter  quarters. 

Another  very  common  form  among  plant-lice  on  garden 
truck  is  the  little  Adalia  hipundatiu  or  Tw^o-spotted  Lady- 
bird. It  is  slightly  smaller  than  the  preceding,  and  with 
only  one  black  spot  on  each  wing-cover  (Fig.  11). 

Several  other  species  in  the  genus  Hippodamia  are  very 
useful,  and  among  them  the  Convergent  Ladybird 
{^Hippodamia  convevgens)  is  one  of  the  best  known.     Its 


32 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


name    is    received    from    two  wliite  dashes  on  the    black 
thorax,  which  converge  posteriorly.     The  thorax  has  also 


'^ 


03 


CC 


c3   £ 

r 1  ^_| 

.-  o 
1=1 

go. 


0^< 


25 

M 


a  white  margin,  and  there  are  thirteen  black  dots  on  its 
orange  wing-covers.  These  larva?  and  l^ectles  are  very 
common  among  the  plant-lice  on  melon-vines,  and  are  an 
important  factor  in  their  extermination.     They  have  also 


BKNEFICIAL   INSECTS,    PREDACEOUS    AND    PARASITIC       33 


been  noted  for  eati7?g  the   Black  Peach  Aj^his  and  many 
other  plant-lice. 

A  form  which  is  often  very  abundant  among  lice  on  corn 


Fig  12.— 1,  the  Fifteeu-spotltd  Ladybird:  a,  larva  eating  plant- 
louse;  b,  pupa;  d,  beetle.  2,  the  Convergent  Ladybird  {Hippo- 
damia  convergens.,  larva,  pu])a,  and  beetle.  8,  the  Nine- 
spotted  Ladybird  {Coccinella  0-tiotata).  4,  Megilla  maculaia. 
(After  Riley.) 

is  Megilla  macuhita.  The  head,  thorax,  and  wing-covers 
are  a  dark  pink,  with  two  black  spots  on  the  thorax  and 
ten  on  the  wing-covers.  Such  numbers  of  these  little 
fellows  have  frequently  been 
found  huddled  together  un- 
der the  rubbish  at  the  base 
of  some  tree  in  a  last  yearns 

cornfield  that  they  might  be 

,    1  1.      ^1       1        i-P  1  FiGt-     13.  —  The    Twice-stabbed 

t'dken    up     by    tlie    iiancltui      Ladybird    (Chilocorus    Uvulne- 

without     difficulty.         Many      ^ws):  «,  beetle;  6,  larva.     (After 

Riley. ) 
other     species     feed     upon 

plant-lice,  but  the  above  are  the  most  common,  and  all 

bear  a  resemblance  to  one  another,  being  generally  orange 

or  red  with  black  spots,  and  of  a  characteristic  round  or 


34  INSECTS   INJURIOUS   TO    STAPLE    CROPS. 

oval  form,  flattened  below,  so  that  the  legs  may  be  drawn 
in  under  tlie  wing-covers. 

Those  Ladybirds  which  feed  upon  scales  are  much 
smaller  and  black,  though  sometimes  s^iotted  with  red  or 
orange. 

As  fa,r  as  known,  there  is  no  .way  in  which  these  useful 
allies  may  be  encouraged  or  increased  in  numbers,  but  it 
is  trusted  that  the  above  may  give  such  a  brief  view  of 
their  habits  that  fewer  may  be  killed  through  ignorance 
concerning  their  true  Avorth. 

Syrphus-flies. 

Besides  the  little  beetles  described  above  there  is  a 
family  of  flies,  the  SyrphidcBy  many  of  whose  larvae  feed 
upon  plant-lice.  This  family  is  a  very  large  one,  and  thus 
the  habits  of  its  different  mombers  vary  considerably. 
One  of  them  so  closely  resembles  a  honey-bee  as  to  be 
almost  indistinguishable  from  it.  The  larva  of  this  fly 
{Eristalis  tenax)  is  one  of  the  common  Rat-tailed  Maggots 
which  is  found  in  putrid  matter.  It  is  thought  that  the 
old  '^  bugonia  "  superstition  of  the  ancients  that  bees  came 
from  maggots  in  dead  animals,  etc.,  was  due  to  the  con- 
fusion of  this  fly  with  the  honey-bee. 

In  another  group  of  the  family,  the  adult  flies  of  which 
also  quite  closely  resemble  bees,  the  larv^  are  parasitic  in 
the  nests  of  honey-  and  bumble-bees,  feeding  upon  their 
larvae. 

But  the  larvae  of  possibly  the  most  typical  portion  of  the 
family,  embracing  the  genus  Syrplms  and  its  near  allies, 
are  entirely  predaceous  upon  plant-lice.  Rarely  can  a 
colony  of  plant-lice  be  found  without  some  of  these  little 
enemies  hard  after  them. 


BENEFICIAL    INSECTS,    PR:EDA('K01:S    AND    PAHASITIO.       35 


The  adult  syrplius-fi}^  is  a  very  striking  insect,  with  its 
dark  green  metallic  thorax,  and  abdomen  variously  banded 
with  yellow  and  black.  The 
female  fly  lays  her  eggs 
upon  some  plant  bearing 
plant  lice.  The  1  a  r  v  ae 
which  hatch  from  these  are 
elongate,  flattened  mag- 
gots,about  one -half  an  inch 

long,   with    hardlv   a    trace  Fig    U.  —  Syrphm  rihesii.     (Au- 

°  -^    ,  thor's  illustration. ) 

of   a   head,   but   with   four 

small  hooks,  which  serve  as  jaws,  projecting  from  the  more 

pointed  end  of  the  body.     These  maggots  are  often  of  a 

light  green  color,  and  so  like  the  color  of  the  plants  as  to 

render  them  most  ditflcult  to  be  recognized.     The  young 

larvae  at  once  commence  crawling  over  the  plant  in  search 

of  the  aphids,  and  as  soon  as  they  come  in  contact  with 

one  it  is  firmly  clasped  by  the  small  booklets  until  the 

juices  are  sucked  from  its  body.     In  this  manner  very 


Fig.  15. — The  Koot-loiise  Syrphus-fly  {Pipiza  radicans).     a,  mag- 
got; b,  piiparium;  r,  fly.      (After  Riley.) 

large  numbers  are  destroyed,  a  single  maggot  of  tlie 
American  Syrphus-fly  {Syrphus  ainericanus)  having  been 
observed  to  eat  twenty-five  Apple  Plant-lice  {AjjJiis  mali) 


36  INSECTS   INMURIOUS  TO   STAPLE    CROPS. 

in  as  many  minutes.  When  the  larva  is  ready  to  pupate 
it  attaches  itself  to  a  leaf,  and- the  larval  skin  dries  up  and 
forms  a  case  or  puparium  inside  of  which  the  pupa  remains 
until  it  transforms  to  the  adult  fly. 

Though  most  of  these  larvae  feed  upon  plant-lice  upon 
the  leaves,  one  of  them,  the  Root  -  louse  Syrphus  -  fly 
{Pipiza  radicans),  lives  entirely  underground  during  that 
stage,  and  feeds  upon  the  root-lice  of  the  apple  and  the 
grape.  None  of  this  family  are  injurious,  and  as  a  large 
portion  of  them  are  so  beneficial  as  to  frequently  destroy 
whole  broods  of  plant-lice,  they  should  not  be  disturbed 
in  their  good  work  if  possible  to  avoid  it. 

The  Ground-beetles. 

If,  as  you  scrape  away  the  loose  chips  at  the  base  of  a 
tree  in  your  door-yard,  turn  over  an  old  log  in  the  wood- 
land, or  pick  up  a  fallen  fence-rail,  you  will  scrutinize  the 
inhabitants  under  these  shelters,  a  number  of  shining 
black  beetles  varying  in  length  from  one-fourth  to  one  and 
one-half  inches  will  usually  be  noticed.  If  the  city  reader 
be  not  so  fortunate  as  to  be  fa-miliar  with  or  have  access 
to  these  hiding-places,  he  may  find  large  numbers  of  the 
beetles  under  any  electric  arc  light  during  the  warm 
summer  evenings;  for  there  they  are  having  a  sumptuous 
banquet  upon  the  small  flies  and  moths  attracted  by  the 
glare.  They  are  rarely  seen  at  large  during  the  day,  as 
they  are  almost  exclusively  nocturnal  insects,  and  from 
their  habit  of  remaining  almost  entirely  in  or  on  the 
ground  they  are  usually  known  as  '^Ground-beetles.'' 
As  might  therefore  be  inferred,  they  are  exceedingly 
valuable  to  the  farmer  by  destroying  large  numbers  of 
noxious  insects  which  ])ass  a  part  or  all  of  their  existence 


BENEFICIAL    INSECTS,    PUEDACEOIS    AND    PARASITIC.       3T 

ill  the  soil.  Besides  tlio  glos^^y  black  forms  which  are 
most  commonl}"  seen,  mniiy  are  brilliantly  marked  with 
gold,  green,  purple,  and  iridescent  tints. 

The  Fiery  Ground-beetle  {Calosoma  caJidnni),  so  called 
on  account  of  the  wing-covers  being  dotted  with  bright 
gold,  has  many  times  been  of  great  assistance  in  helping 
to  rid  a  corn-field  of  Cutworms.      The  larvae  of  this  insect 


Fig,  16.— The  Fiery  Ground- 
beetle  ( Calosoma  calidum). 
a,  beetle;  h,  larva.  (After 
Riley.) 


Fig.  17. -''The  Searcher"  {Car 
losoma  serutator).  (After  Ri- 
ley.) 


are  about  one  inch  in  length,  of  a  dark  brown  color,  with 
the  skin  of  a  hard,  horny  texture  like  that  of  the  beetle. 
They  have  strong,  prominent  jaw\s,  and  at  the  posterior 
end  of  the  body  is  a  forked  appendage  looking  much  like 
another  pair  of  jaws.  It  is  not  only  surprising  that  these 
larvae  will  eat  so  large  a  number  of  cutworms,  as  they  have 
frequently  been  known  to  do,  but  also  that  they  will 
dare  to  attack  such  a  formidable  creature  fully  tliree  or 
four  times  as  large  as  themselves.  But  their  assault  is 
sharp  and  vigorous,  and  a  single  larva  has  often  been  seen 


38        INSECTS  INJURIOUS  TO  STAPLE  CROPS. 

to  kill  and  eat  in  a  short  time  several  fnll-grown  cutworms. 
Many  instances  of  the  good  work  of  this  heetle  are  on 
record,  among  which  one  by  the  late  Prof.  J.  A.  Lintner 
might  be  cited,  where  he  found  them  eating  large  numbers 
of  the  Corn-crainbus — sometimes  locally  known  as  the 
Corn  Bud-worm.  Another  somewhat  larger  beetle,  called 
by  Prof.  J.  H.  Comstock  ^'  the  Searcher"  {CaJosoma  scru- 
t((ior),  and  in  fact  one  of  the  largest  of  the  family,  is  a 
brilliant  metallic  green,  bordered  with  a  dark  purplish 
blue,  and  has  the  good  quality  of  having  a  very  particular 
appetite,  causing  it  to  kill  large  numbers  of  caterpillars, 
but  eating  only  part  of  each. 

While  in  the  earth  as  pup*  large  numbers  of  the  Colo- 
rado Potato-beetles  are  destroyed  by  members  of  this 
family,  and  one  species,  Lehia  grandis,  which  is  peculiar 


Fig.  18. 


Lehia  grandis. 
Riley.) 


(After      Fi(i.   19.— The  Murk}-  Ground 
beetle  (Harpalus  culiginosuL  . 
(After  Riley.) 


in  that  the  wing-covers  are  somewhat  abbreviated,  thus 
leaving  the  tip  of  the  abdomen  exposed,  has  been  noticed 
on  the  plants  eating  the  eggs  and  young  larvae  of  this  old 
potato  pest. 

Another  valuable  species  is  one  called  by  Dr.  Riley  the 


BEITEFICIAL    INSECTS,    PKEUACEOUS   AND   PARASITIC.      39 

Murky  Ground-beetle  {Harpalus  caligiiioms).  Its  larva 
is  of  considerable  assistance  to  fruit-growers  by  eating  large 
numbers  of  Curculio  larvae,  which  it  secures  from  the 
plums  after  tliey  have  fallen  to  the  earth.     From  a  glance 


Fig.  20.—^,  larva  of  Murky  Ground-beetle;  B  head  of  same;  G , 

mandible. 

at  its  formidable  jaws.  Fig.  20,  h-c,  it  is  easy  to  conjec- 
ture the  fate  of  man}^  a  curculio  grub. 

Thus  here  again  are  found  some  "  bugs ''  that  are  friends 
and  not  foes,  worthy  of  all  the  protection  that  can  be 
aiforded  them,  and  well  repaying  such  careful  observation 
of  their  habits  as  may  be  bestowed  upon  them. 


Insect  Parasites. 

Though  large  numbers  of  injurious  insects  are  annually 
destroyed  by  those  which  are  purely  predaceous  upon 
them,  many  more  succumb  to  those  minute  forms  which 
live  parasitically  within  them.  A  few  of  these  parasites 
belong  to  the  order  Diptern,  or  true  flies,  but  most  of  them 
are  classed  in  the  order  Hymenoptera,  in  which  order  are 
also  included  the  saw-flies,  ants,  wasps,  and  bees. 

Of  the  half-dozen  families  of  hymenopterous  parasites 
one  of  the  largest  and  most  beneficial  is  that  of  the 
Ichneumon-flies.  The  illustrations  will  best  show  the 
form   and    structure  of   these  insects,  which   the   casual 


40  INSECTS    INJURIOUS   TO   STATLE    CROPS. 

observer  will  luirdly  be  able  to  diftijiguisli  from  other 
families  of  the  group.  Bat  it  will  be  noticed  that  the  fine 
yeius  of  the  wings  vary  considerably  in  the  different  jDara- 
sites  figured,  and  it  is  by  these  that  the  entomologist  is 
enabled  to  separate  the  different  groups  and  often  to 
identify  the  species  at  a  glance.  Both  this  and  the  fol- 
lowing family  are  2)eculiar  in  having  an  exceedingly  long 


Fig.  21.— a  Plant-louse  Fiu-nnite  (Aphidius  gr-inaj'iaphis),  showing 
above  the  parasitized  louse  from  which  it  has  issued.  (Copied 
from  J.  B.  Smith  ) 


ovipositor  or  egg-tube,  of  which  it  will  be  seen  that  they 
make  a  very  good  use.  It  is  with  this  extensile  tube  that 
the  female  deftly  punctures  the  skin  of  some  unsuspecting 
caterpillar,  and  under  it  inserts  her  eggs.  In  a  few  days 
there  hatch  from  these  a  host  of  young  grubs,  which  feed 
npon  the  Juices  and  tissues  of  the  caterpilhir,  but  are 
seemingly  careful  to  avoid  injuring  any  of  its  vital  organs, 
for  as  soon  as  the  caterpillar  reaches  its  full  growth    it 


BENEFICIAL   INSECTS,    PREDACEOUS    AND    PAKASITIC.      41 

changes  to  a  pupa,  apparently  iinaffected.  But  now  the 
maggots  have  reached  their  full  size,  and  each  spms  up  a 
small  silken  cocoon  inside  the  2:»upa,  entirely  filling  up  its 
now  dead  shell,  and  instead  of  a  beautiful  moth  apj^earing 
in  the  spring,  from  a  round  hole  in  the  side  of  the  pupa, 
or  cocoon,  a  horde  of  small  flies  are  seen  to  emerge. 

Thus  large   numbers  of   such  pests  as  the   Apple-tree 
Tent-caterpillar     {CUsiocam2)a     americaiia),     Bag-worms 


Fig.  22. — Maggots  of  Pimj)la  iriqiiisUor,  a  parasitic  Ich 
fly,  feeding  on  a  caterpillar  which  had  spun  its  cocoon 
ready  to  pupate.     (Original.) 


ncumon- 
spun  its  cocoon  and  was 


{Tliyridopteryx  ep1iemer(efor})iis),  cater^jillars  of  the  swal- 
low-tailed butterflies  which  feed  upon  parsley,  carrots, 
etc.,  and  a  host  of  others,  are  consumed  by  members  of 
this  family. 

Those  belonging  to  the  genus  Opliion  are  partial  to  the 
large  American  silkworms  which  produce  some  of  our 
largest  and  most  beautiful  moths,  and  difficulty  is  fre- 
quently experienced  in  rearing  a  desired  number  of  moths 
on  account  of  the  large  ^^er  cent  of  cocoons  parasitized. 

The  species  of  the  family  Braconidce  are  very  similar  to 
those  of  the   preceding  one,  and   contain    some    eqiiany 


42 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


beneficial  insects,  feeding  jis  tliey  do  upon  sucli  pests  as 
the  Codling-moth,  Web-worms,  Plum-cnrciilio  grub.  Plant- 
lice,  etc.  Some  of  the  more  common  forms  of  this  family 
belong  to  the  genus  Microgaster,  and  their  small  white 
cocoons  may  frequently  be  seen  almost  covering  one  of 
our  large  tomato-  or  tobacco-worms  (see  page  237),  the 


Fig.  23. — The  Long-tailed  O^hion  {Ophion  macrurum).     a,  adult; 
h,  maggot.     (After  Riley.) 


pupae  of  which  are  often  known  as  "'  horn-blowers.^'  Many 
mistake  these  cocoons  for  the  eggs  of  the  worms,  and  there- 
fore destroy  some  of  their  best  friends.  Though  some 
thus  spin  their  cocoons  on  the  outside  of  the  host,  others 
remain  inside  of  the  parasitized  insect  until  the  adult  fly 
emerges.  Thus  dead  plant-lice  may  often  be  found  with 
a  large  round  hole  in  the  abdomen — the  only  evidence  of 


BENEFICIAL    INSECTS,    PKEDACEOUS    AND    PARASITIC.       43 

where  one  of  these  pcarasites  has  emerged.  For  this  reason 
as  a  general  rule  dry,  shrunken  plant-lice  shonld  never  he 
destroyed. 

The  Ohalcis-flies,  which  comprise  another  closely  re- 
lated famih',  are  exceedingly  minnte  insects,  sometimes 
not  over  one  one-hundredth  of  an  inch  long.  They  are 
generally  of  a  metallic  black  color,  and  the  nsnal  veins  of 
the  wings  are  almost  entirely  absent.  Many  of  these  flies 
are  parasitic  npon  plant-lice,  while  a  large  number  of  their 
larva?  live  and  mature  in  the  eggs  of  other  insects. 

Very  similar  to  the  Chalcis-flies  in  their  habits  of  infest- 
ing plant-lice  and  insect  eggs  are  some  even  smaller  insects 
— in  fact  the  smallest  known,  the  largest  being  rarely  over 
one  twenty-fifth  and  the  smallest  only  six  or  seven  one- 
thousandths  of  an  inch  in  length — with  a  correspondingly 
tremendous  and  unpronounceable  name,  known  to  science 
as  the  Proctotryjndce, 

But  enough  has  been  said  to  indicate  the  important  j^art 
which  the  immense  hordes  of  these  apparently  insignificant 
insects  play  in  the  economy  of  Nature,  by  often  clearing 
off  a  most  dreaded  insect  pest  in  a  few  days  almost  as  if 
by  miracle. 


CHAPTER  V. 

INSECTS   INJURIOUS   TO   THE   GRAINS  AND   GRASSES. 

Ukder  the  above  head  several  common  insects  which 
are  injurious  to  almost  all  of  the  grains  and  grasses  may 
be  conveniently  grouped,  thus  distinguishing  them  from 
those  which  affect  a  few  or  an  individual  species. 

White  Grubs  {Lachnosterna  spj^.). 

Of  all  the  insects  attacking  cereal  crops  none  are 
better  known  than  the  so-called  "white  grubs/^  I  say 
"  so-called,"  for  the  Englishman  has  styled  this  larva  the 
"cockchafer  grub,"  the  Frenchman  calls  it  "  ver  blanc," 
and  the  German  has  named  it  the  "engerling,"  while 
here  in  America  the  adult  beetles  are  known  both  as  May- 
beetles,  June-bugs,  and  dor-bugs,  and  when  flying  in  the 
windows  and  buzzing  around  the  ceilings  are  often  termed 
"  pinching-bugs."  In  Europe  white  grubs  have  long  been 
recognized  as  one  of  the  agriculturist's  worst  insect  foes, 
and  their  depredations  were  noted  in  this  country  as  early 
as  the  middle  of  the  seventeenth  century.  • 

Life-history. — As  for  most  of  our  grain  insects,  grass 
land  is  their  favorite  haunt,  and  the  female  beetle  usually 
lays  her  eggs  in  old  meadows,  though  not  infrequent!}^  in 
corn  land.     The  eggs,  which  are  glossy  white,  about  one 

44 


INSECTS    IXJUUIOUS    TO    THE    GRAlJsS    AND    GRASSES.       45 

eighth  of  an  inch  long,  and  broadly  oval,  are  laid  early  in 
June  and  hatch  in  from  11  to  13  da3's.  The  grubs  hatch- 
ing from  these  feed  upon  the  plant-roots,  growing  but 
slowly,  as  they  require  a  bout  two  years  to  become  full- 


grown.  Meanwhile,  however,  each  grub  does  its  full  share 
of  damage,  especialh^  to  corn  and  grass,  and  often  to  the 
smaller  grains.  Its  attacks  have  also  long  been  feared  by 
the  growers  of  straAvberries,  potatoes,  and  garden  truck. 


46  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

as  well  as  by  nurserymen  and  greenhouse  florists.  The 
grub  becomes  full-grown  in  the  summer  of  the  second  year 
after  hatching  from  the  egg. 

It  then  forms  a  small  oval  cell  from  three  to  ten  inches 
below  the  surface  of  the  soil,  and  here  changes  to  the 
pupa.  The  pupal  stage  lasts  slightly  over  three  weeks. 
Late  in  August  or  early  in  September  another  transforma- 
tion takes  place  and  the  adult  beetle  wriggles  out  of  the 
pupal  skin,  but  remains  m  the  earthen  cell  until  the  fol- 
lowing spring,  when  it  comes  forth  fully  hardened  in  May 
or  June.  The  beetles  at  once  pair,  and  the  females 
deposit  their  eggs  and  soon  die.  Thus  three  full  years  are 
consumed  in  the  complete  life-cycle  of  each  brood. 

hijiiry. — Having  seemingly  formed  a  dislike  to  the  light 
of  day  from  their  long  subterranean  existence,  the  adult 
beetles  feed  and  pair  entirely  at  night.  The  foliage  of 
almost  all  of  the  common  forest-  and  shade-  and  occa- 
sionally fruit-trees  suifers  from  their  attacks.  Injury  to 
maple-trees  has  been  specially  observed.  About  9  p.m.  of 
an  evening  early  in  June,  thirty-five  beetles  were  once 
taken  by  the  writer  from  a  small  silver-maple  tree  about 
eight  feet  in  height,  and  they  were  equally  numerous  on 
all  of  a  long  row  of  these  trees. 

But  the  grubs  and  beetles  are  too  common  to  need 
description  and  may  be  recognized  from  the  figures.  It 
may  not,  however,  be  known  that  the  term  ^^  white 
grubs  ^'  is  generally  applied  to  the  larvae  of  many  distinct 
species  of  the  genus  Lachnosterna  and  one  of  Cyclocephala, 
which  so  far  as  known  have  practically  the  same  habits, 
except  that  the  larvae  of  the  latter  genus  remain  over 
winter  as  dormant  larv^  and  pupate  in  May. 

By  cutting  off  the  tap-root  and  feeding  roots  of  corn. 


INSECTS    IXJURIOUS   TO    THE    GRAINS   AND    GRASSES.       47 

white  grubs  have  often  been  responsible  for  the  total  or 
partial  failure  of  large  areas  of  corn  land.  In  1805  the 
grubs  so  injured  one  twenty -year-old  meadow  of  250  acres 
in  Illinois  that  the  sod  could  be  rolled  up  like  a  carpet 
over  the  entire  field. 

Remedies. — Unfortunately,  as  regards  remedies  for  this 
pest  little  is  known.  Though  eaten  by  various  birds  and 
^parasitized  by  a  half-dozen  or  so  insects,  yet  these  natural 
enemies  seem  to  be  of  little  value  for  holding  the  grubs  in 
check.  Leaving  land  in  meadow  for  several  years  is 
undoubtedly  conducive  to  their  rapid  increase;  and  hence 
a  short  rotation  in  ^\'hicli  clover  follows  grass  and  which  is 
in  turn  followed  by  the  small  grains  before  corn  will  very 
largely  prevent  serious  damage  to  the  latter  crop.  Poisoned 
bran  mash  such  as  used  for  cutworms  (see  page  217)  is 
reported  as  having  been  used  successfully  against  the  grubs 
by  scattering  it  over  infested  land. 

If  turned  loose  in  infested  grass  land,  swine  will  fairly 
gorge  themselves  on  the  grubs,  and,  prior  to  plowing  grass 
land  for  corn,  this  will  be  found  to  be  one  of  the  best 
means  for  ridding  it  of  grubs.  The  hogs  will  also  feed  as 
freely  upon  the  beetles  which  drop  to  the  ground  from  the 
trees  and  hide  during  the  day,  and  hence  they  may  be  of 
considerable  benefit  in  woodland  adjoining  infested  fields. 
A  flock  of  chickens  or  turkeys  following  the  plow  or  culti- 
vator will  also  be  found  to  consume  not  a  few  of  the  grubs. 
In  Europe  the  beetles  are  systematically  jarred  from  the 
trees  in  the  early  morning  by  organized  bands  composed 
mostly  of  women  and  boys,  in  much  the  same  manner  as  we 
**  jar"  for  the  Plum-curcnlio.  But  such  methods,  as  well 
as  spraying  seem  hardly  practicable  in  our  larger  country, 
except  possibly  for  young  orchard-trees,  which  are  often 


48  IXSKCTS    INJURIOUS   TO    STAPLE    CROPS. 

seriously  defoliated.  As  the  beetles  remain  in  the  pupal 
cells  over  winter  and  are  still  tender,  not  fully  hardened, 
deep  fall  plowing  will  destroy  a  large  number  of  them  by 
breaking  open  the  pupal  cells  and  exposing  them  to  the 
weather,  and  by  burying  or  crushing  them.  But  possibly 
the  best  method  of  preventing  serious  injury  by  white 
grubs,  and  one  which  will  not  only  be  of  benefit  in  securing 
immunity  from  the  attacks  of  this  as  well  as  many  other 
insect  pests,  but  will  also  cause  less  drain  upon  the  soil, 
is  a  judicioiTS  rotation  of  crops,  avoiding  a  continual 
growth  of  grass  in  any  one  field. 

Wireworms  {Elateridm). 

Injury.  — The  ^o\\  has  been  properly  prepared  and  the 
field  carefully  planted.  Day  after  day  the  anxious  farmer 
awaits  the  sprouting  of  the  young  shoots  of  grain.  But 
all  in  v^nl  Still  no  signs  of  growth  appear.  So,  appre- 
hensive that  he  lose  the  use  of  the  land,  he  removes  the 
earth  from  some  of  the  seed  and  there  finds  the  kernels  of 
corn  or  wheat  either  with  a  small  round  hole  drilled 
through  them  or  some  "  hard,  smooth,  shining,  reddish 
or  yellowish-brown,  slender,  cylindrical,  six-legged  larvae  " 
still  devouring  the  seeds,  with  their  heads  firmly  embedded 
in  them.  If  he  be  a  man  of  any  experience,  he  at  once 
recognizes  the  work  of  wireworms  and  wastes  no  time  in 
reseeding  his  field,  for  of  all  the  insects  attacking  grain  in 
the  seed,  these  are  the  most  common  and  destructive.  If 
later  on  the  resown  seed  secures  a  start,  its  growth  is 
exceedingly  liable  to  be  stunted  by  the  worms  attacking 
the  smaller  roots,  and  it  may  even  be  killed  when  several 
inches  high  by  their   boring   through  the  underground 


INSECTS    IXJURIOL'S   TO    THE    liKAINS    AND    GRASSES.      49 

stalk.  All  the  grains  are  attacked  by  wireworms,  but 
wheat  and  corn  suffer  most,  as  well  as  potatoes,  turnips, 
and  many  garden  crops. 

Description. — Wireworms,    which   are  the  young  of  a 
number  of  beetles,   which,  from  their  habit  of  snapping 


~^M 
■^.-t 


s 


Fig.  25. 
The  Corn  Wireworm  {Melanotiis      The  AVireworm  of  Drnsterius  ele- 
crihulosus),  enlarged  4|  diam-  guns,    enlarged    seven    diam- 

eters.    (After  Forbes.)  eters.     (After  Forbes.) 

their  bodies  up  in  the  air,  are  known  as  ''click-beetles,'' 
are  all  more  or  less  like  Fig.  25  in  general  appearance. 
Although  the  common  wireworms  are  usually  suj^jjosed  to 
be  of  but  one  kind,  upon  examination  several  species  will 


50 


INSECTS    INJURIOUS   TO    STAPLE    CHOI'S. 


often  be  found  which  niiiy  be  distinguished  by  a  compari- 
son of  the  caudal  segment  with  the  illustrations  (Figs.  27 
and  28).  The  adult  beetles  arc  mostly  about  one-half  to 
three-fourths  of  an  inch  long,  decidedly  flattened,  of  a 
dark  brown  coJor,  with  short  heads  and  shield-shaped 
thoraxes,  as  in  Fig.  2G. 

Life-history. — Land  wliich  has  been  in  grass  for  several 
years  is  their  native  breeding-ground,  and  here  the  eggs 


Fig.  26. — A,  Beetle  of  Wheat  Wirew^^rm;    B,  Dmsterius  elegnns, 
both  enlarged  about  4  diameters.     (After  Forbes.) 

are  deposited.  Much  concerning  the  life-histories  of  these 
important  pests  is  still  unknown,  but  it  seems  safe  to  assert 
that  the  larvae  require  from  three  to  five  years  to  become 
full-grown.  Thus  the  second  year  after  grass  land  has 
been  planted  in  grain  is  that  in  which  the  worst  injury 
occurs,  and  this  is  especially  true  with  corn,  wliich  covers 
the  ground  less  completely  than  do  the  smaller  grains, 
The  larvffi  become  full-grown  in  midsummer,  form  a  small 
earthen  cell,  and  there  transform  to  the  pup^e.  Three  or 
four  weeks  later  the  adult  beetles  shed  the  pupal  skin,  but 
only  a  few  of  them  make  their  way  to  the  surface  during 


/ 


INSECTS    INJURIOUS   TO    THE    GRAINS    AND    GRASSES.      51 

the  fall,  the  most  of  the  brood  remaining  in  the  pnpal 
cells  as  partially  hardened  beetles  until  the  following 
spring. 

Means   of   Comldting. — Eemedies    galore    have    been 
advised  for  these  insects,  almost  every  farmer  having  his 


Fig.  21.^ a,  last  segment  of  Melnnotus  communis,  dorsal  view. 
(After  Forbes.)  B,  the  Wheat  Vvlreworm.  Agriotes  7n(incu8. 
a,  b,  c,  d,  details  of  month-parts,  enlarge. I.  (After  Slinger- 
land.) 


favorite  expedient,  but  in  recent  years  a  careftil  testing  has 
shown  that  a  satisfactory  remedy  or  preventive  for  wire- 
worms  is  vet  to  be  discovered.     Professors  Comstock  and 


Fig.  28. — C,  caudal  segment  of  the  Wireworm  of  Drasterius  elegnns 
D,  caudal  segment  of  the  Wireworm  of  Asaphes  decoloraiu^, 
much  enlarged.     (After  Forbes.) 

Slingerland  performed  extensive  experiments  for  nearly 
three  years  in  attempting  to  sttccessfnlly  combat  these 
insects  by  (1)  the  protec^tion  of  the  seed,  and  (2)  the 
destruction  of  the  larvse  by  {a)  starvation  in  clear  fallow 


52  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

and  supposedly  immune  crops,  and  {b)  by  the  use  of  in- 
secticides and  fertilizers.  But  all  the  remedies  or  pre- 
ventives tested  resulted  in  failure,  and  this  has  been  the 
experience  of  several  other  leading  entomologists.  It  was 
ascertained,  however,  that  they  may  be  more  or  less 
checked  by  destroying  the  beetles.  This  can  be  done  both 
by  fall  plowing  or  by  trapping.  By  plowing  late  in  sum- 
mer and  keeping  the  earth  stirred  for  a  period  of  a  month 
or  so,  large  numbers  of  the  newly  transformed  beetles  which 
do  not  become  fully  hardened  until  spring,  and  pupae,  will 
be  destroyed.  When  the  wireworms  are  numerous  in  re- 
stricted areas,  as  they  often  are  on  spots  of  low  moist  land, 
they  may  be  effectually  trapped  with  but  little  labor  by 
placing  under  boards  bunches  of  clover,  or  sweetened 
corn  meal  poisoned  with  Paris  green. 

A  short  rotation  of  crops,  in  which  land  is  never  allowed 
to  remain  in  grass  for  any  length  of  time,  will  undoubtedly 
secure  comparative  immunity  from  serious  attack. 

The  Chinch-bug  (Blissus  le^icopteriis  Say).* 

Though  individually  insignificant,  when  assembled  in 
countless  myriads  Chinch-bugs  have  doubtless  been  of 
greater  injury  to  the  farmers  of  the  Mississippi  Valley  than 
any  other  insect  attacking  grain  crops,  and  are  responsible 
for  hundreds  of  millions  of  dollars'  loss. 

Distrihntion, — This  insect  may  be  found  over  all  the 
eastern  United  States  to  the  Rockies,  and    in  restricted 

*See  "The  Chinch-bug,"  F.  M.  Webster,  Bulletin  15,  n.  s.. 
Div.  Ent.,  U.  S.  Dept.  Ag. ;  Dr.  S.  A.  Forbes,  12th,  16th,  and  20th 
Ilepts.  St.  Ent.  Illinois. 


INSECTS    INJUKIOUS   TO    THE    GIJATNS    AND    GRASSES.       53 


localities  in  Cuba,  Central  America,  Panama,  Lower  and 
Central  California;  but  the  area  in  which  it  has  been  most 
injurious  lies  in  the  Central  and  North  Central  States. 
During  the  last  fire  years,  however,  its  attacks  have  been 
increasingly  wide-spread  in  Ohio  and  Kentuck}^,  and  in 
August.  1898,  some  damage  was  done  by  it  in  Pennsyl- 
vania and  New  York. 

Description. — The  adult  bug  is  about  one-fifth  of  an  inch 
long,  with  a  black  body.     Its  white  wings  lie  folded  over 


Fig.  29.— The  Adult 
Chmc\\-\i\xg{Blissus 
leucopterus  Say) 
enlarged.  (After 
Riley.) 


Fig.  30. — a,  h,  eggs  magnified  and  natural 
size;  c,  young  nymph;  e,  second  stage  of 
nymph;  /,  third  stage;  g.  full-grown 
nymph  or  pupa;  d,  h,  j,  legs;  i,  beak 
through  which  the  bug  sucks  its  food. 
(After  Riley.) 


each  other  on  the  back  of  the  abdomen,  and  are  marked 
by  a  small  black  triangle  on  their  outer  margins,  while  the 
bases  of  the  antennae,  or  feelers,  and  the  legs  are  red.  The 
young  bugs  are  mostly  red,  but  vary  in  the  different  stages. 
Life-history . — During  the  winter  the  bugs  hibernate  in 
clumps  of  grass  and  under  boards  and  rubbish.  With  the 
first  warm  days  of  spring  they  come  forth  and  spread  about 
the  neighboring  wheat-fields,  but  there  do  little  harm. 
Very  soon  they  pair,  and  the  females,  each  of  which  is 


54 


INSECTS    INJUllIUUS   TO    STAPLE    CKUPSo 


Ft«.  81. — Corn-plant  two  feet  tali  infested  with  Chinch  bu.os. 
(After  Webster,  Bull.  15,  n.  s.,  Div.  Eat.,  U.  S.  Dept.  Agr.) 


INSECTS    INJURIOUS   TO   THE    GRAINS   AND    GRASSES.       55 

capable  of  laying  150  eggs,  commence  to  deposit  them 
either  upon  the  roots  or  bases  of  the  stalks.  This  occurs 
from  the  middle  of  April  until  the  first  of  June,  depend- 
ing upon  the  latitude  and  weather,  and  the  eggs  hatch  in 
from  two  to  three  weeks.  The  nymphs  often  severely 
injure  the  small  grains,  and  are  full-grown  about  the  time 
of  harvest.  As  the  wheat  is  harvested  they  spread  to  oats 
and  soon  to  corn,  but,  curiously  enough,  though  the  adults 
have  wings  they  prefer  to  travel  from  field  to  field  on  foot, 
much  like  Army-worms,  and  were  it  not  for  this  fact  we 
would  be  at  a  loss  how  to  cope  with  them.  Another  lot 
of  eggs  are  now  laid  under  the  unfolding  leaves  of  the 
corn,  and  the  young  nym^Dhs  emerge  in  about  ten  days. 
This  brood  lives  upon  corn,  and  when  full-grown  is  that 
which  hibernates  over  winter.  South  of  the  latitude  of 
southern  Illinois  there  is  often  an  unimportant  third 
brood.  The  most  extensive  injury  is  done  by  the  mature 
nymphs  and  adult  bugs  of  the  first  brood.  Though  no 
means  is  known  for  preventing  the  ravages  of  this  brood 
in  the  small  grains,  every  effort  should  be  made  to  defend 
the  young  corn  from  its  attacks,  for,  with  the  innumer- 
able little  beaks  of  the  adult  insects  sucking  out  its  life,  it 
soon  succumbs  when  they  are  reinforced  by  the  largely 
multiplied  numbers  of  the  second  brood. 

Methods  of  Prevention  and  Destruction. — During  the 
migration  from  the  small  grains  to  corn  seems  to  be  prac- 
tically the  only  time  when  this  pest  may  be  successfully 
combated.  Just  before  harvest  a  narrow  strip  should  be 
plowed  around  the  corn-field  and  this  thoroughly  pulver- 
ized by  harrowing  and  rolling,  and  then  reduced  to  as  fine 
a  dust  as  possible  by  dragging  over  it  a  brush  composed 
of  dead  limbs,  or  whatever  contrivance  is  most  convenient. 


56  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

A  log  or  block  should  now  be  dragged  through  this  strip 
in  such  a  manner  as  to  form  a  deep  furrow,  with  tlie  incli- 
nation of  its  side  next  the  corn  as  steep  as  possible.  In 
attempting  to  climb  this  barrier,  the  dust  will  slide  from 
under  the  bugs  and  large  numbers  of  them  will  accumulate 
in  the  furrow,  where,  on  a  clear  day,  they  will  soon  be 
killed  by  the  heat  if  the  temperature  of  the  air  be  over 
88  degrees  Fahrenheit  (the  soil  will  then  be  110  degrees 
Fahr.).  The  furrow  may  be  kept  clean  by  redragging  the 
log  through  it  as  often  as  necessary.  If  the  weather  be 
cooler,  the  bugs  should  be  further  trapped  by  sinking  holes 
with  a  post-hole  digger  about  one  foot  deep  every  ten  or 
twelve  feet  i]i  the  furrow.  Large  quantities  will  soon 
accumulate  in  the  holes,  and  may  be  there  crushed  or 
killed  with  coal-tar  or  kerosene. 

Of  course  a  sudden  dash  of  rain  will  destroy  such  a 
furrow,  and  the  bugs  will  then  at  once  march  on  to  the 
corn-field.  In  such  an  emergency  a  narrow  strip  of  coal- 
tar,  about  the  size  of  one's  finger,  should  be  run  around 
the  field  a  few  feet  inside  the  former  furrow,  with  post- 
holes  dug  as  before  upon  the  outside  of  the  line.  Dislik- 
ing the  smell  of  the  tar,  the  bugs  will  again  fall  into  the 
traps  and  may  then  be  destroyed.  As  many  strips  may 
be  made  along  the  outer  rows  of  corn  as  seem  necessary  to 
prevent  their  further  progress.  These  strips  of  tar  should 
be  freshened  whenever  dust,  straw,  or  rubbish  has  crossed 
them  at  any  point.  In  this  manner  one  Illinois  farmer 
protected  over  300  rods  with  less  than  a  barrel  of  tar. 
That  this  method  is  practicable  and  efficient  was 
thoroughly  demonstrated  by  Prof.  W.  G.  Johnson  in  a 
series  of  experiments  in  Illinois,  in  the  report  of  whose 
work  Prof.  Forbes  says:     "In  short,  the  success  of  this 


INSECTS   INJURIOUS   TO   THE    GRAINS   AND    GRASSES.      57 

field  experiment,  tried  under  ver}^  difficult  conditions,  was 
substantially  complete,  and  the  value  of  this  method  of 
contest  with  the  Chinch-bug  seems  established  beyond 
controversy." 

Extensive  experiments  have  been  made  in  Illinois  and 
Kansas  in  the  use  of  the  Muscardine  fungus — Sporotrichum 
glohnUfenmi — against  the  Chinch-bug.  Though  the  re- 
sults have  often  seemed  to  indicate  its  use  to  be  profit- 
able, yet  it  has  never  so  commended  itself — even  to  ento- 
mologists— as  of  sufficient  value  to  be  brought  into  general 
use,  and  its  value  must  still  be  considered  as  largely 
problematical. 

If  the  bugs  have  already  become  numerous  in  the  outer 
rows  of  corn,  most  of  them  may  be  destroyed  by  a  si)ray 
of  kerosene,  which,  with  a  tar  strip,  will  effectually  pro- 
tect the  remainder  of  the  field.  Such  a  spray  may  be 
either  (1)  in  the  form  of  an  emulsion,  composed  of  a 
^' stock  solution"  of  one  pound  of  soap,  one  gallon  of 
water,  and  two  gallons  of  kerosene,  prepared  in  the  usual 
manner,  and  diluted  with  fifteen  quarts  of  water;  or  (2) 
may  be  merely  a  mechanical  mixture  of  about  one  part 
kerosene  to  four  parts  of  water  (20  per  cent),  which  can  be 
formed  only  by  pumps  with  a  special  kerosene  attachment, 
and  which  are  now  very  largely  doing  away  with  the  use 
of  the  soap  emulsion.  About  a  teacupful  of  this  spray  to 
a  hill  will  be  ample,  and  at  this  rate  an  acre  will  require 
about  GO  gallons  at  a  cost  of  about  one  dollar. 

In  case  of  serious  attack  by  the  Chinch-bug  the  farmer 
must  at  once  prepare  to  devote  to  combating  it  the  time 
of  as  many  hands  as  his  interests  may  require;  for  the 
above  methods  require  constant  and  j^ersonal  supervision, 
but,  where  carefully  tested  by  practical  farmers,  have  been 


58  INSECTS   INJURIOUS   TO    STAPLE    CROPS. 

found  to  be  the  best  and  only  means  of  preventing  the  loss 
of  then'  crops. 

Locusts  {Acrididce). 

Plagues  of  destructive  locusts — or  what  the  American 
farmer  terms  grasshoppers — have  been  recorded  since  the 
dawn  of  history.  In  America  the  worst  devastation  has 
been  done  by  flights  of  the  Rocky  Mountain  or  Migratory 
Locust  [Melanoplus  spretys  Thos.),  which  swooped  down 
upon  the  States  of  the  western  part  of  the  Mississippi 
Valley  in  the  years  1873-7G  like  a  veritable  horde  of 
mountain  robbers.  Since  then  they  have  several  times 
done  considerable  injury  in  restricted  localities,  but  never 
in  such  numbers  or  so  generally  as  to  cause  apprehension 
of  another  "  grasshopper  plague."' 

Concerning  their  recent  distribution,  numbers,  and 
destructiveness,  Mr.  W.  D.  Hunter  reported  after  the 
season  of  1897  :  '^  There  was,  this  season,  a  general  activity 
of  this  species  throughout  the  permanent  breeding  region 
greater  than  at  any  time  in  many  years.  This  was  brouglit 
about  by  a  series  of  dry  years,  which  have  resulted  in  the 
abandonment  of  farms  in  many  places.  It  is,  of  course, 
well  understood  that  the  absence  of  serious  damage  since 
1876  has  been  partially  due  to  the  settling  w^  of  valleys 
in  the  permanent  region.  I  wisli  to  make  it  clear,  how- 
ever, that  the  dryness  is  the  primary  and  the  abandoning 
a  secondary  cause. "' 

The  Rocky  Mountain  Locust. 

Let  us  first  consider  this  the  most  injurious  species,  as 
the  other  locusts  differ  from  it  in  but  few  essential  points 
other  than  in  being  non-migratory. 


INSECTS    INJURIOUS   TO   THE    GRAINS    AND    GRASSES.       59 

To  correctly  understand  its  habits  the  reader  should 
first  divide  the  area  which  this  species  affects  into  three 
parts.  Of  these  the  (1)  ''  Permanent  Eegion,  including 
the  highlands  of  Montana,  Wyoming,  and  Colorado,  forms 
the  native  breeding-grounds,  where  the  species  is  always 


Fig.  32. — Rocky  Mountain  Locust. 

found  in  greater  or  less  abundance.'^  *  (2)  The  Sub- 
permanent  Region,  including  Manitoba,  the  Dakotas,  and 
western  Kansas,  is  frequently  invaded.  Here  the  species 
may  perpetuate  itself  for  several  3^ears,  but  disappears 
from  it  in  time.  (3)  The  Temporary  Region,  including 
the  States  bordering  the  Mississippi  River  on  the  west,  is 
that  only  periodically  visited  and  from  which  the  species 
generally  disappears  within  a  year. 

Spread. — When  for  various  reasons  the  locusts  become 
excessively  abundant  in  the  Permanent  Region  they  spread 
to  the  Subpermanent  Region,  and  from  there  migrate  to 
the  Temporary  feeding-grounds.  It  is  the  latter  area 
which  suffers  most  severely  from  their  attacks,  but,  for- 
tunately, they  generally  do  not  do  serious  injury  the  next 
year  after  a  general  migration.  In  the  Subpermanent 
Region  their  injuries  are  more  frequent  than  in  the  Tem- 
porary, but  hardly  as  severe  or  sudden  as  farther  east. 
Immigrating  from  their  native  haunts,  flights  of  the  grass- 
hoppers usually  reach  southern  Dakota  in  early  summer, 
Colorado,  Nebraska,  Minnesota,  Iov\'a,  and  western  Kansas 

*Bull.  25,  U.  S.  Dept.  Ag.,  Div.  Entomology.     C.  V.  Riley. 


GO 


INSKCTS   INJURIOUS    TO    STAPLIC    CROPS. 


during  midsummer,  and  southeastern  Kansas  and  Missouri 
during  late  summer,  apj^earing  at  Dallas,  Texas,  in  1874, 


Fig.  33. — Rocky  Mount aiu   Locust.      Different   stages  of  growth 

of  young. 

about  tlie  middle  of  October,  and  even  later  in  1876.     As 
thus  indicated,  the  flights  are  in  a  general  south  to  south - 


Fig.  34.— Rocky  Mountain  Locusts,  a,  a,  a,  females  in  different 
positions,  ovipositing;  b,  egg-pod  extracted  from  ground,  with 
end  broken  open;  c,  a  few  eggs  lying  loose  on  ground;  d,  e, 
show  the  earth  partially  removed,  to  illustrate  an  egg-mass 
already  in  place  and  one  being  placed ;  /  shows  where  such  an 
egg- mass  has  been  covered  up.     (After  Riley. ) 

easterly  direction,  while  west  of  the  Rockies  they  descend 
to  the  more  fertile  valleys  and  plains,  but  without  any  such 
regularity   as   east.     While   the  rate   of   these   flights   is 


INSECTS    IXJUIllOUS   TO    THE    GRAINS    AND    GRASSES.       Gl 

variable  and  entirely  dependent  upon  local  weather  condi- 
tions, twenty  miles  a  day  may  be  considered  a  fair  average. 
The  flights  are  more  rapid  and  more  distance  is  covered  in 
the  early  part  of  the  season,  when,  while  crossing  the  dry 
prairies,  a  good  wind  will  often  enable  them  to  cover  200 
to  300  miles  in  a  day.  As  they  first  commence  to  alight 
in  their  new  feeding-grounds  their  stay  is  limited  to  but 
two  or  three  days,  but  later  in  the  season  it  is  considerably 
lengthened,  and,  after  being  once  visited,  in  an  infested 
country  swarms  will  be  seen  to  be  constantly  rising  and 
dropping  during  the  middle  of  the  day. 

Life-history. — Over  all  the  infested  area,  and  while  still 
sweeping  it  bare  of  croj)s  and  vegetation,  the  females  com- 
mence to  lay  their  eggs,  and  continue  to  deposit  them  from 
the  middle  of  August  until  frost.  For  this  purpose  ''  bare 
sandy  places,  especially  on  high,  dry  ground,  which  is 
tolerably  compact  and  not  loose, ^^  are  preferred.  "  Meadows 
and  pastures  where  the  grass  is  closely  grazed  are  much 
used,  wliile  moist  or  wet  ground  is  generally  avoided.^' 

In  such  places  the  female  deposits  her  eggs  in  masses  of 
about  thirty.  These  are  placed  about  an  inch  below  the 
surface  in  a  pod-like  cavity,  which  is  lined,  and  the  eggs 
covered  by  a  mucous  fluid  excreted  during  oviposition. 
Erom  two  to  five  hours  are  required  for  this  operation,  and 
an  average  of  three  of  these  masses  is  deposited  during  a 
period  of  from  six  to  eight  weeks. 

As  the  time  of  ovipositing  varies  with  the  latitude,  so 
the  hatching  of  the  eggs  occurs  from  the  middle  or  last  of 
March  in  Texas  till  the  middle  of  May  or  first  of  June  in 
Minnesota  and  Manitoba.  Until  after  the  molt  of  the 
first  skin,  and  often  till  after  the  second  or  third  molt, 
the  young  nymphs  are  content  to  feed  in  the  immediate 


63  INSECTS   IKJUUIOUS   TO   STAPLE    CHOPS. 

vicinity  of  their  birth.  But  upon  such  food  becoming 
scarce  they  congregate  together  and  in  solid  bodies,  some- 
times as  much  as  a  mile  wide,  march  across  the  country, 
devouring  every  green  crop  and  weed  as  they  go.  During 
cold  or  damp  weather  and  at  night  they  collect  under 
rubbish,  in  stools  of  grass,  etc.,  and  at  such  times  almost 
GBcm  to  have  disappeared;  but  a  few  hoars  of  sunshine 
brings  them  forth,  as  voracious  as  ever.  When,  on  account 
of  the  immense  numbers  assembled  together,  it  becomes 
impossible  for  all  to  obtain  green  food,  the  unfortunate 
ones  first  clean  out  the  underbrush  and  then  feed  upon  the 
dead  leaves  and  bark  of  timber  lands,  and  have  often  been 
known  to  gnaw  fences  and  frame  buildings.  Stories  of 
their  incredible  appetites  are  legion ;  a  friend  informs  me 
that  he  still  possesses  a  rawhide  whip  which  they  had  quite 
noticeably  gnawed  in  a  single  night! 

By  mathematical  computation  it  has  been  shown  that 
such  a  swarm  could  not  reach  a  point  over  thirty  miles 
from  its  birthplace,  and  as  a  matter  of  fact  they  have 
never  been  known  to  j^roceed  over  ten  miles. 

As. the  nymphs  become  full-grown  they  are  increasingly 
subject  to  the  attacks  of  predaceous  birds  and  insects, 
insect  parasites,  fungous  and  bacterial  diseases,  as  well  as 
being  largely  reduced  by  the  cannibalistic  appetites  of 
their  own  numbers.  When  the  mature  nymphs  transform 
to  adult  grasshoppers  and  thus  become  winged,  large 
swarms  are  seen  rising  from  the  fields  and  flying  toward 
their  native  home  in  the  Northwest.  This  usually  takes 
place  during  June  and  early  July  in  the  North,  and  as 
early  as  April  in  Texas,  so  that  it  is  frequently  im.possible 
to  distinguish  the  broods  of  the  temporary  region  from 
the  incoming  brood  which  has  migrated  from  the  perma- 


INSECTS    INJURIOUS   TO    THE    GRAINS    AND    (UlASSES.       63 

nent  region.  Although  the  eggs  for  a  second  brood  are 
sometimes  laid,  these  seldom  come  to  maturity,  and  the 
species  is  essentially  single-brooded. 

Emmies. — As  before  mentioned,  large  numbers  of  the 
nymphs  are  destroyed  before  reaching  maturity  by  their 
natural  enemies.  Among  these  a  minute  fungus  un- 
doubtedly kills  many  of  those  already  somewhat  exhausted, 
especially  during  damp  weather.     Almost  all  of  our  com- 


FiG.  35. — Antliomyia,  egg-parasite,     o,  fly;  h,  puparium;  c,  larva; 
d,  head  of  larva.     (After  Riley.) 

mon  birds,  as  well  as  many  of  the  smaller  mammals,  are 
known  to  feed  quite  largely  upon  them. 

A  small  red  mite  {TromhicUum  locustanun  Riley),  some- 
what resembling  the  common  Red  Spider  infesting  green- 
houses, is  often  of  great  value  not  only  in  killing  the 
nymjihs  by  great  numbers  of  them  sucking  out  the  life- 
juices  of  the  young  hopper,  but  also  in  greedily  feeding 
upon  the  eggs. 

The  maggots  of  several  species  of  Tachina-flies  are  of 
considerable  value  in  parasitizing  both  nymphs  and  adult 
locusts.     Their  eggs  are  laid  on  the  neck  of  a  locust,  and, 


G4 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


upon  hatching,  the  maggots  pierce  the  skin  and  live  inside 
by  absorbing  its  juices  and  tissues.  When  full-grown  the 
maggots  leave  the  locust,  descend  into  the  earth,  and  there 


transform  to  pupae  inside  of  their  cast  skins,  and  from  the 
pupa?  the  adult  flies  emerge  in  due  time. 

The  maggots  of  one  of  the  Bee-flies  (Systcecltus  oreas) 
feed  upon  grasshopper-eggs,  but  their  life-history  is  not 


INSECTS    INJURIOUS    TO    THE    GRAINS   AND    GRASSES.       G5 


fully  known.  The  common  Flesh-fly  {SarcopJiaga  car- 
naria  Linn.),  Fig.  39,  is  also  very  destructive,  though 
largely  a  scavenger. 


Fig.  37.— Tachina-fly.  {Exo- 
rista  leucanice  Kirk).  (After 
Riley.) 


Fig.  38.  —  Tachina-fly.  (E. 
lidvirauda  Riley).  (After 
Riley.) 


Fig.  39. — Common  ¥\e^\i-^j  {SareojyJiagn  carnaria  Linn.),    a,  larva; 
6,  pupa;  c,  fly.     Hair-lines  show  natural  size.     (After  Riley.) 


Fig.  40. — Various   stages   of  a   Blister-beetle   {Epicauta  vittaia). 

(After  Riley.) 

But  of  all  the  insects  attacking  locusts,  the  Blister- 
beetles,  which,  unfortunately,  are  often  known  to  its  as 
very  injurious  to  various  garden  cro^DS,  are  probably  of  the 


66  INSECTS   INJURIOUS   TO    STAPLE    CROPS. 

most  Tiiliie.  The  female  beetle  deposits  from  four  to  five 
hundred  of  her  yellowish  eggs  in  irregular  masses  in  loose 
ground,  and  in  about  ten  days  there  hatch  from  these  eggs 
some  "  ver}^  active,  long-legged  larvae,  with  huge  heads  and 
strong  jaws,  which  run  about  everywhere  seeking  the  eggs 
of  locusts/^  Each  of  these  larvae  will  consume  one  of  the 
masses  or  about  thirty  eggs.  The  subsequent  life-history 
of  these  insects  is  very  complicated  on  account  of  their 
peculiar  habits,  but  the  various  stages  are  shown  in  Fig. 

40. 

The  Lesser  Migratory  Locust. 

Besides  the  Rock}''  Mountain  Locust  there  is  only  one 
other  species  that  truly  possesses  the  habit  of  migrating, 
though  to  a  far  lesser  extent,  and  which  is  therefore 
known  as  the  Lesser  Migratory  Locust  (Mekuioplus  atlanils 
Eiley).  It  is  considerably  smaller  than  its  western  relative 
and  somewhat  resembles  the  Red-legged  Locust  both  in 
size  and  appearance.  The  species  of  very  vridely  dis- 
tributed, occurring  from  Florida  to  the  Arctic  Circle  east 
of  the  Mississippi,  and  on  the  Pacific  sloj^e  north  of  the 
40th  parallel  to  the  Yukon.  The  habits  and  life-history 
of  the  species  are  in  all  essentials  practically  the  same  as 
of  the  former  species  except  that  they  have  no  particular 
breeding-grounds.  Injuries  by  this  grasshopper  were  first 
noticed  in  1743,  almost  seventy-five  years  before  the  first 
record  of  the  Rocky  Mountain  Locust,  and  since  then  they 
have  done  more  or  less  serious  damage  in  some  part  of  the 
territory  inhabited  every  few  years. 

Non-migratory  Locusts. 

There  are  several  species  of  locusts  which,  though  lack- 
ing the  migratory  habit,  and  thus  being  more  easily  con- 
trolled, often  become  so  numerous  as  to  do  serious  damage 


INSKCTS    IXJUlilOrS    TO    THE    GRAIXS    AND    GRASSES.       6T 


Fig.   41. — The  Two-striped    Locust    {Mel moplus  hivittdtus  Scud.). 

(After  Pviley.) 


Fig.  42. — The  DilTerential  Locust  {Melaiioplua  differentialis  Thos.) 

(After  Riley.) 


Fig.  43. — The  American  Acridium  {ScMstocerca  americnna  Scud.). 

(After  Riley.) 


Fig.   44.  — Rcd-leg-ged   Locust    (Mehinoplus  femur-rubrum  Harr.). 

(After  Riley.) 


68        i^'SECTS  INJURIorS  TO  STAPLE  CROPS. 

over  limited  areas.  Both  as  regards  the  regions  inhabited, 
its  habits,  and  life -history,  the  common  Red-legged  Locust 
(Melajioplus  feniur-7-uhrum  Har.)  hardly  differs  from  the 
last  species  and  is  often  found  m  company  with  it.  It  is 
non-migratory,  however,  and  though  its  injuries  are  thns 
entirely  local,  they  are  often  of  considerable  importance. 

Records  of  locust-j^lagues  in  California  date  back  as  far 
as  1722.     Many  of  them  were  doubtless  due  to  the  Cali- 


FiG.  45. — The  Pellucid  Locust  {Ctnnuula  pellucida  Scud.).     (iVfter 

Einerton.) 

fornia  Devastating  Locust  [Melnnoplus  devastator  Scud.), 
and  in  the  last  inyasion  of  1885  this  species  outnumbered 
all  others  seven  to  one.  Resembling  the  last  two  species 
in  size  and  markings,  the  habits  and  life-history  of  this 
species  are  also  supposed  to  be  similar  to  them,  though 
they  have  not  as  yet  been  thoroughly  studied. 

Together  with  the  last  species  the  Pellucid  Locust 
{Camnula  pellucida  Scud.)  has  been  largely  responsible  for 
the  losses  occasioned  by  locusts  in  California,  and  has  also 
been  found  in  New  England,  but  not  noted  there  as 
specially  destructive. 


INSECTS    IXJURIOUS    TO    THE    GRAIXS    AND    GRASSES.       60 

Considerably  larger  than  the  preceding  species  are  the 
Differential  Locust  {Melanoplus  dijfereniialis  Thos.)  and 
the  Two-striped  Locust  [Melanophis  Mvittatus  Scud.),  of 
which  the  former  is  peculiar  to  the  central  States  of  the 
Mississippi  Valley,  Texas,   New  Mexico,   and  California, 


Fig.  46. — A  Swarm  of  Grasshoppers  Attacking  a  Wheat-field.  (After  Riley.) 
while  the  latter  has  a  more  extended  range  from  Maine  to 
Utah  and  as  far  south  as  Carolina  and  Texas.  These  two 
differ  from  the  smaller  species  in  laying  only  one  or  two 
masses  of  eggs,  and  the  eggs  of  differ  en  fialis  have  often 
been  found  placed  under  the  liark  of  logs,  but  otherwise 
their  habits  are  very  similar.     The  Two-striped  Locust  is 


70  INSKCTS   INJUIITOUS   TO    STAPLE    CROPS. 

characterized  by  two  yellowish  stripes  extending  from  the 
eyes  along  the  sides  of  the  head  and  thorax  to  the  extremi- 
ties of  the  wing-covers,  and  is  probably  the  species  most 
commonly  observed  by  the  farmer. 

The  Differential  Locust. 

An  nnusnally  severe  outbreak  of  the  Differential  Locust 
occurred  in  Mississippi  and  Louisiana  in  1899  and  1900 
and  was  quite  fully  investigated  by  Prof.  H.  A.  Morgan^ 
and  interestingly  reported  upon  by  him.*  It  seems  that 
outbreaks  of  this  grasshopper  invariably  occur  immediately 
after  an  overflow  of  the  Mississippi  or  crevasses  through 
the  levees,  which  inundate  the  surrounding  country,  caus- 
ing a  rank  growth  of  vegetation  and  rendering  the  land 
unfit  for  cultivation  for  a  season  or  two,  during  which  time 
the  grasshoppers  have  every  opportunity  for  rapidly 
increasing  in  abnormal  numbers.  *^  Should  heavy  rains 
prevail  during  May  and  June  of  the  season  immediately 
following  the  crevasse,  nothing  is  heard  of  the  ravages  of 
grasshoppers;  but  should  dry  summers  follow,  the  condi- 
tions for  grasshopper  propagation  and  development  are 
much  more  favorable  and  complaints  are  common." 
"  The  habits  of  young  grasshoppers  to  seek  the  soil-crevices 
during  rain  results  in  the  burial  of  millions  beyond  the 
hope  of  resurrection.  This,  with  the  development  and 
propagation  of  fungous  diseases  among  the  nj^mphs,  are 
the  most  potent  natural  agencies  which  destroy  grass- 
hoppers during  wet  summers."  f  In  1899  thousands  of 
acres  of  cotton,  corn,  and  other  crops  were  totally  destroyed 

*See  Bulletin  30,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  7-33. 
\  Morgan,  1.  c,  p.  33. 


INSECTS    INJURIOUS   TO    THK    GR.VIXS    AND    GRASSES.       71 

or  seriously  injured,  and  only  saved  by  a  most  persistent 
fight  against  the  locusts. 

The  eggs  are  deposited  in  a  single  mass  of  from  103  to 
132,  mostly  from  August  10  to  September  15.  The  young 
hatch  from  the  eggs  during  the  first  three  weeks  of  May 
and,  after  molting  five  times,  become  full-grown  by  the 
last  week  in  June.  They  mate  about  the  middle  of  July, 
and  the  eggs  are  laid  a  few  weeks  later. 

Our  largest  American  locust,  the  American  Acridium 
(Schisfocerca  ainericaiia  Scud.),  is  practically  confined  to 
the  Southern  States  from  the  District  of  Columbia  to 
Texas,  and  thence  south  through  Mexico  and  Central 
America,  being  rarely  found  in  the  Xorth.  This  species 
is  essentially  a  tropical  one,  and  has  often  been  exceedingly 
destructive,  being  especially  so  in  1876  in  Missouri, 
Tennessee,  North  Carolina,  Georgia,  and  southern  Ohio. 

Remedies  and  Preventives. — All  of  our  destructive 
locusts  having  essentially  the  same  life-history  and  habits 
except  that  of  migrating,  methods  of  combating  them  will 
apply  almost  equally  well  to  all,  but  must,  of  course,  be 
judiciously  determined  according  to  existing  local  condi- 
tions. 

Destruction  of  the  Eggs. — Of  first  importance  in  this 
warfare  is  the  destruction  of  the  eggs.  In  Europe,  where 
labor  is  cheap,  this  is  often  done  by  hand-picking.  That 
would  hardly  do  in  a  western  corn-field  or  wheat-ranch, 
They  may,  however,  be  quite  successfully  destroyed  either 
by  fall  plowing  or  harrowing.  In  harrowing,  ''the  object 
should  be  not  to  stir  deeply,  but  to  pulverize  the  soil  as 
much  as  possible  to  about  the  depth  of  one  inch.  Where 
the  cultivator  is  used,  it  would  be  well  to  pass  over  the 
ground  again  with  a  drag-  or  brush-harrow  for  this  pur- 


72  INSECTS   INJURIOUS   TO   STAPLE    CROPS. 

pose,*  In  this  way  many  of  the  egg-pods  may  be  broken 
up  or  left  exposed  on  the  surface.  Prof.  Morgan  has 
shown  that  of  eggs  in  land  thus  treated  80  per  cent  failed 
to  hatch. 

By  plowing  in  the  fall  to  a  depth  of  about  eight  inches 
the  same  result  is  more  surely  accomplished  by  turning 
the  eggs  under  to  such  a  depth  that  the  young  hoppers 
upon  hatching  are  unable  to  reach  the  surface.  This  will 
be  made  more  eifectual  by  then  harrowing  and  rollirg,  so 
as  to  compact  the  surface  as  much  as  possible.  .  Such 
plowing  might  even  be  profitable  if  done  in  very  early 
spring  were  it  then  followed  by  the  usual  spring  showers, 
but  in  all  probability  it  Avould  be  better  to  wait  till  the 
young  are  hatching,  when  large  numbers  of  them  can  be 
buried  by  plowing  infested  fields  in  a  square  from  the 
outside  inward. 

Destroying  the  Kymplis. — Burniug. — After  hatching 
every  effort  should  be  made  to  destroy  the  locusts  while 
still  young.  The  burning  of  straw  or  hay  stubble,  dead 
grass,  or  rubbish,  where  it  is  present  in  sufficient  quanti- 
ties, or  even,  if  need  be,  by  augmenting  such  with  rows 
of  straw,  is  one  of  the  best  methods,  esj)ecially  on  cold 
days  when  the  young  hoppers  are  congregated  under  such 
materials.  Several  machines  have  been  devised  both  for 
burning  and  crushing  the  nymphs,  but  all  are  of  doubtful 
utility. 

Crushing. — When,  however,  the  surface  of  the  ground 
is  smooth  and  hard,  a  heavy  roller  will  crush  large  num- 
bers of  the  nymphs  while  they  are  still  young,  especially 
in  the  morning  and  evening. 


*  Riley,  Bull.  25,  1.  c. 


INSECTS    INJCUIOLS   TO    THE    GRAINS    AND    GRASSES.       To 

Duelling. — Of  the  various  means  devised  for  trapping 
the  nymphs  "ditching"  is  one  of  the  best,  and  is  of 
especial  advantage  when  the  crops  become  too  large  for  the 
effective  use  of  other  methods.  Simple  ditches  two  feet 
wide  and  tw^o  feet  deep,  with  nearly  perpendicular  sides, 
form  effectual  barriers  to  young  grasshoppers.  The  sides 
next  to  the  field  to  be  protected  must  be  kept  finely  pul- 
verized and  not  allow^ed  to  become  washed  out  or  hardened. 
This  may  be  done  by  a  brush  composed  of  dead  branches 


Fig.  47.  — Simple  Coal-oil  Pan  or  Hopperdozer.     (After  Riley.) 

being  hauled  through  the  ditch,  which  has  been  dug  in  a 
strip  of  finely  pulverized  soil.  The  young  locusts  tumble 
into  the  ditch,  and,  failing  to  climb  the  steep  and  slippery 
sides,  die  there,  from  their  exertions  and  the  heat,  in  large 
numbers.  To  avoid  too  great  an  accumulation,  pits  should 
be  sunk  in  the  ditch  at  short  intervals,  in  which  most  of 
them  will  accumulate,  and  wdiere  they  may  be  easily 
buried.  It  would  seem  that  grasshoppers  w^ould  be  able 
to  leap  across  such  a  small  obstacle,  but  as  a  matter  of 
fact,  like  the  Chinch-bugs,  which  might  fly  across^  they 
very  seldom  do  so. 


74  INSF.CTS   INJUiaoUS   TO    STAPLE   CROPS. 

-  Spraying  Ditches. — Prof.  Morgan  states  that  '^upon 
river  plantations  many  open  ditches  are  indispensable,  and 
when  rains  are  sufficient  to  keep  tlieni  filled  or  partly  filled 
with  water  they  serve  a  most  excellent  purpose  in  the 
destruction  of  the  young  grasshoppers." 

"  The  experience  of  spraying  ditch-banks  soon  developed 
the  method  of  damming  water  in  the  ditches  and  covering 
the  surface  with  coal-oil  or  kerosene  emulsion.  Before 
and  after  rains  the  ditches  were  dammed  and  the  water 


Fig.  48.— The  Price  Oil-pan  or  Hopperdozer.  (After  Riley.  ) 
covered  Avith  a  12  per  cent  coal-oil  emulsion.  The  young 
grasshoj^pers  were  then  driven  into  the  ditches,  with  the 
result  that  very  few,  if  any,  escaped.  In  this  way  a  single 
application  of  oil  would  last  several  days,  as  many  millions 
may  easily  float  upon  the  water  of  a  ditch  not  more  than 
two  feet  wide.  Unless  the  grasshoppers  are  scattered  too 
far  from  the  ditch-banks  no  difficulty  is  experienced  in 
getting  them  to  move  in  the  directiun  of  the  oiled  water 
on  account  of  the  '  homing'  instinct.'' 


7G  INSECTS    INJUUIOL'S    lU    Sl'Al'I.E    CHOPS. 

Hopper  dozers. — One  of  the  methods  most  extensively 
tried  i'or  the  destruction  of  the  nymphs  upon  small  or 
young  crops  is  by  the  use  of  crude  kerosene  or  coal-tar  in 
one  of  the  so-called  ^' nopperdozers."  '^The  main  idea 
embodied  in  these  contrivances  is  that  of  a  shallow  recep- 
tacle of  any  convenient  size,  provided  with  high  back  and 
sides,  mounted  either  on  wheels  or  runners.  If  the  pan 
is  larger  than,  say,  three  feet  square,  it  is  provided  with 
transverse  partitions,  which  serve  to  prevent  any  slopping 
of  the  contents  (in  case  water  and  oil  are  used)  when  the 
device  is  subject  to  any  irregular  motion.  On  pushing 
these  pans,  supplied  with  oil,  over  the  infested  fields,  and 
manipulating  the  shafts  or  handles  so  as  to  elevate  or 
depress  the  front  edge  of  the  pan,  as  may  be  desired,  the 
locusts  are  startled  and  spring  into  the  tar  or  oil,  when 
they  are  either  entangled  in  the  tar  and  die  slowly,  or, 
coming  in  contact  with  the  more  active  portion  of  the  oil, 
expire  almost  immediately.  A  good  cheap  pan  is  made  of 
ordinary  sheet  iron,  eight  feet  long,  eleven  inches  wide  at 
the  bottom,  and  turned  up  a  foot  high  at  the  back  and 
an  inch  high  in  the  front.  A  runner  at  each  end,  extend- 
ing some  distance  behind,  and  a  cord  attached  to  each 
front  corner,  complete  the  ^^an  at  a  cost  of  about  §1.50 
(Fig.  47).  We  have  known  of  from  seven  to  ten  bushels 
of  young  locusts  caught  with  one  such  pan  in  an  afternoon. 
It  is  easily  pulled  by  two  boys,  and  by  running  several 
together  in  a  row,  one  boy  to  each  rope,  and  one  to  each 
contiguous  pair,  the  best  work  is  performed  with  the  least 
labor."  Larger  pans  may  be  drawn  by  horses.  The  oil 
is  best  used  on  the  surface  of  water,  from  which  the  insects 
are  removed  with  a  wire  strainer.  Various  modifications 
of  this  apparatus  have  been  devised,  but  the  more  simple 


INSECTS    INJL'KIOUS   TO    THE    GRAINS    AND    GRASSES.       77 

ones  seem  to  be  fully  as  effective  as  those  more  complicated 
for  which  fancy  prices  are  charged  for  royalty. 

Destroy ing  the  Adults. — The  destruction  of  the  winged 
insects  is  an  entirely  hopeless  task,  for,  though  even  large 
numbers  are  caught,  so  many  will  remain  that  the  damage 
done  the  crops  would  be  but  very  slightly  diminished. 
One  of  the  most  promising  means  for  averting  the  swarms 
of  v/inged  migratory  locusts  from  alighting  in  the  fields  is 
by  a  dense  smudge,  in  which  some  foul  smelling  substances 
are  placed.  Where  strictly  attended,  and  with  favorable 
winds,  this  has  often  proved  highly  successful.  To 
accomplish  the  best  results  farmers  over  an  extensive  area 
should  combine  in  its  use. 

The  South  African  Fuugns. — In  1900    Prof.    Morgan 
made  a  test  of  a  fungous  disease  which  had  been  found  to 
destroy  large  numbers  of  grasshoppers  in  South  Africa, 
to  determine  whether,  after  starting  it  by  artificial  proim- 
gation,  it  would  spread  sufficiently  to  destroy  any  consider- 
able number  of  locusts.      The  weather  was  favorable,  rains 
being  frequent.     Early  in  August  it  was  found  that  "  over 
the  areas  where  the  liquid  infection  was  spread  diseased 
hoppers  were   abundant."     *^  As  many  as  a  dozen    dead 
grasshoppers  could  be  found  upon  a  single  plant,  and  some 
upon  nearly  every  weed  on  ditch-banks  where  grasshoppers 
were  numerous.     From  the  centres  of  infection  great  areas 
had  become  inoculated,  spreading  even  beyond  the  planta- 
tions first  infected."     The  property  upon  which  it  was 
placed    became    thoroughly   infected    with    the   fungus. 
Strangely,   though  many   other   species    of   grasshoppers 
were  abundant,    only  the   Differential   was    killed    by  it. 
Dr.   Howard  states  that  this  disease  has  also  spread  and 
done  effective  work  in  Colorado. 


78  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

Poisoning. — A  mash  composed  of  bran,  molasses,  water, 
and  arsenic  or  Paris  green,  wliicli  has  been  extensively 
used  for  cutworms,  was  found  to  be  quite  successful  in  the 
experiments  of  Mr.  D.  W.  Coquillct  in  the  San  Joaquin 
Vallejs  California,  during  1885,  for  protecting  orcliards, 
vineyards,  gardens,  etc.,  and  might  even  be  of  some  value 
for  grain  crops.  Two  pounds  of  Paris  green,  twenty- five 
pounds  of  bran,  barely  moistened  with  water  and  cheap 
molasses,  will  be  about  the  correct  proportion.  It  should 
be  placed  in  the  fields,  a  tablespoonful  to  each  plant  or 
vine.  At  this  rate  the  cost  per  acre  of  vineyard,  including 
labor,  will  not  exceed  fifty  cents.  The  poison  acts  slowly, 
but  if  judiciously  used  will  be  found  very  effective, 
especially  for  the  non-migratory  forms.  In  Texas  the 
mash  has  been  found  satisfactory  in  destroying  the  grass- 
hoppers attacking  cotton.  One  planter*  writes:  "We 
are  successfully  using  arsenic  (for  grasshoppers)  at  the 
following  rates:  10  pounds  of  wheat  bran,  1^  gallons 
sorghum  molasses,  1  pound  arsenic.  Make  a  thick  mash, 
sow  broadcast  on  infected  ground,  and  it  will  surely  kill 
them.  I  used  40  pounds  last  year  and  made  49  bales  ot 
cotton.  My  neighbors  did  not  do  anything  and  entirely 
lost  their  crop."  However,  Prof.  M^organ  concluded  that 
'Hhe  mash  cannot  be  relied  upon  in  severe  outbreaks,  such 
as  occurred  in  the  delta,  but  may  be  used  in  limited  attacks 
wliere  the  area  affected  would  not  warrant  the  more 
aggressive  methods.'' 


*  S.  D.  Harwell,  Putnam,   Callahan  Co.,    Tex.,  Bull   30,  n.  s., 
Piv.  Ent.,  U.  S.  Dept.  Agr.,  p.  06. 


INSECTS    INJURIOUS   TO   THE    GRAINS    AND    GRASSES.       79 

The  Army-worm  [Leucania  unipiinda  Haworth). 

Almost  every  year  from  some  portion  of  this  large 
country  reports  are  received  of  the  ravages  of  armies  of 
worms  sweeping  over  the  grain-fields,  like  a  horde  of 
Vandals.  Invariably,  also,  there  has  not  been  a  single 
attack  in  the  infested  locality  for  a  number  of  years,  so 
that  the  farmer  is  at  a  loss  to  do  anything  to  protect  his 
crops,  and  by  the  time  information  can  be  received  from 
an  entomologist  a  large  portion  of  them  will  already  have 
been  destroyed.  Thus  previous  knowledge  of  the  habits 
and  remedies  for  these  insects  may  be  of  value  to  him 
when  injury  by  them  is  threatened. 

Being  a  species  native  to  this  country,  these  worms  may 
almost  alwa3^s  be  found  east  of  the  Rockies  in  low,  rank 
growths  of  grass,  which  form  their  habitual  breeding- 
grounds.  Yet,  though  the  moth  is  widely  distributed,  its 
chief  injuries  have  been  in  belts  from  eastern  Iowa  to 
Maine,  from  northern  Texas  to  northern  Alabama,  and 
east  of  the  Blue  Ridge  Mountains  to  northern  North 
Carolina.  Even  in  these  regions,  however,  the  worms  have 
never  been  recorded  as  injurious  for  two  successive  years, 
and  the  only  recent  wide-spread  outbreaks  have  bee*n  in 
1861,  1875,  1880,  and  1896,  though  serious  injury  is 
almost  annually  done  in  restricted  localities.  Only  when 
their  usual  feeding-places  are  exhausted,  or  when  through 
favorable  climatic  conditions  or  the  destruction  of  large 
numbers  of  the  parasites  which  hold  them  in  check,  they 
increase  in  abnormal  numbers,  do  they  assume  the  march- 
ing habit  and  mass  in  armies. 

Life-history. — In  the  North  there  are  usually  three 
broods  each  season^  and  the  insects  pass  the  winter  as  half- 


80 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


grown  caterpillars;  but  in  tlie  South  there  may  be  as  many 
as  six  broods,  and  the  moths  often  hibernate  over  winter, 
laying  eggs  early  in  the  sjiring.  In  the  Northern  States 
these  young  worms  mature,  change  to  puj)a3,  and  from 
them  the  adult  moths  appear  early  hi  June,  the  May 
broods  rarely  doing  serious  injury.  The  female  moths 
now  lay  their  small  yellowish  eggs  in  rows  of  from  ten  to 


Fig.  50  — Army-worm  Moth  (Leueanin  unipunctd),  pupa,  and  eggs 
in  natural  position  in  a  grass- leaf.  Natural  size.  (After 
Comstock.) 

fifty,  inserting  them  in  the  unfolded  bases  of  the  grass- 
leaves,  and  covering  them  with  a  thin  layer  of  glue.  Over 
seven  hundred  may  be  deposited  by  one  female,  and  thus 
it  is  that  the  myriads  of  young  worms  appear  when  they 
hatch  in  about  ten  days,  and  form  the  destructive  army 
of  early  July.  The  worms  usually  feed  entirely  at  night, 
and  thus  whole  fields  will  often  be  ruined  before  they  are 
discovered,  though  a  few  generally  feed  during  the  day, 
as  they  all  do  during  cloudy  weather.  The  leaves  and 
stalks  of  the  grains  and  grasses  form  their  favorite  food, 
the  heads  usually  being  cut  off,  l)ut  various  garden  crops 
have  frequeutly  been  seriously  injured.     As  a  rule  clover 


INSKCTS    INJURIOUS   TO    THE    GRAINS   AND    GRASSES.       81 

is  untouched,  but  even  that  is  not  always  exempt.  In 
from  three  to  four  weeks  the  worms  become  mature  and 
are  then  about  one  and  one-half  inches  long,  of  a  dark-gray 
or  dingy-black  color,  with  three  narrow,  yellowish  stripes 
above,  and  a  slightly  broader  and  darker  one  on  each  side, 
altogether  much  resembling  cutworms,  to  which  they  are 
nearly  allied.  They  now  enter  the  earth  and  there  trans- 
form to  pnpae,  from  which  the  adulb  moths  come  forth  in 
about  two  weeks.  These  again  lay  eggs  for  a  brood  of 
worms  which  appear  in  September,  but  are  rarely  very 
injurious.  The  moths  developing  from  this  last  brood 
either  hibernate  over  winter  or  deposit  eggs,  the  lar^^as 
from  which  become  partially  grown  before  cold  weather 
sets  in. 

•The  moths  very  often  fly  in  windows  to  lights,  and  are 
very  plain  little  "  millers  "'  The  front  wings  are  of  a  clay 
or  fawn  color,  specked  with  black  scales,  marked  with  a 
darker  shade  or  stripe  at  the  tips,  and  a  distinct  white 
spot  at  the  centre — on  account  of  which  they  were  given 
the  specific  name  unipundii.  The  hind  wings  are  some- 
what lighter,  with  blackish  veins  and  darker  margins. 

Enemies. — Were  it  not  for  other  insects  which  prey 
upon  the  worm^,  the  army  habit  would  undoubtedly  be 
assumed  much  more  often;  but  ordinarily  these  very 
efficiently  reduce  their  number,  and  Dr.  L.  0,  Howard 
has  recorded  two  instances  in  w^hich  armies  of  w^orms  were 
practically  destroyed  by  them.  Large  numbers  are  always 
destroyed  by  the  predaceous  ground-beetles  and  their 
larvse,  but  their  most  deadly  enemies  are  two  small 
Tachina-flies.  These  lay  from  half  a  dozen  to  fifty  eggs 
upon  a  worm,  and  the  maggots  from  them  enter  the  body 
of  the  worm  and  there  absorb  its  juices  and  tissues,  thus 


83 


INSECTS   INJURIOUS   TO    STAPLE    CHOPS. 


soon  killing  it.  Ordinarily,  when  feeding  at  night,  the 
worms  are  free  from  these  parasites,  bnt  when  the  marcli- 
ing  habit  is  assumed  these  little  flies  swarm  aroand  them 
on  cloudy  days,  and  before  the  next  year  will  again  have 
the  voracious  army  under  subjection.  Thus  worms  with 
eggs  upon  them  should  never  be  destroyed  if  avoidable. 


Fig.  52. — The  Farmer's  Friend,  the  Red-tailed  Tachina  fly  (  Win- 
themiit  4-pustulat<i).  a,  natural  size;  b,  much  enhirged;  c,  army- 
worm  on  which  fly  has  laid  eggs,  natural  size;  d,  same,  much 
enlarged.     (After  Slingerland.) 

Remedies. — When  detected,  all  efforts  should  be  centred 
on  keeping  the  worms  out  of  crops  not  yet  attacked  and 
confining  their  injury  to  one  point.  As  a  barrier,  there 
is  nothing  better  than  a  steep  ditch  with  the  side  next  to 
the  crop  to  be  protected  as  nearly  vertical  as  possible.  In 
the  bottom  of  this  dig  some  deep  holes  every  ten  feet. 
Not  being  able  to  easily  scale  the  steep  wall,  the  worms 
will  look  for  some  easier  ascent,  and  become  accumulated 
in  large  numbers  in  the  holes,  where  they  may  be  destroyed 


Fig.  51. — Army-worms  at  work  on  Corn-plant.      (After  Slingerland.) 


83 


84  INSECTS    IXJUIITOUS   TO    STAPLE    CROPS. 

by  kerosene  or  by  burning  straw  on  them.  Several  deep 
parallel  furrows  will  act  in  the  same  way,  and  if  a  series 
are  properly  made,  they  will  also  be  found  efficient.  If  it 
be  possible  to  turn  water  in  the  ditches,  or  if  they  become 
filled  by  rains,  the  addition  of  a  little  kerosene,  so  as  to  form 
a  thin  scum  over  the  surface,  will  soon  kill  the  caterpillars. 
By  thoroughly  spraying  or,  perhaps  better,  dusting  a 
small  strip  of  the  crop  in  advance  of  the  worms  with  Paris 
green,  and  liberally  distributing  poisoned  bran  mash  (com- 
posed cf  fifty  pounds  of  bran  and  one  pound  of  Paris  green 
with  about  enough  molasses  and  water  to  sweeten  it)  large 
numbers  may  be  destroyed.  But  be  careful  not  to  pasture 
cattle  in  a  field  so  poisoned  until  rain  has  thoroughly 
washed  it.  A  flock  of  poultry  will  also  do  good  service  in 
consuming  them.  Burning  stubble,  grass  land,  and 
rubbish  is  also  of  considerable  importance  for  this  as  well 
as  all  similar  insects.  But  whatever  is  done  to  combat  the 
Army-worm  must  be  done  quickly  and  at  once,  for  a  single 
day's  delay  may  often  mean  the  ruin  of  a  valuable  croj^. 
Deep  fall  plowing  followed  by  a  thorough  harrowing  or 
rolling  will  do  much  to  destroy  the  hibernating  larvae  and 
thus  prevent  their  attack  the  next  season. 

The  Fall  Army-worm  {Lajihygw a  fni giperda  S.  &  A.). 

Description. — ^Very  similar  in  its  destructive  habits  to 
the  true  Army-worm  is  the  Fall  Army-worm  or  Grass- 
worm.  At  first  glance  the  worms  have  much  the  same 
general  appearance,  bat  upon  close  examination  consider- 
able difference  in  the  markings  is  noticeable.  Along  each 
side  of  the  body  is  h  longitudinal  pitch-colored  strij)e,  and 
in  the  middle — betw^een  them — is  a  yellowish -gray  stripe 
about    twice   as   wide,    which   includes   four    black   dots 


INSECTS    IN'JUlUOrS    TO    T^HE    GRAINTS    AND    GRASSES.       85 

arranged  in  pairs.  These  worms  assume  the  habit  of 
working  in  armies,  bnt  usually  do  not  feed  in  such  large 
bodies  as  those  of  the  trne  Army-worm  and  are  thus  even 
more  difficult  to  combat.  They  appear  later  in  the  season, 
the  other  species  rarely  being  destructive  after  August 
first,  and  have  thus  been  termed  the  Fall  Army-worm. 
The  Army-worm  proper  rarely  feeds  upon  anything  but 
grasses  aud  cereals,  while  the  Fall  Army-worm  feeds  upon 
a  large  variety  of  cultivated  crops,  including  sugar-beets, 
cow-peas,  sweet-potato  vines,  millet,  and  many  other 
general  and  truck  crops.  In  Nebraska  it  has  developed  a 
l^eculiar  fondness  for  alfalfa  and  has  there  been  styled  the 
Alfalfa-worm.  It  is  also  sometimes  very  destructive  to 
city  lawns,  as  it  was  in  Chiccigo  during  1899.  Indeed, 
that  season  witnessed  an  unusual  outbreak  of  this  species 
in  widely  distant  localities,  it  having  been  exceptionally 
destructive  in  the  Carolinas  and  Virginia,  Illinois,  and 
Nebraska,  as  well  as  other  districts.  The  insect  is  more 
of  a  native  of  the  Southern  States,  but  occurs  from  Canada 
and  Maine  south  to  the  Gulf  States  and  west  to  Colorado 
and  Montana. 

Life-history. — The  life-history  of  this  insect  differs  from 
that  of  the  true  Army-worm  in  that  it  passes  the  winter 
in  the  pupal  stage.  The  pupae  are  about  one-half  an  inch 
Ions:  and  mav  be  found  in  small  cells  from  one-half  to  one 
and  one-quarter  inches  beneath  the  surface  of  the  soil. 
The  exact  time  of  the  emergence  of  the  moths  in  the 
spring  has  not  been  definitely  observed,  but  the  first  gen- 
eration of  worms  appears  in  May  or  June.  The  moths 
deposit  their  eggs  on  blades  of  grass,  in  clusters  of  50,  60, 
or  more,  each  mass  being  covered  with  mouse-colored 
down  from   the   body  of  the  moth.     The  eggs  hatch  in 


86 


INSECTS  INJURIOUS  TO  STAPLE  CROPS. 


about  ten  days.  The  exact  time  required  for  the  growth 
of  the  larva  or  the  time  occupied  in  the  pupal  stage  does 
not  seem  to  have  been  definitely  observed.  ''Present 
knowledge  indicates  that  the  number  of  generations  that 
are  normally  produced  each  year  is  two  in  the  most 
northern  range  of  the  species  (in  years  Avhen  it  develops 
northward),  three  for  central  localities  like  central  and 
southern  Illinois  and  the  District  of  Columbia,  and  prob- 
ably four  for  the  extreme    South.     We  know,   however, 


Fig.   53. — Yall  Army -worm  {LnpJiygma  frugiperda  S.  &  A.).     1,2, 
moth;  3,  pupa;  4,  5,  larva.     (After  W.  D.  Hunter.) 

practically  nothing  of  the  development  of  this  sjDecies  in 
the  Gulf  States."* 

Prof.  Morgan  states  that  this  insect  often  makes  its 
appearance  in  damaging  numbers  in  the  States  around  the 
Mississippi  Delta,  in  sections  behind  the  levees  immediately 
after  an  overflow  or  crevasse.  This  seems  to  be  largely 
due  to  the  predaceous  ground-beetles  (see  page  36),  which 
usually  prey  upon  the  army-worms  in  such  numbers  as  to 

*F.  H.   Chittenden,  "The  Fall  Army-worm,"  Bulletin  29,  n.  s., 
Div.  Ent  ,  U.  S.  Dept.  Agr. 


INSECTS  INJURIOUS   TO   THE    GRAINS   AND    GRASSES.      87 

hold  them  in  check,  being  destroyed  or  carried  to  other 
places  by  the  rush  of  water. 

The  parent  moth  is  very  dissimilar  from  that  of  the 
Army- worm.  It  is  of  a  "  general  yellowish,  ash-gray  color, 
with  the  second  pair  of  wings  almost  transparent,  but  with 
a  purplish  reflection.  In  extent  of  wings  it  measures  about 
one  and  one-quarter  inches,  and  when  these  are  closed  the 
length  of  the  insect  is  about  three-quarters  of  an  inch. 
The  front  wings  are  mottled  or  marbled,  especially  near 
the  central  area,  and  usually  there  is  visible  a  fine  white 
line  a  short  distance  from  the  edge  and  parallel  to  it. 
The  hind  wings  have  a  fringe  of  darker  hair  as  well  as 
veins  that  contrast  somewhat  with  the  lighter  portion/'* 

Remedies. — As  before  stated,  this  species  is  even  more 
difficult  to  combat  than  the  true  Army-worm  on  account 
of  the  fact  that  its  attacks  are  scattered  over  a  wider  area, 
the  individuals  being  of  more  solitary  habits.     The  same 
methods  of  combating  it  will  be  found  profitable,  however, 
and  especially  that  of  deep  fall  plowing  and  harrowing, 
which  in  this  case  will  break  up  the  pupal  cells  and  prevent 
the  development  of  the  moths.      ''  In  the  case  of  perennial 
crops  fall  plowing  is  not  practicable.     For   alfalfa    Mr. 
Hunter    has    recommended    that    the     field    should    be 
thoroughly   'disked,'  or    cultivated   with    a    disk-harrow, 
giving  practically  the  same  results  as  plowing  other  fields. 
For  lawns  a  thorough  going  over  with  a  long-toothed  steel 
rake  is  the  treatment  recommended.'' 

"In  fields  of  young  grain  and  on  lawns  many  of  the 
worms  may  be  killed  by  rolling  with  a  heavy  roller,  prefer- 
ably when  the  insects  are  at  work  early  in  the  morning  or 


*  Press  Bulletin  Xo.  2,  Nebr.  Ag.  Exp.  Sta.,    "The  Fall  Array 
Worm,"  W.  D.  Huuter. 


88        INSECTS  INJURIOUS  TO  STAPLE  CROPS. 

late  in  the  afternoon.  In  pasture-lands  and  in  fields  that 
are  injured  beyond  recovery,  sheep  or  cattle  could  be 
turned  in  in  numbers  with  benefit,  as  they  will  crush  the 
larvae  by  trampling  upon  them.^' 

The  worms  may  often  be  destroyed,  when  not  occurring 
in  too  large  numbers  and  especially  while  young,  by  spray- 
ing the  food  with  Paris  green  or  other  arsenicals,  and 
when  present  in  only  ordinary  numbers  like  cutworms  they 
may  be  killed  with  poisoned  bran  mash  as  advised  for  the 
latter  on  page  217. 

'^  Lawns  can  be  freed  from  the  insects  by  the  application 
of  kerosene  emulsion,  followed  with  as  copious  a  drench- 
ing of  water  as  possible  from  a  hose.  This  remedy  should 
not  be  employed  in  bright  sunlight  or  on  a  hot  day,  but 
preferably  toward  sundown.  ^^ 

When  the  worms  occur  in  armies  they  may  be  combated 
in  the  same  way  as  the  true  Army-worm. 

But  too  much  emphasis  cannot  be  placed  upon  the  im- 
portance of  clean  cultural  methods  a7icl  the  rotation  of  crops 
in  the  control  of  both  this  and  the  true  Army-worm. 
This  has  been  well  expressed  by  Mr.  Chittenden  (1.  c.)  as 
follows:  "  Kotation  of  crops  should  always  be  practiced,  as 
well  as  the  burning  over  of  fields  in  the  fall,  when  they 
are  too  badly  infested  to  recover  from  injury.  Above  all 
other  precautions  which  it  is  necessary  to  take  to  secure 
immunity  from  attack  is  that  of  keeping  the  fields  free 
from  volunteer  grain  and  wild  grasses,  since  experience 
shows  that  these  are  the  favorite  breeding-grounds  of  the 
insect;  in  other  words,  they  attract  the  female  moths  for 
the  deposition  of  their  eggs,  and  when  the  larvae  hatching 
from  these  eggs  have  devoured  the  grain  and  grasses  which 
grow  in  batches  they  are  driven  to  cultivated   fields  for 


INSECTS   INJURIOUS   TO    THE    GRAINS   AND   GRASSES.      89 

food.  One  of  the  most  important  sources  of  injury  is  the 
rotation  of  one  cereal  crop  with  another  or  with  grasses, 
and  the  planting  of  crops  in  fields  that  have  been  allowed 
to  run  waste  to  wild  grasses  and  weeds.  As  grasses  and 
cereals  are  the  crops  most  affected  by  the  Fall  Army- worm, 
the  soil  should  always  be  very  thoroughly  plowed  before 
planting  to  any  crop,  particularly  a  similar  one,  and  it  is 
inadvisable  (not  alone  on  account  of  the  Fall  Army-worm, 
but  on  account  of  the  numerous  other  common  cutworms, 
wireworms,  and  white  grubs)  to  plant  wheat,  corn,  or  any 
other  cereal  in  pasture-land  unless  a  crop  which  is  not  so 
subject  to  infestation  by  this  insect  intervenes. ^^ 


CHAPTER  VI. 

INSECTS   INJURIOUS   TO    WHEAT. 

INJURING    THE    ROOTS. 

Meadow-maggots  or  Leather-jackets  {TipulidcB). 

Several  instances  have  been  recorded  in  which  serious 
injury  has  been  done  to  wheat,  clover,  timothy,  and  bkie 
grass  by  the  larvae  of  Crane-flies.  These  insects  are  never 
so  injurious  in  this  country  as  in  Europe,  where  they  are 
known  as  ''Daddy-long-legs,"  the  common  name  of  our 
harvest-spiders,  though  doubtless  injury  done  by  them  is 
often  attributed  to  other  insects.  The  farmer  usually 
declares  the  work  to  be  that  of  wireworms  or  cutworms, 
the  adults  often  being  known  as  ''cutworm-flies,'' unless 
the  maggots  are  so  abundant  as  to  attract  his  attention. 
When  the  maggots  are  abundant  enough  to  do  much 
injury,  they  usually  occur  in  very  large  numbers,  but 
ordinarily,  though  common  everywhere,  they  occur  in  such 
small  numbers  as  to  escape  notice. 

Several  species  [Tipula  bicornis  Loew,  T.  costalis  Say, 
and  Paclujrrliini.^  sp.?)  have  at  various  times  done  con- 
siderable damage  in  localities  in  Ohio,  Indiana,  Illinois, 
and  elsewhere. 

Life-history. — So  far  as  studied,  the  life-histories  of 
these   species    seem   to   be  much  the   same.     The    larvae 

90 


INSECTS    INJURIOUS   TO    WHEAT. 


91 


remain  dormant  over  winter,  bnt  evidently  commence 
feeding  again  very  early  in  the  spring,  a  wheat-field  having 
shown  the  effects  of  their  injuries  from  February  first  to 


Fig.  54. — A  Crane-fly   (Tipula  Jiebes  Loew).     a,  larva;  h,  pupa;  c, 
male  adult.     (After  Weed.) 


April  first.  The  larvae  become  full-grown  from  the  latter 
part  of  April  until  the  middle  of  May,  depending  upon 
the  species  and  season.  The  full-grown  maggots  are  about 
an  inch  long,  of  a   dirty-grayish  color,   and  of  a  tough 


93  INSECTS    IXJUHIOUS   TO    STAPLE    CROPS. 

leathery  texture.  They  are  nearly  C3^1iiidrical,  somewhat 
taj)ering  in  front  and  terminating  bluntly  behind.  Legs 
are  entirely  wanting,  but  at  the  blunt  end  are  a  few  fleshy 
processes  and  a  pair  of  small,  horny  hooks.  The  larya3 
seem  to  prefer  low,  moist  ground,  and  will  live  for  some 
time  on  land  entirely  flooded  or  in  a  ditch.  They  feed 
very  largely  on  dead  vegetable  matter,  but  when  excessively 
abundant  they  attack  the  roots  of  wheat,  grass,  and  clover, 
so  weakening  them  near  the  surface  that  the  plants, 
deprived  of  pro^^er  nourishment,  are  killed  and  loosened 
from  the  ground. 

Pup^e  may  be  found  during  the  latter  2^art  of  May, 
occupying  small  cells  near  the  surface  of  the  soil  in  a 
vertical  position.  Prior  to  emerging  the  adult  pushes 
from  one-half  to  two-thirds  of  the  body  above  the  surface 
and  remains  in  this  pose  for  several  hours.  The  males 
usually  emerge  first,  as  their  assistance  is  required  by  the 
females,  which  are  loaded  down  with  eggs,  to  extricate 
themselves  from  the  pupal  skins.  The  sexes  pair  imme- 
diately, there  being  many  more  males  than  females — one 
observer  states  one  hundred  to  one — and  the  females 
deposit  their  eggs  ujDon  grass  and  clover  lands,  to  the 
number  of  three  hundred  each.  Eggs  are  laid  for  another 
brood  in  September,  the  maggots  from  which  live  over 
winter. 

Remedies. — Injury  to  wheat  land  may  be  largely  pre- 
vented by  plowing  early  in  Se2:)tember. 

No  satisfactory  remedy  for  the  maggots  is  known  when 
injuring  clover,  timothy,  or  grass,  although  large  numbers 
have  been  knoAvn  to  be  destroyed  by  driving  a  flock  of 
sheep  over  infested  land.  Dr.  S.  A.  Forbes  states  that 
"close  trampling  of  the  earth  by  the  slow  passage  of  a 


IN^SKCTS   INJURIOUS    TO    WHEAT.  93 

drove  of  pigs  avouM  doubtless  answer  the  same  inirpose, 
which  is  that  of  destroying  the  larvae  lying  free  upon  the 
surface  or  barely  embedded  among  the  roots  of  the  grass/' 
Several  of  our  common  birds  feed  upon  the  maggots 
and  flies  as  well  as  a  number  of  ground-beetles.  The 
maggots  are  also  sometimes  attacked  by  a  fungous  disease 
which  in  the  damp  soil  in  which  they  live  would  doubtless 
grow  and  spread  rapidly.  Altogether  these  different 
enemies  keep  them  so  well  in  check  that  they  rarely 
become  of  importance. 

Wheat  Joint-worms  {Isosoma  spp.). 

Injury. — During  midsummer,  shortly  before  harvest, 
many  of  the  ripening  ears  of  wheat  are  seen  to  topjjle  over 
and  fall  to  the  ground,  owing  to  the  breaking  of  the  stalk, 
which  has  been  weakened  at  one  of  the  joints.  Upon 
examination  several  small  gall-like  cavities  will  be  found 
fractured  at  the  broken  joint,  and  at  other  joints  will  be 
found  small  round  holes  leading  to  some  of  these  empty 
cells.  Xow  and  then  one  will  be  found  occupied  by  a 
small  larva  or  pupa,  the  cause  of  all  the  mischief.  Very 
often  this  injury  becomes  quite  serious,  affecting  the  crop 
much  as  does  that  of  the  Hessian  Fly,  though  late  in  the 
season,  and  is  often  mistaken  for  the  Avork  of  that  species. 
The  Joint -worms,  however,  are  larv^  of  small  hymen- 
opterous  insects  which  were  at  first  supposed  to  be  parasitic 
upon  the  Hessian  Fly,  as  they  belong  to  a  family,  the 
Clialcididce,  most  of  the  members  of  which  are  parasites 
of  other  insects.  They  differ  from  the  flies  in  having 
four  wings  instead  of  two,  and  in  many  other  structural 
points,  as  shown  by  the  illustration,  belonging  to  the  same 
order  as  the  bees,  ants,  and  wasps. 


94 


INSECTS    INJURIOUS   TO    STAPLE    CHOPS. 


Two  sj^ecies  are  commonly  injurious,  the  AVheat  Joint- 
worm  {Isoso)ua  tritici  Fitch)  and  another  species  of  the 
same  genus,  more  popuhirly  knoAvn  as  the  Wheat  Straw- 
worm  {hosoma  grande  Riley).  The  adults  of  /.  tritici  are 
small  hlack  flies  from  an  eighth  to  three -sixteenths  of  an 
inch  in  length,  and  with  wings  expanding  about  one  fourth 
of  an  inch.  The  larvae  are  yellowish-white  with  the  tips 
of  the  jaws  brown,  of  about  the  same  length  as  the  fly,  and 
of  the  form  shown  in  the  figure. 

Life-Mdory. — The  larvae  of  /.  grande  are  much  the 
same;  but  while  the  former  species  has  but  a  single  brood 
each  season,  this  is  double-brooded.     The  summer  brood 


Fig.  55. — a,  Wheat-straw  affected  by  Joint- worm;  b,  adult  as  seen 
from  above.     (After  Riley.) 

is  similar  to  that  of  tritici,  but  the  spring  brood  is  peculiar 
in  that  the  females  are  much  smaller  and  almost  wingless, 
so  that  the  pest  is  spread  only  by  the  later  brood.  The 
larv*  of  tritici  hibernate  over  winter  in  the  wheat-stubble, 
coming  to  maturity  in  June,  and  the  next  brood  feeds 
upon  volunteer  wheat  and  the  fall  planting.  /.  grande, 
however,  passes  the  winter  in  the  pupal  state,  also  in  the 


INSECTS    INJURIOUS    TO    WHEAT. 


95 


stubble.  From  them  the  wingless  females  emerge  in  early 
spring  and  j^lace  their  eggs  upon  the  young  wheat,  usually 
on  or  near  the  growing  head.  These  become  mature  in 
June,  and  from  them  the  winged  females  develop.  Singu- 
larly, there  are  no  males  in  this  brood,  they  appearing  only 
in  the  spring,  while  in  the  summer  brood  the  females  are 
so  large  and  robust  that  they  were  at  first  mistaken  for  a 


Fig.  56. — Adult  of  Joint-worm  {Isosoimi  irlticl  Harr.).  a,  female; 
h,  male;  c,  d,  antennae  of  same;  e,  f,  abdomens  of  same. 
(After  Riley.) 

separate  species.  ^' These  deposit  their  eggs  in  or  near 
the  joints  of  the  straw,  more  frequently  the  second  below 
the  head,''  becoming  full-grown  by  fall,  and  passing  the 
winter  in  the  stubble  as  jDupa?.  The  two  species  may  also 
be  separated  by  their  manner  of  injuring  the  straw.  The 
Joint-worm  {tritici)  makes  more  or  less  apparent  galls  in 
the  walls  of  the  culm,  while  the  Straw-worm  [gr ancle) 
forms  no  galls  and  but  fewer  individuals  infest  a  straw. 

Owing  to  their  small  size  and  retiring  habits  these  little 
parasites  of  the  wheat-plant — and  they  also  infest  barley 


96 


INSECTS    INJUKIOUS   TO    STAPLE    CHOPS. 


and    rye — are  not  often   observed,   or  their  injuries   are 
cliarged  against  the  Hessian  Fl)^,  and  not  until  they  do 


Fig.  57. — Wheat  straw  Worm  {Isosoma  gr^mde  Riley  .  n,  ventral 
view;  h,  side  view  of  larva;  c,  antenua^;  d,  mandible;  e,  anal 
segment,  ventral  view;/,  adult  female;  g,  forewing;  h,  hind- 
wing;  i,  aborted  wing.     (After  Riley.) 


Fig.  ^%.—l80soma  grande.   Female  of  summer  brood.    (After  Riley.) 

unusual  and  severe  injury  is  the  difference  in  the  method 
of  their  attack  from  that  of  the  "fly  "  noticed. 


INSECTS   INJURIOUS   TO    WHEAT.  97 

Remedies. — Owing  to  the  fact  that  the  Straw-worm  is 
spread  only  by  the  summer  brood,  a  simple  rotation  of  the 
crop  Avill  keep  them  largely  nnder  control.  However,  as 
both  species  pass  the  winter  in  the  stubble,  most  of  them 
may  be  killed  by  burning  the  stubble  in  fall  and  winter. 

The  Wheat  Saw-fly  Borer  {Cephtis pygmmns  Linn.). 

The  ' '  Corn  SaAv-fly ''  has  been  a  well-known  wheat-pest 
for  many  years  throughout  England,  France,  and  the 
Continent,  but  was  not  noted  as  injurious  in  this  country 
till  1889,  when  Prof.  J.  H.  Comstock  published  *  a  very 
complete  account  of  its  injuries  upon  the  University  Farm 
at  Ithaca,  N.  Y.,  where  it  had  done  more  or  less  damage 
for  two  years,  though  Mr.  F.  H.  Chittenden  states  that 
he  collected  a  single  adult  at  Ithaca  in  the  early  ^80's. 
Specimens  Avere  also  collected  at  OttaAva,  Canada,  and 
Buffalo,  N.  Y.,  in  1887  and  1888,  these  being  the  only 
other  references  to  its  occurrence  in  this  country. 

The  following  is  gleaned  from  Prof.  Comstock^s  interest- 
ing account. 

Injury. — No  external  indications  of  injury  to  the  plant 
can  be  seen  until  the  larva  Avithin  has  almost  completely 
tunneled  the  stalk,  at  which  time  there  is  a  discoloration 
just  beloAV  the  injured  joints.  Thus  damage  by  this 
insect  is  not  readily  noticed,  it  merely  dwarfing  and  stunt- 
ing the  groAvth  of  the  plant  by  boring  in  the  stem. 

'^If  infested  straws  be  examined  a  Aveek  or  ten  days 
before  the  ripening  of  the  Avheat,  the  cause  of  this  injury 
can  be  found  at  Avork  Avithin  them.  It  is  at  that  time  a 
yellowish,  milky-Avhite  Avorm,  varying  in  size  from  one-fifth 


*  Bulletin  11,  Cornell  Univ.  Ag.  Exp,  Station. 


98 


INSECTS    INJURIOUS    TO    STAPLE    CHOPS. 


to  one-half  an  inch  in  length.  The  smaller  ones  may  not 
have  bored  through  a  single  joint;  while  the  larger  ones 
will  have  tunneled  all  of  them,  except,  perhaps,  the  one 
next  to  the  ground. 

Life-history. — "As  the  grain  becomes  ripe  the  larva 
works  its  way  toward   the  ground;   and  at  the  time  of 


Fig.  59. — The  Wheat  Saw-fly  Borer  {Cephus  pygmrfus  Linn.),  n, 
outline  of  larva,  natural  size;  h,  larva,  enlarged;  c,  larva  in 
wheat  stalk,  natural  size;  d,  frass;  e,  adult  female;  /,  Pachyo- 
nerus  calriir-itor,  female,  a  parasite — enlarged.  (After  Curtis, 
from  "Insect  Life.") 

harvest  the  greater  number  of  them  have  penetrated  the 
root.  Here,  in  the  lowest  part  of  the  cavity  of  the  straw, 
they  make  ^^reparations  for  passing  the  winter,  and  even 
for  their  escape  from  the  straw  the  following  year.  This 
is  done  by  cutting  the  straw  circularly  on  the  inside, 
nearly  severing  it  a  short  distance,  varying  from  one-half 
to  one  inch,  from  the  ground.  If  the  wheat  were  growing 
wild,  the  winter  winds  would  cause  the  stalk  to  break  at 


INSECTS   iNJORIOrs  TO    WHEAT.  99 

this  point;  and  thus  the  insect  after  it  had  reached  the 
adult  state  could  easily  escape;  while  but  for  this  cut  it 
would  be  ver}^  liable  to  be  imprisoned  in  the  straw/' 
Ordinarily,  the  straw  is  cut  by  the  reaper  before  it  becomes 
broken;  but  a  strong  wind  Just  before  harvest  will  cause 
a  large  number  of  stalks  to  become  broken,  much  as  if 
affected  by  the  Hessian  Fly. 

''After  the  circular  cut  has  been  made,  the  larva  fills 
the  cavity  of  the  straw  just  below  it  for  a  short  distance 
with  a  plug  of  borings.  Between  this  plug  and  the  lower 
end  of  the  cavity  of  the  straw  there  is  a  place  about  one- 
half  an  inch  in  length.  It  is  here  that  the  insect  passes 
the  winter."  This  cell  is  lined  with  silk  so  as  to  form  a 
warm  cocoon.  Here  the  larva  passes  the  winter  and 
changes  to  a  pupa  in  March  or  April.  The  adult  insect 
emerges  early  in  May.  The  adults  are  four-winded  insects 
and  are  popularly  known  as  Saw-flies  on  account  of  the 
saw-like  ovipositor  of  the  female,  by  means  of  which  she 
inserts  her  eggs  in  the  tissue  of  the  plant.  This  species  is 
quite  different  in  some  respects  from  the  saw-flies  feeding 
upon  the  leaves  of  wheat,  and  belongs  to  the  family 
Cephidce. 

The  female  commences  to  lay  eggs  by  the  middle  of 
May.  By  means  of  her  sharp  ovipositor  she  makes  a  very 
small  slit  any  jilace  in  the  stalk  of  the  plant  and  in  this 
thrusts  a  small  white  Qgg — about  one  one-lmndredth  of  an 
inch  long — which  is  pushed  clear  through  the  walls  of  the 
straw  and  left  adhering  to  the  inside.  Though  several 
eggs  are  deposited  in  a  straw,  but  one  larva  usually 
develops.  '-  The  eggs  hatch  soon  after  they  are  laid,  and 
the  larva?  may  develop  quite  rapidly.  A  larva  which 
hatched  from  an  Qgg  laid  May  13th  was  found  to  have 


loo  INSECTS   INJURIOUS   TO    STAPLE   CROPS. 

tunneled  the  entire  length  of  the  stalk  in  which  it  was" 
on  May  28th. 

liemeclies. — *'  The  most  obvious  method  of  combating 
the  insect  is  to  attack  it  while  it  is  in  the  stubble;  that  is, 
some  time  between  harvest  aud  the  following  May.  If  the 
stubble  can  be  burned  in  the  autumn,  the  larvae  in  it  can 
.be  destroyed.  The  same  thing  could  be  accomplished  by 
plowing  the  stubble  under,  which  would  prevent  the  escape 
of  the  adult  flies.  But  as  it  is  (often)  customary  ...  to  sow 
grass-seed  with  wheat,  it  is  feared  that  the  plowing  under 
of  infested  stubble  would  rarely  be  practicable;  and  it  is 
also  questionable  if  the  burning  of  the  stubble  could  be 
thoroughly  done  without  destroying  the  young  grass.  It 
would  seem  probable,  therefore,  that  if  this  insect  becomes 
a  very  serious  pest,  it  will  be  necessary  .  .  .  either  to  sow 
grass-seed  with  oats  and  burn  or  plow  under  all  the  wheat- 
stubble,  or  to  suspend  growing  wheat  for  one  year,  in  order 
to  destroy  the  insects  by  starvation."    . 

The  Hessian  Fly  {Cccidomyia  destructor  Say). 

Of  the  injurious  insects  peculiar  to  the  wheat-plant  the 
Hessian  Fly  is  undoubtedly  the  most  widely  distributed 
and  most  destructive.  Very  often  it  is  responsible  for  the 
loss  of  from  one-fourth  to  one-half  of  the  crop;  and  one- 
tenth  of  the  whole  yield,  or  from  55  to  65  million  bushels, 
is  estimated  to  represent  the  amount  lost  by  its  annual 
ravages.  Excessive  injury  by  this  as  by  most  other  insects 
comes  periodically.  Thus  '^Hessian  Fly  years"  have 
occurred  in  New  York  in  1779,  1817,  1844,  1845,  1846, 
and  1877,  and  in  the  three  last  years  commencing  with 
1899.  In  184G  it  has  been  ''estimated  that  the  loss  from 
the  pest  in  western  New  York  was  not  less  than  500,000 


IKSKCTS    INJURIOUS   TO    WHEAT.  lOl 

bushels/'  Professors  Roberts,  Slingerland,  and  Stone  (1.  c.) 
state  that  the  destruction  during  the  past  three  seasons 
has  been  the  most  severe  ever  experienced  in  New  York, 
conservatively  estimating  the  loss  in  1901  at  3,500,000 
bushels  of  wheat,  valued  at  about  13,000,000.  Injury  has 
also  been  wide-spread  and  severe  in  Ohio,  Michigan,  and 
neighboring  States  during  the  past  few  seasons,  owing  to 
peculiar  climatic  conditions.  In  1900  Prof.  F.  M. 
Webster  stated  that  a  loss  of  about  60  per  cent  of  the 
wheat  crop  in  Ohio,  amounting  to  24,000,000  bushels  and 
valued,  at  the  market-rate,  at  $16,800,000,  was  due  to 
injury  by  this  pest. 

History. — Having  been  first  noticed  as  injurious  on  Long 
Island,  in  1779,  near  where  the  Hessian  troops  had  landed 
three  years  before,  it  seems  altogether  jorobable  that  it  was 
brought  to  this  country  by  them,  and  it  has  therefore 
been  so  named.  Rapidly  spreading  over  all  the  wheat 
land  in  the  East,  it  aj)peared  in  California  in  1884,  was 
reported  as  injurious  in  England  in  1886,  and  in  1888  was 
found  to  be  destructive  in  New  Zealand. 

Description  and  Li fe-lii story. — The  adult  flies  are  little, 
dark-colored  gnats,  about  one-eighth  of  an  inch  long,  but 
these  are  less  often  seen  than  the  immature  stages.  Each 
of  the  females  lays  from  one  hundred  to  one  hundred  and 
fifty  minute  reddish  eggs,  placing  them  in  irregular  rows 
of  from  three  to  five,  generally  upon  the  upper  surface 
of  the  leaf,  but  in  the  spring  often  beneath  the  sheath 
of  the  leaf.  In  a  few  days  these  hatch  into  small, 
reddish  maggots,  which  soon  turn  white,  are  cylindrical, 
about  twice  as  long  as  broad,  and  have  no  true  head  or 
legs.  The  fall  brood  of  maggots  burrow  beneath  the 
sheath  of  the  leaf  and  its  base,  which  is  still  below  tjie 


102  INSECTS    INJURtOCS   TO    STAPLE    CROPS. 

ground,  causing  a  slight  enlargement  at  the  point  of 
attack;  but  in  the  spring  they  usually  stop  at  one  of  the 
lower  joints  above  the  surface,  in  both  instances  becoming 
fixed  in  the  plant  and  weakening  it  by  absorbing  its  sap 
and  tissues. 


Fig.  61. — The  Hessian  Fly  and  its  various  stages  of  development. 
n,  an  iigg;  b,  larva  or  worm;  c,  flaxseed;  d,  pupa;  e,  adult,  lay- 
ing eggs;  /,  female;  g,  male;  Ji,  stalk  of  wheat  showing  attack; 
i,  natural  enemy  or  parasite— all  enlarged  except  wheat-stem 
and  fig.  e.  (After  Riley,  Burgess,  and  Trouvelot,  from  U.  S. 
Dept.  Agr.). 

This  difference  in  method  of  attack  results  in  a  corre- 
sponding effect  on  the  plant.  The  first  indication  of  the 
work  of  the  maggots  in  the  fall  is  the  tendenc}^  of  the 
plants  to  stool  out;  the  dark  color  of  the  leaves,  which  are 
sopiewhat  broader,  and  the  absence  of  the  central  stems 


INSECTS   INJURIOUS   TO   WHEAT.  103 

also  reveal  their  presence.  Later,  many  of  the  plants  may 
be  observed  to  turn  yellow  and  die.  The  spring  maggots 
attack  the  laterals,  or  tillers,  which  have  escaped  the 
previous  brood,  so  weakening  them  that  the  stems  break 
and  fall  before  ripening,  and  cannot  be  readily  harvested. 

In  about  four  weeks  the  maggots  become  full-grown, 
and  are  then  light  greenish  white  and  about  three-sixteenths 
of  an  inch  long.  The  skin  now  turns  brown,  shrivels 
slightly,  and  inside  of  it  is  formed  the  new  stage,  called 
the  pupa.  This  outside  case,  composed  of  the  cast  larval 
skin,  is  known  as  the  puparium,  and  this  stage  is  generally 
called  the  ''  flax-seed  '^  stage  from  the  close  resemblance  to 
that  seed.  In  this  stage  the  fall  brood  passes  the  winter, 
the  flies  emerging  in  April  or  May,  while  the  spring  brood 
so  remains  during  midsummer,  and  emerges  during  Sep- 
tember. Besides  the  above,  there  are  often  two  supple- 
mental broods,  one  following  the  spring  brood,  and  the 
other  preceding  that  of  the  fall. 

Enemies. — Several  parasites  arc  of  great  value  in  hold- 
ing the  numbers  of  the  fly  in  check,  but  as  yet  no  method 
is  known  whereby  they  mry  be  artificially  encouraged. 
Attempts  to  import  foreign  parasites  have  not,  as  yet,  been 
permanently  successful.  It  is  owing  to  these  parasites 
being  destroyed  by  unfavorable  weather  conditions  that 
the  fly  becomes  excessively  abundant. 

Preventives. — Owing  to  the  wide  distribution  of  this  pest, 
and  the  corresponding  variation  of  latitude  and  altitude, 
it  is  evident  that  the  time  of  its  appearance  will  varv  con- 
siderably, and  any  2:>reventive  measures  must  be  based  upon 
a  previous  determination  of  the  time  of  appearance  of  the 
broods  for  any  given  locality.  Recently  it  has  been  shown 
that  weather  conditions   largely  determine   the   time   of 


104 


INSECTS   INJURIOUS   TO   STAPLE   CROPS. 


appearance  of  the  fall  brood,  a  season  of  drought  in  early 
September  retarding  the  emergence  of  the  flies  until  rain 
falls.     Professors  Roberts  and  Slingerland  state  that  ''a 


mild  October  and  November  often  emphasizes  the  fly's 
destructiveness.  A  damp  spring,  even  though  a  cold  one, 
is  also  favorable  to  the  development  of  the  insect.  On  the 
contrary,   dry    hot    summers   are   unfavorable,  and  often 


INSECTS   INJURIOUS    TO    WHEAT.  105 

cause  a  serious  mortality  to  the  earlier  stages  of  the  fall 
brood  of  adults;  and  a  rainless  August  often  retards  the 
emergence  of  the  flies  until  even  our  latest-sown  wheat  (in 
Xew  York)  is  up  and  ready  to  receive  their  eggs.  Just  such 
weather  conditions  occurred  in  New  York  in  1900  and,  we 
believe,  were  largely  responsible  for  the  fact  that  in  many 
cases  late-sown  fields  were  as  badly  infested  as  those  sown 
earlier/'  If  there  be  a  normal  rainfall  in  August,  the  flies 
will  emerge  as  usual  early  in  September  and  will  lay  their 
eggs  on  volunteer,  early-sown,  and  trap  strips  of  wheat, 
and  late  sowings  will  largely  escape. 

Dr.  A.  D.  Hopkins  has  recently  worked  out  a  most 
valuable  law  governing  the  time  of  appearance  of  this  pest, 
and  from  which  he  has  deduced  a  rule  for  '^the  approxi- 
mate determination  of  normal  dates  for  the  ending  of  the 
fall  swarm  of  the  Hessian  Fly  in  any  locality "  in  West 
Virginia.  "Take  a  knowm  normal  date  of  a  place,  of 
known  latitude  and  altitude,  correct  this  date  to  a  corre- 
sponding date  at  sea-level,  by  adding  one  day  to  each  one 
hundred  feet  of  altitude  above  sea-level;  then  for  any  place 
north  of  this  sea-level  base  subtract  one  day  for  each  one- 
fourth  degree  of  latitude  and  one  day  for  each  one  hundred 
feet  of  altitude  at  the  place  to  be  determined,  and  for  all 
points  south  add  one  day  for  eacli  one-fourth  degree  of 
latitude  and  subtract  from  the  result,  as  before,  one  day 
for  each  one  hundred  feet  of  altitude.  The  resulting  date 
will  be  the  approximate  normal. 

.  "  To  give  an  example  of  this  method  of  determining 
normals,  and  to  demonstrate  its  value,  we  will  take,  as  the 
most  important  and  reliable  data,  the  results  obtained  by 
Prof.  Webster,  by  actual  experiments  and  observations,  at 
Columbus  and  Wooster,  Ohio.     He  found  that  the  normal 


lOG  INSECTS   INJURIOUS   TO    STAPLE    CROPS. 

dtito  for  the  ending  of  the  fall  period  of  active  flight  or 
swarming  of  the  fly  at  Colnmbus,  latitude  40  degrees,  was 
September  25th,  and  that  the  corresponding  date  for 
Wooster,  latitude  40  degrees  and  49  minutes,  was  Septem- 
ber 20th,  which  he  states  agrees  almost  exactly  with  results 
obtained  in  Indiana,  and  forms  the  base  of  conclusions,  as 
set  forth  in  his  Bulletin  No.  107."  Columbus  is  800  and 
Wooster  1000  feet  above  sea-level.  By  applying  the  above 
rule  and  computing  the  date  of  Wooster  from  that  of 
Columbus,  or  vice  ve^^sa,  the  same  dates  will  be  secured  as 
those  determined  by  Prof.  Webster. 

Of  the  various  farm  methods  of  control  the  most  im- 
portant is  the  late  planting  of  winter  wheat  through  the 
Central  States.  In  the  latitude  and  altitude  of  northern 
Ohio  if  this  be  done  after  September  12th  the  flies  will  all 
have  laid  their  eggs  before  the  plants  sprout.  The  time 
of  planting  should  be  later  the  further  south,  but  no  arbi- 
trary dates  can  be  given  for  the  whole  country,  as  those 
must  be  determined  by  altitude,  latitude,  and  local  condi- 
tions. Thus  in  extreme  southern  Ohio  October  10th  is 
stated  to  be  a  safe  time,  while  in  central  Maryland,  in  the 
same  latitude,  wheat  may  commence  to  be  sown  between 
September  25th  and  October  5th.  In  northern  Delaware 
farmers  prefer  not  to  sow  until  October  1st.  Prof.  Roberts 
states  that  though  no  definite  dates  can  be  given  owing  to 
injury  being  most  serious  after  abnormal  weather  condi- 
tions, after  which  the  dates  would  be  different,  yet  that 
"^  New  York  wheat-growers  have  learned  that  wheat  sown 
after  the  20th  to  the  25th  of  September  is  usually  much 
less  infested.  In  Ohio  and  Michigan,  as  elsewhere,  it  has 
been  found  that  wheat  sown  very  early,  i.e  ,  about  Sep- 
tember 1st,  and  late,  i.e.,  after  October  1st,  is  but  slightly 


INSECTS    IXJUllIOUS   TO   AVHKAT.  107 

injured,  while  that  planted  during  the  middle  of  Se2)tem- 
ber  is  largely  or  wholly  destroyed. 

Fig.  63  shows  the  proper  dates  for  j^l^nting  in  Ohio  as 
given  by  Prof.  Webster.  Various  State  experiment  stations 
have  issued  bulletins  giving  the  proper  time  to  plant  in 
those  States,  and  should  the  rule  given  by  Dr.  Ilojikins 
prove  to  be  applicable  throughout  the  country,  the  problem 
of  when  to  plant  will  be  easily  solved.* 

Inasmuch  as  most  of  the  sj^ring  brood  remain  in  the 
stubble  in  the  flaxseed  stage  after  harvest,  if  the  fields  be 
then  burned  over,  large  numbers  will  be  destroyed,  but 
often  this  is  impossible  owing  to  the  j^i'ictice  of  seeding 
wheat  land  to  grass  and  clover,  which  is  quite  a  common 
practice  in  many  sections.  By  tlie  destruction  of  all 
volunteer  wheat  the  two  supplementary  broods  may  be 
reduced,  and  in  the  extreme  North,  where  this  is  the 
principal  means  of  carrying  the  insect  over  winter  and 
spring  wheat  is  grown,  this  will  be  found  of  considerable 
importance. 

By  planting  a  few  strips  of  wheat  late  in  August  or  in 
the  first  weel:  of  September  many  of  the  flies  will  be 
decoyed  into  laying  their  eggs  upon  them,  and  by  then 
plowing  under  these  strips  the  eggs  and  larvae  may  be 
destroyed  and  the  regular  sowing  thus  2)rotected.  The 
trap   strips   should    not  be  allowed  to    stand    over   about 

*  See  W.  Va.  Agr.  Exp.  Station,  Bulletin  Xo.  67  :  The  Hessian 
FlyinW.  Va.,  A.  D.  Hopkins.  Ohio  Agr.  Exp.  Sta.,  Bulletins 
Nos.  107,  119  :  F.  M.  Webster.  Md.  Agr.  Exp.  Sta.,  Bulletin  Xo. 
58:  W.  a.  Johnson.  U.  S.  Dept.  Agr.,  Div.  Ent.,  n.  s. :  The 
Hessian  Fly  in  the  United  States,  Herbert  Osborn.  Cornell 
University  Agr.  Exp.  Sta.,  Bulletin  194:  The  Hessian  Fly,  I.  P. 
Roberts,  M.  V.  Slingerland,  and  J.  L.  Stone. 


108 


INSKCTS   INJURIOUS   TO   STAPLE    CROPS. 


, . ., ^^ 

:  ,'    LUCAS  _    _ 

iwiLLlAMSl       FULTON     f         ../"TottAWA 


Sept.  10 


1 


1899 


!_ \:~ \. 


i-o-^y       I 


\-\ — 


'^^^^  i~CUYAHOGA     'i  GEAUGA  j" 


,.^.^        HENRY    I       v^ooD     I      SANDUSKY    1  ERIE         .  1-.,  .; 1 ■ 

l*NCE     I  I       WOOD      I  I I     LORAIN      I ^,\  TRUMBULl' 

■J._.  I |__    !" !    --— !^^     r       .        I 

iiMt-f  I  I         SENECA  .         .       

^'^'^i      PUTNAM    ! I  f-^— ! I  I 


• I     LUKAIN      I .^.i  I  [TRUMBULLJ 

j   SeptilSj—       i       jpoRTAGEJ j 

;        HURON      i  i       MEDINA    ISOMMlf,  ,  \ 

1  ,--1 1  J  MAHONING* 


I       ' 

}VAN  WERtJ ' 

|_  1  ALLEN 


HANCOCK)' 


JASHLAND| 


-rrrrx 


Z\ 


I  STARK    \  I 

j  Sept.  28,     jcolumeianaJ 

^L     _.L     -LSe^fgo_._.|.i».r--.^^| 

•                            r                                  I    J.                             '                    l_,CARROLl_!  ^,1 

I       MARION     i I*— *■ i      HOLMES      ] J \  \\ 


f  fcRAWFORO  ,  ,  ■  „        ^    ,„        • 
iwYANDOTT                    IfilCHUNlV              ;       WAYNE      j  Sept.  28,       '.COLUMEIANA} 


.=^ 


I  — -1;  „ 

I     COSrtOc;.^!--,  I ;     SON 


i— 1 


i..J 


I       LOGAN       i 


U. 


!u, 


!           .•'MCRROWI 
f-S \ 

'   I     nci    AU/A  DC  ' 


DARKE    •                      !   CHAMPAIGN 
1     MIAMI     j. 


v-i--A  ^ 


' 1899  J"  •-.., 1 .-I 


r         i  / 

;    GUERNSEY  !    BELMONT   'I 


m- 


"A. 


CLARKE      .       i^     (FRANKLIN^ ^ |\;USKINGUM'-| 


!  PREBLE', 


'  ■_? IpickawaT^  Septh:  30  '- 

NE  r      I  oct.i,      ^fi  - 


•  I  j    GREENE  <-)Ct.  1,    j  r    1     PERRY       MORGAN    I      fS      '., 

I ^—. '-_|. JFAYETTEJ       1899       !_,— ~         • :'  !  ^      ^ 


!      BUTLER    I 

h 


CLINTON! 
/warren  j ( 

''     — L- j        /       \ 

HAMILTON   C"  ''T-'' 

f        i  \" 

CLER- 


HIGHLANO 


-j      HOCKING 

I I 

ROSS  .      VINTON     L,  ATHENS  ^S 

I  Oct.  3.: :^^ 

f ' — i— ,   1 

PIKE  I         •*'E'GS 

*^"^^         jackson!_  . 

■' I         )<^ 


WASHINGTON 


Fig.  6B.— Map  indicating,  in  bold  faced  type,  the  approximate  dates 
immediately  after  which  it  is  usually  safe  to  sow  wheat  in  the 
fall,  in  various  sections  of  Ohio,  in  order  to  avoid  the  autumn 
attack  of  Hessian  fly.  Dates  given  in  small  type  show  when 
Avheat  sown  in  the  fall  of  1899  escaped  the  fall  attack,  though 
it  was  in  many  cases  totally  destroyed  by  the  spring  attack.  The 
difference  between  these  dates  is  the  variation  from  the  normal, 
and  where  no  dates  are  given  between  the  cross-lines  there  waa 
no  such  variation.     (After  Webster.) 


INSECTS    INJURIOUS   TO    WHEAT.  109 

four  weeks,  or  three  or  four  days  after  the  main  crop  is 
sown. 

Tliough  none  are  exempt  from  attack,  those  varieties  of 
wheat  ^^  with  large,  coarse,  strong  straw  are  less  liable  to 
injury  than  weak-strawed  and  slow-growing  varieties.'^ 
In  Xew  York  in  many  localities  in  1901  a  wheat  called 
Dawson's  Golden  Chaff  was  found  to  be  but  little  injured, 
where  others  were  nearly  destroyed.  However,  in  Canada, 
where  this  variety  originated,  it  is  as  seriously  injured  as 
other  kinds,  and  may  become  so  in  Xew  York.  Bearded 
Eed  Wheat  No.  8  was  also  found  to  be  a  very  resistant 
variety,  as  were  Prosperity,  Democrat,  Ked  Rusisan,  and 
White  Chaff  Mediterranean.  It  should  be  remembered, 
however,  that  none  of  these  are  invariably  '' fl3'-proof/' 
and  that  though  under  certain  conditions  tbey  maybe  but 
little  injured,  in  other  localities  and  under  less  favorable 
circumstances  they  may  be  injured  as  much  as  any  other 
sorts. 

Among  other  conclusions  Prof.  Koberts  and  his  col- 
leagues state  that  the  fly  '-injures  wheat  more  on  dryish 
and  poor  land  than  on  moist  but  well-drained,  rich  soils." 
Also,  ''that  the  soil  must  be  so  well  fitted  and  so  fertile 
that  a  strong,  healthy  growth  will  be  secured  in  the  fall, 
though  the  sowing  of  the  seed  be  delayed  ten  to  fifteen 
days  beyond  the  usual  time.  Such  preparation  of  the  soil 
will  also  help  the  wheat  to  recover  from  any  winter  injury. 
Thick  seeding  and  vigorous  growth  also  tend  to  ward  off 
the  fly.''  "  Much  stress  should  be  laid  on  the  proper 
fitting  of  the  land  for  wheat  Plowing  should  be  done 
earty — at  least  six  weeks  before  sowing^to  give  abundant 
time  for  the  repeated  working  of  the  soil  in  order  to 
recompact    the    subsurface    soil    and    secure    a    fine    but 


110  INSECTS   INJURIOUS   TO    STAPLE    CHOPS. 

shallow  seed-bed  in  which  there  has  been  developed,  by 
tillage  and  the  action  of  the  atmosphere,  an  abundance  of 
readily  available  plant-food.  Manures  and  fertilizers  should 
be  kept  near  the  surface  and  the  young  roots  encouraged 
to  spread  out  on  the  surface  soil,  thus  avoiding  much  of 
the  damage  by  heaving  in  winter  and  leaving  the  deeper 
soil  for  fresh  pasturage  for  the  plants  during  the  following 
spring  and  summer." 

Prof.  Webster  strongly  recommends  the  rotation  of  the 
wheat-crop,  sowing  it  as  far  from  where  it  was  grown  the 
previous  year  as  possible.  Where  this  has  been  judiciously 
done,  individual  farms  have  often  remained  free  from 
serious  attack  when  neighboring  ones  were  badly  injured. 

Remedies. — After  injury  by  the  fly  has  once  become 
apparent  in  the  fall,  there  is  no  application  known  by 
which  it  may  be  destroyed.  The  application  of  a  liberal 
amount  of  fertilizer  to  land  not  already  well  fertilized  will 
enable  the  plants  to  better  withstand  the  injury  and  possi- 
bly outgrow  it.  Pasturing  shee^D  on  early-sown  fields 
would  doubtless  result  in  crushing  many  of  the  flaxseeds 
and  larvae,  and  give  the  ground  that  compact,  pulverized 
nature  which  it  should  have. 

Nothing  is  known  as  a  remedy  for  injury  by  the  spring 
brood. 

In  summarizing  his  knowledge  of  means  of  controlling 
this  pest,  Prof.  F.  M.  Webster,  who  is  probably  our  best 
authority  upon  it,  says:  "  After  thirteen  [now  fifteen]  years 
of  study  of  the  Hessian  Fly^  I  am  satisfied  that  four-fifths 
of  its  injuries  mmj  he  2)r evented  hy  a  letter  system  of  agri- 
culture. For  years  I  have  seen  wheat  grown  on  one  side 
of  a  division-fence  without  the  loss  of  a  bushel  by  attack 
of  this  pest,  while  on  the  other  side  the  crop  was  invariably 


IK8EC"1S    INJURIOUS   TO    WHEAT.  lU 

always  more  or  less  injured.  No  effect  of  climate, 
meteorological  conditions,  or  natural  enemies  could  have 
brought  about  such  a  contrast  of  results.  The  whole 
secret  was  in  the  management  of  the  soil  and  the  seeding." 

Some  Wheat-maggots. 

Very  similar  in  its  mode  of  injuring  the  wheat-stalk  to 
the  Hessian  Fly  is  the  Wheat  Stem-maggot  {Meromyza 
mnericana  Fitch).  The  adult  flies  were  first  described  by 
Dr.  Fitch  in  1856,  tliough  the  work  of  the  maggots  had 
probably  been  noticed  as  early  as  1821  by  James  Worth  of 
Bucks  County,  Pa.,  and  by  the  Michigan  Farmer  in 
Michigan  about  1845. 

Extending  from  Dakota  and  Manitoba  to  Texas,  the 
range  of  this  insect  practically  covers  all  the  eastern 
United  States  and  southern  Canada. 

Unlike  the  Hessia7i  Fly  it  feeds  and  breeds  upon  wild 
grasses  and  is  thus  much  more  difficult  to  control.  Prof. 
A.  J.  Cook  found  the  larvae  in  both  barley  and  oats  in 
Michigan,  Prof.  Webster  reared  an  adult  from  Blue  Grass 
{Poa  prate7isis),  and  Dr.  Jas.  Fletcher  records  it  as  breed- 
ing in  Agrojyijrum,  Descliampsis,  Elynius,  Poa,  and 
Setaria  viridis  in  Canada. 

Life-history.— lii\e  the  Hessian  Fly  the  adult  flies  lay 
their  eggs  on  fall  wheat  in  September  and  October,  and 
the  young  maggots  when  hatched  work  their  way  down 
into  the  stem,  either  cutting  it  off  or  causing  it  to  discolor 
or  die.  The  eggs  are  about  one-fortieth  of  an  inch  long 
and  of  a  glistening  white  color.  The  larvse  are  a  light 
greenish  color,  about  one-fourth  of  an  inch  long,  tapering 
towards  the  terminal  end  while  subcylindrical  posteriorly, 
being  quite  elongate.     The  piipi^  are  the  same  color  as  the 


112  INSECTS   INJUKIOUS   TO    STAPLE    CROPS. 

larv^,  but  more  rounded,  being  only  one-sixth  of  aji  inch 
long,  and  reveal  the  legs  and  wing-cases  of  the  imago 
forming  within  tliem.  The  external  case  of  the  pupa, 
called  the  puparium,  is  merely  the  shrunken  and  hardened 
cast  skin  of  the  last  larval  stage,  within  which  the  insect 


Fig.  64. — Wheat  Bulb-worm  {Meromyza  amerkana)  a,  mature  fly; 
b,  larva;  c,  puparium;  d.  infested  wheat-stem — all  enlarged  ex- 
cept d.     (After  Marlatt,  U.  S.  Dept.  Agr. ) 

transforms  to  the  pupa.  The  fly  is  abotit  one-fifth  of  an 
inch  long.  It  is  of  a  yellowish- white  color  with  a  black 
spot  on  the  top  of  the  head,  three  broad  black  stripes  on 
the  thorax,  and  three  on  the  abdomen,  which  are  often 
interrupted  at  the  sutures,  so  that  they  form  distinct  spots. 
The  eyes  are  a  bright  green. 

The  winter  is  passed  by  the  larva3  in  the  young  plants, 
and  in  spring  they  transform  to  pupae  and  adult  flies. 
These  in  turn  deposit  eggs  in  such  a  position  that  the 
maggots  issuing  from  them   may  readily  feed  upon    the 


INSECTS    INJURIOUS   TO   WHEAT.  113 

succulent  portions  of  the  growing  stalk.  Numerous  larvae 
thus  sapping  the  life  of  the  plant  soon  kill  it  outright  or 
cause  the  top  and  head  to  wither  and  die.  The  adults  of 
this  brood  emerge  in  July  and  lay  eggs  on  volunteer  wheat 
and  grasses,  the  maggots  working  in  the  same  manner  as 
in  the  fall  and  coming  to  maturity  so  that  another  brood 
of  flies  lay  eggs  for  the  fall  brood  on  the  newly  planted 
wheat. 

Owing  to  the  fact  that  this  insect  breeds  also  in  grasses 
during  late  summer  it  is  much  more  difficult  to  combat 
than  were  it  confined  to  wheat  as  its  food-plant,  as  is  the 
Hessian  Fly. 

Jieniediex. — ''  If  the  grain  is  stacked  or  threshed  and  the 
straw  stacked  or  burned/'  says  Prof.  AVebster,  "  it  is  clear 
that  the  number  escaping  would  be  greatly  reduced,''  for, 
as  the  adults  emerge  soon  after  harvest,  they  would  escape 
to  deposit  their  eggs  were  the  straw  left  in  the  fields,  but 
^Mt  is  not  likely  that  those  in  the  centre  of  the  stacks 
would  be  able  to  make  their  way  out,  and  the  threshing- 
machine  vv'ould  destroy  many  more..  How  much  could  be 
accomplished  by  late  sowing  of  grain  is  uncertain,  as  the 
females  are  known  to  occur  abundantly  up  to  October. 
If  plots  of  grain  were  sowed  immediately  after  harvest  in 
the  vicinity  of  the  stacks,  many  of  the  females  could,  no 
doubt,  be  induced  to  deposit  their  eggs  therein,  and  these 
could  be  destroyed  by  plowing  under."  Burning  of  the 
stubble  will  also  aid  in  keeping  this  jiest  under  control. 

There  are  several  undetermined  species  of  flies  belong- 
ing to  the  genus  Oscinis,  and  very  closely  resembling  the 
common  house-fly  in  miniature,  being  about  one-fourth  as 
larcre,  whicli  have  nracticallv  the  same  life-historv  as  tlie 
Wheat  8tem-maggot  and   injure  the  wheat    in  tlie  same 


114 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


manner.  They  will  not  need  consideration  by  the  prac- 
tical farmer  other  than  in  applying  methods  of  control  as 
already  given.  One  species  of  this  genus,  determined  by 
Prof.  H.  Garman  as  Oscinis  variabilis  Loew  and  christ- 
ened the  American  Frit-fly,  has  been  found  common  in 
Kentucky   and    Canada,    but   is    so    nearly   identical    in 


Fig.  65. — The   American    Frit-fly   (Oscinis    virinMlis  Loew).      a, 
larva  or  maggot;  b,  puparium;  c,  adult  fly.     (After  Garman.) 

appearance  and  habit  in  the  larval  stage  that  it  can  with 
difficulty  be  distinguished  from  the  Stem-maggot. 

That  these  pests  do  not  do  more  injury  is  probably  due 
to  a  considerable  extent  to  the  fact  that  large  numbers  of 
them  are  destroyed  by  a  small  hymenopterous  parasite, 
known  as  CoBlimis  meromyzce  Forbes,  which  very  commonly 
infests  the  larvse,  and  by  other  parasites  and  predaceous 
insects. 

Rarely  will  these  pests  do  serious  damage,  but  very  often 


INSECTS    INJURIOUS   TO    WHEAT.  115 

it  is  sufficient  to  merit  consideration,  and  only  a  knowledge 
of  their  life-history  can  give  a  key  to  their  successful 
control. 

IXJURIXG  THE  LEAVES  AND  HEAD. 

The  Wheat-louse  {Nectar o pi mr a  avenm^2^.^. 

History  and  Distrihution. — At  comparatively  long  inter- 
vals the  wheat  crop  is  extensively  injured  by  the  Wheat- 
louse  or  Grain-aphis.  In  1861  and  1862  serious  damage 
was  done  throughout  New  York  and  New  England,  which 
seems  to  have  been  the  first  serious  outbreak  of  the  jDest 
in  this  country,  it  being  a  native  of  England.  Since  then 
the  crop  of  1889  throughout  Kentucky,  Ohio,  Indiana, 
Illinois,  Wisconsin,  and  Michigan  was  the  worst  damaged, 
sometimes  to  the  extent  of  60  per  cent.  The  follow^ing 
year  the  lice  appeared  on  the  eastern  shore  of  Maryland  in 
large  numbers,  causing  a  total  failure  of  the  crop  in  some 
sections,  and  in  1894  they  did  serious  damage  in  Washing- 
ton and  northern  Idaho,  wdiere  they  had  been  known  for 
some  years.  Though  no  record  of  its  distribution  is  to  be 
found,  it  would  seem  probable  from  the  above  that  the 
Wheat-louse  occurs  throughout  the  northern  half  of  the 
United  States,  as  no  mention  of  its  occurrence  in  the  South 
is  found. 

Like  many  aphids  it  rarely  becomes  excessively  injurious, 
being  usually  held  in  check  by  internal  parasites,  ^Dre- 
daceous  insects,  diseases,  and  weather  conditions.  Just 
how  far  the  weather  is  directly  responsible  for  their 
increase  or  decrease  is  unknown;  but  it  has  been  observed 
that  an  outbreak  is  usually  preceded  by  several  dry  seasons, 
and  that  cold,  damp  weather  during  late  sjoring  and  early 
summer   seems   to   favor   their   development.       Parasitic 


116 


INSECTS    INJURIOUS   TO    STAPLE    CHOPS. 


fungous  diseases — mostly  of  the  genus  Empusa — are  one 
of  the  most  important  checks  to  the  multiplication  of 
plant-lice,  and,  as  they  require  wet  weather  for  their  best 


Fig.  66. — Wbeat-louse  Parasite  (Aphidius  gr<i.n(iri(iphis  Cook),  and 
parasitized  louse  from  which  it  has  issued.  (Copied  from 
J.  B.  Smith.) 


Fig.  67. — The  l^he^it-Xoum  (Nectar ophor a  amnm  Fab.).     Wingless 
and  winged  forms.     (After  Garman.) 

development,  it  is  not  surprising  that  several  dry  seasons 
should  precede  an  abundance  of  lice.     Prof.  F.  M.  Webster 


INSECTS    INJURIOUS   TO    WHEAT.  117 

thinks  that  cold,  wet  weather  in  May  and  June  is  favor- 
able to  the  lice,  in  that  it  retards  the  development  of  their 
parasites. 

Description  and  Life-liisiory. — The  first  individuals  are 
found  on  the  young  wheat  in  the  latter  part  of  April, 
though  during  open  winters  they  may  remain  on  the 
young  wheat,  as  observed  by  Dr.  Cyrus  Thomas  in  1875 
and  Prof.  H.  Garman  in  1889.  Until  early  July  the  lice 
feed  upon  the  wheat,  first  upon  the  stalk  and  leaves  and 
later  upon  the  head,  breeding  in  the  parthenogenetic 
manner  of  most  aphids.  (See  life-history  of  Corn  Eoot- 
aphis,  page  13G.)  The  color  of  the  lice  varies  greatly,  as 
does  also  the  size.  In  the  spring  the  winged  lice  are 
green,  with  head,  antennae,  thorax,  femora,  tarsi,  corni- 
cles, and  a  series  of  spots  on  the  sides  of  the  abdomen 
black.  As  the  grain  matures  and  the  lice  migrate  to  the 
head,  many  of  them  become  yellow,  reddish,  and  some  of 
the  winged  forms  almost  black.  The  wingless  lice  are  of 
a  pale  green. 

Oats,  barley,  rye,  corn,  blue  grass,  and  many  other 
grasses  furnish  food  for  this  pest,  and  after  the  wheat 
becomes  mature  it  may  commonly  be  found  on  volunteer 
oats  until  the  fall  wheat  appears.  During  the  hot  weather 
of  midsummer,  however,  it  is  not  much  in  evidence. 

The  true  sexes  occur  in  the  fall,  and  eggs  are  laid  upon 
the  fall  wheat. 

Enemies. — "Were  it  not  for  its  parasites  and  the  preda- 
ceous  insects  which  feed  upon  it,  the  Wheat-aphis  would  in- 
deed be  a  most  serious  past,  but  ordinarily  these  keep  it  well 
under  control,  and  when  for  some  reason  they  are  them- 
selves killed  off  for  a  season  and  the  lice  have  opportunity 
to  multiply,  they  soon  become  so  numerous  as  to  again 


118  INSECTS   INJURIOUS   TO   STAPLE    CROPS. 

destroy  so  many  as  to  prevent  serious  injury.  The  effect 
of  these  parasites  and  predaceous  insects  is  indeed  marvel- 
lous and  is  always  a  matter  of  observation  to  the  farmer, 
who  wonders  if  they  are  to  finish  the  work  of  the  lice  and 
utterly  destroy  the  crop.  Prof.  Webster  says  of  them: 
"The  effect  of  the  parasites  upon  the  grain-louse  was 
simply  astonishing,  while  their  numbers  were  myriad. 
Going  to  the  fields  of  recently  harvested  grain,  if  one  stood 
in  a  position  to  bring  the  newly  made  shocks  between 
himself  and  the  setting  sun,  he  could  clearly  observe  the 
swarms  of  minute  hymenoptera  arising  therefrom  and 
flying  away.  Besides,  the  stubble-fields  were  overrun  with 
lady-beetles  and  their  larvae. ^'  Several  internal  parasites 
belonging  to  the  family  Braconidm  (see  page  41)  are  con- 
cerned in  this  good  work,  one  variety,  described  by 
Prof.  A.  J.  Cook  as  Aphidiiis  granariaphis  (Pig.  ^Q), 
having  been  especially  namerous  in  'Michigan  in  1889. 
All  the  common  ladybird-beetles  feed  upon  these  lice,  and 
with  an  abundance  of  food  increase  in  numbers  very 
rapidly.  Several  species  of  syrphus-flies  and  Clirysopa  are 
equally  fond  of  them,  and  are  very  numerous  in  infested 
fields. 

Remedies. — As  far  as  known  no  artificial  remedy  for  the 
Wheat-louse  has  yet  been  found.  Though  the  lice  might 
be  destroyed  with  various  sprays,  this  is  hardly  practicable 
in  a  wheat-field;  and  inasmuch  as  the  lice  breed  upon  so 
many  species  of  the  grass  family,  there  seems  to  be  no  cul- 
tural method  for  combating  them.  Ordinarily,  therefore, 
we  will  have  to  trust  to  the  good  woebnrk  of  the  eficial 
insects  and  diseases  to  prevent  their  depredations. 


INSECTS   INJURIOUS   TO    WHEAT.  119 

Wheat  Saw-flies  {Dolerus  spp.). 

Several  species  of  saw-fly  larvae  sometimes  feed  upon  the 
leaves  and  rarely  the  heads  of  wheat,  but  seldom  do  serious 
injury.  Dolerus  arvensis  Say  and  Dolerus  collar  is  Say 
have  both  been  reared  upon  wheat  from  Ohio  and  New 
Jersey,  though  both  species  occur  throughout  the  United 
States  and  southern  Canada  east  of  the  Rockies.  The 
adult  flies  "are  comparatively  large,  robust  insects,  of  a 
dull  black  or  bluish  color,  varied  with  yellow  or  reddish.^' 
*^The  larvae  are  quite  uniform  in  color  and  general  char- 
acteristics. They  have  twenty-two  legs,  are  cylindrical; 
and  generally  of  a  uniform  grayish  o^  slaty  color,  dorsally 
and  laterally,  but  nearly  white  ventrally."  * 

The  adults  deposit  their  eggs  in  the  spring,  and  larvae 
are  to  be  found  early  in  June.  The  only  record  found  of 
the  life-history  is  that  of  D.  collaris  by  Prof.  Webster, 
who  found  that  a  larva  collected  on  June  15,  1897,  entered 
the  ground  in  about  ten  days,  and  the  flrst  adult  emerged 
January  11,  1898,  though  the  adults  usually  appear  later. 

The  most  common  saw-fly  feeding  upon  wheat-foliage  is 
Pacliynematus  extensicornis  Norton.  "The  adult  insects 
ap23ear  during  the  latter  part  of  April  and  first  of  May, 
the  males  antedating  the  females  several  days.  The  eggs, 
when  first  laid,  are  of  a  light  green  color.  They  are 
inserted  to  the  number  of  two  to  five,  or  more,  together 
along  the  edges  of  the  wheat-blades  and  just  beneath  the 
epidermis.  Some  fifteen  or  sixteen  days  elapse  before 
hatching.      The  newly  hatched  larva  is  rather  slender  and 

*  Wheat  and  Grass  Saw-flies.  C.  V.  Riley  and  C.  L,  Marlatt, 
"Insect  Liie,"  Vol.  IV,  p.  169. 


120 


INSECTS  INJURIOUS   TO   STAPLE   CROPS. 


elongate,  tapering  gradually  from  the  head  to  the  last 
segment;  head  yellowish,  eyes  black.  Full  growth  is 
attained  in  about  five  weeks,  the  mature  larva  having  a 
length  of  about  four-fifths  of  an  inch.  The  head  is  of  a 
pale  clay-yellow  color,  the  eyes  are  black,  and  the  color 
of  the  body  is  green  or  yellowish  green.     The  larva  is  at 


Fig.  68. — Dolerus  nrvensis  Say,  female.     (After  Riley  and  Marlatt, 
"Insect  Life,"  U.  S.  Dept.  Agr  ) 

once  separated  from  the  Dolerus  larvae  by  the  possession 
of  but  seven  pairs  of  abdominal  feet.^^  (R.  &  M.,  1.  c. ) 
When  full-grown  the  larvae  enter  the  earth  and  construct 
silken  cocoons,  in  which  they  doubtless  remain  unchanged 
over  winter,  transforming  to  i^upae  shortly  before  the 
adults  emerge  the  next  spring.  The  form  of  the  adults  is 
well  shown  in  the  illustration.  "  The  female  is  stout  and 
in  general  light  j^ellowish  or  ochraceous  iu  color.  The 
abdomen  is  for  the  most  part  dark  brown  or  black, 
dorsally,  except  the  posterior  lateral  margin  and  the 
extreme  tip.  The  male  is  much  more  slender  and  elon- 
gate than  the  female,  and  is  almost  black  in  color,  the  tip 


INSECTS   INJURIOUS  TO   WHEAT. 


121 


of  the  abdomen  being  reddish  and  part  of  the  legs 
whitish/'  This  species  has  been  taken  on  wheat  in 
Illinois,  Nebraska,  Delaware,  Maryland,  Ohio,  Indiana, 
and  Pennsylvania.  During  1886  and  1887  it  did  con- 
siderable damage  by  cutting  off  the  heads, — sometimes,  as 


Fig,  69. — The  Grass  Saw-fly  {Parhynemntus  extensirornis  Norton). 
n,  (1,  eggs  on  wheat -blade;  />,  young  larva?;  c,  full-grown  larva; 

d,  cocoon  from  which  adult  has  emerged;  e,  f,  adult  insects — 

e,  male;  /,  female,  a  and  />,  natural  size;  c-f,  enlarged.    (After 
Riley  and  Marlatt,  U.  S.  Dept.  Agr.) 

stated  by  a  Maryland  man,  cutting  fully  one-half  of  them. 
No  more  recent  damage  has  been  recorded,  and  owing  to 
the  slight  damage  usually  done  no  remedies  have  received 
a  practical  test.  Deep  fall  plowing  might  be  of  advantage 
by  burying  the  larvae  so  deeply  that  the  adults  would  be 
unable  to  escape. 


122  INSECTS   INJURIOUS  TO   STAPLE   CROPS. 

INJURING   THE    HEAD. 

The  Wheat-midge  {Diplosi.^  tritici  Kirby). 
History. — While  the  Hessian  Fly  attacks  the  stalk  of 
the  wheat-plant,  another  species  of  the  same  genus,  known 
as  the  Wheat-midge,  or  "  Red  Weevil,"  often  does  very 
serions    damage    to    the    maturing    head.     It,    too,    is    a 
foreigner,  having  first  been  noticed  as  injurious  in  Suffolk, 
England,    in    1795,    though    probable    references    to    its 
depredations  date  back  as.  early  as  1741.      ''In   '  Ellis^s 
Modern  Husbandman'  for  1745  the  attacks  of  the  vast 
numbers    of   black   flies    (the   ichneumon    j^arasites)    are 
noticed  in  the  following  quaint  terms :  '  After  this  we  have 
a  melancholy  sight,  for,  as  soon  as  the  wheat  had  done 
blooming,  vast  numbers  of  black  flies  attacked  the  wheat- 
ears  and  bio  wed  a  little  yellow  maggot  which  ate  up  some 
of  the  kernels  in  other  parts  of  them,  and  which  caused 
multitudes  of  ears  to  miss  of  their  fulness,  acting  in  some 
measure  like  a  sort  of  locust,  till  rain  fell  and  washed  them 
off;  and  though  this  evil  has  happened  in  other  summers 
to  the  wheat  in  some  degree,  yet  if  the  good  providence  of 
God  had  not  hindered  it  they  might  have  ruined  all  the 
crops  of  wheat  in  the  nation.^     (Hind's  ''  Essay  on  Insects 
and  Diseases  Injurious  to  Wheat  Crops,'  page  76.)"  *     It 
seems  probable  that  it  was  first  introduced  into  America 
near  Quebec,  where   it   ''ajDpears   to   have  occurred"  in 
1819,    and  was   first  observed    in  the    United    States    in 
northwestern  Vermont  in  1820.      It  did  not  become  very 
destructive,  however,  until  1828,  from  which  time  until 
1835  it  kept  increasing  in  such  numbers  as  to  cause  the 

*The  Wheat-midgc.     Bulletin  No.  5,  Vol.  1,  2d  Ser.,   Ohio  Ag. 
Exp.  Sta.,  F.  M.  Webster. 


INSECTS    INJURIOUS    TO    WHEAT.  123 

abandonment  of  the  wheat  crops  in  some  localities  through- 
out northern  New  England.  Serious  damage  was  reported 
as  due  to  this  pest  every  few  years  until  about  1860,  being 
most  severe  in  1854, — in  which  j^ear  Dr.  Fitch  estimated 
the  loss  in  Nevv  York  alone  at  815,000,000, — 1857,  and 


Fig.   70. — Wheal -midge  (Diplosis  triU-i).     a,  female  fly;    h,  male 
fly;  c,  larva  from  below.     (After  Marlatt,  U.  S.  Dept.  Agr.) 

1858.  Since  then  no  wide-spread  injury  has  occurred, 
though  local  outbreaks  are  frequent,  and  it  has  spread 
south  to  the  Gulf  States  and  westward  to  Iowa,  Minnesota, 
and  Arkansas. 

Life-lmtovy. — The  adult  flies  are  small,  two-winged 
insects,  about  an  eighth  of  an  inch  long,  of  a  yellow  or 
orange  color.  They  appear  about  the  middle  of  June  and 
lay  the  eggs  "'in  a  small  cavity  at  the  summit  of,  and 
formed  by  a  groove  in,  the  outmost  chaff  covering  the 
incipient  kernel.^'  They  hatch  in  about  a  week,  according 
to  Dr.  Fitch,  and  the  maggots  burrow  into  the  fonning 
t.ernels.     The  maggots  are  of  a  reddish  color,  and  when 


124  INSECTS    INJURIOUS   TO    STAPLE    CUOI'S. 

an  car  is  badly  infested  give  it  a  reddish  tinge,  on  account 
of  which  the  insect  is  often  called  the  ''  Eed  Weevil." 

When  full-grown  the  larvae  enter  the  ground  and  usually 
form  cocoons,  in  which  they  pass  the  winter  in  the  pupal 
stage,  though  they  often  hibernate  without  such  protec- 
tion. Though  doubtless  there  is  usually  but  one  brood  in 
a  season,  observations  by  Prof.  F.  M.  Webster  and  others 
seem  to  point  to  the  fact  that  there  sometimes  are  two 
broods,  as  adults  have  been  observed  from  August  into 
November. 

Besides  wheat,  the  wheat-midge  also  sometimes  injures 
rye,  barley,  and  oats. 

Remedies. — Plowing  infested  fields  in  the  fall  so  deeply 
that  the  midges  will  be  unable  to  reach  the  surface  upon 
developing  in  the  spring  is  by  far  the  best  means  of  con- 
trolling this  2^est;  while  burning  the  stubble  previous  to 
plowing,  and  a  rotation  of  the  crop,  will  also  be  of  con- 
siderable aid.* 


*  See    "The    Principal  In.  ect  1  nemies  of   Growing  Wheat,"  C. 
L.  Marlatt,  Farmers'  Bulletin,  No.  182,  U.  S.  Dept.  Agr. 


CHAPTER   VIL 

INSECTS   IXJURIOUS   TO   CORN 

IN^JUKIKG    THE    ROOTS. 

Corn  Root-worms. 

The  Western  Corn  Root-worm  {Diahrotica  longicornis  Say). 

The  farmers  and  entomologists  of  the  Central  States 
have  long  known  this  as  one  of  the  worst  pests  with  which 
they  have  to  deal,  and  its  progress  eastAvard  through  Ohio 
has  been  a  matter  of  considerable  interest. 

Hidorii. — Outside  of  entomological  collections,  the 
beetle  was  hardly  known  until  1878,  when  it  first  appeared 
in  Illinois  in  such  numbers  as  to  cause  any  wide-spread 
damage.  First  observed  by  Say  in  1823,  who  gave  its 
habitat  as  Arkansas  Territory,  it  was  not  again  noticed 
until  found  numerous  upon  sorghum  by  Prof.  AV.  S. 
Robinson  of  Kansas  in  1866,  who  gave  a  large  thistle  as 
its  native  food-plant.  In  1874  Prof.  C.  V.  Riley  received 
a  larva  from  Kirkland,  Mo. ,  which  had  been  found  bur- 
rowing into  the  roots  of  corn  with  considerable  injury, 
and  again  in  1878  from  Eureka,  Mo.  Prof.  Webster  states 
that  in  Illinois  from  the  spring  of  1874  he  collected  only 
two  specimens  until  the  fall  of  1877,  when  quite  a  number 
were  taken  in  corn-fields.  A  rapid  increase  in  numbers 
occurred   during  the  next   three  years,   and  by  1880   its 

125 


126 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


injuries  to  corn  in  Illinois  were  so  severe  as  to  demtind 
investigation.  At  tliat  time  it  was  stated  by  several 
farmers  that  the  larvae  had  been  noted  feeding  on  corn- 


FiG.  11.  —  Diahroiicd  longicornis  Say.  a,  beetle;  h,  larva — Western 
corn  root-worm;  c,  pupa;  d,  egg;  d' ,  portion  of  egg  enlarged 
(X40);  e,  mandible  of  larva;  /,  Lead  of  larva  from  above.  Hair- 
lines at  sides  natural  size.     (Redrawn  from  Forbes.) 


Fig.  72. — a,  Diahrotien  12-punctata  Ollv.  Beetle  of  Southern  corn 
root-worm;  b,  Diabrotica  mttata  Fab.  Striped  Cucumber- 
beetle.     (Redrawn  from  Forbes.) 

roots  for  ten  or  twelve  years,  and  that  serious  damage  had 
been  done  for  at  least  seven  years.  Thus  it  is  evident  that 
in  all  probability  the  injuries  to  corn  commenced  in 
Missouri  and  Kansas  during  the  early  ^70's,  and,  as  soon 


INSECTS    INJURIOUS   TO    CORN.  127 

as  the  larvae  had  acquired  a  decided  taste  for  corn,  spread 
gradually  eastward  into  Illinois,  where  that  is  the  staple 
crop. 

In  the  spring  of  1882  Professors  Forbes  and  Webster 
began  a  careful  study  of  the  life-history,  habits,  and 
injuries  of  the  insect,  and  to  them  we  owe  almost  all  our 
knowledge  of  it.  At  that  time  its  injuries  were  found  to 
be  general  throughout  western  Illinois,  north  of  Centralia, 
and  also  in  southeastern  Iowa,  destroying  from  five  to  ovei' 
fifty  per  cent  of  the  crop.  In  1885  Prof.  Webster  found 
it  abundant  at  Lafayette,  Indiana,  where  the  owner  of  one 
large  estate  estimated  his  loss  at  fifteen  per  cent  of  the 
wiiole  crop,  or  a  cash  loss  of  $60,000. 

Unnoticed  in  Ohio  till  1892,  in  that  year  it  was  reported 
from  Hamilton  County,  in  the  extreme  southwestern 
corner  of  tbe  State,  and  was  also  found  in  Van  Wert 
County,  in  tlie  nortlnvestern  part.  Since  then  it  has 
steadily  advanced,  each  year  spreading  over  one  and  one- 
half  counties  to  the  eastward,  until  in  1895  it  had  been 
reported  from  over  almost  the  entire  western  half  of  the 
State.  jS^o  special  notice  has  been  seen  of  any  spread. 
While  thus  spreading  eastward,  it  has  become  generally 
recognized  in  Kansas,  Nebraska,  Iowa,  northern  Missouri, 
Illinois,  and  Indiana. 

Though  never  known  to  have  been  seriously  injurious 
east  of  Ohio,  the  writer  found  ears  of  corn  in  a  field  near 
Ithaca,  N.  Y.,  which  had  been  planted  in  that  crop  for 
several  years,  attacked  by  large  numbers  of  the  beetles. 
On  September  15,  1897,  the  corn  w^as  fairly  alive  with  the 
beetles,  as  many  as  a  dozen  being  found  eating  the  silk  of 
a  single  ear,  generally  well  under  the  husk.     Mr.  Harring- 


128  INSh:CTS    INJURIOUS   TO    STAPLE    CROPS. 

ton  has  found  the  beetles  on  thistles  as  far  east  as  New 
Brunswick.  The  only  previous  records  of  it  in  New  York 
are  those  of  Prof.  Webster,  who  quotes  Mr.  Fred.  Blanchard 
of  Lowell,  Mass.,  as  having  specimens  from  New  York, 
and  Mr.  Ottomar  Reinecke  of  Buffalo,  who  wrote  that  he 
had  collected  it  there  on  willow  j^rior  to  1880.  Though 
these  statements  are  doubtless  correct,  there  certainly  is 
no  record  of  it  during  the  last  fifteen  years,  and  never  of 
its  having  been  injurious. 

Life-liistory. — The  life-history  of  the  pest,  though  not 
comjDletely  known,  is  3'et  comparatively  simple.  The  eggs 
are  laid  in  the  early  fall,  within  a  few  inches  of  the  base 
of  the  stalk,  from  one  to  five  inches  deep  in  the  soil.  The 
larvae  hatch  from  June  to  August,  and  at  first  eat  the 
small  roots  entire,  and  then  commence  burrowing  under 
the  outer  layers  of  the  larger  roots,  causing  the  stalks 
to  be  easily  blown  over  if  on  a  rich  loam,  or  small  ears 
and  a  general  dwarfing  of  the  plant,  if  on  poorer  land. 
The  adult  worm  is  nearly  white,  with  brown  head,  a  little 
less  than  half  an  inch  long  by  less  than  one-tenth  of  an 
inch  in  diameter.  Three  pairs  of  short  legs  are  found  on 
the  segments  immediately  back  of  the  head,  but  otherwise 
the  long,  cylindrical  body  appears  perfectly  smooth  to  the 
unaided  eye,  though  seen  to  have  numerous  hairs  and 
bristles  under  the  microscope.  Before  pupation  the  color 
becomes  slightly  darker  and  the  body  shortens,  becoming 
more  like  a  common  grub.  They  then  leave  the  roots, 
form  a  small  oval  cell  in  the  soil,  transform  to  pup^e,  and 
in  a  short  time  come  forth  as  adult  beetles 

The  beetles  are  of  a  greenish  or  greenish-yellow  color 
and  about  one-fourth  of  an  inch  long,  resembling  in  form 


INSECTS    INJURIOUS   TO    CORN.  129 

the  common  Striped  Cucumber-beetle.  The  adults  are 
found  in  the  fields  from  the  latter  part  of  July  until  the 
corn-silk  becomes  brown  and  dry,  and  often  later,  feeding 
upon  the  silk  and  pollen,  thus  doing  more  or  less  damage, 
though  slight  when  compared  with  that  of  the  larva3. 
Though  feeding  almost  entirely  upon  corn,  they  have 
occasionally  been  recorded  as  eating  various  weeds,  clover, 
beans,  cucumber-  and  squash-vines,  apples  of  which  the 
skin  had  been  broken,  cotton-flowers,  pumpkins,  and 
various  fungi. 

[Remedy. — See  below.) 

The  Southern  Corn  Root-worm  or  Twelve-spotted  Diabro- 
tica  (Diabrofiva  (hiodecempu)ictata  Oliv.). 

This  beetle  is  distinguished  from  the  above  by  being 
larger  and  having  three  transverse  rows  of  four  black 
spots  on  the  wing-covers.  Its  larva,  which  has  very 
similar  habits  and  is  very  injurious,  by  eating  the  corn- 
roots  in  the  South,  has  not  been  knovrn  to  do  so  in  the 
North,  but  is  everywhere  exceedingly  abundant.  The 
beetle  is  ]3robably  best  known  as  attacking  squash-,  melon-, 
and  cucumber-vines,  of  which  it  eats  voraciously  both 
leaves  and  fruit,  but  has  also  been  noticed  on  clover, 
cabbage,  cauliflower,  beans,  beets,  hops,  cotton,  chrysan- 
themums, and  various  fruit-trees. 

Remedy. — The  remedy  for  both  these  pests  is  so  simple 
and  effective  that  it  would  seem  that  no  one  ought  to 
suffer  from  their  injury.  As  far  as  known,  they  have 
never  been  injurious  to  corn  after  a  j^revious  crop  of 
wheat,  rye,  or  barley,  though  the  field  may  have  been 
infested  before  that,  and  a  crop  of  corn  is  then  safe  for  at 


130  INSECTS   INJURIOUS   TO    STAPLE    CROPS. 

least  two  years.  Thus  a  simple  rotation,  which  is  also  to 
bo  recommeuded  on  many  other  grounds,  is  entirely 
effectual.  * 

The  Corn-root  Web-worm  (Crambus  caliginosellus  Clem.). 

Injury. — When  young  corn-plants  are  seen  to  stop 
growing,  become  deformed,  and  to  die  off  in  such  numbers 
as  to  frequently  necessitate  replanting,  upon  examination 
of  the  roots  the  iujury  will  often  be  found  to  be  due  to 
the  work  of  a  small  caterpillar.  Two  or  three,  very  often 
five  or  six,  and  sometimes  as  many  as  eight  or  nine  will 
be  found  at  the  base  of  a  plant  about  an  inch  below  the 
surface  of  the  soil,  and  not  o\er  four  to  six  inches  from 
the  stalk,  usually  being  in  close  proximity  to  it.  Each 
larva  is  covered  with  a  fine,  loose  web,  to  which  cling 
particles  of  earth,  forming  a  sort  of  case,  and  on  account 
of  which  these  insects  are  known  as  Web-worms. 

Where  the  web-worms  are  present  in  any  number  they 
will  often  necessitate  the  second,  third,  and  sometimes  a 
fourth  planting,  making  the  corn  very  late  and  involving 
considerable  expense.  The  worms  bore  into  the  youug 
stalks  just  above  the  ground,  frequently  cutting  them  off 
entirely.  Later  on  the  larger  stalks  are  gouged  out  at  or 
slightly  above  the  surface  of  the  ground,  and  the  larvae 
burrow  into  the  folded  leaves,  which  when  they  unfold 
have  several  transverse  rows  of  three  to  five  holes.     On 


*See  : 

1882.  Forbes,  S.  A.  First  Ann.  Kept.  12th  Kept.  St.  Ent.  111.. 

p.  10. 

1890.  Forbes,  S.  A.  6tli  Ann.  Rept.,  p.  71. 
1892.  "  "      Tth     "  "       pp.  146,  154. 

1894.  Webster,  F.  M.  Bull.  No.  51  Ohio  Ag.  Exp.  Sta.,  p.  89. 
1896.  ''  "         "        "    68      ''       "        "         "      p   39. 


INSECTS    iXTURIOtJS   TO   CORK".  ISl 

account  of  this  habit  these  insects  are  sometimes  known 
as  '^bnd-worms/^  Strong  plants  will  often  make  a  new 
start  and  survive  the  injury,  but  remain  much  behind 
those  not  attacked,  while  most  of  the  weaker  plants  will 
decay  and  rot  off. 

Tlie  Motli. — As  one  walks  through  jiasture  or  grass  land, 
many  little  white  and  yellowish  moths  are  seen  flying 
about  on  all  sides,  but  quickly  disappear  as  they  alight  on 
the  grass.  If  a  single  individual  be  watched  more  closely, 
it  will  be  noticed  that  in  alighting  upon  a  blade  of  grass 
it  quickly  rolls  its  wings  very  tightly  around  its  body,  and 
hugs  up  close  to  the  grass  so  that  it  is  hardly  distinguish- 
able from  it.  Projecting  from  the  head  in  front  is  what 
appears  to  be  a  long  beak  or  snout,  on  account  of  which 
these  moths  are  often  known  as  '•snout-moths,"'  but 
which  really  consists  of  the  j)alpi  or  feelers.  The  '^  Grass- 
moths,"  as  they  are  sometimes  called,  belong  to  the  genus 
Cramius  and  include  several  common  species,  being 
marked  with  silver  stripes  and  bands,  as  well  as  golden 
lines  and  markings,  so  that  they  often  present  a  very 
handsome  appearance. 

Life-liistory. — These  are  the  parents  of  the  Web-worms 
which  do  so  much  injury  to  the  young  corn-roots,  the 
principal  depredators  ujjon  corn  belonging  to  the  species 
Oramlus  caliginoselhis.  They  lay  their  eggs  in  grass  land 
in  May  or  early  June,  dropping  them  on  the  surface  among 
the  rubbish  or  vegetation,  or  attaching  them  to  the  grass. 
They  are  oval  in  form  and  of  a  yellowish  color,  each  being 
marked  with  regularly  placed  ridges.  About  two  hundred 
eggs  are  laid  by  each  female.  In  from  six  to  ten  days  the 
eggs  hatch.  The  young  larva3  soon  form  their  loose  silken 
webs  or  tubes  at  or  a  little  below  the  surface  of  the  soil, 


132 


INSECTS    INJURIOUS   TO    STAPLI-:    CKOl'S. 


Fig.  73. — The  Corn-root  Web-worm  {Cramhvs  ailiginosellnb)  n 
larva;  b,  pupa;  c,  moth;  d,  segment  of  larva;  e,  parasite 
(After  Johnson. ) 


INSECTS    INJURIOUS   TO    CORN".  133 

burrowing  among  the  roots,  and  feeding  upon  the  stalk 
and  outer  leaves,  or  killing  the  phint  by  attacking  the 
crov>'n.  The  larvs  vary  considerably  in  color,  from  a 
yellowish  white,  through  pink,  to  a  reddish  or  brownish 
shade,  and  are  studded  with  small  tubercles,  each  bearing 
a  tuft  of  bristly  liairs.  The  larvae  become  full-grown  in 
from  five  to  seven  weeks  and  are  then  from  one-half  to 
three-fourths  of  an  inch  long.  During  the  latter  part  of 
July  they  form  cocoons,  sometimes  in  the  larval  tubes,  in 
which  they  pass  the  pupal  stage  and  from  which  the 
moths  emerge  some  twelve  to  fifteen  days  Liter.  Eggs  are 
laid  in  grass  lands  during  August  and  September  for 
another  brood,  the  larv»  hatching  in  September  and 
October  and  becoming  part-grown  before  winter.  They 
hibernate  in  their  webs  over  winter,  and  as  soon  as  the 
grass  commences  its  growth  in  the  spring  they  are  to  be 
found  feeding  upon  it,  becoming  full-grown  early  in  May. 
Preventive, — As  the  natural  food  of  these  insects  is  grass, 
it  is  not  surprising  that  corn  planted  on  sod  land  should 
be  worst  injured;  and  though  the  injury 'done  the  grass 
may  not  have  been  noticeable,  wdien  the  available  food  is 
so  greatly  diminished  by  substituting  for  grass  land  the 
comparatively  few  hills  of  corn  the  injury  becomes  much 
more  serious  and  apparent.  Though  the  planting  of  corn 
on  sod  land  is  a  most  common  practice,  injury  by  this  and 
many  other  insect  pests  of  corn — most  of  w^hose  native 
food  is  grass— might  be  avoided  by  planting  any  other  crop 
than  a  grain,  such  as  potatoes.  Otherwise  plowing  late  in 
the  fall  and  harrowing  so  as  to  expose  the  larva?  to  the 
weather,  or  plowing  so  deeply  that  they  will  be  buried  so 
that  they  cannot  regain  the  surface,  will  do  much  to  pre- 
vent injury  the  next  season.     Inasmuch  as  the  moth  will 


134  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

not  It^iy  her  eggs  upon  plowed  land,  if  the  land  he  plowed 
early  she  will  he  driven  to  other  fields;  hut  the  exact  time 
of  oviposition  varies  for  different  latitudes. 

Generous  fertilization  Avill  aid  the  plants  in  overcoming 
injury  very  considerahly.  Dr.  J.  B.  Smith  advises  "the 
application  of  all  the  necessary  potash  in  the  form  of 
kainit,  put  on  as  a  top-dressing  after  the  field  is  prepared 
for  planting,"  and  sa3"s:  "Fall  plowing  and  kainit  as  a 
top-dressing  in  spring  will,  I  feel  convinced,  destroy  by 
all  odds  the  greater  proportion  of  the  web  worms  that  in- 
fest the  sod,  and  would  also  destroy  or  lessen  many  other 
pests  which  trouble  corn  during  the  early  part  of  its  life.'' 

The  Corn  Root-louse  (Aphis  maidiiuaUcis  Forbes). 

Description. — Where  joatches  of  corn  become  dwarfed, 
the  leaves  becoming  yellow  and  red,  with  a  general  lack 
of  vigor,  one  may  well  be  suspicious  of  the  work  of  the 
Corn  Root-louse.  Though  such  an  appearance  may  be 
due  to  the  Root-blight  or  the  Grass  Root-louse  [Schizo- 
neura  panicola  Thos.),  the  cause  of  the  trouble  may 
usually  be  ascertained  by  an  examination  of  the  roots.  If 
due  to  root-lice,  they  will  be  readily  seen  gathered 
together  in  large  masses.  The  Root-louse  may  be  recog- 
nized by  being  of  a  blnish-green  color,  with  a  white,  waxy 
bloom,  of  an  oval  form,  with  two  short,  slender  tubes 
projecting  from  the  posterior  part  of  the  abdomen.  These 
have  open  ends  and  were  formerly  supposed  to  excrete  the 
sweet  liquid  "  honey-dew ''  upon  which  the  ants  feed,  and 
were  therefore  called  "  honey-tubes. '^  If  the  Grass-louse 
be  the  depredator,  however,  it  may  be  recognized  by  its 
white  color,  its  blackish  head  and  markings,  and  the 
absence  of  the  honey-tubes,  their  position  being  indicated 


INSECTS   INJURIOUS   TO    CORN.  135 

by  two  small  openings  surrounded  by  narrow  brownish 
rings.  The  latter  species  is  common  upon  the  roots  of 
grasses,  among  which  may  be  mentioned  bhie  grass, 
timothy,  and  Paniciim  glahruw,  and  though  it  rarely 
becomes  of  any  great  economic  importance,  it  is  well  to  be 
able  to  distinguish  it  from  the  more  injurious  Corn  Eoot- 
louse. 

Distrihution  and  Food. — The  Corn  Root-louse  has  been 
reported  from  Illinois,  where  it  occurs  in  all  parts  of  the 
State,  Maryland,  Xew  Jersey,  Delaware,  Indiana,  Ohio, 
Kentucky,  Minnesota,  and  Nebraska,  so  that  it  doubtless 
occurs  to  some  extent  through  the  whole  Corn  Belt. 
Besides  broom-corn  and  sorghum  no  other  cultivated  crop 
has  been  known  to  have  been  injured  l)y  this  pest,  though 
it  feeds  in  early  spring  and  even  as  late  as  June  upon 
the  roots  of  smaitweed,  purslane,  Fortiilaca  solcracco, 
ragweed,  foxtail,  and  crab-grasses.  The  economic  bearing 
of  its  feeding  upon  these  weeds  will  be  seen  in  discussing 
the  life-history. 

Care  of  the  Ants. — If  you  will  break  open  the  nests  of 
the  small  brown  ants  {Lasius  niger  and  var.  alienvs), 
which  are  common  in  corn-fields  which  have  been  infested 
w^ith  the  root-louse,  during  the  winter,  you  will  doubtless 
find  many  of  the  little  black  aphis-eggs,  which  have  been 
carefully  stored  by  the  ants  and  which  will  be  well  cared 
for  by  them  during  the  winter.  They  are  of  a  glossy 
black  color  and  an  oval  shape,  and  will  sometimes  be  found 
in  small  piles  in  the  chambers  of  the  ants^  nests.  On 
warm  days  the  ants  bring  them  up  to  the  warmer  surface- 
soil,  and  in  cold  weather  carry  them  far  down  into  the 
unfrozen  earth.  With  the  appearance  of  the  young  smart- 
weed  plants  [Polygo7ium  pcrsicaria)   in    early  spring,  the 


130       INSECTS  INJURIOUS  TO  STAPLE  CROPS. 

eggs  commence  to  hatch.  The  ants  at  once  lay  hare  the 
smartweed  roots  and  carry  their  young  wards  to  them, 
where  large  colonies  soon  become  established. 

Life-liidory — If  the  field  is  not  planted  in  corn,  the 
lice  will  later  feed  upon  the  roots  of  the  pigeon-grass  or 
purslane.  About  the  first  of  May  the  second  generation 
of  lice  commences  to  appear,  among  them  being  both 
winged  and  wingless  forms.  Like  most  j^lant-lice,  this 
brood,  and  all  daring  the  summer,  are  produced  by 
females  known  as  agamic  females,  without  any  intervention 
of  the  male  form,  the  young  lice  being  borne  directly  by 
the  female  without  any  Qgg  stage.  Such  females  are  called 
viviparous  in  contrast  to  those  laying  eggs,  which  are  called 
ovijDarous,  and  such  a  process  is  termed  "  budding '' or 
partlienogenesis.  The  little  brown  ants  again  transfer  the 
lice  to  the  roots  of  the  young  corn-plants  about  this  time, 
burroAving  around  the  roots  of  the  corn  so  as  to  lay  them 
bare,  and  even  carrying  hither  winged  lice.  All  through 
the  summer  they  attend  the  lice,  burrowing  around  the 
roots  of  the  corn,  and  carrying  them  from  plant  to  plant, 
in  return  for  which,  upon  stroking  the  lice  with  their 
antennae,  the  lice  give  off  the  sweet  "  honey- dew"  upon 
which  the  ants  feed;  indeed,  the  lice  have  been  well 
likened  to  herds  of  cattle,  cared  for  by  the  ant  herds- 
men. The  first  three  generations  each  require  about 
nineteen  days  to  become  full-grown.  During  the  summer 
the  lice  continue  breeding  with  extreme  rapidity,  the 
broods  becoming  mature  in  an  average  of  eleven  days,  , 
some  twelve  broods  occurring  before  the  middle  of  Sep- 
tember. During  the  summer  both  winged  and  wingless 
agamic  females  occur,  but  about  the  middle  of  September 
appears  a  brood  of  wingless  lice  including  both  true  sexes. 


INSECTS    INJUIITOUS   TO    C()R:N'.  137 

The  females  of  this  brood  hxy  the  eggs  until  the  middle  of 
November.  This  generatiou  is  usually  carried  by  the  ants 
to  their  nests,  of  which  they  are  given  the  freedom  and  in 
which  they  lay  their  eggs. 

Bemcdics  — Owing  to  the  fact  that  the  lice  do  not 
migrate  until  the  second  generation,  a  rotation  of  crops 
will  be  of  considerable  service  in  checking  their  injuries, 
as  corn  planted  on  uninfested  land  will  not  be  attacked 
until  it  has  been  able  to  secure  a  good  start,  and  if  well 
fertilized  may  be  able  to  successfully  withstand  the  injuries 
of  the  lice.  The  proper  fertilization  of  plants  infested 
with  root-insects  is  always  of  the  greatest  importance,  and 
usually  the  corn-plant  will  readily  throw  out  sufficient 
roots  to  enable  it  to  mature  a  crop,  if  the  soil  contains 
sufficient  nourishment  and  is  under  proper  cultivation. 

As  the  ants  not  only  care  for  the  lice  during  spring  and 
summer,  being  largely  responsible  for  their  spread,  but 
house  the  eggs  in  their  nests  over  winter,  any  means  by 
which  the  nests  may  be  destroyed  together  with  their 
inmates,  the  adult  ants,  their  larvae,  and  aphis-eggs,  will 
therefore  be  of  considerable  value  in  controlling  the  lice. 
Deep  fall  plowing  and  harrowing,  thoroughly  breaking  up 
the  ants'  nests  just  before  early  winter,  has  been  found  to 
accomplish  this  end  to  a  large  extent,  and  is  also  excellent 
practice  for  destroying  the  hibernating  larv^  of  cutworms 
and  the  Corn  Stalk-borer.  Furthermore,  inasmucli  as  the 
lice  feed  upon  various  weeds  in  early  spring,  if  these  be 
kept  cultivated  out,  the  probability  of  injury  to  the  corn 
will  be  greatly  lessened.  These  weeds  are  usually  thickest 
in  low  spots,  and  it  is  in  just  these  places  that  the  lice 
appear  first  and  do  their  worst  damage. 

Injury  done  by  the  Corn  Eoot-aphis  is  often  overlooked 


138 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


'■-'    "■'■':>liiSi 


Fig.  74.— The  Corn  ^o<di2i\s\\\'&  {Aphis  inaidiT(idiiis  Forbes);  Ovip- 
arous female,    n,  hiud  tibia,  showing  sensoria.     (After  Forbes.) 


Fig.  75. — The  Corn  Root  aphis;  male,    a,  antenna?.    (After  Forbes.) 


INSECTS    INJUKIOUS   TO    CORN. 


139 


4  5 

Fig.  76.  —The  Corn  Root-aphis  i Aphis  mndirddi'-is  Forbes).  1, 
wingless  viviparous  female;  a,  apex  of  abdomen;  2,  antennae 
of  same;  S,  pupa;  4,  winged  viviparous  femal?;  5,  antenna  of 
same.     (After  Forbes.) 


140 


INSKCTS    INJURIOUS    TO    STAPLH    CHOPS. 


or  attributed  to  other  'causes,  as  is  much  of  that  done 
l)y  root-lice  on  other  plants,  largely  on  account  of  igno- 
rance concerning  it.     From  the  above  desciiption  of  its  life 


be 


i  ^ 


CQ 


C 

o 


03 


M 


its  destructive  capacity  may  readily  be  seen,  and  also  the 
weak  points  in  its  career,  at  which  times  it  may  be  most 
successfully  combated.  With  such  a  knowledge  to  guide 
us,  the  application  of  the  cultural  methods  outlined  is  but 


INSECTS    INJURIOUS   TO    CORN. 


141 


a  simple  matter,  and  a  most  practical  and  efficient  method 
of  dealing  with  this  troublesome  pest. 


J 


k 


Fig.  78. — Grass  Root-louse;   wingless  viviparous  female.      (After 

Forbes.) 


INJURING    THE    STALK. 

Corn  Bill-bugs  {Sphenophorns  spp.). 

Description. — Throughout  the  South  and  often  in  the 
more  Northern  States,  Canada,  and  the  West  the  Corn 
Bill-bugs  sometimes  become  serious  enemies  of  young 
corn-plants.  They  belong  to  the  same  class  of  "  snout- 
beetles  "as  the  Plum  Curculio  and  Grain-weevil,  and  to 
the  same  family  as  the  latter — the  Cidandridce.  They  are 
called  "  Bill-bugs"  on  account  of  the  prolongation  of  the 
head,  termed  a  bill  or  snout,  by  means  of  which  they  are 
enabled  to  drill  holes  in  the  corn-stalks.  Several  species 
belonging  to  the  genus  Sphe?iophor2{s  are  commonly  in- 
jurious to  corn.  One  of  these,  S.  parvidus  GylL,  also 
attacks  small  grains  and  timothy,  and  is  therefore  known 
as  the  Grain  Sphenophorus.  xA.nother  species,  S.  ohscurus 
Boisd.,  does  considerable  injury  to  sugar-cane  in  Hawaii, 


143  INSECTS   IXJUKIOUS   TO    STAPLE    CROPS. 

The  adult  beetles  are  from  one-fourth  to  three-fourths  of 
an  inch  long,  of  the  form  shown  in  the  illustration,  and 
are  of  a  brown  or  black  color,  marked  with  darker  longi- 
tudinal ridges  on  the  wing-covers.  The  larvge  are  of  from 
one-fourth  to  five-eighths  of  an  inch  long,  thick  fleshy 
white  grubs,  with  brown  heads  and  cervical  shields  on  first 
segments,  and  footless. 

Life'liistories. — The  life-histories  of  the  different  sj)ecies 
are  but  partially  known  and  vary  somewhat, 

S.  parvnhis  hibernates  over  winter  as  a  beetle,  appear- 
ing in  March  and  April.  The  female  punctures  the  stalk 
of  wheat  or  timothy — oats  and  barley  are  also  sometimes 
attacked — a  little  above  the  roots,  and  deposits  her  egg  in 
the  cavity.  This  is  done  in  May  or  June  even  up  to  July 
1st.  The  larv^  are  to  be  found  during  July,  becoming 
full-grown  and  pupating  during  the  latter  part  of  that 
month.  The  larvae  will  eat  out  quite  a  cavity  in  the 
interior  of  the  stalk  or  bulb,  and  then  attack  the  roots, 
thus  often  killing  a  whole  clump  or  stool  of  small  grain 
or  timothy.  The  pupal  stage  is  passed  in  a  small  cell  in 
the  earth  and  lasts  from  two  to  three  wrecks,  adult  beetles 
emerging  from  the  middle  of  August  to  the  first  of 
October. 

The  life-history  of  S.  7'ohustns  ic  not  known,  though 
larvae  and  pupse  were  collected  in  South  Carolina  on 
August  20th,  and  adults  in  early  sj^ring  and  late  August. 
So  far  this  species  has  been  found  only  on  corn.  "  Wher- 
ever, ^^  says  Dr.  Howard,  "the  larva  had  reached  its  full 
size  the  pith  of  the  stalk  was  found  completely  eaten  out 
for  at  least  five  inches.  Below  ground  even  the  hard, 
external  portions  of  the  stalk  were  eaten  through,  and  in 
one    instance   everything    except   the    rootlets   had   dis- 


INSECTS    INJUIilOUS   TO    CORN  143 

appeared  and  the  stiilk  had  fallen  to  the  ground,  Jn  a 
great  majorit}^  of  instances  but  a  single  larv'a  was  found 
in  a  stalk,  but  a  few  cases  were  found  where  two  larvae  were 
at  work.  In  no  case  had  an  ear  filled  on  a  stalk  bored 
by  this  larva.  The  stalk  w^as  often  stunted  and  twisted, 
and  the  lower  leaves  were  invariably  brown  and  twisted." 

One  of  the  most  injurious  species  to  corn  is  *S'.  ochrens 
Lee.  The  life-history  is  much  the  same  as  that  of 
S.  parviilns,  though  eggs  have  been  found  as  late  as  July 
30th.  The  natural  food-plant  of  this  Sjoecies,  however,  is 
the  common  Club-rush  (Scirpns fluvia tills),  the  roots  of 
which  consist  of  bulbs  connected  by  smaller  slender  roots. 
The  eggs  are  deposited  in  or  about  the  roots  of  this  rush, 
never  having  been  found  on  corn.  The  bulbs  of  the  rush 
are  very  hard  and  oftentimes  as  large  as  hens'  eggs.  In 
them  the  larva?  burrow,  becoming  full-grown  aiul  trans- 
forming to  pupa?,  from  which  the  adult  beetles  ap2")ear  in 
August  and  September.  When  the  rush  becomes  too  hard 
for  the  beetles  they  often  attack  a  comm.on  reed  (PIivckj- 
mites  commnuis),  piercing  and  splitting  lengthwise  the 
unfolded  terminal  leaves,  and  eating  out  the  succulent 
portions  within.  The  injury  to  corn  is  done  by  the  beetles 
while  the  corn  is  still  young,  feeding  upon  it  in  the  same 
manner  as  do  the  other  species.  ''  Standing  with  the  head 
downward  and  the  feet  embracing  the  lower  part  of  the 
stalk.-'  says  Dr.  Forbes,  ''they  slowly  sink  the  beak  into 
the  plant,  using  the  jaws  to  make  the  necessary  perfora- 
tion. Bv  movincr  forward  and  backward  and  twistins:  to 
the  right  and  left,  the  beetle  Avill  often  hollow  out  a  cavity 
beneath  the  surface  much  larger  than  the  superficial  injury 
will  indicate.''  As  the  lower  part  of  the  stalk  becomes 
hardened,  they  leave  it  for  the  terminal  ]iortion,  and  when 


144 


INSECTS   INJURIOUS   TO    STAPLE    CHOPS. 


the  ears  commence  to  form  often  penetrate  the  husk  and 
gorga  out  the  soft  cob.  Sometimes  the  injury  thus  in- 
flicted is  but  slight,  merely  resulting  in  a  puncturing  of 
the  leaves  when  they  unfold,  these  being  in  a  series  across 
the  leaf  resulting  from  a  single  puncture  when  the  leaf  was 
folded,  and  looking  much  like  the  work  of  the  Corn  Eoot- 
web-worm.    But  when  several  beetles  attack  a  young  plant, 


Fig.  79.— *Si.  ochreus,  larva,  adult,  and  work  in  roots  of  Srirpus. 
(After  Webster,  "Insect  Life.") 

they  will  either  kill  it  outright  or  so  deform  the  foliage 
and  stalk  that  no  ear  will  mature. 

Several  other  species  have  also  been  known  to  do  more 
or  less  injury  to  corn,  viz.,  ;S'.  sropan'iis,  ])Iacidus,  cariosus, 
S('(il/)filis^  and  pertinax,  but  so  far  as  known  their  habits 
and  injuries  are  much  the  same  as  of  those  already  described. 


INSECTS  INJURIOUS  TO  CORN. 


145 


Means  of  Control. — The  control  of  these  pests  is  rather 
a  difficult  task.  S.  rohustiis,  which  breeds  in  corn  and 
winters  in  a  pnpal  cell  in  the  roots  and  stalk  as  an  adult 


Fig.  80. — Sections  of  Sugar  cane  showing-  work  of  Sphenojilwrvs 
ohacnrus.  a,  larva;  b,  papa;  c,  probable  points  of  ovipo!;ition. 
(After  Riley  and  Howard,  "Insect  Life.") 

beetle,  might  be  destroyed  by  plowing  np  and  burning  the 

stubble.    '8.  oclireus,  as  are  in  fact  all  of  the  species,  is 

most  injurious  on  recently  cleared  swamp-land,  and  usually 

disappears  as  fast  as  these  lands  are  drained  and  cultivated. 

Planting  llax,  potatoes,  or  some  crop  not  attacked  by  these 


146  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

insects  for  the  first  crop  will  largely  prevent  so  serious 
injury  to  a  subsequent  corn  crop.  The  burning  over  of 
grass-  and  swamp-land  infested  with  the  beetles  will-also 
be  of  considerable  value. 

The  Larger  Corn  Stalk-borer  {Diatrcea  saccharalis  Fab.).* 

I)) jury. — Every  season  corn  throughout  the  district  from 
Alabama  to  Maryland  is  more  or  less  seriously  injured  by 
large,  white,  brown-spotted  caterpillars,  which  bore  into 
the  stalks,  especially  the  young  stalks.  When  abundant 
a  loss  of  from  "Zh  to  50  j^gi'  cent  of  the  crop  results.  In 
Louisiana  and  the  West  Indies  this  pest  is  known  as  the 
Sugar-cane-borer.  It  is  found  as  far  west  as  Kansas,  and 
is  frequently  injurious  in  the  southern  parts  of  Maryland, 
Delaware,  and  New  Jersey. 

Life-liistorii. — In  the  fall  when  the  caterpillars  become 
full-grown  they  burrow  down  into  the  tap-root  and  there 
pass  the  winter  in  a  small  cavity  at  or  near  the  surface  of 
the  ground.  In  the  spring  they  transform  to  pup^  (Fig- 
81),  from  which  the  adults  soon  emerge.  The  eggs  are  laid 
upon  the  leaves  of  the  young  corn  near  the  axils,  and  the 
young  larvae  hatching  from  them  bore  into  the  stalk  and 
upward  through  the  pith.  As  the  borers  grow  they 
become  very  active  and  frequently  leave  and  re-enter  the 
stalk,  thus  making  several  holes.  When  the  caterpillars 
are  full-grown  they  bore  outwards  to  the  surface  of  the 
stalk,  making  a  hole  for  the  escape  of  the  adult  moth,  and 
then  transform  to  pupa?  in  the  burrows.  This  takes 
place  from  the  middle  of  July  (m,  and  the  adult  moths 
emerge  from   ten  days  to  two  weeks  later.     The  second 

*SeeL.  O.    Howard,  Circular  16,  n,  s,,  Div.  Entomology,  U.  S, 
Dept.  Agriculture, 


INSECTS   INJURIOUS   TO    CORN. 


ir. 


brood  of  larva?  feed  on  the  old  stalks,  tunneling  them 
between  the  second  joint  and  the  ground,  and  become 
full-grown  about  harvest-time,  when  they  go  into  winter 


— v.^ 


r^- 


FiG.  81. — Work  of  the  larger  Coru  Stalk-borer,  a,  general  appear- 
ance of  stalk  infested  by  the  early  o;eneration  of  borers;  h,  same 
cut  open  to  sll0^v  pupa  and  laryal  b^rro^y.  (After  Howard, 
U.  S.  Dept.  Agr.) 

quarters  as  alread}^  described.  "  The  damage  done  by  the 
second  generation  consists  largely  in  weakening  the  stalk 
so  that  it  is  readily  blown  to  the  ground,  whereas  damage 


148 


INSECTS    INJURIOUS   TO    STAPLH:    CROPS. 


Fig.  82. — a,  b,  c,  varieties  of  the  larva  of  the  larger  Corn  Stalk- 
borer;  d,  third  thoracic  segment;  e.  eighth  abdominal  segment; 
/,  abdominal  segment  from  side;  g,  same  from  above— enlarged. 
(After  Howard,  U.  S.  Dept.  Agr.) 


Fig.  83. — The  larger  Corn  Stalk-borer,  a,  female;  h,  wings  of 
male;  c,  pupa— all  somewhat  enlarged.  (After  Howard,  U.  S. 
Dept.  Agr.) 


INSECTS  INJURIOUS  TO  CORN.  149 

by  the  first  generation  results  in  serious  injury  to  the  crop, 
preventing  the  growth  of  the  ears/' 

Description. — When  full-grown  the  larv^  are  about 
three-fourths  of  an  inch  long,  with  six  true  legs  and  five 
pairs  of  pro-legs,  and  of  a  white  color  marked  with  brown 
as  shown  in  Fig.  8*?.  These  brown  markings  often  become 
indistinct  or  lost  in  larvae  hibernating  over  winter. 

Preve7itive. — Dr.  Howard  states  that  "in  1891  it  was 
found  that  of  corn  planted  during  the  first  and  second 
weeks  in  April,  25  per  cent  was  damaged;  of  that  planted 
the  third  and  fourth  weeks,  20  per  cent  was  damaged:  of 
that  planted  May  1st  to  15th,  15  per  cent  was  damaged: 
of  that  planted  May  15th  to  31st,  12  per  cent  was 
damaged;  of  that  j^lanted  from  June  1st  to  15th,  8  per 
cent  or  less  was  damaged.  In  fact,  corn  planted  after  the 
first  of  June  was  practically  uninfested. " 

Remedies. — Where  corn  has  been  seriously  infested  the 
old  stalks  or  butts  should  be  dragged  off  the  field  and 
burned  late  in  the  fall,  thus  destroying  the  over-wintering 
borers.  Where  corn  is  stripped  for  fodder,  the  stalks  left 
standing,  and  the  land  sown  in  small  grain,  the  most 
favorable  conditions  are  allowed  the  borers  for  safely  pass- 
ing the  winter  and  developing  into  moths  which  will  fly 
to  new  fields  in  the  spring.  Besides  corn,  sugar-cane,  and 
sorghum,  this  insect  also  attacks  a  rank-growing  grass 
which  grows  upon  swampy  land,  known  as  Ga ma-grass, 
or  Sesame-grass  (Tripsacum  dad ylo ides).  Where  such 
grass  adjoins  corn-fields,  therefore,  it  would  be  well  to 
burn  it  over  in  the  summer.  A  simple  rotation  of  crops 
will  also  do  much  to  lessen  the  numbers  of  this  pest.  It 
has  been  observed  by  Dr.  Howard  that  crops  on  fields 
planted  in  corn  the  previous  year  have  been  damaged  to 


150 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


the  extent  of  25  per  cent,  whereas  injury  to  corn  planted 
on  sod  land  was  only  10  per  cent,  though  reasonably  close 
to  land  which  had  been  in  corn. 

Cutworms  [NncJuidce). 
Almost  all  of  our  common  cutworms  attack  young  corn 
to  a  greater  or  less  extent,  sometimes  doing  considerable 


Fig.  84. — The   Well-marked    Cutworm-moth    [Noctua  clandestina 
Harris).     (After  Slingerland.) 


Fig.  85. — The  Dingy  Cutworm  {Feltia  subgothica  Haworth);  male  and 
female  moths.      (After  Slingerland.) 

damage.  The  same  species  affect  corn  as  tobacco,  and  the 
account  given  on  page  214  is  therefore  equally  applicable 
to  corn  cutworms.      For  large  areas  clover  or  grass  might 


INSECTS    INJURIOUS   TO   CORN.  151 

be  sprayed  with  an  arseuite,  then  cut,  and  bunches  of  it 
scattered  over  the  fields,  as  a  jDoisoned  bait,  instead  of  the 
bran  mash,  being  cheaper  and  more  easily  prepared  and 
applied  in  large  quantities. 

INJURING    THE    EAR. 

The  Corn  Ear-worm  (HeliothU  armiger  Hubn.). 

Practically  the  only  insect  seriously  injuring  the  ears  of 
field-corn,  and  the  worst  insect  pest  of  sugar-corn,  is  the 
Ear-worm.  In  the  extreme  South  the  growing  of  sugar- 
corn  successfully  is  almost  an  impossibility  on  account  of 
the  injury  done  by  these  worms,  while  further  north  it 
often  reduces  the  profits  by  far  too  large  an  amount. 

This  insect  also  does  considerable  damage  to  tomatoes 
by  boring  into  the  green  and  ripening  fruit,  being  known 
as  the  '^Tomato  Fruit-worm";  it  bores  into  the  "bud," 
or  unfolding  leaves,  of  tobacco,  being  known  to  planters 
as  the  '^Tobacco  Bud-worm"  (see  page  218);  and  is  also 
one  of  the  most  serious  j)ests  of  cotton  (see  page  201), 
being  called  the  ''Cotton  Boll-worm "  from  its  habit  of 
boring  into  the  b)ll.  It  also  has  many  other  food-plants 
and  is  a  cosmopolitan  insect,  being  found  in  many  parts 
of  the  world. 

Life-hi story. — In  this  latitude  the  moths  appear  during 
May  and  deposit  their  eggs  on  corn  or  other  food-plants, 
such  as  beans.  The  eggs  (Fig.  2)  are  small,  yellow,  cir- 
cular, flattened  disks,  prettily  corrugated  by  ridges  radiat- 
ing from  the  centre.  They  hatch  in  three  or  four  days. 
When  deposited  upon  corn  they  are  usuall}^  laid  in  the  silk 
or  tassels.  Upon  hatching,  the  young  worms,  after  feeding 
upon  the  silk  for  a  day  or  two,  find  their  way  down  into 


152 


INSECTS    INJURIOUS   TO   STAPLE    CHOPS. 


the  ear,  where  they  feed  upon  the  tip  of  the  young  ear. 
Very  often  one  worm  will  feed  upon  several  ears  before  it 
becomes  full-grown,  eating  its  way  out  through  the  husk, 


^-#» 


Fig.  86. — Corn  Ear-worms  at  Work.  The  central  cob  has  been 
attacked  by  a  nearly  full-grown  worm,  which  has  bored  through 
the  husk  near  the  middle.     (Original.) 

in  which  it  leaves  a  large  round  hole  (Fig.  87),  marking 
its  exit.  When  full-grown  the  worms  leave  the  ears  and 
go  into  the  ground,  where,  three  or  four  inches  below  the 
surface,  they  hollow  out  small  oval  cells  and  in  them 
transform  to  pupae.  From  ten  days  to  two  weeks  later  the 
next  brood  of  moths  emerges.  Thus  the  complete  life-cycle 
is  completed  in  about  thirty- eight  days,  the  exact  time 


INSECTS   INJURIOUS   TO   CORN. 


153 


varying  with  the  hititiide  and  season.      In  the  South  there 
are  five  broods  in  a   vear;    in   Delaware  there  are  three 


Fig.  87.— Corn  Ear-worm.  Husk  of  ear  of  sugar-corn  torn  open, 
showing  worms  at  work  on  tip,  and  hole  tlirongli  which  a  full- 
grown  worm  has  left.     (Original.) 

broods,  further  nortli  but  two,  and  in  some  sections  possi- 
bly  only   one   brood  may   occur.      The    second    Ijrood    of 


154  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

moths  appears  in  northern  Dekiware  about  the  middle  of 
July,  and  the  third  brood  during  the  first  two  weeks  of 
September.  In  northern  Delaware  only  the  hist  brood 
of  worms  in  Sejotember  is  injurious,  but  in  the  southern 
part  of  the  State  corn  is  injured  at  all  seasons,  but  worst 
in  July  and  September.  In  Delaware  but  little  corn  is 
canned  after  September  1st,  but  in  Maryland,  where  it  is 
canned  until  frost,  the  late  corn  is  always  more  or  less 
seriously  injured. 

Reinedies. — As  yet  no  thoroughly  satisfactory  method  of 
combating  this  pest  upon  corn  is  known.  As  the  jmp^e 
of  the  last  brood  in  the  fall  hibernate  in  the  ground  over 
winter,  many  of  them  may  be  killed  by  deep  plowing  late 
in  the  fall  or  early  in  the  spring,  but  as  the  moths  are 
strong  fliers  this  probably  would  not  appreciably  lessen  the 
number  of  worms  unless  generally  practiced  throughout  a 
community.  Evidently  the  time  of  planting  is  a  point 
Tvhich  should  be  carefully  considered.  As  the  moths 
prefer  to  lay  their  eggs  on  the  silk,  corn  which  is  in  silk 
when  they  emerge  from  the  ground  will  be  most  seriously 
injured,  while  corn  which  has  finished  silking  at  that  time 
will  be  but  little  injured.  Thus  a  few  days'  difference  in 
the  time  of  planting  may  mean  immunity  from  injury  or 
serious  loss.  In  this  locality  corn  planted  between  the 
15th  and  22d  or  23d  of  June — the  exact  dates  varying  with 
the  season — escapes  injury  by  the  fall  brood,  but  that 
planted  later  than  this  is  more  or  less  injured,  the  later 
plantings  being  injured  worst.  The  time  of  appearance 
of  the  different  broods  in  different  localities  is  therefore  a 
matter  of  considerable  importance,  and  a  careful  study 
may  show  that  by  proper  planting  injury  can  be  largely 
escaped. 


CHAPTER    VIII. 
"WEEVIL"   IN   GRAIN. 

The  enterprising  farmer  who  stores  his  grain,  awaiting 
a  higher  price,  is  often  sadly  disappointed,  when  he  sells  at 
the  top  of  the  market,  to  find  that  it  has  been  so  riddled 
by  '^weevil"  that  it  brings  no  more  than  had  it  been  sold 
previonsly. 

The  term  '^  weevil'^  is  rather  a  comprehensive  one, 
being  commonly  applied  to  almost  every  insect  infesting 
stored  food-products.  But  only  four  species  are  commonly 
injurious  in  the  farm -granary. 

Grain-weevils, 

Of  these  the  Granary-weevil  (Calandrn  granaria  Linn.) 
and  the  Rice-weevil  {C.  oryzce)  (Fig.  88)  are  the  most 
common  and  widely  distributed.  Both  of  these  insects 
have  infested  grain  from  the  most  ancient  times,  so  long, 
in  fact,  that  the  granary-weevil  has  lost  the  use  of  its  wings 
and  remains  entirely  indoors.  They  are  small,  brown 
beetles,  from  one-eighth  to  one-sixth  of  an  inch  in  length, 
with  long  snouts  which  are  of  great  service  in  boring  into 
the  kernels  of  grain.  By  means  of  them  the  females 
puncture  the  grain  and  then  insert  an  egg  iii  the  cavity. 
The  larva  hatching  from  this  is  without  legs,  somewhat 
shorter  than  the  adult,  white  in  color,  and  of  a  very  robust 

155 


156 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


Fig.  88. — Cnlaridra  uranaria.     a,  beetle;    h,  larva;    c,  pupa;   d,  G. 
oryz'i.   beetle— all  enlarged,      i After    Chittenden,    U.  S.  Dept. 

Agr.) 


Fig.  89. — Bilvanus  surinamensis.  ((,  adult  beetle;  b,  pupa;  c,  larva 
—  all  enlarged;  d,  antenna  of  larva— still  more  enlarged;  e, 
Cathnrtus  yemellatus.     (After  Chittenden,  U.  S.  Dept.  Agr.) 


"weevil"    IX    GRAIN".  157 

build,  being  almost  as  broad  as  long.  It  soon  devours  the 
soft  interior  of  the  kernel  and  then  changes  to  a  ])ui^a, 
from  which  the  adult  beetle  emerges  in  about  six  weeks 
from  the  time  the  egg  was  laid. 

Only  a  single  larva  inhabits  a  kernel  of  wheat,  but 
several  will  often  be  found  in  that  of  corn.  Not  only  do 
the  larva?  injure  the  grain,  but  the  beetles  feed  npon  it, 
and  then  hollow  out  a  shelter  for  themselves  within  the 
hull.  The  beetles  are  quite  long-lived  and  thus  do  con- 
siderable damage.  The  egg-laying  pewod  is  equally  long, 
and  as  there  are  three  or  four  broods  in  the  Xorth  and  six 
or  more  in  the  South,  it  has  been  estimated  that  the 
progeny  of  one  pair  would  amonnt  to  6000  insects  in  a 
single  season. 

Grain-beetles. 

Another  beetle  very  common  in  the  granary,  but  of 
quite  different  appearance,  is  the  Saw-toothed  Grain-beetle 
{Silvaniis  stirinamensis  Linn.)  (Fig.  89).  It  is  a  cosmo- 
politan pest  and  is  also  nearly  omnivorons.  The  beetle  is 
only  about  one-tenth  of  an  inch  long,  very  much  flattened, 
of  a  dark-brown  color,  and  may  be  easily  recognized  by  the 
six  saw-like  teeth  on  each  side  of  the  thorax.  The  larva 
is  of  a  dirty-white  color,  and  quite  dissimilar  from  that  of 
the  Granary-weevil.  Having  six  legs  to  cj^rry  it  about,  it 
is  not  satisfied  with  a  single  seed,  but  runs  about  here  and 
there,  nibbling  at  several.  When  full-grown'  the  larva 
glues  together  several  grains  or  fragments  into  a  little  case, 
and  inside  of  this  transforms  to  the  pupa  and  then  to  the 
beetle.  In  early  spring  this  life-cycle  requires  from  six  to 
ten  weeks,  but  in  summer  it  is  reduced  to  about  twenty- 
five  days.  Thus  there  are  from  three  to  six  or  more 
generations  during  a  season,  according  to  the  latitude. 


158 


INSECTS    INJURIOUS    TO    STAPLE    CROPS. 


The  Red  or  8qiiare-necked  Grain-beetle  {Catharius 
gemellatus  Duv.)  (Fig.  89)  is  about  the  same  size  as  the 
last  species,  but  is  of  a  reddish-brown  color,  and  the 
thorax  is  nearly  square,  nearly  as  broad  as  the  abdomen, 


Fig.  90.—Tenebroides  mauritanicus.  a,  adult  beetle  with  greatly  en- 
larged antenna  above;  h,  pupa;  c,  larva— all  enlarged.  (After 
Chittenden,  U.  S.  Dept.  Agr.) 

and  not  notched  on  the  sides.  It  breeds  in  corn  in  the 
field  and  in  the  granary,  first  destroying  the  germ,  so  that 
it  is  especially  injurious  to  seed-corn.  It  feeds  mostly  out 
of  doors,  though  sometimes  infesting  the  granary. 

The  Foreign  Grain-beetle  {Cathartus  advena  Waltl.)  is 


"weevil"    in    GRAIN".  159 

of  mucli  the  same  general  appearance,  but  smaller  and  of 
a  more  robust  appearance.  It  feeds  upon  a  great  variety 
of  stored  products  as  well  as  grain,  but  rarely  becomes 
troublesome. 

The  Cadelle  (Tenehroides  mauritcmicns  Linn.)  (Fig.  00) 
rJso  has  the  bad  habit  of  first  attacking  the  embryo  or 
germ  of  the  kernel,  and  going  from  one  kernel  to  another, 
thus  destroying  a  large  number  for  seed  purjooses.  It 
possesses,  however,  the  good  trait  of  destroying  other 
injurious  grain-insects.  The  beetle  is  oblong,  flat,  nearly 
black,  and  about  one-third  of  an  inch  long.  The  larva  is 
of  a  whitish  color,  with  brown  head,  the  thoracic  segments 
marked  with  brown,  and  the  abdomen  terminating  in  two 
dark  horny  processes.  It  is  a  long  fleshy  grub,  nearly 
three-fourths  of  an  inch  long  when  full-grown. 

Flour-  and  Meal-moths. 

The  larvae  of  several  small  moths  sometimes  infest  grain 
in  store,  but  rarely  do  it  serious  damage,  preferring  the 
softer  flour,  meal,  and  food-products. 

The  most  destructive  of  these  is  the  Mediterranean  Flour- 
moth  [Ephedia  Jctieliniella  Zell.)  (Fig.  91).  This  insect 
was  jDractically  unknown  until  1877,  but  during  recent 
years  it  has  occasioned  the  loss  of  many  thousands  of 
dollars  to  mill-owners.  It  occurs  throughout  Europe,  and 
is  found  in  Mexico  and  Chili.  It  was  first  recognized  in 
America  in  1889,  and  has  since  done  an  increasing  amount 
of  damage  in  California,  in  New  York  and  Pennsylvania, 
while  it  has  been  reported  as  occurring  in  North  Carolina, 
Alabama,  New  Mexico,  and  Colorado,  and  seems  to  be 
constantly  spreading.  "  The  caterpillars  form  cylindrical 
silken  tubes  in  which  they  feed,  and  it  is  in  great  part 


160 


INSECTS   INJUllIOUS    TO    STAPLE    CKOPS. 


Fig.  91. — Ej)hestia  kuehniella.  a,  moth;  h,  same  from  side,  resting; 
c,  larva;  d,  pupa — enlarged;  e,  abdominal  joint  of  larva— more 
enlarged;  /,  larva,  dorsal  view.  (After  Chittenden,  Y .  S.  Dept. 
Agr.) 


Fig.  92. — Plodia  inter punctella.  a,  moth;  h,  chrysalis;  c,  cater- 
pillar; /,  same,  dorsal  view— somewhat  enlarged;  d,  head,  and  e, 
first  abdominal  segment  of  caterpillar — more  enlarged.  (After 
Chittenden,  U.  S.l)ept.  Agr.) 


Fig.  93. — Pyralis farinalis.      a,  adult   moth;   h,  larva;  c,  pupa  in 
cocoon — twice  natural  size.      (After  Chittenden,   U.  S.    Dept. 

Agr.) 


"weevil''  in  grain.  161 

their  habit  of  web-spinning  that  renders  them  so  injurious 
where  they  obtain  a  foothold.  Upon  attaining  full  growth 
the  caterpillar  leaves  its  originrJ  silken  domicile  and  forms 
a  new  web,  which  becomes  a  cocoon  in  Avhich  to  undergo 
its  transformations  to  pupa  and  imago.  It  is  Avhile  search- 
ing for  a  suitable  place  for  transformation  that  the  insect 
is  most  troublesome.  The  infested  flour  becomes  felted 
together  and  lumpy,  the  machinery  becomes  clogged, 
necessitating  frequent  and  prolonged  stoppage,  and  result- 
ing in  a  short  time  in  the  loss  of  thousands  of  dollars  in 
large  establishments/'* 

The  life-cycle  of  this  insect  requires  ordinarily  about 
two  months,  but  may  be  completed  in  thirty-eight  days 
under  the  most  favorable  conditions.  The  adult  moth 
measures  a  little  less  than  an  ioch  across  the  expanded 
wings.  The  fore  wings  are  of  a  lead -gray  color,  with 
transverse  black  markings,  while  the  hind  wings  are  dirty 
whitish,  with  a  darker  border. 

The  Indian  Meal-moth  {Ploclia  interpiDictella  Hbn.) 
(Fig.  92)  larvae  resemble  those  of  the  grain-beetles  in 
having  a  special  liking  for  the  embryo  of  wheat-grains. 
They  spin  a  fine  silken  web  as  they  go  from  seed  to  seed, 
to  which  they  become  attached,  and  to  wliieh  is  added  a 
large  amount  of  excrement,  thus  spoiling  for  food  much 
more  grain  than  is  actually  injured. 

The  moth  has  a  wing-exjDanse  of  an  inch;  the  inner 
third  of  the  fore  wings  being  a  whitish  gray,  and  the  outer 
portion  reddish  brown,  with  a  coppery  lustre. 

The  Meal  Snout-moth  {Pyrcdis  farinalis  Umn.)  (Fig. 
93)  is  of  a  light-brown  color,  the  thorax,  base,  and  tips  of 

*"Sorae  Insects  lujurious  to  Stored  Grain,"  U.  S.  Dept.  Agr., 
Farmers'  Bulletin,  No.  45,  F.  H.  Chittenden. 


162  INSECTS    IXJUHIOUS   TO    STAPLE    CROPS. 

the  fore  wings  being  darker  brown.  The  wings  expand 
nearly  an  inch  and  are  otherwise  marked  with  Avhitish  lines 
as  shown  in  the  fignre.  It  is  very  similar  to  the  last-men- 
tioned species  in  its  habits,  constructing  long  tubes  with 
silk  and  particles  of  the  food  in  which  it  is  living.  The 
life-history  is  completed  in  about  eight  weeks,  and  four 
generations  may  occur  in  a  year.  The  moisture  of 
'' heated  ^^  grain  is  most  favorable  for  the  development  of 
this  pest,  and  it  need  not  be  feared  if  grain  is  kej)t  in  a 
clean,  dry  place. 

The  Angumois  Grain-moth. 

By  far  the  worst  granary  pest  throughout  the  South  is 
the  '*  Fly- weevil/'  or  Angumois  Grain-moth  [Sistotroga 
cerealella  Oliv.). 

History. — This  insect  is  an  importation  from  Europe 
and  receives  its  name  from  the  fact  that  in  1760  it  ''^was 
found  to  swarm  in  all  the  wheat-fields  and  granaries  of 
Angumois  and  of  the  neighboring  provinces  [of  France], 
the  afflicted  inhabitants  being  thereby  deprived  of  their 
principal  staple,  and  threatened  with  famine  and  pestilence 
from  want  of  wholesome  bread/'  The  insect  was  first 
noted  in  this  country  in  Xorth  Carolina  in  1730,  and  in 
1796  was  so  abundant  as  to  extinguish  a  lighted  candle 
when  a  granary  was  entered  at  night.  It  is  essentially  a 
southern  insect,  in  the  Gulf  States  being  very  injurious  to 
stored  corn.  Of  late  years  it  seems  to  be  moving  steadily 
northward,  being  reported  as  injurious  in  central  Pennsyl- 
vania and  Ohio.  Wheat,  corn,  oats,  rye,  barley,  sorghum- 
seed,  and  even  cow-peas  are  subject  to  injury. 

Life-history. — The  injury  is  not  done  by  the  moth,  as 
might  be  reasonably  supposed  from  the  fact  that  it  is  the 


^^ weevil''  in  grain.  163 

only  form  of  the  insect  usually  seen,  but  is  done  by  the 
small  caterpillars  which  feed  within  the  grain,  where  they 
may  be  found  during  the  winter.  The  caterpillar  eats  to 
the  surface  of  the  kernel,  but  not  through  it,  thus  leaving 
a  thin  lid  which  the  moth  can  easily  push  aside  when  it 
comes  out  in  the  spring,  and  then  covers  itself  with  a  fine 
silken  web.  At  this  time  the  caterpillar  is  usually  fully 
grown  and  is  about  one -fifth  of  an  inch  long,  of  a  white 
color,  with  the  head  yellowish  and  harder,  having  six 
jointed  legs  in  front,  a  series  of  four  pairs  of  fleshy  pro-legs 
along  the  middle,  and  another  pair  of  soft  legs  at  the  end 
of  the  body.  With  warm  spring  weather  the  caterpillar 
changes  to  a  pupa,  and  about  the  time  that  the  wheat 
comes  into  head  the  adult  moth  emerges.  As  soon  as  it 
emerges,  whether  outdoors  or  in  a  barn,  the  moth  at  once 
flies  to  the  grain-field,  where  the  eggs  are  deposited.  The 
exact  time  at  which  the  moths  emerge  varies,  but  occurs 
some  time  late  in  May  or  in  June.  The  moths  quite 
closely  resemble  the  clothes-moths  often  found  flying  about 
houses.  The  wings  are  quite  narrow,  and  when  expanded 
measure  about  one-half  an  inch  from  tip  to  tip,  being  of 
a  yellowish  or  buff  color,  marked  with  black.  The  eggs  i, 
are  laid  in  the  longitudinal  channel  on  the  side  of  the  i 

grain.     Each  female  lays  from  sixty  to  ninety  eggs  in  lotSr  ^ 
of  about  twenty  each,  one  lot  thus  being  about  enough  tq     /^ 
infest  the  kernels  of  a    head.      The   eggs  hatch  in  fror^,  lI 
four  to  seven  days.      The  young  caterpillars  are  at  fir^i.i 
very  active  and  soon  find  tender  places  and  bore  into  tl|e  ^ 
kernels,  leaving  almost  invisible  openings.     These  cat^ 
pillars  become  full-grown  in  about  three  weeks,  just  abqmtjQ 
the  time  the  grain  is  mature.     About    harvest-time  the    , 
second   brood    of    moths    appear.      Tiiese  lay  their   eggi^^l 


164 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


during  July,  depositing  tliem  on  tbo  ripe  heads  if  the 
harvest  be  a  little  delayed,  but  on  the  wheat  in  stacli  if 
harvest  is  prompt.  Usually  the  caterpillars  hatching  from 
these  eggs  become  full-grown  and  remain  in  the  grain  over 
winter,  but  in  warm  seasons,  esj^ecially  if  warm  in  Sep- 
tember, and  when  the  pest  is  unusually  abundant,  a  third 
brood  of  moths  appear  early  in  September.  These  lay 
another  batch  of  eggs  about  the  middle  of  September, 
depositing  them  upon  the  open  ends  of  grain  in  stack  or 


Fig.  M.—Sitotrogi  rerexlelln.  a,  eggs;  b,  larva  at  work;  c,  larva, 
side  view;  d,  pupa,  e,  moth:/,  same,  side  view.  (After  Chit- 
tenden, U.  S.  Dept.  Agr. ) 

mow,  which  thus  becomes  more  infested  than  that  in  the 
centre.  In  grain  stacked  outside,  the  caterpillars  of  this 
brood  become  fnll-grown  slowly  and  remain  in  the  grain 
over  winter,  but  if  in  the  mow  they  grow  faster  and  a 
fourth  brood  of  moths  appear  about  the  middle  of 
October,  the  moths  being  noticed  in  threshing.  The 
insects  continue  to  breed  within  doors  all  winter  as  long 
as  any  grain  remains,  though  they  become  sluggish  and 
cease  feeding  during  a  very  cold  spell.      The  number  of 


weevil"  in  ORAIN". 


165 


^' 


broods  is  entirely  dependent  npon 
the  latitude  and  weather  condi- 
tions; in  the  South,  where  they 
can  breed  continuously,  there 
being  as  many  as  eight  in  a  j^ear. 

Corn  is  frequently  attacked,  but 
not  until  it  is  ripe  and  husked, 
and  then  but  rarely  when  husked 
in  October  and  November  and 
stored  outdoors  in  shitted  cribs.  I" 
Seed-corn  stored  in  barns,  and  in 
the  South  in  almost  any  situation, 
is  often  badly  injured. 

Aside  from  loss  in  weight, 
grain  when  badly  infested  becomes 
unfit  for  milling  j^urposes,  and 
will  even  be  refused  by  cattle 
and  horses,  which  should  not  be 
urged  to  eat  it.  In  that  case 
hogs  and  fowls  Avill  readily  con- 
sume it. 

Remedies. — Dr.  J.  B.  Smith, 
in  an  interesting  bulletin  upon 
this  23est,  to  which  we  are  in- 
debted for  much  of  the  above, 
advises  as  follows:  -'Thresh  as 
soon  after  harvest  as  j^ossible,  and 
bulk  in  tight  bins  or  in  good 
sacks.  [By  ''tight  bins"  are 
meant  those  which  will  not  per- 
mit the  entrance  or  exit  of  the 
moths.  ]     If  the  grain  is  dry  when 


X  '^■ 


L!La* 


o»: 


©^   '^' 


-=^9 


^  ©^ 


^     '5 


L'^  et 


•  r 


-"Ui 


:2^: 


^  e^Q  *'  f 


V 


:^ 


'y 


'^ 


166  INSECTS  TXjrRiors  to  staple  crops. 

harvested,  it  may  be  threshed  at  once;  if  not,  as  soon  as  it 
is  in  good  condition.  If  the  sacked  grain  is  infested,  there 
will  not  be  wormy  kernelc  sufficient  to  heat  the  grain. 
The  moths  cannot  make  their  way  out  and  are  stifled. 
Nothing  can  come  in  from  outside  and  the  grain  remains 
safe.  The  threshing  itself  kills  many  of  the  insects  and 
jars  and  rubs  off  many  of  the  eggs.  If  binned,  the  bins 
should  be  tight  and  the  grain  should  be  tested  occasionally 
for  any  ajDpreciable  heating.  If  it  heats  perceptibly,  it 
indicates  considerable  infestation,  and  it  should  be  treated 
with  carbon  bisulfide  at  once,  used  at  the  rate  of  one  drachm 
per  cubic  foot,  or  one  pound  for  250  cubic  feet  bin-space." 
We  have  sometimes  found  two  or  three  pounds  for  100 
bushels  of  grain  necessary,  though  one  or  one  and  one-half 
pounds  for  100  bushels  has  been  often  recommended.  The 
bisulfide  should  be  placed  in  shallow  plates  or  pans  on  top  of 
the  grain,  preferably  not  over  a  pound  in  a  vessel,  and  the 
bin  should  then  be  covered  with  boards,  canvas,  or  olankets, 
and  allowed  to  remain  at  least  twenty-four  hours.  If  to 
be  used  for  seed,  it  should  not  be  left  for  over  thirty-six 
hours;  but  if  not,  leave  it  forty-eight  hours,  which  will  do 
it  no  injury  for  food.  After  treating  kee})  the  grain 
covered  to  prevent  reinfestation. 

Those  having  wheat  unthreshed,  whether  in  stack  or 
mow,  should  thresh  at  once,  and  treat  as  above  directed, 
except  that  if  much  of  it  is  noticed  to  be  wormy,  it  should 
be  treated  with  carbon  bisulfide  at  once,  as  soon  as 
threshed,  which  if  done  thoroughly  will  prevent  any 
further  infestation  this  year. 

Barns  and  storehouses  should  be  cleaned  up  and  freed 
from  all  loose  and  scattered  grain — chickens  will  help  in 
this — before  April  1st,  so  that  no  moths  will  be  allowed  to 


''weevil'^  tx  grain.  16T 

develop  and  infest  the  grain  in  tlie  field.  Places  where 
grain  has  been  in  shock  the  previous  season  should  be 
cleaned  up  by  the  aid  of  chickens.  Thus  if  there  is  any 
probability  of  grain  being  infested,  it  should  be  kept  tightly 
covered  in  the  sj)ring  so  as  not  to  permit  the  spread  of  the 
moths  to  the  fields. 

Prevention  of'^  Weevil." — Undoubtedly  grain-insects  can 
usually  be  more  successfully  combated  by  a  proj)er  housing 
of  the  grain.  No  matter  how  often  the  insects  in  a 
granary  are  destroyed,  if  the  remainder  of  the  barn  is  full 
of  dust,  sweepings,  and  refuse,  as  it  generally  is,  on  which 
the  beetles  can  feed  and  in  which  they  will  breed,  and  if 
the  granary  is  not  absolutely  tight,  as  soon  as  the  gas 
passes  off  the  insects  from  the  barn  will  again  enter  the 
granary,  and  soon  it  will  be  as  badly  infested  as  ever. 

Cleanliness. — "  Cleanliness  will  accomplish  much  toward 
the  prevention  of  injury  from  these  pests,  the  cause  of  a 
great  j)roportion  of  injuries  in  granaries,  mills,  elevators, 
and  other  structures  where  grain  and  feed  are  stored  being 
directly  traceable  to  a  disregard  of  neatness.  Dust,  dirt, 
rubbish,  and  refuse  material  containing  sweepings  of 
grain,  flour,  and  meal  are  too  frequently  permitted  to 
accumulate  and  serve  as  breeding-places  for  a  multitude 
of  injurious  insects. 

"The  floors  or  corners  and  walls  of  the  barn  or  store- 
house should  be  frequently  swept,  and  all  material  that 
has  no  commercial  value  burned.'^ 

The  Granary. — "  The  ideal  farmer's  granary,  from  the 
standpoint  of  insect  ravages,  should  be  built  at  some  dis- 
tance from  other  buildings,  and  the  rooms  constructed  of 
matched  flooring  so  as  to  be  as  near  vermin-proof  as  possi- 
ble.    The  doors  should  fit  tighth^,  closing  upon  a  rabbet, 


168  IXSECTS   IXJURIors   TO    STAPLE    CROPS. 

which  may  be  covored  with  felt  or  packing,  and  the 
windows  covered  with  frames  of  wire  gauze  to  j)reYent  the 
passage  of  insects.  The  floor,  wails,  and  ceilings  should 
be  smooth,  so  as  not  to  afford  any  lurking-places  for  the 
insects,  and  it  would  be  well  to  have  them  oiled,  painted, 
or  whitewashed  for  further  security.  A  coating  of  coal- 
tar  has  been  strongly  recommended  for  the  latter  pur- 
pose." 

"The  value  of  a  cool  place  as  a  repository  of  grain  has 
been  known  of  old,  and  a  building  in  which  any  artificial 
heat  is  employed  is  undesirable  for  grain  storage.  The 
'heating'  and  fermentation  of  grain,  as  is  well  known,  is 
productive  of 'weevil,' and  this  should  be  prevented  by 
avoiding  moisture  and  by  ventilation. 

''TJie  storage  of  grain  in  large  hulk  is  to  be  com- 
mended, as  the  surface  layers  only  are  exposed  to  infesta- 
tion. This  practice  is  particularly  valuable  against  the 
moths,  which  do  not  penetrate  far  beneath  the  surface. 
Frequent  agitation  of  the  grain  is  also  destructive  to  the 
moths,  as  they  are  unable  to  extricate  themselves  from  a 
large  mass,  and  perish  in  the  attempt.  The  true  granary- 
weevils  (small  dark-brown  beetles  with  long  curved  snouts, 
similar  to  the  pea-weevil),  however,  penetrate  more  deeply, 
and  although  bulking  is  of  valtie  against  them,  it  is  not 
advisable  to  stir  the  grain,  as  it  merely  distributes  them 
more  thoroughly  through  the  mass." 

Destruction  of  "  Weevil." 

Carhon  Bisvlficle.- — '•  The  simi)lest,  most  effective,  and 
most  inexpensive  remedy  for  all  insects  that  affect  stored 
grain  and  other  stored  products  is  the  bisulfide  of  carbon, 
a  colorless  liquid,  with  a  strong  disagreeable  odor,  which, 


'Mveeyil"  tx  PtRaix.  169 

however,  soon  passes  away."  At  ordinary  temperature  it 
vaporizes  rapidly,  forming  a  heavy  gas,  which  is  highly 
inflammable  and  a  powerful  poison. 

Ap])lication. — It  may  be  apj)lied  directly  to  the  infested 
grain  or  seed  without  injury  to  its  edible  or  germinative 
principles  by  spraying  with  an  ordinary  watering-can 
having  a  fine  rose  nozzle.  In  moderately  tight  bins  it  is 
more  effective,  however,  evaporating  more  slowly  and 
diffusing  more  evenly,  if  placed  in  shallow  dishes  or  pans, 
or  on  bits  of  cloth  or  cotton  waste  distributed  about  on 
the  surface  of  the  grain  or  infested  material.  The  liquid 
volatilizes  rapidty,  and,  being  heavier  than  air,  descends 
and  permeates  the  mass  of  grain,  killing  all  insects  and 
other  vermin  present. 

Amount  to  Use. — The  bisulfide  is  usually  evaporated  in 
vessels  containing  one-fourth  or  one-half  of  a  pound 
each,  and  is  applied  in  tight  bins  at  the  rate  of  one  to 
three  pounds  to  100  bushels  of  grain,  and  in  more  open 
bins  a  larger  quantity  is  used.  For  smaller  masses  of 
grain  or  other  material  an  ounce  is  evaporated  to  every 
100  pounds  of  the  infested  matter.  Bins  may  be  rendered 
nearly  air-tight  by  covering  with  cloths,  blankets,  or 
canvas. 

The  amount  of  bisulfide  to  be  used  depends  very  largely 
upon  the  shape  of  the  space  to  be  fumigated.  If  the  grain 
is  in  approximately  a  cubical  form,  the  above  amounts  will 
be  sufficient;  but  if  spread  out  with  but  little  depth,  two 
to  four  or  five  times  as  much  will  be  found  necessary. 

Time  to  Fumigate. — '^Infested  grain  is  generally  sub- 
jected to  the  bisulfide  treatment  for  twenty-four  hours,  but 
may  be  exposed  much  longer  without  harming  it  for  mill- 
ing purposes.     If   not  exposed  for  more  than  thirty-six 


170  INSECTS    IXJURIOrS   TO    STAPLE    CROPS. 

hours,  its  germinating  power  will  be  unimpaired.  In  open 
cribs  and  badly  infested  buildings  it  may  sometimes  be 
necessary  to  use  a  double  quantity  of  the  reagent  and 
repeat  treatment  at  intervals  of  about  six  weeks  during 
the  warmest  weather.^' 

When  possible  it  is  always  desirable  to  fan  the  grain 
immediately  after  fumination,  thus  removing  the  dead 
insects,  and  to  thoroughly  clean  the  granary  before  refill- 
ing it. 

"Mills  and  other  buildings,  when  fonnd  to  be  infested 
throughout,  may  be  thoroughly  fumigated  and  rid  of 
insects  by  a  liberal  use  of  the  same  chemical.  A  good  time 
for  this  work  is  during  daylight  on  a  Saturday  afternoon 
or  early  Sunday  morning,  closing  the  doors  and  windows 
as  tightly  as  possible  and  observing  the  precaution  of 
stationing  a  watchman  without  to  prevent  any  one  from 
entering.  It  is  best  to  begin  in  the  lower  story  and  work 
upward  to  escape  the  settling  gas.  The  building  should 
then  be  thoroughly  aired,  and  the  grain  stirred  early 
Monday  morning. 

"  For  the  fumigation  of  a  building  or  a  reasonably  close 
room  it  is  customary  to  evaporate  a  pound  of  bisulfide  for 
every  thousand  feet  of  cubic  space.  In  comparatively 
empty  rooms,  and  in  such  as  do  not  admit  of  being  tightly 
closed,  two  or  three  times  the  above  quantity  of  the  chem- 
ical is  sometimes  necessary. 

Cauiio)].  — "  Certain  precautions  should  always  be 
observed.  The  vapor  of  bisulfide  is  deadly  to  all  forms  of 
animal  life  if  inhaled  in  sufiicient  quantity,  but  there  is  no 
danger  in  inhaling  a  small  amount.  The  vapor  is  highly 
inflammable,  but  with  proper  care  that  no  fire  of  any  kind, 
as,  for  example,  a  lighted  cigar,  lantern,  or  light  of  any 


"weevil"  in  grain.  171 

kind,  be  brought  into  the  vicinity  until  the  fumes  have 
entirely  passed  away,  no  trouble  will  be  experienced." 

Cost. — Carbon  bisulfide  may  be  secured  through  any 
retail  or  wholesale  druggist  in  cans  of  various  sizes.  In 
considerable  quantities  it  may  usually  be  secured  from 
wholesale  houses  and  manufacturers  at  from  8  to  10  cents 
per  pound,  and  in  smaller  quantities  from  retailers  at  15 
or  20  cents. 


CHAPTER  IX. 
INSECTS   INJURIOUS   TO   CLOVER. 

Both  for  its  value  as  forage  and  as .  a  fertilizer,  clover 
holds  a  peculiar  place  among  our  crops.  In  the  Mississippi 
Valley  and  the  Eastern  States  we  have  nothing  to  occupy 
its  place,  and  without  it  the  farmer  would  be  at  a  loss  to 
make  a  suitable  rotation  of  crops. 

Some  eighty-two  insects  have  been  noted  as  doing  more 
or  less  injury  to  the  clover-plant,  but  hardly  a  dozen  of 
these  can  be  considered  as  serious  pests.  The  insects 
doing  the  most  injury  to  clover  have  so  far  not  become 
widely  spread  and  are  largely  confined  to  certain  States 
and  latitudes.  Bat  in  these  sections  they  have  often  been 
exceedingly  destructive,  and  they  seem  to  be  constantly 
spreading. 

INJURIN^G    THE    ROOT. 

The  Clover  Root-borer  [Hylastes  obsciirus  Marsh). 

This  is  the  only  serious  pest  preying  upon  the  roots,  but 
on  account  of  the  difficulty  with  which  it  is  fought  makes 
a  formidable  opposition  to  the  successful  growth  of  the 
crop.  Thus  in  the  southern  part  of  Michigan  hardly  one- 
half  a  crop  was  secured  in  1894  on  account  of  its  ravages. 
Though  the  l^eetles  have  been  well  known  in  Europe  for 
over  a  century,  their  habits  there  seem  to  be  but  little 

173 


INSECTS  IXJURIOrS  TO  CLOVER.  173 

understood.  In  this  country  the  pest  has  been  noticed 
since  1876,  when  it  was  first  found  in  three  counties  in 
western  Xew  York.  Since  then  it  has  been  noted  as  doing 
injury  on  Long  Island  and  in  several  parts  of  Canada. 
Some  ten  years  later  it  appeared  in  Michigan,  and  in  1894 
was  found  in  northwestern  Ohio.  Thus  it  has  not  become 
very  generally  distributed,  and  seems  to  be  confined  to  the 
Northern  States. 

Life-history. — If  one  tears  open  a  clover-root  in  an 
infested  field  during  the  winter,  he  will  usually  find  the 
beetles  hibernating  in  the  burrows.  They  will  not  be 
readily  distinguished,  as  they  are  scarcely  an  eighth  of  an 
inch  Ions:  and  are  of  a  reddish -brown  color  much  like  that 
of  the  Inirrow.  With  the  warmer  weather  of  spring  they 
commence  burrowing  and  feeding  in  the  roots,  and  during 
the  latter  part  of  May  the  females  deposit  their  eggs  along 
the  sides  of  the  tunnels.  The  eggs  are  shining  white,  and 
are  i^laced  in  the  sides  of  the  galleries  and  then  covered 
and  packed  with  refuse,  so  as  to  separate  them  from  the 
rest  of  the  burrow.  In  a  few  days  the  eggs  hatch,  and  the 
small  white  grubs  emerge  and  continue  the  attack  upon 
the  roots.  Here  they  grow  fat  during  the  summer  months 
and  ultimately  transform  to  pupa?,  which  again  change  to 
beetles  during  the  early  fall.  This  life-history  varies  con- 
siderably, and  the  grubs  are  often  found  much  earlier  and 
the  beetles  much  later  than  usual.  The  spread  of  the 
insect  occurs  very  largely  in  the  spring  when  the  beetles 
fly  from  field  to  field,  seeking  uninfested  plants  in  which 
to  perpetuate  their  kind.  Their  entrance  is  usually  made 
below  the  surface  of  the  ground,  though  sometimes  the 
burrow  is  started  from  the  crown  of  the  plant. 

It  has  been  observed  that  alsike  clover  is  not  so  badly 


ir-i 


IXSECTS    IXJURIOUS    TO    STAPLE    CROPS. 


injured  as  the  mammoth  and  common  red,  on  account  of 
its  fibrous  roots  and  the  tendency  of  its  tap-root  to  divide. 


a 


Fig.  96.— The  Clover  Root-borer  {Hylastes  ohf<curus  Marsh),  a, 
adult  beetle;  6.  larva;  c,  pupae;  d,  eg^;  e,  f,  showing  appear- 
ance of  infested  roots.     (After  Webster.) 

Remedies. — On  account  of  its  underground  life  tliis  pest 

is  not  readily  combated.     The  only  remedy  known  is  that 


lifSECTS    INJURIOUS    TO    CLOVER. 


175 


suggested  by  Prof.  F.  M.  Webster,  who  advises  ^^  plowing 
the  infested  fields  as  soon  as  the  hay  cro2:>  is  removed  and 


Fig.  96. — Continued. 


before  the  larvae  have  advanced  to  the  pupal  stage.  If  the 
roots  are  thrown  up  to  the  hot  sun  and  dry  winds  at  this 
time,  they  will  dry  out  and  thus  starve  the  young  larva?, 


176 


INSECTS    INJURIOUS    TO    STAPLE    CROPS. 


thereby  preventing  their  developing  and  migrating  to  other 
fields."  A  more  frequent  and  thorough  rotation  of  the 
crop  will  thus  be  of  value. 

Meadow-maggots.     (See  page  90.) 

INJURING    THE    STEM. 

The  Clover  Stem-borer  [Laugmna  mozardi  Fab.). 

Early  in  June  one  frequently  finds  the  beetles  of  the 
Clover  Stem-borer  here  and  there  in  the  clover-field. 
They  are  slender,  shining  beetles,  about  one- third  of  an 
inch  long,   with   red   head  and  thorax  and  bluish-black 


Fig.  97. — Clover  Stem-borer  {Languria  moz((rdi).  Shows  the  eggs 
natural  size  and  magnified,  the  beetle,  larva,  and  pupa  much 
enlarged,  and  above,  a  clover-stem  with  the  larva  at  work  in 
it.     (After  Comstock.) 

wing-covers.  The  beetles  themselves  seem  to  do  little  or 
no  harm.  Hibernating  over  winter,  they  lay  the  eggs  in 
the  pith  of  the  stems  early  in  June,  and  the  larvae  emerg- 
ing from  these  feed  upon  the  pith  of  the  stem,  often  ver}- 
seriously  weakening  or  killing  it.  The  larvae  become  full- 
grown  in  a  short  time,  transform  to  pupge,  and  the  beetles 
appear  by  August. 

Clover  is  only  one  of  a  dozen  food-plants  of  this  insect, 
which  is  widely  distributed.     It  rarely  does  any  consider- 


IN^SECTS    INJURIOUS   TO    CLOVEll. 


177 


able  injury  whore  clover  is  regularly  cut  in  early  summer 
and  fall,  and  need  not  be  feared  when  this  is  not  neglected. 

iNJURixG  tup:  leaves. 
The  Clover  Leaf-weevil  (Pliytonomus  pundcdus  Fab.). 
TJie  Clover  Leaf-weevil  is  also  a  native  of  Europe,  and 
made  its  first  appearance  in  this  country  in  the  same  sec- 


FiG.  98.— Clover  Leaf-weevil  {Phytonomus  punctatus  Fabr.).  a,  egg 
magnified  and  natural  size;  b  b  b  b,  larvce;  c,  recently  hatched 
larva;^  d,  head  of  larva;  e,  jaws  of  the  same;  /,  cocoon;  g,  same 
magnified  to  sliow  tlie  meshes;  7^  pupa;  i,  weevil,  natural  size; 
j,  the  same  magnified;  k,  top  view  of  the  beetle;  I,  tarsus  and 
claws  of  the  beetle;  m,  antenna  of  the  beetle.     (After  Riley.) 

tion  of  western  l^ew  York  as  the  root-borer,  in  1881.  Its 
injuries  during  that  and  the  following  year  seem  to  have 
been  the  worst  on  record.     Since  then  it  has  spread  east 


178  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

into  Connecticut,  south  to  Maryland  and  AVcst  Virginia 
and  as  far  west  as  Ohio  and  Micliigan.  Every  few  years 
the  weevils  and  larva?  destroy  much  of  the  foliage,  but 
rarely  are  as  bad  the  next  season.  The  weevil  is  about 
one-third  of  an  inch  long,  of  a  stout,  oval  form,  with  a 
long,  thick  snout.  It  is  of  a  brown  color,  with  several 
narrow  gray  lines  above  and  broad  gray  stripes  on  each 
side,  and  with  twenty  rows  of  small,  deep  punctures  on  the 
wing-covers. 

Life-liistorij. — In  early  fall  the  females  lay  their  eggs  in 
crevices  among  the  stems  near  the  base  of  tlie  plant.  The 
young  larvae  emerging  from  them  are  without  legs,  but 
manage  to  climb  quite  well  by  means  of  the  prominent 
tubercles  on  the  lower  surface  of  the  body.  They  are  light 
yellowish  green,  which  usually  becomes  deej)er  green  as 
they  grow  older.  The  larvse  become  partially  grown  before 
winter  sets  in,  when  they  go  into  a  dormant  stage,  hiding 
in  rubbish  or  under  the  soil  till  spring,  when  they  continue 
to  feed  upon  the  foliage  and  become  full-grown  in  May 
and  June.  The  larvae  feed  mostly  at  night  and  will  not 
be  noticed  during  the  day,  when  they  lie  protected  around 
the  base  of  the  phmt.  The  injury  done  to  the  foliage  is 
very  characteristic,  the  edges  of  the  leaves  being  eaten  in 
a  very  regular  manner  as  shown  in  the  illustration.  Before 
transforming  to  the  pupa  the  larva  constructs  a  very  deli- 
cate cocoon  of  a  greenish-yellow  color,  which  is  left  on  the 
surface  of  the  ground.  In  this  the  joupal  stage  is  passed, 
occupying  about  a  month,  the  beetles  being  most  common 
in  Julv  and  Ausfust.  The  damage  which  the  beetles  do  to 
the  second  crop  of  clover  is  fully  equal  that  done  by  the 
larva?  to  the  first,  and  is  more  apparent,  because  the  soil 
is  then  dry  and  the  plant  makes  a  slower  growth.      In 


INSECTS  INJURIOUS  TO  CLOVER.  1?9 

some  cases  the  beetles  have  been  known  to  hibernate  ovei 
winter,  when  the  larv^  would  occur  correspondingly 
earlier. 

Enemies. — The  reason  that  this  insect  has  not  become  a 
more  serious  pest  is,  that  as  often  as  it  becomes  excessively  ■ 
abundant  the  larvae  are  attacked  by  a  fungous  disease 
AV'hich  carries  them  off  by  the  millions.  When  affected  by 
this  they  climb  to  the  top  of  a  blade  of  grass,  curl  tightly 
around  the  tip,  and  soon  die,  first  becoming  covered  with 
a  white  mold  and  then  turning  to  a  jelly-like  mass.  The 
spores  of  the  fungus  become  scattered  to  healtlw  indi- 
viduals, which  soon  succumb.  Larva?  affected  in  this 
manner  may  be  easily  recognized,  and  when  diseased  larvae 
are  found  in  any  quantity  care  should  be  taken  not  to 
pasture  cattle  on  land  infested  with  them,  as  instances  are 
on  record  in  which  there  seems  little  doubt  that  cattle  have 
been  seriously  poisoned  by  eating  these  diseased  larvae. 

The  Clover-mite  (B?^yoMa  praieiisis). 

The  spraying  of  fruit-trees  for  various  in  sect -pests  in 
winter  has  been  found  to  be  one  of  the  best  means  of 
keeping  in  control  those  which  hibernate  or  whose  eggs  are 
on  the  trees  during  that  season.  One  of  these  is  the 
Clover-mite  {Bryohia  pratensis),  an  insect  Avidely  dis- 
tributed and  of  most  variable  habits. 

As  its  name  indicates,  this  insect  is  nearly  related  to  the 
common  red  spider  of  greenhouses,  belonging  to  the  family 
of  vegetable-feeding  mites  {Tetranychidce),  and  with  which 
it  is  often  confused.  It  is,  however,  about  twice  the  size 
of  the  red  spider,  being  fully  three-tenths  of  an  inch  long. 

Though  knovrn  as  the  Clover-mite,  on  account  of  its 
feeding  upon  that  jDlant,  yet  this  insect  was  first  known 


180  INSECTS    INJURIOUS    TO    STAPLE    CROPS, 

as,  and  is  still,  an  important  enemy  of  fruit-trees,  more 
especially  on  the  Pacific  coast  and  in  the  Western  States, 
but  also  in  other  sections  of  the  country.  The  most 
injury  seems  to  have  been  done  to  clover  in  the  Central 
States  as  far  south  as  Tennessee,  though  it  has  suffered 
somevi^hat  even  in  the  East. 

When  attacked  by  the  mite  the  leaves  of  the  clover  or 
fruit-trees  become  yellow  and  have  a  sickly  appearance,  as 


Fig.  99. — The  Clover-mite  {Bryobia  pratensis). 

if  affected  with  a  fungous  disease.  Especially  upon  the 
upper  sides  of  the  tender  leaves  of  clover  the  juices  are 
extracted  over  irregular  areas,  looking  more  or  less  like 
the  burrows  of  some  leaf-mining  larvae.  Owing  to  the 
small  size  of  the  mites  they  may  be  doing  considerable 
damage  to  the  foliage  and  yet  remain  unnoticed;  but  in 
the  egg  stage  the  pest  is  much  more  readily  detected  and 


INSECTS    i:N^JrilTOFS    TO    TLOVER.  181 

attacked.  In  the  more  northern  States  the  eggs  are  laid 
in  the  fall,  and  do  not  hatch  until  the  next  spring. 
Further  south,  however,  the  adult  mites  hibernate  over 
winter.  The  eggs  are  of  a  reddish  color,  laid  upon  the 
bark  of  trees,  especially  in  the  crotches,  and  in  the  West 
are  sometimes  so  thickly  placed  as  to  cover  considerable 
areas  two  or  three  layers  deep.  When  the  adult  mites 
leave  the  clover-fields  in  the  fall  to  fiiul  hibernating  quar- 
ters upon  fruit-trees  for  the  winter,  they  often  become 
quite  a  nuisance  by  invading  dwelling-houses  which  are  in 
their  path.  This  is  more  j)articularly  the  case  throughout 
the  Mississij^pi  Valley. 

I^einedies. — AVhen  swarming  into  a  house  their  progress 
may  be  arrested  by  spraying  the  lower  part  of  the  building, 
walls,  etc.,  with  23ure  kerosene  as  often  as  necessary. 
Inside  the  house  they  may  be  destroyed  by  the  use  of 
pyrethrum  powder  (Persian  insect-powder),  burning  brim- 
stone, or  S23raying  with  benzine,  care  being  taken  not  to 
bring  the  latter  substance  near  the  fire. 

The  only  practical  way  of  protecting  clover  from  the 
mite  is  by  destroying  the  eggs  and  hibernating  mites  upon 
the  fruit-trees  in  winter.  This  may  be  done  by  burning 
all  the  prunings  and  thoroughly  spraying  the  trees  with 
kerosene  emulsion  diluted  with  five  parts  of  water,  or  with 
a  mechanical  mixture  of  twenty  or  twenty-five  per  cent 
kerosene  and  water.  Such  a  si^raying  will  also  j^rotect  the 
fruit-trees  from  tlie  mite,  and  will  also  destroy  numerous 
other  insects,  such  as  the  j^ear-leaf  blister-mite,  which 
hibernates  upon  the  trees.  Such  small  insects,  so  minute 
as  to  usually  escape  notice,  are  often  responsible  for  a  poor 
growth,  and  should  be  i)roperly  checked  whenever  known 
to  be  injurious. 


182  INSECTS    IXJURIOUS    TO    STAPLE    CROPS. 

The  Destructive  Pea-louse  or  "Green  Dolphin"  (Xectaro- 
pli ora  p is i  Kalt . ) . 

Considerable  injury  was  done  to  both  red  and  scarlet 
clover  by  this  pest  in  the  spring  of  1900  in  Virginia,  Dela- 
ware, and  Maryland,  and  to  crimson  clover  in  Delaware  in 
1890.  In  Europe  the  "  Green  Dolphin  ''  has  been  known 
as  one  of  the  worst  pests  of  peas,  vetches,  and  clovers  for 
the  past  century.  The  aphids  leave  the  clover  about  May 
1st  in  the  above  States,  and  feed  upon  peas  during  the 
early  summer,  practically  destroying  the  crop  of  late  peas 
in  1899  and  1900.  During  October  and  November  they 
return  to  the  clover  and  pass  the  winter  upon  it. 

Many  predaceous  and  parasitic  insects  prey  u2:>on  this 
pest,  but  it  is  held  in  check,  especially  on  clover,  chiefly 
by  a  fungous  disease  (Empusa  aj^hidis).  This  disease  is 
prevented  by  dry  weather,  and  hence  the  pest  is  most 
injurious  in  dry  seasons. 

As  yet  no  remedy  for  the  pest  on  clover  or  means  for 
prevention  of  injury  are  known.* 

IXJUEIXG   THE    SEED. 

The  Clover-seed  Midge  {Cecidofuvia  legumhiicola  Lint.). 

This  is  also  a  native  of  western  New  York,  where  its 
first  injuries  were  recorded  in  1878,  but  since  then  it  has 
spread  to  almost  every  section  where  clover  is  grown,  and 
is  so  serious  a  pest  that  it  has  become  quite  an  art  to  raise 
a  crop  of  clover-seed.     The  parent  of  all  this  trouble  is  a 

*See  Bull.  XLIX,  Del.  Agr.  Exp.  Sta.,  "The  Pea-louse,"  E.  D. 
Sanderson  ;  and  Circular  43,  2d  Ser.,  Div.  Ent.,  U.  S.  Dept.  Agr., 
F.  H.  Chittenden. 


f 


wg. 


apt. 


Fig.  100. — The  Ve?L-\o\i^e  [Nectarophora  pisiKdiii.).  p,  pupa:  irg., 
winged  viviparous  female;  apt.,  wingless,  or  apterous,  vivip- 
arous female  and  newlv  born  young,  all  enlarged.  (Author's 
illustration  in  Bulletin  49,  Del. 'Coll.  Agr.  Eip.'Sta.) 

183 


184 


INSECTS   INJURIOUS   TO    STAPLE   CROPS. 


little  fly,  resembling  a  mosquito,  but  only  about  one-tenth 
as  large;  so  small,  in  fact,  that  it  is  rarely  noticed. 

Life-liistory. — The  eggs  are  laid  among  the  hairy  spines 
of  the  clover-head  or  beneath  the  bracts  around  the  head. 
They  are  of  a  reddish  color  and  scarcely  one-tenth  of  an 
inch  long.     When  the  maggots  emerge  from  them  they 


Fig.  101. 


-The  Clover  Seed-midge  (^Cecidomyia  leguminicola). 
fly;  h,  larva,  enlarged.     (After  Riley.) 


a, 


enter  the  undeveloped  florets,  which  they  often  prevent 
from  flowering.  In  this  case  some  of  the  flowers  in  the 
head  will  bloom,  but  the  field  as  a  whole  does  not  blossom 
as  usual.  Once  inside  the  floret  the  maggots  feed  on  the 
developing  seed.  They  are  of  a  dark-red  color,  of  a  plump, 
oval  form,  and  without  feet.  When  full-grown  they  leave 
the  florets  and  drop  to  the  ground,  into  which  they  enter 
and  form  a  little,  tough,  papery  cocoon,  just  under  the 
surface.  In  it  they  transform  to  the  pupa,  which  ulti- 
mately transforms  to  the  adult  fly. 

In  the  North  two  broods  of  the  midge  occur  each  year. 
The  maggots  of  the  flrst  and  principal  brood  become  full- 
grown  about  the  middle  of  June,  and  those  of  a  smaller 


INSECTS  INJURIOUS  TO  CLOVER.         185 

one  following  during  July  and  August.  White  and  alsike 
clover  have  not  been  molested  by  the  midge  to  any  extent, 
but  good  judgment  and  a  knoAvledge  of  the  habits  of  the 
insect  are  needed  to  harvest  a  crop  of  seed  from  the  red  or 
mammoth. 

Remedies. — Two  methods  are  in  practice  for  controlling 
this  pest.  The  first,  wxll  adapted  for  dairy  farms,  consists 
in  pasturing  the  clover  until  the  10th  or  loth  of  June,  and 
then  securing  a  late  crop  of  seed.  The  other  method  is 
to  cut  the  clover  for  hay  before  the  maggots  have  become 
full-grown  and  left  the  flowers,  and  then  harvest  a  late 
crop  of  seed.  Usually  for  red  clover  this  will  be  any  time 
during  the  latter  part  of  June,  and  some  two  wrecks  earlier 
for  the  mammoth,  as  the  latter  will  not  mature  a  crop  of 
seed  if  left  later.  But  the  exact  time  for  cutting  must 
depend  upon  the  latitude  and  season,  and  to  secure  success 
will  need  good  judgment  on  the  part  of  the  farmer.  K 
good  rule  for  red  clover  is  to  start  the  seed  crops  a  few 
days  before  timothy-heads  apjDcar. 

The    Clover-seed  Caterpillar   {Grajjholitlia   inter stinctana 

Clem.). 

The  larva  of  a  small  moth  known  as  the  Clover-seed 
Caterpillar  [GraijholitJta  inter sti7ict.ana  Clem.)  has  also 
done  serious  damage  to  the  seed  in  Iowa  and  is  common 
in  clover-fields  elsewhere.  The  greenish-white  larvse  are 
about  one-fourth  of  an  inch  long,  and  destroy  the  seed  by 
gnawing  through  the  florets  at  the  base.  The  larvae  pupate 
in  thin  cocoons  spun  in  the  clover-head,  and  from  them 
emerge  the  small  brown  moths,  which  lay  eggs  for  another 
brood  at  the  base  of  the  head.  Three  broods  occur  in 
Iowa;  in  June,  August,  and  September. 


186 


INSECTS   INJURIOUS   TO    STAPLE   CROPS. 


The  remedies  advised  for  the  midge  have  also  been  found 
satisfactory  for  this  pest. 


Fig.  103.  —  Clover  Seed-caterpillar  {GraplwlitJia  inter stinrtana^. 
a,  caterpillar;  6.  pupa;  e,  moth,  all  much  enlarged;  d,  moth 
natural  size.     (After  Osborn.) 


Fig.  103. — 0\oYex 'R2LY-yvorm.{PyraUscostaUs).  1  and  2  show  larvae 
suspended  by  threads;  3  represents  the  cocoon;  4,  the  pupa; 
5  and  6,  the  moths;  and  7,  larva  in  a  case  which  it  has  spun; 
all  natural  size.     (After  Riley.) 

INJURING   THE   HAY. 

The  Clover-hay  Worm  {Pyralis  costalis  Fab.). 
Even  after  all  the  above  pests  have  been   successfully 
combated,  another  insect,  known  as  the  Clover- hay  AVorm, 


IXSECTS  IXJURIOUS  TO  CLOVER.  187 

often  does  clover-hay  considerable  injur}^  in  the  mow  or 
stack.  The  caterpillars  will  usually  be  noticed  toward  the 
bottom  of  tlie  stack  if  that  part  be  searched  in  March 
or  April.  They  are  shown  natural  size  in  the  illustration, 
and  are  of  a  dark-brown  color,  each  segment  being  ringed 
with  a  band  of  darker  brown.  Hay  infested  by  them  has 
a  moldy  appearance  from  the  numerous  fine  silken  threads 
which  they  spin  through  it,  often  forming  webs,  and  is  so 
badly  chewed  and  covered  with  w^ebs  as  to  unfit  it  for  stock. 

Life-histonj. — The  laiva?  forjn  small  silken  cocoons  in 
the  cracks  and  crevices  of  the  barn,  from  which  the  moths 
emerge  early  in  June.  As  soon  as  the  females  find  some 
clover-hay  they  deposit  their  eggs  upon  it,  and  from  these 
the  worms  emerge  and  continue  the  destruction.  Usually 
no  serious  injury  is  done  except  where  clover-hay  is  kept 
over  the  second  year  or  longer.  When  it  is  fed  out  each 
spring,  before  the  next  crop  is  harvest^ed,  there  is  no  food 
for  the  young  caterpillars,  and  they  perish  before  the  new 
crop  comes  in. 

Remedies. — Thus  these  worms  may  be  easily  controlled 
by: 

1.  Xever  stacking  clover-hay  two  successive  seasons  in 
the  same  place. 

2.  Cleaning  the  mow  out  each  spring  so  that  no  old 
clover  w411  be  left  over  in  the  barn  until  the  new  comes. 

3.  Never  patting  new  clover-hay  on  top  of  old,  in  stack 
or  mow. 

Though  the  clover-plaut  has  numerous  and  serious 
enemies,  almost  all  of  them  may  be  controlled  by  simple 
means,  the  successful  use  of  which  depends  almost  entirely 
upon  a  thorough  understanding  of  the  habits  of  the  insect 
to  be  fought. 


CHAPTER  X. 

INSECTS   INJURIOUS   TO   COTTON. 

INJURING   THE   LEAVES. 

The  Cotton-worm  (Aletia  xylina  Say). 

Best  known  of  all  the  insect  enemies  of  the  cotton-plant 
is  the  Cotton-worm.  Though  the  subject  of  numerous 
extensive  investigations,  it  is  such  an  ever-present  pest  that 
practical  information  concerning  those  habits  which  must 
be  considered  in  successfully  combating  it  is  always  perti- 
nent. Let  us  commence,  then,  with  the  new  year,  and 
follow  the  species  through  the  season. 

L\fe-liidory. — During  the  winter  months  the  adult 
moths  hibernate  in  the  most  southern  portion  of  the 
cotton  belt,  principally  Florida  and  Texas,  in  the  rank 
wire-grass  occurring  in  the  more  thickly  timbered  regions. 
Only  a  few  of  these  survive,  but  they  are  very  capable 
ancestors,  and  in  early  March  lay  their  eggs  upon  ratoon 
cotton  where  it  is  only  an  inch  or  two  high.  The  eggs 
are  laid  singly,  usually  upon  the  under  surface  of  the 
leaves,  preferably  near  the  top  of  the  plant,  and  about  five 
hundred  are  laid  by  each  female  moth.  They  are  of  a 
flattened  convex  shape,  bluish  green  in  color,  and  with  a 
number  of  prominent  ridges  converging  to  the  apex.  In 
midsummer  the  eggs  hatch  in  three  or  four  days,  but  in 
the  spring  and  autumn  a  much  longer  period  is  required. 

188 


INSECTS   IXJURIOUS   TO    COTTON, 


189 


When  first  emerged  from  the  eggs  the  young  larvae  are 
of  a  pale  yellow  color,  but  soon  assume  a  greenish  tinge, 
and  are  marked  with  dark  spots,  which  become  more  dis- 
tinct after  the  first  molt.     Thev  then  become  marked  as 


Fig.  104.— Egg  of  Cotton  Worm- 
moth,  a,  top  view;  h,  side  view; 
greatly  enlarged.  (From 
Fourth  Kept.  U.  S.  Entom. 
Comm.) 


Fig.  105. — Cotton-caterpillar. 
a,  from  side;  h,  from  above 
— t  w  i  c  e  natural  size. 
(Fourth  Kept.  U.  S.  Entom. 
Comm.) 


when  adult,  being  more  or  less  striped  with  black  and  are 
distinctly  greenish.  During  the  early  season  the  green 
worms  are  the  more  common,  while  later  the  black  forms 
predominate.  The  appetites  of  these  caterpillars  are  only 
too  well  known  to  the  cotton-grower.  At  first  they  are 
content  with  eating  only  the  under  surfaces  of  the  leaves, 
occasionally  piercing  through.     Then  the  leaves  commence 


190 


Il^SECTS    INJURIOUS   TO    STAPLE    CROPS. 


to  look  ragged,  and  Avlien  these  become  scarce  the  tender 
twigs  and  bads  are  attacked.  When  excessively  abundant, 
like  the  Boll-worm,  the  larger  larvae  develop  cannibalistic 


Fig.  106. — Pimpln  conquisitor,  one  of  the  principal  Parasites  of  the 
Cotton-caterpillar,  a,  larvae,  enlarged:  h,  head  of  same  still 
more  enlarged;  c,  pupa;  d,  adult  female  enlarged;  e,  f,  end  of 
abdomen  of  adult  male,  still  more  enlarged.  (From  Fourth 
Kept.  U.  S.  Entom.  Comm.) 


Fig.  107.— Cotton  Worm-moth,     a,  with  wings  expanded  in  flight; 
h,  wings  closed,  at  rest— natural  size.     (After  Kiley.) 

tendencies  and  often  feed  upon  the  weaker  caterpillars. 
It  requires  from  one  to  three  weeks  for  the  larv^  to  become 
full-grown,  during  whi(jh  time  it  is  necessary  for  them  to 
shed  their  skins  some  five  times. 

The   caterpillar  now   crawls  into   a  folded  leaf,  which 


INSECTS    INJURIOUS    TO    COTTON.  191 

sometimes  is  eaten  away  so  that  the  pupa  hangs  exposed, 
and  there  sj)ins  around  it  a  silken  cocoon  and  transforms 
to  the  chrysalis  or  pupa.  In  this  stage  the  insect  remains 
dormant  for  from  one  week  to  a  month,  when  the  adult 
moth  emerges. 

The  imago  is  of  a  dull  olive-gray  color  with  a  wing- 
expanse  of  about  one  and  one-third  inches,  with  wings 
marked  as  shown  in  Fig.  107,  and  sometimes  with  a 
purplish  lustre.  Like  most  of  its  relatives  of  the  Xoctuidce^ 
or  ''night-flying  moths,''  it  flies  only  after  sunset,  but, 
unlike  them,  it  is  not  confined  to  the  nectar  of  flowers  for 
fool,  -''s  its  mouth  is  peculiarly  adapted  to  piercing  the 
skin  ol  rij)e  fruit  and  feeding  upon  its  tissues.  They  are 
strong  flyers,  the  moths  of  the  later  broods  frequently 
flying  as  far  north  as  Canada.  At  such  times  they  have 
been  known  to  do  serious  damage  to  peaches  in  Kansas, 
and  to  cantaloups  in  Wisconsin. 

The  first  two  broods  develop  rapidly,  and  in  the  extreme 
South  and  by  early  April  the  moths  emerge  and  are  carried 
northward  by  the  prevailing  winds.  Eggs  deposited  by 
them  develop  into  moths,  which,  in  turn,  fly  further 
northward,  and  thus  the  worms  are  gradually  found 
throughout  the  whole  cotton  belt,  though  with  a  consider- 
able confusion  between  the  various  broods.  At  least  seven 
broods  occur  in  the  far  South  and  three  at  the  northern 
limit  of  the  species  range.  With  this  number  of  genera- 
tions, it  is  readily  perceived,  considering  the  number  of 
eggs  laid  by  each  female,  how  such  great  numbers  of  the 
caterpillars  may  arise  by  the  latter  part  of  the  season, 
in  a  region  where  practically  none  remain  over  winter. 
The  progeny  of  a  single  moth  after  four  generations  would 
amount  to  over  300,000,000,000  individuals,  or,  if  placed 


192 


INSECTS    INJURIOUS    TO    STAPLE    CROPS. 


end  to  end,  at  the  end  of  the  third  brood  there  would  be 
enough  to  encircle  the  earth  at  the  equator  over  four  times. 
Eyiemies. — It  is  thus  very  fortunate  that  the  cotton- 
worms  have  many  deadly  enemies  which  commence  their 
warfare  upon  them  as  soon  as  the  first  aj^pearance  of 
spring,  and  continue  it  with  increasing  ardor  throughout 


Fig.  108. — Cotton-worm  ^gg-Y>dir2i^\te  {Trichogramma pretiosa).  a, 
adult  female,  greatly  enlarged;  b,  ovipositor;  c,  female  antenna; 
d,  male  antenna.  (From  Fourth  Kept.  U.  S.  Entomological 
Commission.) 


the  season.  A  little  insect  which  lives  inside  of  the  eggs 
and  is  known  to  science  as  Trichogramma  pretiosa  is  one  of 
the  most  efficient  of  these.  Mr.  Hubbard  once  observed 
in  Florida  that  from  75  to  90  jDer  cent  of  the  fourth  brood 
of  eggs  and  90  per  cent  of  the  fifth  were  destroyed  by  this 
parasite,  while  only  three  or  four  eggs  in  a  hundred 
escaped  in  the  sixth  brood. 

One  of  the  most  useful  parasites  of  the  caterpillar  was 
noticed  to  destroy  nearly  all  of  the  chrysalids  of  the  last 


II^SECTS    INJURIOUS    TO    COTTOX.  193 

brood  as  early  as  1847.  The  eggs  of  these  insects  are  laid 
upon  the  caterpillars,  and  the  maggots  hatching  from  them 
bore  into  the  worm  and  there  feed  upon  its  tissues.  It 
transforms  to  a  pupa  as  usual,  but  the  pupa  soon  dies,  and 
large  numbers  are  thus  killed.  Several  similar  parasites 
prey  upon  the  cotton-worm,  among  the  more  important  of 
which  may  be  mentioned  EiqAedrus  comstockii.  It  is  to 
be  regretted  that  we  have  no  way  of  encouraging  the  good 
work  of  these  valuable  parasites.  But  the  common  insec- 
tivorous birds  which  eat  large  numbers  of  the  worms, 
especially  when  they  are  yet  scarce  in  early  spring,  may 
and  should  be  protected  by  enacting  and  enforcing  the 
most  stringent  laws  against  their  wanton  destruction. 

Remedies. — Paris  green  is  an  effectual  and  now  widely 
used  remedy  for  this  pest.  When  the  United  States 
Entomological  Commission  made  their  extensive  investi- 
gations of  remedies  for  cotton-insects  in  the  early  80's, 
they  devised  some  very  tremendous  apjiliances  for  spraying 
this  upon  as  many  as  sixteen  rows  at  once.  But  such 
machines  have  not  proved  practical,  and  it  was  found 
useless  to  attempt  spraying  over  four  rows  at  once.  In 
fact  they  have  never  been  used  throughout  the  South  in 
other  than  in  an  experimental  capacity. 

Besides  the  general  use  of  the  dry  Paris  green  by  dust- 
ing it  upon  the  plants  as  described  below  there  have  been 
several  important  factors  which  have  so  worked  against 
the  cotton-worm  that  the  problem  of  keeping  it  in  check 
is  now  considered  practically  solved  by  many  authorities. 

The  most  important  of  these,  and  a  most  beneficial 
change  as  regarded  from  other  than  an  entomological 
standpoint,  is  the  diversification  and  rotation  of  crops, 
now  coming  to  be  more  and  more  widely  practiced  by  the 


194  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

progressive  agriculturist  of  the  South.  This  alone  has 
been  very  largel}^  responsible  for  checking  the  rapid  spread 
of  the  pest. 

Now  that  the  seed  has  become  such  a  valuable  joroduct 
of  the  cotton-plant,  smaller  varieties  with  many  seeds  and 
a  short  fibre  are  being  grown,  in  contrast  with  the  rank- 
growing,  long-fibre  sorts  formerly  preferred.  Thus  the 
rows  are  more  open,  the  work  of  the  worms  is  more  readily 
detected,  and  remedies  more  easy  of  application.  With 
these  advantages  in  their  favor,  the  more  southern  planters 
have  come  to  realize  the  importance  of  destroying  the 
early  broods,  and  by  doing  so  have  been  able  to  keep  them 
in  a  state  of  comparative  subjection. 

For  many  years  the  most  commonly  used  and.  exj)erience 
has  shown,  effective  remedy  is  the  use  of  the  dry  Paris 
green.  It  is  usually  dusted  upon  two  rows  of  j^lants,  from 
bags  fastened  at  the  ends  of  a  pole,  and  carried  by  a  man 
on  horseback,  who  can  thus  poison  from  15  to  20  acres  per 
day.  These  sacks  are  about  ten  inches  long  by  four  inches 
in  diameter,  open  the  whole  length  of  one  side  and  firmly 
sewed  at  the  ends.  Eight-ounce  Osnaburg  is  the  best 
cloth  for  the  purpose.  A  strip  of  oak  or  strong  wood 
about  one  and  one-half  by  two  inches,  and  five  feet  long, 
has  a  one-inch  hole  bored  through  it  at  five  inches  from 
each  end,  and  to  this  the  sack  is  tacked,  fastening  one  of 
the  edges  of  the  opening  to  each  of  the  narrow  sides  of 
the  pole.  The  sacks  are  filled  through  the  holes  in  the 
pole.  When  freshly  filled  a  slight  jarring  will  shake  out 
a  sufficient  amount  of  the  poison,  but  when  nearly  empty 
the  pole  should  be  frequently  and  sharply  struck  with  a 
short  stick,  or  S2:)aces  in  the  rows  will  be  missed.  The 
poison  has  been  found  most  effective  without  the  admix- 


INSECTS   IJ^JURlors   TO    COTTOK.  195 

ture  of  flour.      If  that  be  added,  lighter  cloth  should  be 
used  for  the  sacks. 

The  remedy  for  the  cotton -worm  is  sim23le  and  effective. 
It  simply  needs  careful  watching,  especially  upon  the  part 
of  the  southernmost  planters,  and  prompt  work  immedi- 
ately upon  its  appearance. 

Cutworms. 

For  very  few  plants  could  a  list  of  their  insect- pests  be 
made  without  mentioning  the  destructive  cutworms  (see 
page  214:  to  217),  and  cotton  is  no  exception.  Their  char- 
acteristic manner  of  cutting  off  the  young  plants  at  the 
surface  of  the  soil  is  so  familiar  to  every  planter  and 
trucker  that  no  discussion  of  their  life-history  and  habits 
is  here  necessary.  The  best  method  for  their  destruction 
is  by  distributing  through  the  field  bunches  of  clover  or 
grass  poisoned  with  Paris  green.  This  may  be  best  done 
by  spraying  a  patch  of  grass  or  clover  with  the  poison, 
then  cutting  it,  loading  it  on  a  wagon,  and  scattering 
bunches  over  the  field  with  a  fork.  For  best  results  such 
traps  should  be  spread  over  the  field  just  as  the  plants  are 
appearing  above  ground,  or  even  a  day  or  two  before ;  some 
care  is  necessary  in  so  doing  this  that  it  will  not  result  in 
injuring  the  young  leaves. 

Grasshoppers. 

A  much  similar  treatment  will  prove  effectual  for  grass- 
hoppers, which  frequently  do  considerable  damage  to  the 
foliage.  Twenty-five  pounds  of  bran,  one  pound  of  white 
arsenic,  mixed  dry  and  then  slightly  moistened  with  water 
and  cheap  molasses,  will  form  an  excellent  '^  mash  "for 
their  destruction,  by  placing  a  teaspoonful  at  the  base  of 


196 


INSECTS   INJURIOUS   TO    STAPLE    CROPS. 


each  plant.  Some  fourteen  different  kinds  of  grasshojipers 
have  been  known  to  injure  cotton,  but  of  these  the  Ameri- 
can Acridium  [ScUistocerca  ame7'icana)  and  the  Differential 
Locust  (see  page  69)  are  the  most  injurious. 


Fig.  109.  —  Granulated  Cnt-worm  {Agroiis  annexa).     n,  larva;  /, 
pupa;  7i,  adult— natural  size.     (After  Howard,  U.  S   Dept.  Agr.) 


Fig.  110. — The  American  Acridium  {ScMstocerca  americana  Scud.). 

(After  Riley.) 

Caterpillars. 

Many  species  of  Lepidopterous  larvae  occasionally  defoli- 
ate the  cotton-plant,  among  the  most  common  being  the 
Bag-worm  {Tliyridopterijx  e2)hemercBformis),  Fall  Army- 
worm  (Laphygma  friigiperda)  (see  page  84),  Garden  Web- 
worm  {Loxostege  similalis)  (see  page  260),  and  the  Leaf- 
roller  [Caccecia  rosaceana).    Any  of  these  may  be  destroyed 


INSECTS    IXJURIOrS    TO    COTTOX. 


197 


by  applying  Paris  green  in  a   spiay  or  dust,  as  for  tiie 
cotton-worms. 


Ftg.  111. — Garden. "Web- worm  {Loxostege  similalls).     a,    larva,  en 
larged;  b,  side  view  of  abdominal  segment  of  same;  c,  dorsal 
view  of  anal  segment;   d,  pupa;  /,   moth,  enlarged.      (xlfter 
Riley,  U.  S.  Dept.  Agr.) 

Plant-lice  (Aphidce). 
The  plant-louse  Avhich  is  most  frequently  found  injuring 
the  leaves  of  the  cotton-plant  is  the  same  as  the  melon- 
louse  {Aphis  gossypii).  As  upon  melons,  its  worst  injury 
is  done  while  the  plants  are  yet  young,  and  in  such  cases 
the  best  practice  is  to  destroy  the  infested  plants  and 
replant  in  their  place.  A  spray  of  kerosene  emulsion  and 
water  or  similar  irritant  will  kill  them,  and  sometimes  may 
be  used  to  advantage;  but  owing  to  the  rapid  and  hardy 
growth  of  the  plant,  and  the  fact  that  large  numbers  of 
them  are  consumed  by  their  insect  enemies,  plant-lice  are 
seldom  of  any  great  importance. 

IXJURIXG    THE    STALK. 

If  it  escapes  the  cutworms,  the  stalk  of  the  plant  will 
not  be  troubled  further  with  insects,  as  long  as  it  is  in  a 
healthy  condition.  Occasionally  plant-bugs  puncture  the 
new  growth,  but  such  damage  is  rarely  of  importance. 
One  of  the  boring-beetles,  known  as  Ataxia  crypta  (Fig. 
112),  has  been  supposed  to  injure  the  stalk  b}^  boring  in 


198 


INSECTS   INJURIOUS   TO    STAPLE   CROPS. 


it,  but  investigation  shows  that  its  eggs  are  laid  only  upon 
stalks  which  have  already  been  damaged  in  some  other 
manner. 


Fig,  112. — Cotton  Stalk  borer  (At  xi'  cryytci).  a,  larva  from  above; 
h,  larva  from  side;  c,  tunneled  cotton-stalk  showing  exit-hole; 
d,  adult  beetle — all  enlarged  except  c.  (After  Howard,  U.  S. 
Dept.  Agr.) 


INJURING    THE    BOLL. 

Sharpshooters. 

Bolls  are  frequently  damaged  by  leaf -hoppers,  known  to 
science  as  Homalodisca  coagulata,  which  injury  is  termed 
''Sharpshooter  work"  by  the  planters.  Usually  they  do 
not  make  their  appearance  till  after  the  first  of  June. 
Before  that  they  prefer  the  foliage  of  poplar  and  other 
shade  trees  near  the  cotton-field.  Where  the  injuries  are 
of  annual  occurrence  it  would  be  well  to  ascertain  the 
trees  upon  which  the  insects  are  feeding,  early  in  the 
season,  and  give  them   and  neighboring  undergrowth  a 


INSECTS    INJURIOUS    TO    COTTON. 


199 


thorough  spraying  with  strong  kerosene  emulsion  during 
May. 


^^ 


Fig.  113. — Hoimdodisca  codgulata.    ((,  aclull  female  seen  from  above; 
b,  same,  side  view.     (After  Howard,  U.  S.  Dept.  Agr.) 

"Cotton-stainer." 

The  Red  Bug  or  Cotton-stainer  [Dysclerciis  suturelhis) 
once  did  considerable  damage  to  the  bolls  in  Florida, 
Georgia,  and  neighboring  parts  of  Alabama  and  South 
Carolina,  but  of  late  years  has  devoted  most  of  its  atten- 
tion to  oranges.  Early  in  the  season  they  stunted  the 
bolls  and  made  them  abortive  by  sucking  the  vsap;  but  the 
most  serious  damage  was  done  later,  wdien  they  entered 
the  open  bolls,  "puncturing  the  seed  and  damaging  the 


200 


INSECTS   INJURIOUS   TO   STAPLE    CROPS. 


fibre  "  by  their  yellowish  excrement.  This  indelible  stain 
greatly  depreciated  the  market  value  of  the  fibre,  and 
was  a  vexing  loss.  Though  never  of  commerical  impor- 
tance, it  was  found  by  experiments  that  a  rich  orange  dye 
could  be  made  from  these  insects,  which  could  be  easily 


Fig.  114. — The  Red  Bug  or  Cotton-stainer  {Dysdereus  suturelluft) 
enlarged,     a,  nymph;  h,  adult.     (From  "Insect  Life.") 

fixed  upon  silks  and  woolens  by  an  alum  mordant.  In 
winter  these  insects  congregate  in  heaps  of  cotton-seeds, 
and  by  using  these  as  traps  the  insects  may  be  killed  with 
hot  water. 


Several  other  insects  attack  the  bolls,  but  never  very 
extensively.  Among  them  is  a  weevil  (Arcecerus  fascicu- 
latus)  often  mistaken  for  the  Mexican  Boll-weevil  and 
which  closelv  resembles  that  insect.     It  is  a  '^  cosmopolitan 


-  +j  ^    ^    '^    ^    f 

re  ij  ^  ^  •"   •-  ^ 


^'  §-?  si'i5 


■^ 

z: 

o 

o 

X 

C) 

.Z3 

:^ 

X 

_ 

_ 

b/: 

.rH 

5 

=fH 

^^ 

.9 

r 

r 

■r 

>> 

t:; 

r 

— 

:z 

•^ 

— 

^ 

> 

^ 

.u, 

^  — 

=c 

■  ^ 

F— I 

-r 

- 

> 

a 

:2 

>> 

^ 

ir 

^ 

— 

> 

-ri 

=0 

:J. 

— 

t: 

^ 

cT 

- 

-^ 

X 

u 

.B 

p 
bio 

■? 

s 

bO 

d 

> 

- 

^ 

-5 

^ 

5  •-..         C  ?  ii  -<"-  -"^ 

X  "te  "o  JJ  J  -5  ^  .2  ^ 

"   a   C         ^   ^   ':/:  -    ::. 


INSECTS    INJURIOUS    TO    COTTON.  201 

insect  living  in  the  pods  of  various  plants,  among  others 
in  those  of  the  coffee-plant  in  Brazil,  but  is  never  shown 
to  attack  healthy  plants/' 

Various  leaf -eating  caterpillars  often  gnaw  the  bolls,  but 
will  be  destroyed  by  poisoning  the  foliage  as  previously 
described. 

If  the  Paris  green  be  aj^plied  for  the  Cotton-worm,  and 
the  general  methods  advised  for  the  control  of  the  Boll- 
worm  and  Mexican  Boll-Aveevil  be  followed  out,  little  fear 
need  be  had  of  these  minor  insects,  though  a  knowledge 
of  the  best  remedies  for  them  is  always  desirable  in  case  of 
their  apppearing  in  unusual  numbers. 

The  Cotton  Boll-worm  (Heliothis  armiger  Hubn.). 

The  Cotton  Boll-worm  is  one  of  the  pests  most  widely 
dreaded  by  the  cotton-grower,  and  differs  from  the  Cotton- 
worm  in  that  it  is  found  in  other  parts  of  the  world  as  well 
as  America,  and  is  not  restricted  to  a  single  plant-food, 

Tlie  Moth. — The  adult  moth  is  about  the  same  size  as 
the  Cotton-worm  moth,  but  has  a  larger  body  and  a  greater 
variety  of  markings.  When  at  rest  the  fore  wings  of  the 
Cotton  Boll-worm  moth  are  slightly  parted,  while  in  the 
Cotton-worm  moth  they  are  closed.  The  Boll-worm  moth 
varies  much  in  color;  both  wings  are  bordered  with  dark 
bands,  the  wing-veins  are  black,  and  there  are  other  black 
spots  upon  the  fore  wings.  It  may  generally  be  seen  about 
dark,  and  hides  itself  during  the  day  in  cow-peas  and 
clover,  sipping  the  honey  from  the  blossoms  of  these  and 
other  honey-secreting  plants,  but  does  not,  like  the  Cotton- 
worm  moth,  feed  upon  fruit. 

Life-history. — It  deposits  its  yellowish-white  eggs  upon 
all  parts   of  the   cotton-plant,    but  prefers  the   silk  and 


202  INSECTS   INJURIOUS   TO    STAPLE   CROPS. 

tassels  of  corn.     If  hatched  on  the  cotton-plant,  the  worms 
attack  the  young  buds  or  bolls,  rapidly  destroying  them. 

Tlie  young  worms  resemble  the  cotton-worms,  and  walk 
like  the  familiar  measuring- worms,  but  are  darker  in  color. 
With  age  the  w^orms  exhibit  great  variety  in  appearance, 
from  light  green  to  dark  brown  or  rose,  and  may  be  either 
striped  or  spotted  or  perfectly  plain. 

The  life  of  the  insect  from  egg  to  adult  averages  about 
thirty -eight  days,  and  there  are  usually  five  generations 
each  year.  The  worms  of  the  first  brood,  as  a  rule,  appear 
about  the  first  of  May,  and  feed  almost  entirely  upon  the 
young  leaves  and  buds  of  the  corn;  the  second  brood, 
appearing  in  early  June,  eat  the  tassels  and  forming  ears 
of  corn;  the  third  brood,  in  July,  attack  the  hardening 
ears.  The  fourth  and  fifth  broods,  appearing  successively 
in  August  and  September,  appreciate  the  cotton  as  food, 
the  corn  having  become  too  hard.  About  the  middle  of 
October  the  worms  of  the  last  brood  descend  into  the  earth 
to  pupate,  which  state  lasts  from  one  to  four  weeks. 

Food. — The  worm  is  known  by  various  names  according 
to  the  plant  upon  which  it  feeds,  as,  for  instance,  the 
Cotton  Boll -worm,  the  Corn  Ear-worm  (see  page  151),  and 
the  Tomato  Fruit-worm.  It  is  also  found  upon  ^^eas, 
beans,  tobacco,  pumpkins,  squash,  and  many  flowering 
plants.  A  strange  but  mitigating  characteristic  of  this 
pest  is  its  tendency  to  feed  upon  its  kind,  especially  if 
large  numbers  are  crowded  together,  thus  materially 
reducing  its  own  numbers. 

Remedies. — Poisoning  the  young  worms  by  spraying 
with  arsenic  was  a  method  formerly  used,  but  as  it  proved 
only  partially  successful,  and  as  another  and  better  method 
has  been  discovered,  it  is  now  comparativel}''  little  used. 


INSECTS    IXJURIOCS   TO    COTTOX.  203 

The  more  effective  method  of  keeping  the  insect  in  con- 
trol is  the  result  of  practical  experience,  and  consists  in 
the  wise  use  of  what  are  known  as  trap  crops.  Let  five 
acres  be  planted  with  cotton  and  corn  alternately  with  every 
seventy-five  or  one  hundred  acres  of  cotton,  or  in  tlie  same 
relative  proportion  for  smaller  areas.  Of  the  five  acres, 
for  every  twenty-five  rows  of  cotton  let  five  rows  he  left 
vacant.  In  these  five  vacant  rows  plant,  as  early  as  possi- 
ble, one  row  of  an  early-maturing  sweet  corn,  planted 
sparsely,  as  only  a  small  number  of  plants  are  desired. 
During  the  silking  period  let  frequent  search  be  made  for 
the  yellowish-white  eggs,  and  when  fresh  eggs  Cvin  no 
longer  be  found  let  the  silk  ends  of  the  corn  covered  with 
eggs  and  young  worms  be  cut  off  and  destroyed  by  burn- 
ing or  feeding  to  stock;  or  better  still,  to  insure  perfect 
safety,  let  the  entire  plant  be  destroyed.  Let  three  other 
rows  be  planted  with  dent  corn  so  as  to  bring  the  silking 
period  about  the  first  of  July.  The  larger  number  of  eggs 
which  will  be  laid  on  these  three  rows  should  be  allowed 
to  mature  for  the  j^i'^servation  of  the  natural  enemies 
which  parasitize  the  eggs  and  young  worms.  The  crowded 
condition  of  the  worms  in  these  rows  will  result  in  a  large 
amount  of  cannibalism,  so  that  only  a  small  number  will 
reach  maturity,  recompense  for  which  will  be  found  in  the 
parasites.  But  to  entrap  these  individuals,  let  the  fifth 
row  be  planted  so  as  to  reach  the  silking  j^eriod  about 
August  first,  and  let  this  row  be  cut  and  destroyed  as  soon 
as  the  laying  of  eggs  upon  it  ceases.  It  has  been  found 
that  the  corn  produced  from  the  second  planting  Avill 
generally  j^ay  for  the  expense  of  cultivation  and  the  sacri- 
fice of  the  five  rows  of  corn.  In  many  cases,  if  the  other 
two  be  properly  cared  for^  the  third  planting  will  not  be 


204 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


1       r.             ^ 

'-0              z 

ACRE 

CORN 

AND 

OTTO 

^z 

S2aP 

c  o  •::  H 

aj  o 

<  t  '^  o 

«  ? 

.n               O 

o  r 

tn              ^ 

o  r 

"^^  b 

so 

S  o 

CC 

CC              >z; 

?5         z 

<o 

?; 

<85s 

o 

go 

O 

w  Z  c  o 
K  K  S  2 

O  O  5  H 

•z 

z 

z 

<:  o  ^  o 

AJ 

u-i             o 

tf 

0d 

o              O       i 

E-i 

t3 

g^ 

Ed    ,^ 

«^ 

^z 

P3p 

03  O 

«  2 

°i 

<  O 

g'^ 

o  ^ 
in 

go 

S  o 

C/2                5^ 

CC                5^ 

5  ACRE 
CORN 
AND 
COTTO 

^  ^  Q  O 

<  2  <b 

in              O 

^  z 

03  2 
O  H 

<  o 

g  o 

o  O 

o  r 

M    Z 

§  o 

^  o 
S  o 

'^            z 

y<          z 

=  8 

S  !^  C  O 

ggSr: 

O  Q  Z  c^ 

<J  8  -^  b 

in              O 

in              O 

Ed   ^' 

Ed  '^ 

gz 

Ed  5 

^  o 

c^  2 

S  P 

o  r^ 

s  ^ 

30 

o  o 

so 

73 

S  o 

?Zi  .         z 

O 

o 

CC                 >z 

<  S  -<  o 

o 

ACR^ 
CORN 
AND 
OTTO 

W 
Z 

^^ 

K 
Z 

z 

'i^ 

rri 

tf  P 

aj 

o; 

05  2 

o            u 

D 
H 

"  o 

p 

.n              O 

o  t 

so 

S  o 

CRES 
FTON 

5iH 

CC                ^ 

y^  K       ^ 

^  b 

g  -^.  ^  O 

-<  o 

oo5^ 
<i  o  -^^  b 

g  ^ 

«  Si  g  Eh 

<J  o  "^^  o 

9  o 

in 

o           o 

in              C^ 

Fig.  117. — Diagram  of  Cotton-field  showing  location  of  trap-corn, 
(After  Howard,  U.  S.  Dept.  Agr.) 


INSECTS    INJURIOUS    TO    COTTON.  205 

necessary.  The  entire  success  of  this  latter  method  of 
combating  the  Cotton  Boll-worm  depends  upon  careful 
observations  and  judicious  planting,  based  upon  a  correct 
knowledge  of  the  life  and  habits  of  the  insect. 

The    Mexican    Cotton   Boll-weevil   {Anthoiioinus  grandU 

Boh.). 

Several  of  the  worst  insect  pests  of  the  South  have 
immigrated  thither  from  Mexico.  About  1890  some  small 
beetles  came  across  the  Eio  Grande  near  Brownsville, 
Texas,  which  so  rapidly  multiplied  in  numbers  during  the 
following  seasons  that  in  certain  sections  the  crojD  was 
entirely  ruined.  As  early  as  1862  these  insects  caused  the 
growers  at  Monclova,  Mexico,  to  abandon  the  culture  of 
cotton,  and  when  they  again  planted  it,  about  1893,  the 
beetles  promptly  appeared  and  destroyed  the  entire  crop. 

At  the  close  of  1894,  an  agent  of  the  United  States 
Department  of  Agriculture  (Mr.  C.  H.  Townsend),  sent 
especially  to  investigate  their  ravages,  reported  that 
between  one-fifth  and  one-sixth  cf  the  cotton-growing 
section  of  Texas  was  infested,  there  being  a  loss  of  from 
25  to  90  per  cent  of  the  crop.  This  meant  15  per  cent  of 
the  whole  crop  of  the  State,  3  per  cent  of  that  of  the 
United  States,  and  in  round  numbers,  2  per  cent  of  the 
world's  product,  with  a  cash  value  of  over  $8,000,000. 
The  outlook  was  certainly  alarming. 

Fortunately  its  worst  ravages  have  been  confined  to  the 
southern  portion  of  Texas.  This  is  largely  because  the 
damage  done  and  the  spread  of  the  weevils  are  worst  where 
the  top  crop  is  most  valued,  which  is  the  condition  in 
southern  Texas.     Its  ultimate  spread  to  other  regions, 


206 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


"however,  seeruB  inevitable;  and  a  knowledge  of  its  habits 
and  methods  for  its  control  are  therefore  not  nntimely. 

The  parent  of  all  the  mischief  is  a  small,  grayish  beetle, 
hardly  one- fourth  of  an  inch  in  length,  wdiile  the  per- 
petrators of  the  worst  injury  are  the  little,  fleshy  grubs  or 
larvae,  which  live  and  feed  within  the  squares  and  bolls. 

Li fe-lii story. — Until  late  in  December,  or  as  long  as  any 


Fig.  116.— The  Cotton  Boll-weevil  (AutJionomns  grandis  Boh.),     a, 
adult  beetle;  b,  pupa;  c,  larva — enlarged.     (From  "Insect  Life.") 

part  of  the  plants  are  green,  the  beetles  may  be  found 
upon  them.  During  the  winter  they  hide  in  the  rubbish 
on  the  field  or  among  the  weeds  surrounding  it,  and  there 
hibernate  until  the  sunshine  of  early  spring  brings  them 
forth  for  another  season  of  dej^redation.  As  soon  as  the 
buds  have  formed  on  the  volunteer  plants  the  beetles  are 
upon  them  and  lay  their  eggs  in  the  early  squares.  Almost 
invariably,  the  work  of  a  larva  hatching  from  one  of  these 
eggs  causes  the  '''square^'  infested  to  drop  to  the  ground^ 
where  the  larva  becomes  full-grown,  transforms  to  a  pupa, 
and  comes  forth  as  a  beetle  in  about  four  weeks  in  all. 


INSECTS    INJURIOUS   TO    COTTON. 


207 


Fig.  118. — The  Cotton  Boll-weevil,  a,  newly  hatched  larva,  in 
square;  b,  nearly  full-grown  larva  in  situ;  c,  pupa  in  young 
boll  picked  from  ground.     (After  Howard,  U.  S.  Dept.  Agr.) 


Fig.  119.— Mature  Boll  cut  open,  at  left  showing  full-grown  larva; 
one  at  right  showing  feeding-punctures  and  oviposition  marks. 
(After  Howard,  U.  S.  Dept.  Agr. 3 


208 


IKSECTS    IXJURIOUS   TO    STAPLE    CROPS. 


Thus  one  or  two   generations  develop  on  the   vohinteer 

cotton.     By  the  time  the  planted  cotton  is  high  enough 

to  form  squares  the  weevils  have  become  quite  numerous, 

and,  as  a  result,  a  large  portion  of  the  squares  soon  drop. 

The  first  indication  of  tlie  preseuce 

of  the  pest  is  by  the  absence  of  the 

blooms.     The  squares  also   drop  in 

much  more  than  ordinary  numbers 

and   though  this  might   be  due   to 

other   causes,   if  they   are  cut  open 

the  presence  of  the  weevil  will  soon 

become    apparent.       Infested    bolls 

are  characteristically  discolored  and 

-p        ^^Q  J   .     -p  J,   punctured.     '' Late  in  the  season  the 

Boll,    showing    how  weevils    themselves   will    be    found 
beetles   hide  between    ^     ^  ,i       •        i  t  - 1      i    n 

boll    and    involucre,    between  the  involucre  ana  the  boll, 

(After  Howard,  U.  S.    ^^     j^^   ^i^gj^.   absence,    the    feeding 
Dept.  Agr.)  '  ° 

marks  and  the  yellow,  granular  ex- 
crement wdiich  collects  at  the  base  of  the  boll  are  excellent 
indications." 

The  bolls  are  attacked  in  the  same  manner  as  the 
squares,  but  do  not  drop.  The  weevils  also  do  consider- 
able injury  by  eating  into  the  bolls,  making  ugly  punctures 
with  their  stout  little  snouts.  Although  a  single  larva  will 
ruin  a  boll,  as  many  as  a  dozen  are  often  found  in  one. 
Thus  the  destruction  goes  on,  and  inasmuch  as  it  takes 
each  female  several  days  to  complete  her  egg-laying,  by 
July  the  different  generations  or  broods  have  become  so 
intermingled  that  it  is  impossible  to  make  a  distinction. 
Not  until  the  frosts  of  late  fall  do  the  weevils  cease  to 
breed  and  feed.  Then  they  go  into  winter  quarters,  and 
almost  all  of  the  larvae  are  killed  by  the  frosts. 


IKSECTS   IXJURIOUS   TO    COTTON.  209 

Remedies. — The  following  suggestions  as  to  the  best 
methods  for  the  control  of  this  pest  have  been  largely 
gleaned  from  a  forthcoming  report  of  Mr.  W.  D.  Hunter,* 
a  special  agent  of  the  Division  of  Entomology,  U •  S.  Dept. 
Agriculture,  who  has  made  an  extended  investigation  of  the 
matter  daring  the  season  of  1001  (Mar. — Dec.)  and  which 
comprises  the  previously  expressed  opinions  of  Dr.  Howard f 
and  his  assistants,  Messrs.  Maria tt  and  Schwarz,  as  to  the 
importance  of  better  cultural  methods  for  its  control. 

Inasmuch  as  the  pest  is  notably  w^orst  where  the  top 
crop  is  gathered  late  into  the  fall,  the  most  obvious,  and 
as  the  experience  and  investigations  of  the  past  five  years 
have  shown,  the  best  and  most  practical  means  for  its 
control  is  in  the  entire  abandonment  of  the  top  crop  and 
the  destruction  of  the  plants  by  October,  or  earlier.  The 
value  of  the  late  fall  top  crop  seems  to  be  very  much  over- 
estimated, as  very  often  it  hardly  pays  for  the  picking  and 
in  the  last  twenty  years  onh^  four  or  five  top  crops  of  any 
value  have  been  secured.  As  the  beetles  hibernate  over 
winter  in  the  bolls  and  among  the  old  plants,  the  immediate 
destruction  of  the  plants  in  the  fall  will  destroy  most  of 
the  weevils.  The  plants  may  be  cut  with  a  stalk-chopper 
or  thrown  out  with  a  plow,  and  should  then  be  burned. 
After  this  the  plowing  of  infested  land  to  the  depth  of 
6  or  8  inches  is  advisable.  Tn  this  way  all  the  larvae  and 
pupfe  in  the  cotton  at  the  time  are  destroyed,  as  well  as 
many  of  the  weevils;  the  adult  beetles  are  buried  by  the 
deep  plowing  and  will  never  again  reach  the  surface;  the 
removal  of  the  stalks  and  rubbish  prevents  their  hiberna- 

*  To  appear  in  Yearbook,  U.  8.  Dept.  Agr.,  1901. 
t  "The  Mexican  Cotton  Boll-weevil,"  Circular  14,  3d   Ser.,   Div. 
Eut.,  U.  S.  Dept.  Agr.,  L.  O.  Howard. 


210  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

tion  in  the  field;  tlie  growth  of  volunteer  cotton  has  been 
largely  prevented;  and  the  field  is  left  clean  of  old  stalks, 
facilitating  thorough  cultivation  the  following  year. 
'*  Fields  treated  in  this  w^ay  have  given  a  practical  demon- 
stration of  the  usefulness  of  this  method."  (Howard,  I.e.) 
Where  the  fields  are  free  from  grass,  cattle  may  be  turned 
in  to  graze  on  the  green  tips  of  the  cotton  and  will  thus 
consume  and  destroy  many  of  the  beetles.  Inasmuch  as 
a  comparatively  small  number  of  the  beetles  which  go  into 
hibernation  pass  through  the  winter  alive,  it  is  of  the 
utmost  importance  that  their  numbers  be  reduced  as  much 
as  possible  in  the  fall. 

Those  beetles  which  do  winter  successfully  appear  in  the 
spring  rather  late  and  as  a  consequence  early  cotton  is  but 
little  injured.  The  importance  of  cultivating  early  varie- 
ties of  w^hich  the  bolls  develop  before  the  pest  becomes 
abundant  is  therefore  apparent.  Furthermore,  early 
cotton  brings  by  far  the  best  prices  and  is  usually  not 
subject  to  serious  injury  by  other  insect  pests.  Plants 
grown  from  northern  seed  seem  to  mature  earlier  than 
those  grown  in  southern  Texas.  The  selection  and  breed- 
ing of  early  maturing  varieties  is  therefore  of  considerable 
importance  in  this  connection.  Growers  in  the  heart  of 
the  badly  infested  regions  of  Texas  have  found  that  by 
merely  growing  early  varieties  they  can  secure  a  yield  as 
good  as  the  average  throughout  the  country. 

Injury  being  worst  on  low,  moist  ground,  it  would  seem 
best  to  reserve  such  land  for  other  crops. 

^'  In  connection  with  the  system  of  fall  treatment  of  the 
cotton,  constant  and  thorough  cultivation  of  the  growing 
crop  is  of  considerable  value,  and  is  also  what  should  be 
done  to  insure  a  good  yield.     With  a  cross-bar  to  ])rush 


II^SECTS    IN^JURIOUS    TO    C0TT02^.  211 

the  plants,  many  of  the  blossoms  and  squares  containing 
weevils  will  be  jarred  to  the  ground  and  buried,  together 
with  those  already  on  the  ground,  in  moist  soil,  and  a 
large  percentage  of  the  material  will  rot  before  the  con- 
tained insects  have  developed."     (Howard,  I.e.) 

The  advantage  of  controlling  this  and  other  insect  pests 
by  such  cultural  methods  is  at  once  apparent  when  the 
small  margin  of  profit  in  the  growing  of  cotton  and  the 
economic  conditions  incident  to  large  areas  of  land  being 
farmed  by  tenants  are  considered.  Such  cultural  methods 
involve  no  outlay  of  cash,  which  makes  any  other  method 
prohibitive  to  most  tenants.  There  seems,  also,  to  be  a 
real  danger  of  an  overproduction  of  the  cotton  crop,  and 
a  diversification  and  rotation  of  crops  would  do  much  to 
solve  the  question  of  how  to  combat  this  and  other  insects 
of  the  cotton-plant.  It  seems  certain  that  the  control  of 
this  pest  merely  requires  a  better  system  of  agricultural 
practice,  as  is  the  case  with  the  Hessian  Fly  (see  page  110) 
and  many  of  our  worst  insects. 

On  a  small  scale  much  may  be  done  by  planting  the 
rows  farther  apart  than  usual.  Where  the  roAvs  of  cotton 
are  grown  close  together  the  soil  between  them  is  shaded 
from  the  sun  and  remains  moist,  furnishing  the  best  con- 
dition for  the  development  of  the  larvje  in  the  fallen 
squares.  Where  rows  are  farther  apart  the  soil  is  heated 
by  the  sun  to  such  an  extent  as  to  kill  large  numbers  of 
the  larvae.  That  the  rows  are  usually  placed  too  close  for 
the  proper  growth  of  the  crop  has  been  demonstrated  by 
several  agricultural  experiment  stations.  It  has  been 
shown  that  in  spite  of  the  much  smaller  number  of  plants, 
one-fourth  more  cotton  can  be  secured  from  rows  five  feet 
apart  than  from  those  three  feet  apart. 


212  INSECTS   INJURIOUS   TO   STAPLE   CROPS. 

Upon  small  areas  the  application  of  Paris  green  by- 
spraying  the  volunteer  plants  as  they  appear  in  the  spring, 
and  two  or  three  times  during  the  next  two  weeks,  will 
greatly  check  the  increase  of  the  pest.  The  young  tips 
are  the  parts  which  should  be  most  thoroughly  sprayed, 
and  as  the  number  of  volunteer  plants  will  not  be  very 
great,  such  spraying  will  not  require  much  time.  The 
solution  used  should  be  as  strong  as  one  pound  of  Paris 
green  to  fifty  gallons  of  water,  as  it  does  not  matter  if  the 
volunteer  plants  are  killed  by  it.  Volunteer  plants  appear- 
ing in  deserted  cotton-fields  or  corn-fields  should  be 
destroyed  as  far  as  possible. 

Picking  up  the  fallen  squares  and  burning  them  is  urged 
by  Prof.  Mally*  as  one  of  the  best  means  of  fighting  it. 
He  records  that  one  cotton-grower  ''who  had  fourteen 
acres  of  old  land  in  cotton,  picked  up  his  squares  faithfully 
and  made  seven  bales.  His  neighbor,  who  is  conceded  by 
all  to  be  the  better  farmer,  had  an  adjoining  field  of 
twenty-five  acres  of  cotton,  but  did  not  gather  and  burn 
his  squares,  made  two  bales."  He  states  that  eleven 
negroes  picked  up  the  squares  on  ninety  acres  between 
9  A.M.  and  6.30  p.m.,  at  a  cost  of  $8.00,  or  less  than  10 
cents  per  acre.  The  squares  should  be  picked  up  every 
ten  days  or  two  weeks.  This  method  is  only  practicable, 
however,  upon  small  areas. 

But  few  insect  parasites  seem  to  infest  the  larvae  and 
but  little  aid  can  be  hoped  from  them.  Quail  and  turkeys 
have,  however,  been  reported  as  eating  large  quantites  of 
the  weevils  and  being  most  beneficial. 


*  "The  Mexican  Cotton  Boll-weevil,"  Farmers'  Bulletin  No.  130, 
U.  S.  Dept.  Agr.,  F.  W.  Mally. 


INSECTS    IX.TURIorS    TO    COTTON.  213 

The  Mexican  Cotton  Boll-weevil  is  only  one  of  the  many 
insect  j)ests  which  are  becoming  permanent  factors  in 
agriculture  and  which  are  forcing  the  American  farmer  to 
adopt  better  agricultural  methods,  which,  if  generally 
practiced,  would  result  not  only  in  their  control,  but  cause 
less  drain  upon  the  soil  through  a  better  rotation  of  crops, 
and  better  crops  as  a  result  of  more  constant  and  thorough 
cultivation. 


CHAPTEK   XI. 

INSECTS   INJURIOUS   TO   TOBACCO. 

It  would  hardly  be  supposed  that  a  plant  like  tobacco, 
which  when  dried  is  used  as  an  insecticide,  would  be 
troubled  Avitli  many  insect  enemies,  and  experience  has 
shown  this  to  be  very  largely  a  fact,  as  only  three  or  four 
insects  are  recognized  as  what  might  be  termed  ^^  standard 
pests"  of  tobacco  throughout  the  country,  though  an 
equal  number,  whose  injuries  have  not  been  especially 
noticed  hitherto,  have  been  coming  into  prominence  m 
various  sections  in  recent  years;  yet  the  few  insects  which 
do  attack  tobacco,  if  left  to  themselves,  are  entirely  capable 
of  doing  a  vast  amount  of  damage;  for  that  which  would 
be  considered  but  a  slight  injury  to  other  plants  means  a 
considerable  loss  in  the  sale  of  a  tobacco-crop  with  imper- 
fect leaves. 

INJURING    THE    TOUXG    PLANTS. 

Cutworms. 

To  begin  with,  as  soon  as  the  plants  are  set  out  they  are 
attacked  by  those  old  foes  of  the  farmer,  with  which  he 
has  to  contend  in  the  growing  of  almost  every  truck  and 
garden  crop,  the  Cutworms.  The  cutting  of  the  stems  of 
the  young  plants  by  these  worms  often  necessitates  replant- 
ing, sometimes  a  second  time.     This  injury  is  especially 

214 


INSECTS    IXJURIOrS    TO    TOBACCO. 


215 


severe  where  a  crop  of  grass  or  clover  has  been  turned 
under  as  a  soil  crop  in  the  spring  and  there  furnishes  a 
good  su23pl3"  of  food  for  the  cutworms  till  the  tobacco  is 
set  out.  Not  only  is  this  replanting  expensive  and  tedious 
itself,  but  it  makes  the  crop  mature  unevenly  and  thus 
entails  unnecessary  expense  in  handling. 

Descriptimi  and  Life-history. — Under  the  general  term 
'^cutworms"  we  commonly  designate  the  larvae  of  several 
species  of  moths,  which  are  very  similar  in  general  apj^ear- 
ance  and  habits.     Both  the  moths  and  larv»  are  readily 


Fig.  121. — Greasy  Cutworm  {Agrotis  ypsilon),  one  of  the  Tobacco 
Cutworms,  a,  larva;  h,  head  of  same;  c,  adult — natural  size. 
(After  Howard,  U.  S.  Dept.  Agr. ) 

distinguished  by  one  familiar  with  them.  Though  the 
life-histories  of  the  different  species  vary  more  or  less,  still 
they  are  so  uiuch  alike  that  they  may  be  readily  described 
as  a  class.  Of  those  attacking  tobacco,  the  Greasy  Cut- 
worm [Agrotis  ypsilon)  and  Granulated  Cutworm  {Agrotis 
annexa)  are  among  the  most  common.  The  adults  of 
cutworms  are  moths  with  dark  fore  wings,  variously 
marked,  which  are  folded  over  the  back  when  at  rest,  and 


216  INSECTS   INJURIOUS   TO    STAPLE   CROPS. 

with  lighter  hind  wings,  as  shown  in  the  ilhistration — 
natural  size.  Like  the  cutworms,  they  feed  at  night, 
sipping  the  nectar  from  flowers,  and  the  family  to  which 
they  belong  has  therefore  been  named  the  Noduidce.  As 
a  rule  there  is  but  a  single  brood  of  worms  in  a  season, 
thouofh  a  second  one  is  not  unusual.  The  female  moths 
lay  the  eggs  on  stones,  leaves,  trees,  etc.,  almost  any  place 
where  the  ground  is  well  covered  with  vegetation,  so  that 
the  young  worms  can  readily  find  food.  They  are  usually 
deposited  during  midsummer  and  the  larvae  become  par- 
tially grown  before  winter,  when  they  hollow  out  an  oval 
cell  in  the  earth,  curl  up,  and  hibernate  till  spring,  seem- 
ingly unaifected  by  freezing.  The  next  spring,  after  their 
long  fast,  the  young  vegetation  is  eaten  with  surprising 
voracitv.  When  full-OTown  a  cutAvorm  is  of  a  dull 
brown,  gray,  or  greenish  hue,  generally  marked  with 
longitudinal  stripes,  oblique  dashes  and  dots,  and  is  from 
one  and  one-fourth  to  two  inches  long.  The  head  and 
segment  back  of  it  are  reddish  brown  and  horny.  There 
are  eight  pairs  of  legs;  the  first  three  jointed  and  tapering, 
the  last  five  short  and  stout.  As  soon  as  full-grown  the 
worm  enters  the  earth  to  pupate,  and  from  the  pupa 
transforms  to  the  adult  moth  from  late  July  to  early 
August.  Though  besides  the  larvae  all  the  other  stages  are 
known  to  sometimes  hibernate  over  winter,  nevertheless 
the  life-cycle  is  usually  so  that  the  worms  are  hungry  for 
the  young  spring  plants,  and  though  numerous  during  the 
whole  season,  it  is  during  the  spring  that  their  devastation 
is  worst  and  most  noticed. 

Bemedies. — From  the  habits  above  outlined  it  may  be 
seen  that  much  can  be  done  to  exterminate  these  pests  by 
a  thorough  cultivation  of  the  land  to  be  planted,  during 


INSECTS    INJURIOUS   TO   TOBACCO.  217 

the  spring,  thus  depriving  the  worms  of  any  food  during 
that  time.  The  most  successful  method  yet  found  for 
destroying  the  worms  is  in  the  use  of  a  poisoned  bran 
mash.  This  is  composed  of  forty  parts  of  Avheat-bran, 
two  quarts  of  cheap  molasses,  and  one  ]Dound  of  Paris 
green,  with  enough  water  to  thoroughly  moisten  the 
whole.  The  bran  and  Paris  green  should  be  thoroughly 
stirred  together  while  dry  and  the  molasses  diluted  with 
water,  and  then  poured  on  and  stirred  in.  The  land 
where  the  tobacco  is  to  be  set  out  should  be  prepared 
several  days  before.  Then  dro])  about  a  tablespoonful  of 
the  mash  near  each  hill,  doing  thi^  from  three  to  five  days 
before  the  plants  are  set  out,  and  as  near  evening  as  possi- 
ble. Chickens,  etc.,  should  be  kept  out  of  the  field  for 
several  days.  The  cutworms  are  attracted  by  the  smell  of 
the  molasses  and  seem  to  relish  the  mash,  coming  out  of 
the  ground  and  making  a  liberal  meal  upon  it — a  meal 
which  almost  always  proves  fatal.  This  remedy  is  at  once 
simple  and  inexpensive  and  has  been  found  most  satisfac- 
tory by  growers  who  have  used  it.  Any  other  arsenite 
could  be  used  instead  of  Paris  green,  though  the  amount 
used  would  vary  according  to  the  strength  of  the  j^oison. 

The  Tobacco  Stalk-worm  [Cr ambus  caligmoselUis).     (See 

page  130.) 

Prof.  W.  G.  Johnson*  has  found  this  species,  also  known 
as  the  Corn-root  Web-worm,  to  be  a  serious  pest  to  grow- 
ing tobacco-plants  in  southern  Maryland,  where  it  seems 
to  have  been  a  tobacco-pest  for  at  least  fifteen  years,  and 
it  has  also  been  noted  in  Delaware. 

The  Injurtj. — The  injury  to  tobacco  is   described  by 

^  Bull.  20,  n.  s.,  U.  S.  Div.  Ent.,  U.  S.  Dept,  Agr.,  pp.  99-101,  1899. 


218  IN'SECTS    INJURIOUS    TO    STAPLE    CROPS. 

Prof.  Johnson  as  follows:  ''The  uninjured  tobacco  had  a 
leaf- spread  of  from  ten  to  twelve  inches.  A  few  rods 
beyond,  where  the  soil  was  not  so  gravelly  and  better,  we 
found  the  larv^  had  literally  destroyed  the  first  and  second 
plantings,  and  were  at  work  upon  the  third,  damagiug  it 
severely,  although  the  ground  had  been  replanted  before 
tlie  last  planting.  Here  and  there  was  a  young  plant  just 
beginning  to  wilt,  and  invariably  we  found  the  larva  at 
work  either  in  the  stalk  or  at  the  base  of  the  plant  just 
below  the  surface  of  the  ground.  So  far  as  I  could  ascer- 
tain the  attack  is  always  at  the  surface  or  just  below.  In 
many  instances  the  larv^  had  hollowed  out  the  stalks  from 
the  base  of  the  roots  to  the  branches  of  the  first  leaves. 
Many  plants  were  gnawed  irregularly  around  the  stalk 
below  the  surface,  and  some,  in  fact,  were  completely  cut 
pff  at  the  surface,  the  insect  always  working  from  below. 
In  the  great  majority  of  cases  the  larvse  were  found  in  a 
small  mass  of  web  near  the  plant,  and  sometimes  within 
it.  In  one  plant,  less  than  six  inches  high,  we  found  four 
larvae  within  the  stalk,  but  as  a  rule  only  a  single  one  was 
present." 

Prof.  Johnson  concluded  "  (1)  that  it  is  most  likely  to 
occur  over  local  areas  in  tobacco  following  timothy  or 
grass;  (2)  that  the  character  of  the  soil  has  little  or  noth- 
ing to  do  with  its  ravages;  (3)  that  the  attack  u])o\\  corn 
is  also  a  frequent  occurrence  in  the  same  section,  esj)ecially 
when  following  grass  or  timothy." 

Remedies. — He  recommended  "(1)  that  growers  of 
tobacco  avoid  planting  upon  grass  or  timothy  sod;  (2) 
that  where  grass  land  is  plowed  down  it  would  be  well  to 
put  it  in  wheat,  following  with  clover,  before  tobacco.  If 
desirable,  corn  could  follow  the  grass  and  the  land  could 


INSECTS  INJURIOUS  TO  TOBACCO.  219 

be  seeded  in  crimson  clover  at  the  last  working.  This 
would  serve  a  twofold  object  by  revealing  the  exact  location 
of  larva3  in  the  area  nnder  cultivation  by  their  attack  upon 
corn,  when  they  could  be  destroyed  largely  by  frequent 
harrowing  and  rolling,  and  by  affording  a  most  excellent 
soil  crop  to  turn  down  the  following  spring,  which  would 
be  a  decided  advantage  to  the  tobacco;  that  if  it  is  found 
necessary  to  have  tobacco  following  grass,  it  should  be 
broken  in  the  spring  as  early  as  jDOssible,  and  frequently 
rolled  and  harrowed,  at  the  same  time  delaying  the  setting 
of  the  plants  as  long  as  possible  in  order  to  destroy  and 
starve  the  larva3  within  the  ground.  ^^ 

INJURING    THE    STEM. 

The  Spined  Tobacco-bug  {Eusclnstus  variolarius). 
Prof.  H.  Garman  has  found  a  small  bug,  which  he  has 
termed  the  Spined  Tobacco-bug,  doing  more  or  less  injury 
to  plants  in  Kentucky,  and  as  this  insect  is  widely  dis- 
tributed throughout  the  country,  it  probably  does  more  or 
less  damage  elsewhere,  though  never  a  serious  pest.  Con- 
cerning its  work,  he  says:*  ^'  Occasional  plants  in  tobacco- 
lields  are  at  times  observed  to  haA'e  become  suddenly 
wilted,  the  leaves  hanging  limj),  much  as  if  the  stalk  had 
been  severed.  After  a  time  they  recover  again,  aiid,  beyond 
a  temporary  check  on  their  growth,  appear  to  have  suffered 
but  little  injury.  If  such  plants  are  searched  carefully 
while  still  wilted,  a  flat,  brown  bug  with  each  side  of  the 
body  produced  into  an  angle,  or  sharp  spine,  will  be  found 
upon  the  stalk  along  the  base  of  the  leaves.  It  is  very  shy 
and  keeps  out  of  sight,  hence  any  brisk  movement  on  the 
injured  plants  is  likely  to  cause  it  to  dro^)  to  the  ground 


*  Bulletin  No.  66,  Ky.  Agr.  Exp.  Sta.,  p.  33. 


220  INSECTS  IXJUKIOUS  TO  STAPLE  CROPS. 

and  conceal  itself."  These  insects  are  true  bugs,  sucking 
their  food  through  a  beak,  which  is  bent  under  the  body 
between  the  legs  when  not  in  use.  They  are  about  half 
an  inch  long,  of  a  drab  color  above  and  greenish  or 
yellowish  below.  Usually  only  one  bug  is  found  on  a 
plant,  so  that  the  best  way  to  ^^I'event  the  injury  is  to 
pick  them  from  the  plants,  and  keep  down  such  weeds  as 
thistles  and  mulleins,  upon  which  such  insects  feed,  in 
the  adjoining  fields. 


Fig.  122. — EuscMsius  variolarius.    Nymph  at  left;  adult  at  right- 
enlarged.     (After  Howard,  U.  S.  Dept.  Agr.) 


INJURING    THE    *'BUD." 

Bud- worms  {Heliothis  armiger  and  rliexim). 

Before  the  leaves  of  the  tobacco  have  unrolled  they  are 
subject  to  the  attacks  of  two  larvse,  known  as  ^'Bud- 
worms."  Though  the  adult  moths  of  these  two  insects 
are  very  different  in  appearance,  the  larvae  are  much  alike. 

The  Corn-worm,  Cotton  Boll-worm,  or  Tomato-worm 
{Heliothis  armiger),  as  it  is  called  in  different  sec- 
tions, is  well  known  to  all  groAvers  of  these  crops 
and  needs  no  extended  description.  Corn  is  the  favorite 
food  of  these  worms,  on  which  they  first  riddle  the  leaves 


IKSECTS  INJUEI0U8  TO  TOBACCO,  221 

and  then  bore  into  the  forming  ear,  but  as  the  corn 
hardens  they  leave  it  for  cotton,  tobacco,  etc.  When 
an  abundant  food-supply  of  corn  or  cotton  is  not  found 
by  them  during  the  early  part  of  the  season,  they 
turn  to  tobacco.  On  tobacco  the  moths  deposit  their 
eggs  in  the  buds,  and  when  the  larvae  emerge  from  them 
a  few  days  later,  they  do  very  serious  injury  by  eating 
the  unrolled  leaves,  boring  into  the  bud,  which  may 
be  entirely  consumed  by  a  large  worm.  As  the  leaves 
grow,  these  holes  become  larger,  and  the  leaves  are  thus 
ruined  for  the  best  grade  of  tobacco.  The  later  broods 
seem  to  prefer  the  unripened  seed-capsules,  and  eating 
into  them  they  devour  the  immature  seed.  From  two 
weeks  to  a  month  are  required  for  a  larva  to  become  full- 
grown,  when  it  descends  into  the  ground  and  constructs  a 
loose  silken  cocoon  just  below  the  surface.  In  this  it 
transforms  to  the  pupa,  or  chrysalis,  and  remains  dormant 
for  from  one  to  four  weeks,  when  the  adidt  moth  emerges. 
The  moths  are  about  the  same  size  and  belong  to  the  same 
family — Noctuidce — as  those  of  the  Cutworms.  The  color 
varies  from  dull  ochre-yellow  to  dull  olive-green;'  both 
wings  are  bordered  with  dark  bands;  the  wing-veins  are 
black,  and  there  are  several  other  dark  markings  on  the 
fore  wings.  Throughout  the  cotton -belt  there  are  four  or 
five  broods  during  a  season,  but  fewer  farther  north,  the 
number  depending  upon  the  latitude  and  season. 

Another  species  of  this  genus  {Heliothis  rhexm)  has 
been  found  to  be  more  common  in  Kentucky,  and,  as  it  is 
not  known  to  attack  any  other  cultivated  plant,  is  known 
as  the  '-Tobacco  Bud-worm."  Both  species  are  usually 
found  where  tobacco  is  raised  and  in  Florida  the  Corn- 
worm  (^H.  armigei')  is  the  most  injurious.     They  are  alike 


222 


i:5^SECTS    II^JURIOUS   TO    STAPLE    CHOPS. 


Fig.  123,— The  True  Bud-worm  iHeliothis  rhexm).  a,  adult  moth ; 
b^  full-grown  larva,  from  side;  c,  same,  from  above;  d,  seed- 
pod  bored  into  by  larva;  e,  pupa — natural  size.  (After  How- 
ard, U.  S.  Dept.  Agr.) 


Fig.  124. — False   Bud-worm   or   Cotton   Boll- worm  {HeliotMs  ar- 
miger).     a,  adult  nroth;  h,  dark  full-grown  larva;  c,  light-col- 
ored full-grown  larva;  d,  pupa— natural  size.     (After  Howard 
U.  S.  Dept.  Agr.) 


INSECTS  INJURIOUS  TO  TOBACCO. 


223 


in  their  habits  and  depredations  upon  the  tobacco-2)lant. 
The  original  food-plant  of  rliexia  is  probably  one  of  our 
common  weeds  such  as  the  horse-nettle,  which  should 
therefore  be  kept  cut  down  along  the  edges  of  the  tobacco- 


FiG.  125. — Larva  of  Bud-worm  {Heliothis  armiger.)     Showing  work 
on  seed-capsules  of  tobacco-plant.     (After  Quaintance.) 

fields  and  in  those  adjoining.  The  moths  of  this  species 
are  quite  different  from  those  of  armiger,  the  fore  wings 
being  of  a  sea-green  color,  crossed  by  three  white  bands, 
and  the  hind  wings  white  with  a  dark  margin.  Only  one 
or  two  broods  occur  during  a  season. 

Remedies. — Poisoned  corn-meal  has  been  found  to  be  a 


224      INSECTS  INJURIOUS  TO  STAPLE  CROPS. 

sjitisfactory  remedy  for  both  species.  Into  a  quart  of  finely 
ground  corn-meal,  a  half  teaspoonful  of  Paris  green  is 
thoroughly  mixed  by  stirring,  and  sprinkled  on  the  buds 
from  a  can  perforated  like  a  pepper-can.  This  should  be 
applied  frequently,  especially  after  heavy  rains.  Large 
buds  should  be  opened  and  a  pinch  of  the  poison  placed 
within.  When  spraying  with  Paris  green  is  practiced 
against  the  Horn- worm,  it  will  also  be  of  service  against 
the  Bud-worms.  AVhen  the  Corn-w^orms  are  the  more 
common  species,  it  would  seem  that  the  use  of  strips  of 
corn  used  as  a  catch  crop,  as  used  in  protecting  cotton  from 
the  same  insect,  would  be  of  value.  By  j^lanting  a  row  of 
corn  here  and  there  around  the  tobacco-field,  the  moths 
will  preferably  deposit  their  eggs  upon  it,  and  it  can  then 
be  cut  and  a  large  part  of  the  injury  to  tobacco  thus  pre- 
vented. 

INJURING    THE    LEAVES. 

The  Suck-fly  (JJici/jyJiys  minimus  Uhl.  Mss.). 

As  tobacco  has  become  more  generally  grown  in  Florida, 
a  small  bug  known  to  the  planters  as  the  "  Suck-fly  ^^  has 
become  increasingly  injurious,  until  it  is  now  considered 
as  the  worst  insect  pest  of  tobacco  in  many  parts  of  that 
State.  So  far  as  known  it  has  not  been  recorded  as 
injurious  elsewhere,  though  it  has  been  noticed  in  Florida 
plantations  for  at  least  ten  years. 

Life-history. — The  adult  is. a  small  bug  about  one-eighth 
of  an  inch  long,  with  rather  long,  yellowish-green  legs. 
The  upper  surface  of  the  insect  is  black,  except  the  front 
margin  and  a  central  stripe  of  yellow  on  the  first  segment 
back  of  the  head,  while  the  under  side  is  greenish.  The 
wings  are  folded  over  the  back  when  at  rest.     The  ^'  flies" 


INSECTS  INJURIOUS  TO  TOBACCO.  225 

become  numerous  enough  to  be  injurious  during  the  first 
two  weeks  in  June,  usually  being  first  noticed  in  one 
corner  of  a  field,  from  which  they  rapidly  spread  over  the 
whole.  The  eggs  are  deposited  singly,  in  the  tissues  of 
the  leaf,  mainly  on  the  smaller  veinlets,  and  hatch  in 
about  four  days.  The  young  nymphs  at  once  attack  the 
foliage,  and  after  molting  about  four  times  transform  to 
adults  about  eleven  days  later.  The  full-grown  njmiphs 
are  of  the  same  general  aj^pearance  as  the  adults,  except 
that  the  wings  are  still  undeveloped  and  form  small  wing- 
pads,  but  are  of  a  greenish  color.  As  it  requires  but  a 
fortnight  for  the  development  of  a  brood,  these  insects 
multii^jy  very  rapidly  and  in  a  few  weeks  become  so 
numerous  as  to  seriously  damage  the  foliage,  hundreds  of 
them  being  found  on  a  single  leaf.  The  injury  is  done  by 
their  inserting  their  small  beaks  into  the  tissue  of  the  leaf 
and  sucking  the  juices,  causing  the  leaf  to  become  yellowish 
or  wilted,  and  cracking  older  leaves  so  that  they  become 
ragged.  "Experienced  growers  say  that  the  leaves  badly 
infested  with  the  Suck-fly  are  very  difficult,  if  not  impossi- 
ble, to  properly  cure.^'  The  weather  plays  an  important 
part  in  the  control  of  this  pest.  ''According  to  an 
observant  grower,  '  an  important  factor  in  bringing  about 
their  disappearance  has  been  the  absence  of  rain  duriiio- 
the  latter  part  of  August  and  early  September.  The  sticky 
exudation  from  the  glandular  hairs  of  the  tobacco-plant 
causes  many  of  these  insects  to  become  stuck  to  the  leaf 
and  in  this  way  a  great  many  are  killed.  Frequent  showers 
keep  this  washed  off  to  a  considerable  extent,  and  thus 
favor  the  insects.^  ^'  (Quaintance.)  A  veritable  fl3^-trap ! 
Remedies. — In  experimenting  with  insecticides  for  this 
pest,  Prof.  Quaintance  has  found,  curiously  enough,  that 


226 


INSECTS    IXJURIOUS    TO    STAPLE    CROPS. 


the  only  ones  fatal  to  it  are  preparations  of  its  own  food — 
tobacco.  A  solution  of  one  part  of  ''Xikoteen"  to  sixty 
of  water  is  a  very  satisfactory  remedy.     This  insecticide 


Fig.  126. — The  Suck-liy  {Dicyphus  minimus),  a,  uewly  hatched; 
b,  second  stage;  c,  nymph;  d,  adult;  e,  head  and  beak  from 
side — enlarged.     (After  Howard,  U,  S.  Dept.  Agr.) 

is  a  concentrated  solution  of  nicotine  and  is  manufactured 
by  the  Scabcura  Dip  Co.,  Union  Stock  Yards,  Chicago, 
111.     It  should  be  sprayed  over  the  plants,  using  a  bent- 


INSECTS  IXJURIOUS  TO  TOBACCO.  227 

necked  nozzle  which  will  throw  a  fine  mist  upon  both  the 
upj)er  and  nnder  surfaces  of  the  leaves,  as  most  of  the 
young  are  on  the  lower  surfaces.  Where  refuse  tobacco  is 
at  hand  a  good  decoction  can  be  made  by  boiling  it  at  the 
rate  of  one  pound  to  a  gallon  of  water  for  an  hour,  then 
draining  off,  and  straining  well  before  spraying.  This 
will  not  keep  for  more  than  two  or  three  days  before  fer- 
menting, but  where  it  can  be  used  at  once  is  less  expensive 
than  "  Nikoteen."  The  spraying  should  be  done  early  in 
the  day,  when  the  adult  bugs  are  sluggish  and  do  not  fly 
readily.  Keep  a  sharj^  watch  for  the  ' '  flies ''  early  in 
June,  and  by  attacking  them  upon  their  first  ap23earance 
they  may  be  kept  from  s]3reading  and  be  destroyed  before 
they  have  done  much  injury  and  much  more  readily  than 
when  more  numerous. 

MINII^G   THE    LEAF. 

The  Tobacco  Leaf-miner  {Gelechia  solanella  Boisd.). 
The  larva  of  a  small  moth  has  become  quite  injurious  in 
parts  of  Xorth  Carolina  and  Florida  by  mining  the  inside 
of  the  leaf,  and  is  thus  known  as  the  Tobacco  Leaf -miner. 
This  insect  occurs  in  other  parts  of  the  country,  but  has 
become  injurious  only  in  the  States  named  and  in  recent 
years.  The  injury  is  done  by  the  larvae  eating  out  irregular 
patches  of  the  tissue  in  the  leaves,  leaving  only  the  upper 
and  lower  surfaces,  the  lower  leaves  being  infested  the 
worst.  The  leaves  are  rendered  unfit  for  wrappers,  split- 
ting and  tearing  very  easily  on  account  of  these  blotches. 
A  larva  does  not  confine  its  work  to  one  place,  but  makes 
several  mines,  and  a  single  larva  may  thus  destroy  the  value 
of  a  leaf  for  wrapping  purposes.  This  migratory  habit  is 
of  considerable  importance,  as  in  leaving  the  old  and  in 


228 


INSECTS   iKJURlOrs   TO   STAPLE   CROPS. 


making  new  mines  the  larvse  must  necessarily  eat  a  certain 
amount  of  the  surface  of  the  leaf,  and  can  thus  be  killed 
by  an  arsenical  spray.  The  life-history  of  the  insect  is 
not  completely  known,  but  as  only  about  twenty  days  are 
required  for  all  its  transformations,  several  broods  probably 
occur  during  a  season.  The  original  food-plant  of  this 
pest  has  been  found  to  be  the  common  horse-  or  bull-nettle 
(Solamim  carolinense),  which  fact  further  emi^hasizes  the 


Fig,  127. — Tobacco  Split- worm.  Adult  moth  above;  larva  below  at 
right;  pupa  below  at  left,  with  side  view  of  enlarged  anal  seg- 
ment— all  enlarged.     (After  Howard,  U.  S.  Dept.  Agr.) 

caution  already  given,  to  keep  all  weeds  carefully  cut  down 
around  the  tobacco-field,  especially  those  nearly  related  to 
tobacco  botanically.  Many  planters  destroy  the  larvae  by 
simj)ly  crushing  them  with  the  hand,  and  this  can  be  done 
quite  rapidly,  and  if  done  before  the  mines  become  numer- 
ous should  be  sufficient  to  check  the  injury.  Where 
spraying  with  Paris  green  is  practiced  against  the  Horn- 
worm  it  should  be  sufficient  to  destroy  most  of  the  miners, 
as,  if  the  leaf  is  thoroughly  coated  with  poison,  they  would 
get  a  fatal  dose  in  starting  a  new  mine. 


INSECTS  IXJrRIOUS  TO  TOBACCO. 


229 


The  Tobacco  Flea-beetle  (EpUrix parvula  Fab.). 

The  Tobacco  Flea -beetle  is  one  of 
the  insects  which  has  become  in- 
creasingly injurious  upon  tobacco- 
leaves  in  recent  years.  So  far  as 
recorded  its  injuries  have  been  no- 
ticed only  in  the  northern  part  of 
the  tobacco-belt,  viz.,  Kentucky, 
Ohio,  West  Virginia,  Marjdand,  and 
Connecticut.  The  leaves  are  dam- 
aged by  having  small  holes  eaten  in 
the  upper  or  nnder  surfaces,  or  some- 
times clear  through  them.  When 
badly  eaten  the  leaves  appear  as  if 
peppered  with  shot,  the  injury  being 
esj)ecially  severe  to  young  plants. 
The  adult  beetles  which  do  this  in- 
jury are  very  small,  hardly  more 
than  one-twentieth  of  an  inch  long, 
of  a  light  brown  color,  with  a  dark 
band  across  the  wing-covers.  A  few 
of  them  could  do  but  little  injury, 
but  they  soon  increase  nntil  they 
swarm  over  the  leaves  and  injure  them 
badly.  The  life-history  of  this  sj)ecies 
has  not  been  studied  until  recently 
and  is  not  yet  well  known.  Mr.  F. 
H.  Chittenden  has  ascertained  that 
the  larvae  feed  habitually  uj^on  the 
roots  of  the  common  Nightshade  and 
Jamestown  weed.     These  are  undoubtedly  the  usual  food 


Fig.  128.  —  Work  of 
Split-worm — reduced. 
(After  Howard,  U.  S. 
Dept.  Agr. ) 


230 


INSECTS    TXJURIOUS    TO    STAPLE    CROPS. 


of  the  larvae,  as  of  the  nearly  allied  Potato  Flea-beetles 
{E.  cucnmeris  and  fuscula) ,  but  when  the  beetles  become 
more  numerous  the  larvae  sometimes  feed  upon  tobacco- 
roots,  doing  them  more  or  less  damage,  but  generally  not 
to  a  noticeable  extent.  The  breeding  of  this  insect  upon 
these   common   weeds    further    emphasizes    the    caution 


Fig.  129. — Tobacco  Flea-beetle  {Epitrix  pnriml'i).  a,  adult  beetle; 
b,  larva,  lateral  view;  c,  head  of  iarva;  d,  posterior  leg  of  same; 
e,  anal  segment,  dorsal  view;/,  pupa — a,  b,  f,  enlarged  about 
fifteen  times;  c,  d,  e,  more  enlarged.     (After  Chittenden, 

U.  S.  Dept.  Agr.) 
already  given  in  previous  chapters  to  see  that  they  are  kept 
cut  down.      Spraying  with  Paris  green  as  advised  for  the 
Horn-worm  will  also  keep  this  insect  in  check. 

Grasshoppers. 

Grasshoppers  have  often  been  known  to  eat  tobacco- 
leaves  quite  badly.  Of  these,  our  most  common  species, 
the  Red-legged  Locust  [Melanoplus  femur-rii'brum),  has 
been  recorded  most  often.  If  the  plants  have  been  sprayed 
with  Paris  green,  it  will  usually  be  sufficient  to  prevent 
serious  injury  by  grasshoppers.    If  they  are  very  numerous. 


IKSECTS  INJURIOUS  TO  TOBACCO. 


231 


however,  a  bran  mash  such  as  advised  for  use  against  Cut- 
worms will  be  found  attrac- 
tive to  them.  A  tablespoon- 
ful  placed  at  the  base  of 
each  plant  will  be  sufficient 
to  prove  fatal  to  the  locusts. 

The  Horn-worm  or  Tobacco- 
worm  [Protoparce  celeus, 
P.  ccu'olina). 

Of  all  the  insects  feeding 
upon  tobacco,  this  oue  is  the 
most  injurious  and  conse- 
quently most  generally 
known.  In  many  sections 
on  account  of  its  damage  to 
that  plant  it  is  also  known 
as  the  Tomato-worm.  It 
may  be  well  to  first  state, 
however,  that  two  species 
of  insects  are  ordinarily  in- 
cluded under  this  popular 
name.  The  IN^orthern  To- 
bacco-worm is  the  more 
common  form  in  many  of 
the  more  northern  parts  of 
the  tobacco-belt,  especially 
in  Connecticut,  though  it 
is  generally  found  wherever 
tobacco  is  extensively  grown 

in  the  United   States.      The    Fig.  130.— Tobacco-leaves  dam- 

^igedhj Epitrix pnrmila.  {Miav 
Southern  Tobacco-worm  {P.        Howard,  U.  S.  Dept.  Agr.) 


232 


INSECTS   IXJURlorS   TO   STAPLE   CROPS. 


Carolina)  also  occurs  throughout  all  the  tobacco -j)roclucing 
States  and  is  usually  much  the  more  common   form   in 


the  South.  The  life-history  and  habits  of  these  insects 
are  so  nearly  alike  that  they  may  be  discussed  together. 
The  larvae  of  the  northern  form  may  be  distinguished  from 


IXSECTS  IXJURIOUS  TO  TOBACCO.  233 

the  southern  by  tlie  V-shaped  markings  along  the  sides, 
those  of  the  latter  being  simple  oblique  bands.  The 
differences  between  the  moths  are  well  shown  in  the 
illustrations. 

Life-history. — The  pupae  from  which  these  moths 
emerge  in  May  and  June  remain  in  the  ground  over 
winter.     The  females  then  deposit  their  eggs,  singly,  upon 


Fig.  133. — Southern  Worm  killed  by  Fungus.     (After  Garman.) 

the  lower  surfaces  of  the  tobacco-leaves,  which  hatch  out 
in  three  davs.  The  way  in  which  the  younsr  w^orms  now 
attack  the  tobacco  foliage  is  well  known  to  every  grower. 
During  their  growth,  which  occupies  about  three  weeks, 
the  worms  molt  some  five  times.  They  then  transform  to 
l"»upae,  in  which  state  they  remain  about  three  weeks,  when 
the  adults  emerge  and  the  same  life-cycle — occupying  about 
six  weeks — is  repeated.  The  first  brood  of  worms  usually 
does  not  do  very  serious  damage,  the  one  in  July  being 
that  against  which  the  planter's  attack  should  be  directed. 
Usually  three  broods  occur  in  a  season,  sometimes  but  two 


234 


IXSEOTS    TXJrRIOrS   TO    STAPLE    CROPS. 


in  the  ^^orth  and  four  in  the  South.      Occasionally  the 
worms  are  overlooked  in  cutting  the  tobacco  and  do  con- 


siderable injury  to  it  even  after  it  has  become  partially  dry 
in  the  barn,  though  there  is  little  excuse  for  this. 

nemedies.—The  oldest  and  most   common   method   of 


INSECTS  INJURIOUS  TO  TOBACCO.  235 

controlling  this  j^est  is  that  of  hand-picking.  This  is, 
however,  both  tiresome  and  expensive.  I  am  informed 
that  in  southern  Maryland  this  task  is  willingly  done  by 
large  flocks  of  turkeys,  which  are  kept  largely  for  that 
purpose  and  fed  on  little  else  during  the  time  the  worms 
are  most  numerous. 

In  many  parts  of  Kentucky  a  spray  of  Paris  green  has 
been  used  against  the  Tobacco-worm.  Against  this  there 
has  been  more  or  less  of  a  popular  prejudice  on  account  of 
possible  poisoning.  Such  a  prejudice  having  also  existed 
against  the  use  of  this  well-known  arsenite  upon  apples 
for  the  Codliug-moth  and  on  numerous  other  crops,  and 
with  no  deleterious  results,  it  seems  safe  to  assume  that 
such  a  prejudice  is  unfounded.  Xevertheless  Prof.  H.  A. 
Garman  has  made  a  careful  test  of  such  spraying,  and 
plants  sprayed  were  analyzed  by  Dr.  A.  M.  Peters,  chemist 
of  the  K3^  Agr.  Exp.  Station,  who  found  that  the  amount 
of  arsenic  left  on  leaves  sprayed  three  times  wdth  a  solution 
of  one  pound  of  Paris  green  to  IGO  gallons  of  water  would 
not  be  sufficient  to  be  injurious  to  the  consumer.  In  the 
numerous  tests  made,  one-third  of  a  grain  of  arsenic  per 
pound  of  tobacco  was  the  most  ever  obtained,  and  would 
hardly  be  injurious.  Prof.  G-arman  (Bulletin  No.  63,  Ky. 
Agr.  Exp.  Station)  also  made  thorough  tests  as  to  the 
efficiency  of  this  method  of  controlling  the  worm,  which 
he  found  to  be  entirely  satisfactory.  Usually  it  will  not 
be  necessary  to  spray  over  three  times,  if  aj^plied  at  the 
proper  time.  The  time  of  these  apj^lications  will  vary  for 
different  latitudes  and  seasons,  but  should  be  made  as  soon 
as  the  young  of  each  brood  make  their  appearance.  In 
general  this  will  be  early  in  July,  early  August,  and  middle 
or  late  August.     One  pound  of  Paris  green  to  160  gallons 


236  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

of  water  is  strong  enough  if  properly  applied,  and  in  no 
case  should  it  be  used  stronger  than  one  pound  to  125 
gallons.  The  best  way  of  applying  the  mixture  is  by 
means  of  a  knapsack-pump,  and  both  surfaces  of  the  leaves 
should  be  sprayed. 

Florida  growers  have  used  the  arsenite  of  lead  to  some 
extent,  dusting  it  on  the  plants  dry,  by  means  of  a  bellows 
or  powder-gun,  such  as  is  manufactured  by  Leggett  Bros. , 
301  Pearl  St.,  New  York.  It  is  a  white  powder,  more 
insoluble  than  Paris  green,  but  it  will  not  burn  the  foliage 
as  readily.  It  is  also  more  adhesive  when  thus  applied, 
remaining  on  the  foliage  for  eight  or  ten  days. 

A  method  for  killing  the  adult  moths  has  been  satisfac- 
torily practiced  for  many  years.  It  consists  in  poisoning 
the  flowers  of  the  Jamestown  weed  [Datura  stramonium) 
with  a  sweetened  cobalt  solution.  The  flowers  are  placed 
around  the  fields  in  the  evening,  being  set  upright  in  holes 
of  horizontal  slats,  or  supported  by  sticks.  The  cobalt 
solution  is  then  introduced  into  them  by  means  of  a  quill. 
It  is  composed  of — cobalt,  one  ounce;  molasses,  one-fourth 
of  a  pint;  water,  one  pint.  In  their  search  for  flowers 
the  moths  will  be  attracted  by  the  odor  of  the  molasses  and 
the  cobalt  of  the  solution  will  poison  them,  and  thus  jore- 
vent  the  females  from  laying  some  two  hundred  eggs 
toward  another  brood. 

Enemies. — There  are  also  several  insects  which  tend  to 
keep  this  pest  in  check  by  parasitizing  it,  and  about  which 
many  growers  do  not  seem  to  be  well  informed.  Worms 
covered  with  what  seem  to  be  small  white  eggs  are  ahvays 
common.  They  are  not  eggs,  however,  but  the  cocoons 
of  a  small  hymenopterous  insect  whose  larv«  feed  upon 
tlie  worm  internally  and  thus  ultimately  kill  it  before  it 


INSECTS  INJURIOUS  TO  TOBACCO.  237 

becomes  full-grown  or  transforms  to  the  pupa.  Such 
parasitized  worms  should  never  be  destroyed,  as  the  para- 
sites are  of  more  value  than  the  damage  the  worm  might 
do  (Fig.  134). 


Fic4.   134.  —  Southern   Tobacco-worm   with   Cocoons   of  Parasite. 

(After  Garman.) 


INJURING   STORED   TOBACCO. 

The  Cigarette-beetle  {Lasioderma  serricorne  Fab.).  ' 

Even  after  the  crop  has  been  cured  and  has  been  packed 
away,  sometimes  for  years,  it  is  subject  to  the  ravages  of 
the  larvae  and  adults  of  a  small  beetle,  called  the  Cigarette- 
beetle.  This  pest  also  infests  numerous  other  stored 
products,  household  goods,  upholstery,  etc.  The  beetle 
is  but  one-sixteenth  of  an  inch  long,  of  a  brownish  color, 
with  the  prothorax  bent  under  in  front  so  that  the  head  is 
obscured  as  under  a  hood.  The  pupal  stage  is  passed  in  a 
delicate  cocoon;  the  whole  life  of  the  insect  being  spent 
in  the  infested  goods. 

Remedies. — Infested  tobacco  should  be  o^oened  ujd,  if 
packed  tightly,  placed  in  tight  boxes,  or  a  tight  room,  and 
exposed  to  the  fumes  of  carbon  bisulfide,  using  it  the  same 
as  for  grain-insects.  This  liquid  is  very  volatile,  giving 
off  a  gas  heavier  than  air  and  fatal  to  all  insect  life.  The 
quantity  used  would  depend  upon  the  tightness  of  the 


238 


IXSECTS    INJURIOUS   TO    STAPLE    CROPS. 


enclosure  aud  the  way  in  which  the  tobacco  is  packed. 
One  ounce  to  every  fifty  cubic  feet  of  enclosed  space  will 
doubtless  be  ample.  This  should  be  placed  in  shallow 
vessels  on  top  of  the  tobacco  aud  allowed  to  remain  for 
twenty 'four  hours.     No  injury  will  be  done  the  tobacco. 


a.  h  e 

Fig.  135. — The  Cigarette-beetle,  a,  larva;  h,  pupa;  c,  adult;  d, 
side  view  of  adult:  e,  anteuna — all  greatly  enlarged;  e,  still 
more  enlarged.     (After  Chittenden,  U.  S.  Dept.  Agr. ) 

but  care  should  be  taken  in  the  use  of  this  chemical  that 
no  light,  cigar,  etc.,  be  brought  near  it,  as  it  is  highly 
combustible  and  such  carelessness  might  cause  a  serious 
conflagration. 

Hydrocyanic  acid  gas  has  recently  been  used  very  suc- 
cessfully by  Prof.  AY.  G.  Johnson  in  riddiug  some  large 
tobacco  warehouses  of  this  pest. 


CHAPTER   XII. 
INSECTS  INJURIOUS   TO   THE   POTATO. 

IXJURIXG    THE   TUBERS. 

Potato-scab  and  Insects. 

That  certain  forms  of  what  is  commonly  termed  '^potato- 
scab"  are  due  to  the  work  of  insects  has  frequently  been 
shown.  In  1895  Prof.  A.  D.  Hopkins,  of  the  West  Virginia 
Agr.  Experiment  Station,  reported  some  very  careful  orig- 
inal investigations  upon  two  species  of  gnats,  Epidapns 
scabies  Hopk.  and  Sciara  sp.,  the  larv^  of  which  had  been 
conclusively  shown  to  cause  a  scab  upon  the  tubers  bv 
boring  into  them.  He  found  that  "  they  breed  in  and  are 
especially  common  in  barnyard-manure,"  that  ^'excessive 
moisture  in  the  soil  has  been  observed  to  be  the  most  favor- 
able condition  for  their  development,"  and  that  ''soaking 
the  seed-potatoes  in  a  solution  of  corrosive  sublimate 
previous  to  planting"  will  kill  all  the  eggs  and  youno- 
larvae,  as  it  will  also  destroy  the  spores  of  the  potato-scab 
fungus. 

Prof.  A.  H.  Garman  has  also  recorded  the  injuries  of 
"several  species  of  millipedes,  or  "thousand-legged  worms," 
Camhala  annidata  and  Parajulus  impresstis,  as  causing  a 
scab  by  gnawing  into  the  surface  of  the  tubers.  Though 
both  of  these  observations  are  unquestionably  true,  they 


240  INSECTS    IXJURIOUS    TO    STAPLE    CROPS. 

have  not  been  verified  in  otlier  parts  of  the  country,  and 
it  is  improbable  that  am^  large  ^^ortion  of  potato-scab  is 
due  to  these  insects.  Potato-scab  is  a  fungous  disease, 
which,  as  already  noted,  may  be  destroyed  by  soaking  the 
seed-potatoes  in  a  solution  of  corrosive  sublimate. 

Some  interesting  oliservations  have  been  published  by 
Messrs.  Stewart  and  Sirrine,  of  the  New  York  station,  in 
which  they  attribute  the  peculiar  marking  of  the  skin 
known  as  '^  pimply^'  potatoes  to  the  larva  of  the  small 
black  cucumber  flea-beetle,  Epitrix  cucumeris  Harris, 
which,  as  a  beetle,  does  so  much  injury  to  the  leaves. 
Without  doubt  this  instance  is  a  parallel  to  those  already 
mentioned  concerning  insects  producing  potato-scab. 
Undoubtedly  the  larvae  of  this  beetle  may  have  been  found 
producing  '•  j^imply  "  potatoes,  but  several  other  entomolo- 
gists and  the  writer  have  carefully  examined  hundreds  of 
tubers  in  fields  fairly  alive  with  the  beetles,  and  at  all 
seasons  of  the  vear,  but  all  in  vain  as  far  as  discoverins: 
any  flea-beetle  larvae  is  concerned. 

The  truth  of  the  matter  is  that  the  natural  food-plants 
of  these  larv^  are  some  of  our  commonest  weeds.  Similar 
instances  are  observed  in  the  larva?  of  the  Sweet-potato 
Flea-beetle  {Chceto enema  confinis  Clr.),  Bean  Leaf-beetle 
(Cerotomatrifurcata  Foerst),  Tobacco  Flea-beetle  [Epitrix 
parvuJa),  and  others  which  are  all  occasionally  found  on 
the  roots  of  the  respective  food-plants  of  the  beetles,  but 
which  habitually  feed  in  the  larval  stage  upon  the  roots  of 
such  weeds  as  the  horse-nettle,  Jamestown  weed,  Des- 
modium,  and  various  Solonacem.  In  fact,  the  only  insects 
which  are  habitually  injurious  to  the  tubers  are  white  grubs 
and  wireworms,  both  of  which  are  only  too  familiar  to 
every  farmer.     So  far  as  known,  the  only  remedy  for  these 


INSECTS    IXJURIOUS    TO    THE    POTATO.  241 

will  be  rapid  rotation  of  crops,  until  the  infested  land  has 
become  clear  of  them. 

INJURING    THE    STALK. 

The  Potato  Stalk-borer  {Tricltoharis  trinoiata  Say.). 
In  some  sections  this  insect  has  rivaled  the  famous 
Colorado  Potato-bug  in  the  damage  it  has  inflicted  upon 
potato-yines.  It  was  recorded  in  Iowa  as  badly  damaging 
the  crop  there  in  1890,  and  was  found  by  Dr.  Eiley  in 
Missouri  as  early  as  1869.     The  beetles  were  first  noted  in 


Fig.  13G. — Potato  ^talk-horer  (Trichoharis  tri?wtaia).    Larva,  pupa 
and  adult.     (After  J.  B.  Smith.) 

New  Jersey  in  1895,  and  during  the  last  few  years  have 
been  doing  serious  injury  to  the  fields  of  northwestern 
Maryland. 

Life-history. — The  grubs,  which  bore  into  the  stalk  of 
the  vines,  are  the  larvae  of  some  small  ashen-gray  beetles 
which  appear  early  in  spring  and  into  June.  These  beetles 
are  about  one-fourth  of  an  inch  long,  with  a  long,  black 
beak  or  snout,  and  are  marked  at  the  base  of  the  wing- 
covers  by  three  black  spots  which  give  the  insect  its  specific 


Fig.  137. — Work  of  Potato   Stalk-borer  in  Potato-vines.     (After 

J.  B.  Smith.) 


242 


INSECTS   INJURIOUS   TO   THE   POTATO.  243 

name,  trinotata.  Eacli  beetle  punctures  a  small  hole  in 
the  base  of  a  stem  by  means  of  its  beak,  hollows  out  a 
small  cavity,  and  there  lays  a  single  small,  oval,  whitish 
Qgg.  From  these  eggs  some  small,  white  grubs  with 
brown  heads  hatch  in  a  few  days  and  commence  to  bore 
into  the  stalk.  These  grubs  keep  eating,  either  in  the 
main  stalk  or  branches,  from  August  1st  to  September  1st, 
when  they  have  become  full-grown.  At  this  time  the 
grubs  are  about  one-half  an  inch  long,  of  a  dirty  white  or 
yellowish  color,  with  a  yellowish-brown,  horny  head,  and 
without  legs.  About  the  middle  of  August,  as  a  general 
rule,  the  grub  constructs  a  small,  oval  cocoon  of  chips  and 
fibres  in  the  stalk  of  the  vine  near  the  surface  of  the  soil, 
and  there  transforms  to  the  pupa.  During  late  August 
and  September  the  mature  beetles  shed  the  pupal  skins,  in 
which  they  have  remained  dormant  for  the  last  few  weeks, 
but  remain  in  the  vines  during  the  winter,  and  do  iiot 
come  forth  till  the  following  spring. 

Remedies. — On  account  of  its  internal  feeding  habits  no 
poison  can  be  successfully  used  against  this  2:)est,  and  the 
only  remedy,  but  a  good  one,  is  to  rake  up  the  vines  and 
burn  them  as  soon  as  the  potatoes  have  been  dug.  As  this 
insect  also  feeds  upon  the  Jamestown  weed,  horse-nettle, 
and  other  weeds  of  the  Mghtshade  family,  or  Solonacece^ 
they  should  be  kept  cut  down  very  closely.  When  the 
grubs  are  noticed  in  the  plants,  a  good  allowance  of  fer- 
tilizer will  do  much  to  quicken  growth  and  thus  enable 
them  to  mature  a  crop. 

INJURING   THE    LEAVES. 

Colorado  Potato-beetle  {Lejjtinotarsa  10-lineata  Say.). 
First  and  foremost  among  the  enemies  of  the  potato- 


244 


TXSEOTS    IXJURIOrS    TO    STAPLE    TROPS. 


grower  stands  the  Colorado  Potato-beetle — the  insect  which 
in  the  early  seventies,  on  account  of  our  ignorance  of  \t, 
was  made  an  entomological  bugbear.  But  '^there's  no 
great  loss  without  some  small  gain,"  and  we  may  be 
thankful  that  the  invasion  of  this  beetle  also  brought 
about  the  use  of  Paris  green,  an  insecticide  which  has 
since  saved  thousands  upon  thousands  of  dollars  to  the 
American  farmer.     Thus,  with  an  effectual  remedy  which 


Fig.  138. — The  Colorado  Potato-beetle  {Lepiinotarsa  decemlineata 
Say.),  a,  eggs;  h,  larvji?;  c,  pupa;  d,  beetle;  e,  elytra  or  wing- 
cover  of  beetle;  /,  leg  of  beetle.     (After  Riley.) 

is  now  used  where  this  pest  occurs  as  regularly  as  potatoes 
are  planted,  ^^familiarity"  has  '^bred  contempt,"  and 
to-day  we  have  but  little  fear  of  its  attack. 

History. — As  is  probably  known  to  most  of  the  older 
generation  who  watched  its  spread  eastward,  the  Colorado 
Potato-beetle,  as  its  name  indicates,  was  a  native  of  the 
Rocky  Mountain  region,  and  until  about  1855  was  satisfied 
with   feeding  upon  various  common  weeds  of  the  same 


INSECTS   INJURIOUS   TO   THE   POTATO.  245 

genus  as  the   potato-plant,    principally   Solanum    datura 

Dunal,  and  closely  allied  genera.     But  with  the  settlement 

of  this  country  and  the  introduction  of  the  Irish  potato, 

these  bugs  also  began  to  take  advantage  of  the  fruits  of 

civihzation  and  transferred  their  feeding-grounds  from  the 

roadside  to  the  potato-patch,  and  rapidly  spread  eastward 

from  one  to  another,  as  well  as  being  imported   in  the 

shipj)ing  of  the  potatoes. 

Thus,  in  1859  they  had  reached  a  point  one  hundred 

miles  west  of  Omaha,  N  ebraska ;  five 

years  later  crossed  the  Mississippi 

into  Illinois;  and  advanced  steadily 

eastward   till    recorded  among  the 

Atlantic  States  in   1874.     Though 

slow   to   be  introduced   into   some    ^         o  \C 

„  ..  J,  ^,  ,         .,     .     Fig.  139.— rt,  beakof  pre- 

few    sections  of  the  country,  it    is       daceous  bug;    c,  beak 

safe   to   assert  that   this  pest  may      ?[fJe?Rne^'^/''°    ^""" 

to-day  be   found    almost    wherever 

the  potato  is  grown   in    the   United  States  or  southern 

Canada. 

Life-history.  —  During  October  the  beetles  enter  the 
earth  and  there  hibernate  till  the  warm  sunshine  of  April 
or  May  brings  them  forth.  As  soon  as  the  young  plants 
appear,  the  female  beetles  deposit  their  yellow  eggs  upon 
the  under  side  of  the  leaves  near  the  tips,  each  female  lay- 
ing from  six  hundred  to  one  thousand  eggs  during  the 
course  of  a  month.  Meanwhile  the  beetles  have  done 
considerable  damage  by  eating  the  young  and  tender 
plants.  In  about  a  week,  there  hatch  a  horde  of  very 
small  but  very  hungry  larva3,  which  fairly  gorge  themselves 
with  potato-foliage  and  increase  in  size  with  astonishing 
rapidity.     In  four  or  five  weeks,   after  having  eaten  an 


246  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

amount  of  food  out  of  all  proportion  to  their  size,  the 
larv8B  have  become  full-grown,  and  enter  the  earth,  where 
they  form  smooth,  oTal  cells,  and  transform  to  the  pup^. 
In  a  week  or  two  the  adult  beetles  emerge  from  the  pupal 
skins  and  after  feeding  for  a  couple  of  weeks,  deposit  eggs 
for  another  brood.  The  life-history  of  this  brood  is  the 
same,  except  that  the  time  required  for  it  is  less  than  for 
the  first,  and  following  it  comes  the  third  brood,  the 
beetles  of  which  hibernate  over  winter  as  already  described. 
The  time  required  for  the  development  of  a  brood  is 
exceedingly  variable,  and  owing  to  the  length  of  time 
required  for  laying  the  eggs,  and  the  fact  that  some  larv« 
become  full-grown  much  more  quickly  than  others,  all 
stages  of  the  insect  may  be  found  during  the  summer 
months. 


^ 


Fig.  140. — Tacliinid  Parasite  of   Colorado   Potato-beetle  {Lydelta, 
dorypliorce  Ril.).     (After  Riley.) 

Natural  Enemies. — One  of  the  chief  agencies  to  prevent 
the  excessive  multiplication  of  this  j^est  is  the  weather. 
Thus,  Professor  Otto  Lugger  records  that  in  Minnesota, 
late  in  the  fall  of  1894,  the  beetles  were  lured  from  their 
winter  quarters  by  a  few  warm  days,  and  most  of  them 
subsequently  perished  from  hunger  or  frost.     In  addition 


INSECTS   TXJURIOrS   TO   THE   POTATO. 


247 


to  this  during  the  late  summer  of  1894  there  was  an  exces- 
sive drouth,  so  that  but  feAv  of  the  third  brood  matured. 
Thus  in  1895  there  were  very  few  of  the  insects  to  be  seen. 
Among  the  birds,  the  common  crow,  red-breasted  Gros- 


FiG.  141. — Murky  Ground-beetle  {Harpalus  caUglnosus)  and  Fiery 
Ground- beetle  {Calosoma  calidum).     (After  Riley.) 


Fig.  142. — Larva  of  Murky  Ground-beetle  {Uarpalus  caliginosus). 

(After  Riley.) 

beak,  and  turkeys  often  feed  upon  this  pest  to  a  consider- 
able extent. 

Probably  the  most  destructive  insect-parasite  of  the 
larvae  is  a  Tachinid-fly  known  to  science  as  LydeUa  dory- 
phorcB  Ril.,  which  rather  closely  resembles  the  common 
house-fly,  both  in  size  and  color.  A  single  egg  is  laid  on 
a  potato-bug  and  from  it  hatches  a  small,  footless  maggot 
which  burrows  inside  the  bug.  When  the  larva  enters  the 
earth,  the  effect  of  the  maggot's  work  becomes  aj)parent, 
and   instead    of   transforming   to    a  pupa  and    beetle,    it 


248  INSECTS   INJURIOUS   TO   STAPLE    CROPS. 

shrivels  w}!  and  dies.  But  the  maggot  itself  contracts  into 
a  hard,  brown  pupa,  from  which  the  fly  eventually 
emerges.  Thus  in  1868,  when  first  noted  by  Doctor  C.  V. 
Kiley,  he  asserted  that  in  Missouri  fully  ten  per  cent  of  the 
second  brood  and  one-half  of  the  third  were  destroyed  by 
this  parasite. 

Many  of  our  common  ladybird-beetles  and  their  larvae 
check  the  pest  by  feeding  upon  the  eggs.  Several  pre- 
daceous  bugs  are  of  value  in  destroying  the  larvae,  into 
which  they  thrust  their  short,  powerful  beaks,  and  then 
suck  out  the  juices  of  the  body,  leaving  only  an  empty 
skin.  One  or  two  of  these  closely  resemble  the  common 
squash-bug  [Anasa  fristis  De  G.),  but  are  really  very  dis- 
similar, and  whereas  the  beaks  of  the  predaceous  forms  are 
short  and  thick,  as  in  Fig.  139fr,  those  of  plant-feeders, 
like  the  squash-bug,  are  long  and  slender,  as  in  Fig.  1396-. 

Several  species  of  ground-beetles  are  often  found  preying 
upon  the  larvae  and  beetles,  but,  unlike  the  bugs,  attack 
them  by  means  of  their  powerful  biting  jaws.  These 
beetles  are  also  exceedingly  beneficial  in  feeding  upon 
many  other  injurious  insects,  and  are  among  the  farmers' 
best  insect  friends  (Fig.  141). 

Eemedies. — As  an  artificial  remedy  for  this  pest,  Paris 
green  has  long  been  proven  to  be  both  effectual  and  prac- 
tical. 

For  small  areas  it  may  be  used  dry  by  inixing  it  with 
one  hundred  times  its  weight  of  dry  flour,  land-plaster,  or 
air-slaked  lime,  and  should  be  applied  while  the  plants 
are  still  wet  with  dew,  either  by  a  perforated  can,  or, 
better,  by  one  of  the  improved  powder-guns  such  as 
Leggett's,  by  which  two  rows  of  plants  may  be  powdered  at 
once. 


INSECTS    IXJURIOrS   TO    THE    POTATO.  249 

For  larger  areas  a  Avet  application  will  doubtless  be  found 
more  satisfactory.  For  this  purpose  one  pound  of  Paiis 
green  and  one  pound  of  quicklime  to  one  hundred  and 
fifty  gallons  of  water  will  kill  all  the  insects  biting  the 
foliage.  While  the  vines  are  young,  this  may  best  be 
carried  in  a  half  barrel  placed  on  wheels,  and  applied  with 
a  suitable  pump  and  nozzle.  But  as  the  vines  become 
larger  and  the  field  is  more  difficult  to  traverse,  a  knapsack- 
sprayer  will  be  found  advantageous. 

Either  arsenite  of  lime  or  arsenite  of  soda  is  as  effective 
as  Paris  green  and  very  much  cheaper. 

By  observing  the  pest  and  spraying  when  needed,  no 
fear  need  be  had  of  losses  from  this  insect,  and  if  such 
joolicy  were  adopted  by  every  one,  it  would  be  but  a  few 
years  before  we  would  be  comparatively  free  from  it. 

Flea-beetles. 

Among  the  worst  insect  pests  wdth  which  j)otato-growers 
have  had  to  contend  in  recent  years  are  the  small  black 
beetles,  which,  from  their  power  of  making  long,  quick 
jumps,  are  known  as  flea-beetles. 

Indeed,  in  the  Rural  New  Yorker  2:)otato-contest,  in 
1888,  it  was  reported  that  the  variety  "Rural  Seedling 
No.  3  lost  the  day  and  was  nearly  a  failure  on  account  of 
the  ravages  of  the  common  flea-beetle,  Epitrix  cucuntej-is." 

Several  species  are  known  to  attack  the  potato,  the  two 
most  common  being  the  Cucumber  Flea-beetle  (Epitrix 
cucinneris  Harris)  and  one  which  Prof.  H.  A.  Garman  has 
styled  the  Southern  Potato  Flea-beetle  [Epitrix  fuscula). 
The  Tobacco  Flea-beetle  [Epitrix  parvida)  is  not  uncom- 
monly found  on  the  vines  in  sections  where  its  habitue;  1 
food-plant  is  also  grown.      All  of  these  species  are,  how- 


250 


INSECTS   INJURIOUS   TO    STAPLE    CROPS. 


e\ei%  essentially  the  same  in  habits  and  life-history,  and 
fortunately  the  same  remedies  apply  to  all.  Unfortunately, 
the  complete  life-cycle  of  these  little  insects  has  never  been 
carefully  determined,  so  that  only  a  general  outline  can  be 
given. 

During  the  winter  the  beetles  hibernate  under  leaves, 
rubbish,  etc.,  and  in  the  spring  come  forth  and  lay  their 
eggs  upon  the  roots  of  some  of  our  common  weeds,  such 

as  the  horse-nettle,  Jamestown  weed, 
Desmodium,  and  various  members  of 
the  Nightshade  family,  or  Solanacece. 
Here  the  larvae  feed  upon  the  small 
roots  by  mining  in  them,  and  trans- 
form to  pupae  in  small  cells  among 
the  roots.  From  the  pupae  the 
beetles  emerge  and,  after  becoming 

Fig.   143. —The  Potato  hardened,  come  forth  to  attack  the 
or     Cucumber     Flea-   „  ,.  i  •  i    xi  4.  ^.i,  \^ 

beetle  {Epitrlx  cucum-  foliage,  which  they  most  thoroughly 

eris).      Adult    beetle,  riddle,  a  badly  eaten  leaf  appearing 

much  enlarged.  (After 

Chittenden,  U.  S.  almost  as  if  it  had  been  the  target  for 


Dept.  Agr.) 


a  shotgun. 


There  are  at  least  two,  and  possibly  three,  broods  of  most 
of  the  species,  but  I  can  find  few  accurate  records  con- 
cerning them. 

Remedies. — Prof.  C.  M.  Weed,  of  the  New  Hampshire 
Agricultural  Experiment  Station,  has  successfully  used 
'^a  spray  of  lime-wash  made  by  adding  a  pint  or  more  of 
freshly  slaked  lime  to  two  gallons  of  water,  and  then 
thoroughly  mixing  in  about  half  a  teaspoonful  of  Paris 
green.  ^' 

The  use  of  Bordeaux  mixture  as  a  repellant  for  flea- 
beetles  was  first  tested  and  demonstrated  to  be  effectual  by 


INSECTS    IXJURIOUS    TO    THE    POTATO.  251 

Prof.  R.  L.  Jones,  of  the  Vermont  Experiment  Station. 
Prepare  the  mixture  in  the  usual  manner,  using  six  pounds 
of  copper  sulfate  and  four  pounds  of  freshly  slaked  quick- 
lime to  fifty  gallons  of  water,  to  which  is  added  four  ounces 
of  Paris  green,  for  the  destruction  of  any  other  insect 
pests. 

Spray  this  upon  the  vines  so  that  they  are  well  coated. 
Where  this  has  been  carefully  tested  it  has  been  reported 
as  a  very  successful  repellant. 

A  few  plants  may  be  protected  from  flea-beetles  by 
covering  tiiem  with  a  frame  composed  of  two  crossed 
barrel-hoops  on  which  is  tacked  some  mosquito-netting  or 
other  material;  but  this  method  is  hardly  practicable  upon 
large  areas. 

Blister-beetles  [Meloidce). 

Long  before  we  had  made  the  acquaintance  of  the 
Colorado  potato-bug,  several  species  of  blister-beetles  fre- 
quently brought  themselves  into  notice  by  their  injuries, 
and,  therefore,  are  now  known  as  the  *' old-fashioned 
potato-bugs.^" 

The  name  of  '' blister-beetles"'  has  been  bestowed  upon 
them  because  of  the  blistering  effect  which  they  have  upon 
the  skin,  they  being  nearly  related  to  the  Spanish  Fly, 
used  for  that  purpose,  and  are  themselves  brought  to 
manufacturing  chemists. 

One  of  the  most  common  of  these  is  the  Striped  Blister- 
beetle,  which  has  three  yellow  strij^es  upon  its  wing-covers, 
while  the  other  two  common  forms  are  of  a  slate-black 
color. 

Very  often  when  these  beetles  congregate  in  great  num- 
bers they  are  a  great  nuisance,  not  only  in  the  potato- 


252  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

patch,  but  upon  mauy  otlier  plants  of  the  garden  or  truck- 
farm. 

Unfortunately,  they  present  to  the  farmer  a  very 
peculiar  problem,  for  while  the  beetles  are  often  exceed- 
ingly injurious,  the  larvse  are  even  more  beneficial,  in 
eating  large  quantities  of  grasshoppers'  eggs. 

JAfe-Msiory, — The  life  of  these  insects  is  unique.  The 
female  lays  a  large  number  of  eggs  in  a  small  cavity  in  the 
earth,  and  from  these  hatch  some  small,  long-legged  larvae, 
"which  run  about  searching  for  the  pod-like  masses  of 
grasshoppers'  eggs,  upon  which  they  feed.  As  soon  as  the 
appetite  of  one  of  these  little  egg-hunters  is  appeased,  he 
sheds  his  skin,  and  now  being  surrounded  by  food  and  no 
longer  needing  his  long  legs  for  running,  in  this  next  stage 
of  his  existence  the  legs  are  very  short  and  rudimentary, 
and  he  remains  almost  immobile  while  feeding  upon  the 
rest  of  the  eggs. 

Thus,  if  their  destructiveness  be  not  too  severe,  it  would 
not  be  good  policy  to  destroy  these  beetles  whose  offspring 
are  so  beneficial. 

Three-lined  Leaf-beetle  {Lema  trilineaia  Oliv.). 

Closely  related  to  the  Colorado  Potato-beetle,  and  very 
similar  to  it  in  habits,  is  the  Three-lined  Leaf -beetle 
[Lema  trilineata  Oliv.).  The  eggs  can  scarcely  be  distin- 
guished from  those  of  that  insect  except  by  the  fact  that 
they  are  usually  laid  in  rows  along  the  midrib  on  the 
under  side  of  the  leaf,  while  those  of  the  former  are  laid 
indiscriminately  in  bunches. 

The  larvae,  however,  may  be  readily  distinguished  from 
all  other  insects  attacking  the  potato  by  being  covered 
with  a  disgusting  mass  of  their  own  excrement. 


INSECTS    INJURIOUS   TO    THE    POTATO. 


253 


There  are  two  broods  during  the  season,  the  hirva?  of 
the  first  appearing  in  June,  and  that  of  the  second  in 
August;  but  the  beetles  of  the  second  brood  do  not  emerge 
until  the  following  spring.  In  other  respects  the  life- 
history  is  practically  the  same  as  that  of  the  Colorado 
Potato-beetle.  The  beetle  is  of  a  pale  yellow  color,  with 
three   black   stripes  on  its  back,  and  in   a   general  way 


Fig.   144. — Three-lined    Leaf-beetle   (Lema   trilineata    Oliv.).     a, 
larva;  h,  pupa;  d,  eggs;  beetle  at  right.     (After  Kiley.) 

resembles  the  common  striped  Cucumber-beetle  (Diahrotica 
vittata  Fab.),  though  it  is  somewhat  larger  and  the  thorax 
is  decidedly  constricted. 

In  case  it  becomes  necessary  to  destroy  the  Blister- 
beetles,  both  they  and  the  Three-lined  Leaf -beetle  may  be 
readily  disposed  of  by  applying  Paris  green  or  other  arsen- 
ite  as  advised  for  the  Colorado  Potato-beetle. 


CHAPTER   XIII. 

I:N^SECTS   mJURIOUS   to   the   SUGAR-BEET.* 

INJURIN^G    THE    ROOT. 

White  Grubs  and  Wireworms.     (See  images  44  and  48.) 

FoRTUisrATELY  for  the  sngar-beet  farmer  the  worst  insect 
enemies  of  that  pest  feed  npon  the  tops,  and  very  rarely 
do  we  hear  of  serious  damage  being  done  the  roots.  In 
the  East  most  of  the  damage  to  the  roots  is  done  by  those 
two  familiar  old  farm-thieyes,  the  white  grub  and  the 
wireworm.  As  a  general  rule  they  will  be  found  to  be 
worse  on  lands  previously  in  sod,  which  should  therefore 
be  avoided  when  known  to  be  badly  infested  with  either  of 
these  insects,  as  both  are  diflicult  to  fight  after  they  have 
once  commenced  doing  noticeable  injury. 

As  the  wireworm -beetles  —  "  click-beetles  "  —  become 
mature  in  late  summer,  but  remain  in  the  pupal  cell  in  a 
half-hardened  condition  over  winter,  much  can  be  done 
toward  destroying  them  l)y  plowing  late  in  the  summer 
and  keeping  the  land  stirred  for  a  month  or  so,  in  this  way 
exposing  the  newly  transformed  tender  beetles  to  the  fall 
frosts. 


*  See  Forbes  and  Hart,  "The  Economic  Entomology  of  the 
Sugar-beet,"  Univ.  Ill  Agr.  Exp.  Sta.,  Bull.  Xo.  60,  Aug.  1900, 
for  summary. 

254 


IXSECTS    INJURIOUS    TO    THE    SUGAR-BEET.  255 

The  Beet-aphis  (Pem^jhigus  letce  Doane). 

This  species  was  first  described  by  Mr.  W.  R.  Doane  in 
1900  and  seems  thus  far  to  have  been  found  only  in 
Washington  and  Oregon.  "^Attention  was  first  called  to 
this  pest/^  he  says,*  "in  1896,  when  it  was  found  that  a 
field  of  two  or  three  acres  of  beets  was  generally  infested, 
a  strip  of  twenty-five  to  a  hundred  yards  being  so  badly 
injured  that  the  beets  were  nearly  all  soft  and  spongy,  and 
the  plants  much  smaller  than  the  averiige.  f 

' '  It  has  been  even  more  destructive  in  Oregon  than  in 
Washington,  at  least  a  thousand  tons  of  beets  having  been 
destroyed  by  it  in  one  year  in  a  single  valley  devoted 
largely  to  beet-culture.  Like  very  many  other  beet-insects, 
this  species  infests  also  several  wild  or  useless  plants. 

"The  smaller  rootlets  of  the  beet  are  first  attacked  by 
this  aphis,  and  if  it  occurs  in  considerable  numbers  these 
are  soon  all  destroyed,  and  the  leaves  thereupon  soon 
wither,  and  the  whole  beet  shrivels  and  becomes  spongy. 
This  wilting  of  the  leaves  will  frequently,  in  fact,  be  the 
first  thing  to  attract  the  attention  of  the  beet-grower. 
The  actual  injury  to  the  crop  will,  of  course,  depend 
largely  upon  the  time  when  the  attack  of  the  aphis  is 
made.  If  the  plants  are  small  they  may  be  readily 
destroyed,  while  if  they  are  practically  full-grown  the  loss 
of  the  small  rootlets  will  not  materially  affect  them. 

*  ^  No  sexual  generation  of  this  aphis  has  as  yet  been  dis- 
covered and  no  eggs  have  been  seen,  viviparous  reproduc- 
tion continuing  throughout  the  year  except  when  the  cold 


*  Bull.  No.  42,  Wash.  Agr.  Exp.  Sta. 

t  Forbes  and  Hart,    Bull.    Xo.    60,    Univ.    111.    Agr.   Exp.    Sta., 
p.  507. 


25G  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

of  the  winter  temporarily  suspends  the  physiological 
activities  of  the  species.  The  winged  females,  appearing 
from  time  to  time  during  the  summer  and  fall,  serve  to 
distribute  the  species  generally,  new  colonies  being  started 
wherever  these  females  find  lodgment  and  food.  In  dis- 
tricts liable  to  injury  by  this  insect  it  seems  inadvisable 


k 

Fig.  145. — The  Beet-aphis  {Pemphigus  beire  Doane).  a,  winged 
female;  b,  wingless  female;  c,  antenna  of  winged  female. 
(After  Doane.) 

that  beets  should  be  the  fiist  crop  on  new  land,  or  that 
ground  should  be  continued  in  beets  or  in  any  other  root- 
crop  after  the  pest  has  made  its  appearance  in  the  field." 

CUTTING    THE   TOPS. 

Cutworms. 

Like  all  similar  crops,  the  sugar-beet  is  often  subject  to 
the  midnight  raids  of  the  deadly  Cutworms,  and  when 
present  in  any  number  they  should  be  carefully  guarded 
against  while  plants  are  young.  Like  the  Web -worms, 
they  are  worse  upon  a  sandy  soil,  and  like  the  Wireworms, 
when  the  beets  are  on  land  previously  in  grass. 

These  well-known  depredators  are  the  larvae  of  moths, 
which,  from  their  habit  of  flying  at  night,  are  known  as 


INSECTS    IXJURIOUS    TO    THE    SUGAR-BEET. 


257 


Noctuidas.  The  injurious  species  belong  almost  entirely 
to  the  genera  Mmnestris,  Hadena,  and  Agrotis,  and  are 
sufficiently  alike  in  their  habits  and  life-history  that  the 
same  methods  may  in  general  be  applied  to  all.  The 
worms  are  of  dull  brown,  gray,  or  greenish  hues,  generally 
with  longitudinal  stripes,  and  often  with  oblique  dashes. 


Fig.  146. — Peridromia  snicin.  a,  adult;  b,  c,  d,  full-grown  larvae; 
e,  f,  eggs— all  natural  size  except  e,  which  is  greatly  enlarged. 
(After  Howard,  U.  S.  Dept.  Agr.) 

They  are  one  and  one-fourth  to  almost  two  inches  in  length 
and  rather  stout,  but  tapering.  The  head  and  segment 
back  are  reddish  brown  and  horny.  There  are  eight  pairs 
of  legs;  the  first  three  jointed  and  tapering,  the  last  five 
(pro-legs)  short  and  stout.  Besides  the  beets  they  have 
been  recorded  as  injuring  almost  every  croj^  of  the  farm, 
orchard,  and  garden.  Beets,  turnips,  and  many  of  the 
garden  crops  are  cut  off  at  the  neck  just  below  the  surface 
of  the  soil.     Like  the  adults,  the  worms  feed  only  at  night, 


258 


INSECTS    INJURIOUS    TO    STAPLE    CHOPS. 


excepting  when  a  scarcity  of  food  causes  them  to  assemble 
and  assume  tlie  marching  habit  of  the  army-worm  during 
the  day.  For  this  reason  their  work  often  remains 
unnoticed  until  the  damage  is  done,  and  no  remedy  can 
repair  the  loss.  The  characteristic  mode  of  attack  is  to 
cut  off  the  young  plant  at  the  surface  of  the  ground  and 
leisurely  feed  upon  the  leaves  and  stem,  but  several  species 


Fig.  147.  —  The   Dark-sided  Cutv7orm  {Agrotls  messoria).      (After 

Riley.) 

remain  entirely  under  the  soil,  pulling  the  j^lant  more  or 
less  into  their  subterranean  retreat.  The  life-history  of 
the  various  species  of  cutworms  varies  considerably,  and 
has  not  been  entirely  ascertained  for  many  of  them,  but 
whatever  it  may  be  they  are  always  on  hand,  ready  to  nip 
the  young  jDlants  as  soon  as  set  out. 

Remedies. — All  things  considered,  no  remedy  has  as  yet 
been  devised  which  is  more  satisfactory  or  efficient  than  that 
of  a  mixture  of  bran  or  middlings  and  Paris  green.  This 
consists  of  mixing  one  pound  of  Paris  green  with  forty  of 
bran  or  middlings,  barely  moistening  this  with  water  into 
which  has  been  stirred  about  two  quarts  of  cheap  molasses 


IXSECTS   INJURIOUS    TO    THE    SUGAR-BEET. 


250 


or  sorghum.  The  molasses  gives  the  mash  more  or  less  of 
an  odor,  and  renders  it  slightly  more  palatable.  Do  not 
have  the  mixture  too  wet  or  it  will  "  cake."^  Apply  this 
at  the  rate  of  a  heaping  tablespoonful  about  every  three 
feet  in  the  rows.  Equally  good  results  have  been  obtained 
by  using  thirty  pounds  of  bran  and  middlings,  dr}^  in 
equal  parts,  with  one  pound  of  Paris  green,  which  is  easily 


Fig.   148. — The    Granulated    Cutworm  {Agrotis   annexa).     (After 

Riley.) 

scattered  by  hand  or  by  means  of  an  onion-drill.  When 
the  worms  are  known  to  be  present  the  mash  should  be 
applied  two  or  three  days  before  the  young  plants  appear, 
in  which  case — having  no  other  food — large  numbers  of 
the  worms  will  be  killed.  If  applied  later,  distribute 
the  mash  late  in  the  afternoon,  so  that  it  will  be  fresh 
when  the  worms  come  out  in  the  evening. 


IN^JURIIfG   THE    LEAVES. 

Web-worms  {Loxostege  spp.). 

Possibly  the  most  destructive  sugar-beet  insects  are  the 
common  Garden  Web-worm  [Loxostege  similaJis  Gn.),  and 


260 


INSECTS   INJURIOUS   TO    STAPLE   CROPS. 


ihe  Sugar-beet  Web-worm  {Loxostege  stidUdis  Linn.),  Lirv^ 
of  very  closely  allied  moths  of  the  family  PyralidcB.  Until 
the  summer  of  1892  they  had  not  been  noted  east  of  the 
Mississippi  River,  confining  themselves  to  a  region  west  of 
that  to  the  Rockies  and  north  of  the  Platte  River.  But 
in  September  of  that  year  they  destroyed  fully  fifty  joer 
cent  of  the  tansy  croj),  which  is  largely  grown  for  oil  near 
Menon,  Mich.,  and,  since  the  extensive  growing  of  the 
sugar-beet  had  hardly  commenced  at  that  time,  it  is  safe  to 
assume  that  with  its  more  general  culture  in  the  East  these 
two  pests  will  accompany  it. 


The  Garden  Web-worm. 

The   greatest  injury  seems  to   be   done  by  the  second 
brood  of  caterpillars  in  July,  and  in  Nebraska  there  are 


Fig.  149. — The  Garden  Web-worm  {Loxostege  similalis  Gn.). 

three  broods  during  the  season.  When  the  fall  brood  has 
become  full-grown  it  burrows  into  the  earth,  forms  small 
cells,  neatly  lined  with  silk,  and  there  lies  dormant  during 
the  winter,  transforming  to  pupte  the  next  May.  The  moths 
emerge  in  a  week  or  ten  days,  and  at  once  commence  to 
lay  eggs  upon  the  leaves  of  the  23lants.  They  are  pretty 
little  moths,  with  a  wing-expanse  of  about  three-fourths 


INSECTS   IXJURIOrS   TO   THE    SUGAR-BEET.  201 

of  iin  incli,  quite  variable  in  color,  but  generally  an  orange 
or  reddish  yellow,  inclining  to  a  shade  of  gray.  Their 
characteristic  dark  and  light  markings  are  well  shown  in 
the  figure.  The  eggs  of  the  latter  worm  are  a  pale  yellow, 
circular,  somewhat  flattened,  and  laid  either  singly  or  in 
rows  of  four  or  five.  The  yonng  worms  hatch  in  a  few 
days,  and  often  do  serious  injury  by  feeding  upon  the 
foliage  of  the  plant,  always  spinning  a  light,  silken  web 
over  them.  Most  of  the  feeding  is  done  at  night,  but 
during  the  last  stage  they  may  be  found  during  the  day. 
This  brood  matures  in  about  ten  days  after  hatching, 
pupates,  and  the  moths  emerge  early  in  July,  giving  rise 
to  the  destructive  July  brood  of  worms.  The  larv^,  or 
'*  web-worms, ^^  are  about  five-eighths  of  an  inch  long  when 
full-grown,  and,  like  the  moth,  are  variable  in  color,  being 
either  a  pale,  dark,  or  even  greenish  yellow.  They  are 
distinctly  marked  by  several  rows  of  black  spots,  which  are 
surrounded  by  a  plain  border,  as  in  Fig.  149. 

Jiemedies. — Deep  plowing  or  thorough  harrowing  in  the 
fall  after  the  larvae  have  entered  the  cocoons  in  the  earth 
will  destroy  large  numbers  of  them.  When  the  worms 
appear  in  destructive  numbers  upon  the  foliage  they  may 
be  controlled  by  a  spray  of  Paris  green  or  other  arsenite, 
using  one  pound  to  125  gallons  of  water,  providing,  of 
course,  that  the  tops  are  not  to  be  fed  to  stock.  An 
under- spray  nozzle  should  be  used,  so  as  to  reach  all  parts 
of  the  plant  in  an  effective  manner.  When  present  in 
large  numbers  and  doing  serious  injury  the  worms  can  be 
more  quickly  killed  by  spraying  with  strong  kerosene 
emulsion,  but  this  will  only  kill  those  hit,  and  an  ar- 
senite should  also  be  applied  without  delay. 


^62  INSECTS   INJURIOUS   TO    STAPLE   CROPS. 


The  Beet  Army-worm  {Lajihygma  fiavimaculata  Harr.). 

''This  caterpillar,  which  replaces  the  Grass-worm 
(L.  friigiperda — see  page  84)  in  the  Western  States,  differs 
from  it  by  its  more  decidedly  mottled  ground-color,  by  a 
row  01  white  dots  at  the  lower  margin  of  the  lateral  dark 
band,  and  by  the  yellower  color  of  the  light  stripes.  It  is 
an  interesting  fact  that  while  the  preceding  species  was 
doing  serious,  unusual,  and  wide-extended  injuries  in  the 
Eastern  and  Southern  States  (1899),  the  present  one  was 
similarly  abundant  in  Colorado,  where,  besides  destroying 
many  kinds  of  weeds  and  grasses,  it  completely  defoliated 
thousands  of  acres  of  sugar-beets.  In  some  cases  where 
the  foliage  of  the  beet  did  not  furnish  it  sufficient  food, 
the  root  was  attacked  and  the  upper  surface  was  completely 
gnawed  away.  Late  plantings  of  course  suffered  most 
severely,  especially  when  surrounded  by  newly  broken 
ground.  The  weeds  most  generally  eaten  were  pigweed, 
saltweed,  wild  sunflower,  and  cleome.  Potato-,  pea-,  and 
apple-leaves  were  also  devoured.  These  injuries  occurred 
about  the  middle  of  August,  at  which  time  the  larvae  and 
pupa3  were  abundant,  and  a  few  moths  laden  with  eggs 
were  noticed." 

This  species  evidently  hibernates  as  a  moth,  and  at 
least  two  broods  of  larvae  may  be  looked  for  each  year,  the 
first  about  June  and  the  second  in  August.  The  species 
has  been  reported  thus  far  from  Colorado  and  California, 
but  it  doubtless  has  a  more  extended  range  in  the  moun- 
tain region  of  the  far  West. 

*'  Prof.  Gillette's  field-experiments  showed  that  it  could 


INSECTS    IXJURIorS    TO    THE    SUGAR-BEET. 


263 


be  destroyed  by  dusting  or  spraying  arsenical  poisons  on 

the  leaves. ' '  * 

Plant-bugs. 

The  Tarnished  Plant-bug  [Lygus  pratensis),  False 
Chinch-bug  {Kysius  angustahis),  and  several  of  the 
common  plant-bugs  often  become  so  numerous  as  to  do 
considerable  damage.  When  present  in  large  numbers,  a 
spray  of  kerosene  emulsion  or  kerosene  and  water  might 


Fig.  150 — The  False  Chinch-bug  {JVysivs  angustatus  .  (After  Riley.) 


Fig.  151. — Tarnished  Plant-bug  [Li/gus  p)'aie?is's  Linn.).  «,  young, 
first  stage;  b,  young,  third  stage  (X3);  c,  adult  (x2) — all  en- 
larged.    (After  Stedman.) 

be  used  to  great  advantage.  Recent  experiments  in  New 
York  show  that  the  Tarnished  Plant-bug  can  be  driven 
from,  a  field  by  dusting  the  rows  with  wood-ashes,  beiug 
careful  to  work  on  the  same  side  of  each  row  and  thus 
gradually  driving  them  into  the  field  adjoining. 


*  Forbes  and  Hart,  1.  c.,  facts  derived  from  statements  of  Prof.  C. 
P.  Gillette. 


264  INSECTS   INJURIOUS   TO    STAPLE    CROPS. 

Flea-beetles. 

Several  species  of  flea-beetles,  chiefly  Systena  tcsniata, 
Systena  Mulsonias,  Disonycha  ti'iangularis,  and  Phyllotreta 
vittata,  often  do  considerable  injury  by  gnawing  small 
holes  in  the  npper  and  lower  surfaces  of  the  leaf,  giving  it 
an  appearance  as  if  affected  by  leaf-sj^ot,  or  puncturing  it 
full  of  small  holes,  and  thus  stunting  the  growth  of  the 
plant. 

The  Yellow-black  Flea-beetle  (Diso7iycha  xantliomelcena). 

This  is  one  of  the  common  beet-insects,  both  the  larva 
and  adults  feeding  upon  the  leaves.  It  may  be  distin- 
guislied  among  the  Flea-beetles  by  its  comparatively  large 
size  (its  length  about  a  quarter  of  an  inch),  by  its  metallic 
greenish-blue  or  black  head  and  wing-covers,  with  the 
thorax  uniformly  pale  yellowish  above  and  black  beneath, 
and  the  abdomen  yellow  beneath. 

A  much  smaller,  also  very  abundant,  species  whose 
injuries  in  spring  frequently  attract  attention  is  the  Pale- 
striped  Flea-beetle  {Systena  tmniata).  This  is  about  an 
eighth  of  an  inch  in  length,  light  yellowish  brown  in 
general  color,  with  a  l)road,  pale  stripe  down  each  wing- 
cover. 

Most  of  the  Flea-beetles  are  so  similar  in  their  general 
habits  that  they  may  be  treated  together,  and  the  same 
remedies  will  be  applicable  for  each  species.  The  beetles 
hibernate  over  winter  in  woodlands,  under  rubbish,  etc., 
and  in  the  early  spring  deposit  their  eggs  on  the  roots  of 
common  weeds  of  the  family  Solo7iace(B,  such  as  the  James- 
town weed,  horse-nettle,  etc.  On  these  the  larva?  feed, 
mining  the  roots  and  stems  of  the  plants.     When  full- 


INSECTS    IXJURIOUS    TO    THE    SUCtAR-BEET.  265 

grown  the  larva  transforms  to  a  pupa  inside  a  small 
earthen  cell,  and  a  week  or  ten  days  later  the  adult  beetle 
emerges.  The  beetles  may  feed  for  a  short  time  on  the 
larval  food-plant,  but  they  soon  desert  it  for  some  culti- 
vated crop.  A  spray  of  Paris  green  and  Bordeaux  mixture 
will  be  found  effectual  in  ridding  the  plants  of  these  pests. 
It  should  be  applied  liberally  and  the  spraying  should  be 
repeated,  if  necessary,  after  a  heavy  rain. 

Clean  Culture. — But  there  is  one  very  simple  method 
for  securing  immunity  from  all  the  pests  so  far  mentioned, 
which  should  be  practiced  even  were  no  insects  present. 
There  can  be  no  doubt  that  the  natural  food-plants  of  all 
these  insects.  Web-worms,  Flea-beetles,  and  Plant-bugs, 
consists  of  the  common  pigweeds,  tumbleweeds,  Jamestown 
weeds,  etc.  Thus,  a  field  planted  in  beets,  which  has  been 
idle  and  allowed  to  grow  up  in  weeds,  is  always  the  most 
subject  to  insect  attack,  and  it  is  always  well  to  grow 
some  crop  prior  to  beets,  and  subsequently  to  pursue  as 
much  of  a  rotation  as  possible.  Fields,  fences,  and  road- 
sides should  be  kept  well  cleaned  from  these  weeds,  espe- 
cially during  the  fall,  after  the  crop  is  harvested,  and  with 
such  precautions  the  few  of  these  insects  that  are  always 
present  will  do  but  slight  injury. 

Blister-beetles  (Meloidce). 

Among  those  insects  attacking  the  young  sugar-beets 
and  often  doing  considerable  damage  after  they  have 
become  partly  grown,  few  are  more  wide-spread  or  do  more 
general  injury  than  the  Blister-beetles.  They  have  been 
especially  destructive  in  the  northern  Mississippi  Valley, 
where  they  are  usually  worst  after  a  period  of  unusual 
abundance  of  grasshoppers.      Coming  suddenly  in  a  large 


2B6 


INSECTS   INJURIOUS   TO    STAPLE    CROPS. 


swarm,  tliey  settle  in  a  field  and  tlioroiiglily  riddle  the 
foliage  with  holes  or  strip  it  bare  before  going  to  another 
field. 

One  of  the  most  common  forms  is  the  Striped  Blister- 
beetle,  or  ^^old-fashioned  potato-bug"  (Epicauta  vittata), 
which  is  shown  in  the  illustration,  together  with  the  im- 
mature stages.  The  asli-gray  Blister-beetle  [Meter ohasis 
unicolor)  is  also  a  common  form,  shown  in  Fig.  153. 
Three  or  four  other  forms  are  common  throughout  the 
country,  but  are  especially  numerous  in  the  West,  where 
grasshoppers  are  more  abundant.  The  reason  for  this  is 
apparent  when  we  come  to  consider  the  life-history  of  the 
pest,  for  the  Blister-beetles  are  not  an  unmixed  evil. 

Life-liistory. — In  a  small  cavity  in  the  earth  the  female 
beetle  lays  some  four  or  five  hundred  eggs,  these  being 


Fig.  152. — Striped  Blister-beetle  {Epicauta  mttata).  a,  larva;  c,  d, 
hibernating  stage  of  larva:  adult  beetle  at  right,  and  pupa  at 
a,  b.     (After  Riley.) 

deposited  from  July  to  October.  About  ten  days  later  the 
eggs  hatch,  and  from  them  emerge  some  small  but  very 
active  larv»,  with  long  legs,  large  heads,  and  strong  jaws. 
They  at  once  commence  running  about  in  search  of  the 
pod-like  masses  of  grasshoppers'  eggs,  and  as  soon  as  one 
is  found  the  larva  enters  it  and  commences  a  hearty  meal. 
As  soon  as  his  appetite  has  been  somewhat  satisfied  he 
sheds  his  skin,  and  now  being  surrounded  by  food  and  no 


INSECTS    INJURIOUS    TO    THE    SUGAR-BEET. 


267 


longer  needing  his  long  running  legs,  they  are  changed  for 
very  short,  aborted  legs,  and  the  larva  is  soft  and  sluggish. 
In  another  week  a  second  molt  takes  place,  after  which 
the  legs  and  even  the  mouth-parts  are  still  more  atrophied. 
After  another  molt  and  after  consuming  all  the  eggs  in  the 
pod,  the  larva  now  goes  deeper  in  the  soil,  and  inside  a 
small  oval  cavity  again  sheds  its  skin,  and  hibernates  over 
winter  as  a  sort  of  semipupa.     In  the  spring  the  larva 


Fig.  153. — a,  Ash-gray  Blister-beetle  [Macrobasis  unicolor;  h,  Epi- 
cauta  pennsylvanica.     (After  Riley.) 

appears  again  much  like  the  second  stage,  but  does  not  eat 
much,  and  soon  goes  into  the  pupal  stage  from  which 
emerges  the  adult  beetle.  Altogether  the  life-history  is 
one  of  the  most  peculiar  and  complicated  among  insects. 
Thus  the  Blister-beetles  are  one  of  the  most  important 
factors  in  holding  the  grasshoppers  in  check, 

Bemcdies.  —  However,  when  they  swarm  into  the  beet- 
fields,  potato-  or  garden-patches,  one  cannot  afford  to 
allov/  them  to  consume  one  crop  for  the  good  they  may  do 
in  saving  anotlier  from  still  another  insect  scourge.  ''A 
bird  in  the  hand  is  worth  two  in  the  bush,"  is  equally  true 
of  insects.  So  be  ready  for  them  on  tlieir  first  appearance; 
give  the  plants  a  thorough  spraying  with  Paris  green,  at 
the  rate  of  one  pound  and  one  pound  of  lime  to  125  gallons 


268  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

of  water,  and  when  sprayed,  it  would  be  well  to  spray  it 
with  Bordeaux  mixture,  which  will  prevent  various  fun- 
gous diseases,  and  with  which  Paris  green  can  be  used 
much  stronger  without  danger  of  burning  the  foliage;  or 
it  may  be  ajoplied  dry  by  mixing  with  from  ten  to  twenty 
parts  of  flour  or  plaster,  dusting  it  on  in  early  morning, 
while  the  dew  is  still  on  the  plants.  Any  other  arsenical 
poison  will  prove  equally  effective,  if  used  at  the  proper 
strength. 


CHAPTEE   XIV. 

INSECTS   INJURIOUS   TO   THE   HOP-PLANT. 

INJURING    THE    STALK. 

The  Hop-plant  Borer  {Hydrcecia  immanis  Grt.). 

The  Hop-plant  Borer  is  sometimes  the  occasion  of  a 
considerable  loss  to  the  hop  industry,  Mr.  Chas.  R.  Dodge 
having  estimated  upon  the  basis  of  the  census  of  1879  that 
it  annually  amounts  to  $600,000  in  New  York  State  alone. 
The  moths  have  been  taken  from  Ontario  and  New  Eng- 
land south  to  the  District  of  Columbia,  and  west  to 
Wisconsin,  and  also  from  Colorado  and  Washington,  but 
the  larvffi  have  never  become  injurious  in  the  hop-fields  of 
the  Pacific  Coast.  *^It  is  probable  that  it  is  a  northern 
form,  and  confined,  as  it  seems  to  be,  to  a  single  food- 
plant,  it  will  be  found  only  where  this  plant  is  known  to 
grow. "  * 

Life-liistory . — Many  of  the  moths  emerge  from  the 
pup^e  in  the  fall  and  hibernate  over  winter,  while  others 
do  not  transform  till  spring,  passing  the  winter  in  the 
pupal  stage,  in  a  small  cell  in  the  ground  near  the  roots 
of  the  i^lant  which  the  larv^  have  infested.  The  moths 
appear  during  May,  and  the  females  deposit  their  globular, 

*  "Some  Insects  Affecting  the  Hop-plant,"  L.  O,  Howard,  Bull. 
No.  7,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  p.  41. 

269 


270 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


yellowish -green  eggs  uj^on  the  tips  of  the  hop-vines  just 
as  they  begin  to  climb.  ' '  The  Qgg  hatches  in  a  few  days 
and  produces  a  minute  slender  greenish  larva,  spotted  with 
black,  which  immediately  burrows  into  the  vine  just  below 
the  tip,  and  spends  a  part  of  its  life  in  the  vine  at  this 
point.     The  vine  soon  shows  the  effects  of  the  insects' 


Fig.  154.— Hop-plant  Borer  {Hydrceda  immanis  Grt.).  a,  enlarged 
segment  of  larva;  h,  larva;  c,  pupa;  d,  adult,  natural  size. 
(After  Howard,  U.  S.  Dept.  Agr.) 

work;  instead  of  pointing  upward,  embracing  the  pole 
readily  and  growing  rapidly,  the  tip  points  downward,  will 
not  climb,  and  almost  entirely  ceases  growing.  This 
appearance  is  called  by  growers  a  "^  Muffle-head.'  When 
the  insect  attains  a  length  of  about  half  an  inch,  or 
slightly  less,  it  leaves  the  tip,  drops  to  the  ground,  and 
entering  the  stem  at  the  surface  of  the  vine,  feeds  upward, 
interrupting  the  growth  of  tlie  vine  and  lessening  its 
vitality;  the  larva  now  changes  color,  and  becomes  a  dirty- 
white,  with  a  strong,  deep  reddish  tint,  with  numerous 
black  spots.     The  larva,  now  about  an  inch  in  length,  and 


INSECTS    IXJURIOUS   TO    THE    HOP-PLAXT.  271 

still  slender,  burrows  downward  to  the  base  of  the  vine  at 
its  juncture  with  the  old  stock,  and  eating  its  way  out, 
completes  its  growth  as  a  subterranean  worker;  it  is  in 
this  state  that  it  is  best  and  most  widely  known  as  the  hop 
'  grub,^  and  the  ravages  caused  by  it  are  most  noted."  * 

The  larvae  have  mostly  left  the  stems  by  the  last  of  June 
and  henceforth  are  mainly  sap-feeders.  Eating  into  the 
stem  just  below  the  surface  of  the  ground  and  just  above 
the  old  root,  they  rapidly  grow  fat  upon  the  juices  of  the 
plant.  These  openings  are  gradually  enlarged  so  that  very 
often  the  stem  is  entirely  severed  from  the  root  or  is  so 
slightly  attached  that  the  plant  is  badly  stunted  and  yields 
few,  if  any,  hops.  The  larvj^e  become  full-grown  from 
the  middle  to  the  20th  of  July  and  are  then  ^' about 
two  inches  in  length,  fleshy,  unwieldy,  and  very  slow  in 
their  movements;  they  are  of  a  dirty  white  color,  speckled 
with  line,  brownish  elevated  tubercles,  each  furnished  with 
a  single  stout  hair;  the  head  is  brownish  and  corneous,  as 
is  also  the  top  of  the  first  segment."     (1-c.) 

The  larva3  now  transform  to  pupse  in  rough  cells,  close 
to  the  roots  which  they  have  infested,  and  the  adult  moths 
emerge  during  August  or  September,  or  the  following 
spring.  The  adult  moths  are  found  to  be  most  beautifully 
marked  upon  close  examination,  though  not  of  a  striking 
appearance  at  first  sight.  ' '  The  general  color  is  a  rosy 
broAvn,  paler  at  the  extremity  of  the  wings.  The  darker 
central  portion  is  shaded  with  dark  velvety  bronze  and 
marked  with  two  dull-yellow  spots.  The  fore  wings  are 
divided  into  three  areas  by  narrow  oblique  transverse  lines, 

*  "Hop -insects,"  Dr.  J.  B.  Smith,  Bull.  Xo.  4,  o.  s.,  Div.  Ent. 
U.  S.  Dept.  Agr. 


272  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

edged  outwardly  with  pink.  The  hind  wings  are  paler  in 
color,  crossed  in  the  middle  by  a  slightly  darker  line." 
(Howard,  I.e.) 

Remedies. — Two  points  in  the  life-history  of  the  insect 
a:£ford  oj^portnnity  for  its  control.  The  first  of  these  is 
when  the  young  larvae  are  still  in  the  tips  and  can  easily 
be  crushed  by  the  fingers  when  tying  the  vines.  ' '  Muffle- 
heads  "  should  always  be  picked  off  and  destroyed. 

Early  in  June  when  the  larvae  have  left  the  inside  of  the 
vines  it  is  well  to  remove  all  the  soil  from  the  base  of  the 
vine,  down  to  the  junction  with  the  old  root.  The 
larvae,  which  will  not  feed  above  ground,  will  go  to  the 
old  roots^  to  which  they  will  do  but  little  injury.  The 
roots  should  be  left  thus  exposed  for  about  a  week.  A 
handful  of  mixture  of  coal  and  wood  ashes  or  ammoniated 
phosphate  should  then  be  applied  to  each  and  the  plants 
hilled  high.  The  plant  will  now  send  out  new  rootlets 
from  the  main  root,  and  is  able  to  secure  necessary  nour- 
ishment through  them. 

INJURING    THE    LEAVES. 

The  Hop-louse  {Pliorodon  liumuli  Schr.). 

Like  many  another  aphid  the  Hop-louse  has  a  most 
interesting  life-history,  which  has  been  fully  ascertained 
in  but  recent  years.  During  the  winter  the  small  oval 
black  eggs  may  be  found  in  the  crevices  and  around  the 
buds  of  the  terminal  twigs  of  plum-trees  near  infested  liop- 
fields.  From  these  hatch  a  generation  of  females,  known 
as  '^stem-mothers,"  during  the  following  spring.  The 
lice  of  this  generation  differ  in  being  stouter,  with  shorter 
legs  and  honey-tubes  than  those  of  any  other  generation. 
Three  generations  feed  upon  the  plum,  the  third  becoming 


INSECTS    IXJURIOUS    TO    THE    HOP-PLANT.  273 

winged  and  at  once  flying  to  its  favorite  food  in  the  hop- 
field. 

Throughout  the  summer  the  lice  are  produced  partheno- 
genetically,  as  are  almost  all  plant-lice  (see  page  136). 
They  "  multiply  with  astonishing  rapidity  for  from  five  to 
twelve  generations,  carrying  us  in  point  of  time  to  the 
hop-picking  season.''  '^Each  parthenogenetic  female  is 
capable  of  producing  on  an  average  one  hundred  young 


Fig.  155. — AYinter  Eggs  of  the  Fig.  156.— The  Hop  Plant-louse, 

Hop  Plant-louse,   and   sliriv-  stem-mother,  with  enlarged  an- 

eled  skin  of  the  sexual  female  t^'umie     above.       (After    Riley, 

which   laid    them — enlarged.  U.  S.  Dept.  Agr.) 
(After  Riley,  U.  S.  Dept.  Agr. ) 

(the  stem-mother  probably  being  more  prolific),  at  the  rate 
of  one  to  six,  or  an  average  of  three  per  day^,  under  favor- 
able conditions.  Each  generation  begins  to  breed  about 
the  eighth  day  after  birth,  so  that  the  issue  from  a  single 
individual  easily  runs  up,  in  the  course  of  the  summer,  to 
millions.  The  number  of  leaves  (700  hills,  each  with  two 
poles  and  two  vines)  to  an  acre  of  hops,  as  grown  in  the 
United  States,  will  not,   on  the  average,  much  exceed  a 


274 


INSECTS    INJURIOUS   TO    STAPLE    CROPS. 


million  before  the  period  of  blooming  or  burning;  so  that 
the  issue  from  a  single  stem-mother  may,  under  favoring 
circumstances,  blight  hundreds  of  acres  in  the  course  of 
two  or  three  months. "  * 

Daring  September  a  brood  of  winged  females  are  pro- 
duced which  fly  back  to  the  plum-trees  and  in  the  course 


Fig.  157. — The  Hop  Plaut-louse,  third  generation  on  plum— the 
generation  which  flies  to  the  hop — enlarged;  head  below  at  right 
— still  more  enlarged.     (After  Riley,  U.  S.  Dept.  Agr.) 

of  a  few  days  give  birth  to  three  or  more  young.  These 
never  become  winged,  but  are  the  true  sexual  females 
which  lay  the  winter  eggs.  The  true  winged  males  are 
developed  during  the  latter  part  of  the  season  and  may  be 
found  pairing  with  the  wingless  females  at  that  time,  these 
being  the  only  males  during  the  year. 

Remedies. — From  a  knowledge  of  the  above-described 
life-history  several  methods  of  treatment  have  been 
secured.     By  spraying  plum-trees  neighboring   the  hop- 

*  Rfley,  "The  Hop-louse,"  "  Insect  Life,"  Vol.  I,  p.  135. 


INSECTS    INJURIOUS    TO    THE    HOP-PLANT. 


275 


yard  and  infested  with  lice  while  they  are  laying  the  eggs, 

during  fall  or -in  the  spring,  before  the  winged  generation 

appears,  with  some  substance  which  will  destroy  them,  the 

pest  may  be  prevented  from  getting  a  start  the  next  season. 

Spraying  the  trees  during  the    fall 

is  best,  because  a  stronger  or  more 

caustic  solution  can  then  be  applied 

without    danger    of    injury   to    the  I      V.</ 

tree.     A  winter  wash  of  one  pound  ^    '  '^■ 

of  concentrated  lye  to  two  gallons 

of  water  might  be  used  as  a  spray       /     /     '        \ 

to  advantage  in  killing  a  large  share 

of  the  eggs,  but  should  not  be  applied 

after  the  buds  commence  to  swell  in 

the  spring.     To  lessen  the  number 

of   eggs   all  wild  plum-trees  in  the  Fig.    158. — The    Hop 

.    .  ,       .  11111         1  Plant-louse,   true  sex- 

neighbormg    woods   should    be    de-     ^^.^^  female -enlarged. 

stroyed.       As  soon   as    the    crop  is     (After   Riley,    U.    S. 

•^  .  ^  Dept.  Agr.) 

harvested,  the  hop-vines  should  be 

burned  or  thoroughly  sprayed  with  kerosene  emulsion,  so 
as  to  kill  off  the  males  before  they  have  been  able  to  fer- 
tilize the  females. 

For  spraying  the  plum-trees  and  hop-vines  the  follow- 
ing have  given  excellent  satisfaction : 

'  'Kerosene  Emulsion. 

Cheap  kerosene 8  pints. 

Water 4     '' 

Soap h  pound. 

''  Dissolve  the  soap  in  the  water  and  add  (boiling  hot)  to 
the  kerosene.  Churn  the  mixture  by  means  of  a  force- 
pump  and  spray-nozzle  for  5  or  10  minutes.     The  emul- 


276 


INSECTS    INJURIOUS    TO    STAPLE    CROPS. 


sion,  if  perfect,  forms  a  cream  which  thickens  upon 
cooling,  and  should  adhere  without  oiliness  to  the  surface 
of  glass.  Dilute  one  part  of  the  emulsion  with  25  parts 
of  water."  Kerosene  and  water  mechanically  mixed 
('^  Kerowater ")  would  doubtless  be  equally  effective 
applied  at  a  strength  of  15  or  20  per  cent. 


Fig.  159. — The  Hop  Plant-louse,   male — enlarged.     (After  Riley, 

U.  S.  Dept.  Agr.) 

Fish -oil  or  whale-oil  soap  used  at  the  rate  of  one  pound 
to  eight  gallons  of  water  will  prove  an  effective  spray 
against  the  lice.  It  can  be  purchased  at  from  3  to  5  cents 
per  pound. 

The  Hop-vine  Snout-moth  {Hypena  Immnli  Harr.). 

The  larvae  of  the  Hop-vine  Snout-moth  sometimes 
become  very  formidable  pests  in  the  hop-field,  appearing 


INSECTS    IXJrRIorS   TO   THE    HOP-PLANT.  277 

suddenly  in  large  numbers  and  rapidly  eating  the  foliage 
over  a  large  area. 

They  are  not  known  to  have  any  other  food-plant  than 
the  ho])  and  hence  are  only  found  where  that  plant  occurs, 
though  specimens  have  been  taken  from  almost  all  sections 
of  the  United  States,  southern  Canada,  and  British 
Columbia. 

Life-history. — It  seems  probable  that  the  moths  hiber- 
nate over  winter,  as  they  emerge  in  the  fall,  and  lay  eggs 
for  the  first  brood  early  in  the  following  ^i^j.  The  eggs 
are  of  a  pale-green  color,  and  are  deposited  upon  the  under 
surfaces  of  the  leaves,  sometimes  several  upon  a  single  leaf. 
The  larv^  emerging  from  them  become  mature  late  in 
June  and  early  in  July.  When  full-grown  the  larvge  are 
slightly  less  than  one  inch  long,  and  *^of  a  green  color, 
marked  with  two  longitudinal  white  lines  down  the  back, 
a  dark-green  line  in  the  middle  between  and  an  indistinct 
whitish  line  on  each  side  of  the  body.  The  head  is  green, 
spotted  with  black  piliferous  dots,  and  similar  dots  occur 
on  each  segment,  arranged  in  two  transverse  rows."* 

Before  pupating  the  larva  sjDins  a  thin  silken  cocoon, 
either  among  the  leaves,  under  the  bark  of  the  poles,  or 
at  or  slightly  under  the  surface  of  the  ground,  various 
observers  having  noted  them  in  all  of  these  positions. 
The  pupal  stage  occupies  about  ten  days,  and  the  moths 
emerge  from  the  cocoons  early  in  July.  Another  brood 
follows  with  a  similar  life-history,  the  moths  emerging 
late  in  August  and  in  September  and  probably  hibernating 
over  winter. 

*  "Hop-insects,"  L.  O.  Howard,  Bull.  No.  7,  n.  s.,  Div.  Ent., 
U.  S.  Dept.  Agr. 


278 


INSECTS    INJURIOUS   TO    STAPLE    f'ROPS. 


The  larvae  are  known  as  ''false  loo^^ers/'  on  account  of 
their  bendnig  the  back  slightly  in  creeping,  which  is  due 
to  their  lacking  the  first  pair  of  pro-legs. 

Another  species  of  the  same  genus  {Hypcna  rostralis) 
affects  hop-vines  in  Europe  in  the  same  manner  and  is 
very  similar  to  the  one  above  described. 


Fig.  160. — The  Hop-vine  Snout-moth  {Hypena  Jmmuli  HarrJ.  a, 
egg;  h,  larva;  c,  segment  of  same;  d,  pupa;  e,  cremaster  of 
same;  /,  adult — a,  c,  e,  greatly  enlarged,  others  slightly  en- 
larged.     (After  Howard,  U.  S.  Dept.  Agr.) 

Remedies. — The  larv«  can  be  controlled  by  the  use  of 
any  arsenical  spray,  which  should  be  applied  while  they 
are  still  young. 

Hop-merchants. 

The  so-called  '*  Hop-merchants^^  which  here  and  there 
gleam  from  the  vines  are  the  chrysalids  of  two  common 
butterflies,  whose  larvae  feed  preferably  upon  hops.  The 
chrysalids  are  normally  marked  with  beautiful  gold  or 
silver  spots,  which  sometimes  become  so  diffused  as  to 
tinge  the  whole  chrysalis.  "An  interesting  superstition 
holds  among  hop-growers  to   the    effect   that  when   the 


II^^SECTS    IXJURIOrS    TO    THE    HOP-PLAXT.  279 

golden-spotted  chrysalids  are  plentiful  the  crop  Avill  be 
good  and  the  price  high,  while  if  the  silver-spotted  ones 
are  plentiful  and  the  golden-spotted  ones  are  scarce  the 
price  will  be  low.''     (Howard,  I.e.) 

The  Semicolon-butterfly  (Polygonia  interrogatiooiis 

Godart). 

The  common  names  of  these  two  butterflies  indicate  the 
most  striking  mark  of  distinction  between  them.  P.  in- 
terrogdtionis  bears  a  silver  mark  like  a  semicolon  or 
'"  interrogation'' point  upon  the  under  side  of  the  hind 
wings  (Fig.  161),  while  P.  comma  has  the  same  mark 
without  the  dot,  which  thus  resembles  a  comma  (Fig.  162). 

The  Semicolon-butterfly  is  common  throughout  the 
United  States  east  of  the  Rockies,  and  especially  in  \\o])- 
growing  regions.  It  hibernates  over  winter  and  is  among  the 
first  butterflies  to  be  seen  in  early  spring,  when  it  is  often 
attracted  to  the  flowing  sap  of  newly  cut  trees.  The  eggs 
are  laid  late  in  May  or  early  in  June,  usually  upon  the 
under  surface  of  the  leaves,  of  elm,  blackberrj^,  or  nettle, 
either  singly  or  in  j^tendant  columns  of  from  two  to  eight. 
They  hatch  in  from  four  to  eleven  days  and  the  larvge  grow 
quite  rajjidly. 

When  full-grown  the  larva  is  an  inch  and  a  quarter 
long.  The  head  is  reddish  black,  somewhat  bilobed,  each 
lobe  being  tipped  with  a  tubercle  bearing  five  single, 
black-pointed  spines,  and  covered  with  many  small  white 
and  several  blackish  tubercles.  The  body  is  black,  thickly 
covered  with  streaks  and  dots  of  yellowish  white;  the 
second  segment  is  without  sj^ines,  but  with  a  row  of  yel- 
lowish tubercles  in  their  place;  the  third  segment  has  four 
branching  spines,  all  black,  with  a  spot  of  dark  yellow  at 


280 


IKSECTS   iN.irRIOrs   TO    STAPLE   CROPS. 


their  base;  and  on  the  fourth  segment  are  four  spines,  as 
there  are  on  all  tlie  others,  excepting  the  terminal,  which 
has  two  pairs,  one  posterior  to  the  other.  The  spines  are 
yellow,  witli  blackish  branches,  excepting  the  terminal 
pair,  which  are  black;  and  there  is  a  row  of  reddish  ones 
on  each  side.     TJie  under  surface  is  yellowish  gray,  darker 


a 


Fig.  101. — The  Semicolon-butterfly  {Polygon  i<i  iiterrogationis).  a, 
egg  chain;  h,  larva;  r,  chrysalis;  d,  adult — all  natural  size  ex- 
cept a,  which  is  greatly  enlarged.  (After  Howard,  U.  S.  Dept. 
Agr.) 

on  the  anterior  segments,  with  a  central  line  of  blackish, 
and  many  small  black  dots.      (Saunders.) 

The  chrysalis  is  ash-brown,  with  the  head  deeply 
notated,  and  with  eight  silyery  spots  on  the  back,  this 
stage  lasting  from  eleven  to  fourteen  da3^s  and  the  butter- 
flies emerging  in  July.  These  lay  eggs  for  another  brood 
late  in  July  and   throughout  August,   mainly  upon  the 


IXSEPTS    TXJrRTOrS    TO    THE    HOP-PLAXT. 


281 


hop-plants,  where  tliey  are  to  be  found.  When  the  cater- 
pillars of  this  brood  are  numerous  they  sometimes  do  con- 
siderable damage  to  the  foliage,  but  both  this  and  the 
following  species  are  ordinarily  prevented  from  becoming 


Fig.  162. — The  Comma-butterfly  {Polygonia  comma),  a,  egg-chain, 
h,  larva;  c,  chrysalis;  d,  adult— all  natural  size,  except  a,  which 
is  greatly  enlarged.     (After  Howard,  U.  S.  Dept.  Agr.) 

overnumerous  by  several  parasites  of  the  eggs  and  larvge. 
Only  when  for  some  reason  conditions  are  unfavorable  to 
the  development  of  its  parasites  does  either  S23ecies  become 
especially  abundant.  In  fact.  Dr.  J.  B.  Smith,  who  made 
extensive   observations  upon  hop-insects    in   1883,   states 


282  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

"  that  not  one  in  ten  of  the  insects  ever  attains  the  butter- 
fly state." 

The  chrysalis  stage  of  the  second  brood  is  somewhat 
longer  than  the  first,  sometimes  lasting  twenty-six  days, 
and  the  butterflies  emerge  from  the  latter  part  of  August 
until  the  end  of  October,  and  at  once  seek  quarters  in 
which  to  hibernate  over  winter. 

Both  this  species  and  P.  comma  are  dimorj^hic,  the 
winter  and  summer  forms  differing  in  both  sexes  in  both 
the  upper  and  lower  aspects  of  the  wings.  In  the  South, 
where  from  three  to  five  broods  occur  in  a  season,  both 
+''^rms  are  usually  found  in  the  second  and  third  broods, 
^ummer  form,  var.  twibrosa,  gradually  decreasing 
all  of  the  fourth  brood  are  the  hibernating  winter 

^JL,  va?'.  fahricii. 

The  Comma-butterfly  {Polygonia  comma  Harr.). 

The  Comma-butterfly  is  most  common  throughout  the 
East  from  New  England  to  North  Carolina  and  Tennessee, 
though  occasionally  found  as  far  west  as  Wisconsin,  Iowa, 
Nebraska,  and  Texas. 

Its  life-history  is  practically  the  same  as  that  of  the 
species  just  described.  The  larvae  of  the  first  brood  some- 
times seriously  damage  young  elm-trees,  which  have  been 
Ijut  recently  reset,  by  eating  them  bare  of  the  foliage.  The 
winter  form  hibernates  about  a  month  earlier,  being  rarely 
seen  in  October.  As  a  rule  a  similar  dimorphism  occurs, 
the  hibernating  form  being  known  as  var.  harrisii  and  the 
summer  form  var.  dryas,  though  the  distinction  is  not 
as  marked  in  this  species. 

The  half -grown  larva  is  black,  with  a  yellowish  stripe 
along  the  side  from  the  third  segment,  and  with  yellow 


INSECTS    INJURIOUS    TO    THE    HOP-PLANT.  283 

stripes  across  the  back,  and  spots  of  the  same  color  at  the 
base  of  the  dorsal  spines,  which  are  yellow  tipped  with 
black.  The  mature  caterpillar  is  white,  mottled,  or 
striped  with  gray  or  ashen,  and  with  red  spiracles. 
(W.  H.  Edwards.) 

The  butterflies  of  both  species  are  of  a  rich  brown  color, 
marked  with  black  and  tipped  with  lilac  above,  and  of  a 
much  darker  purplish  brown  with  the  characteristic  silver 
spots  beneath,  which  are  well  indicated  in  the  illustration. 

Remedies. — Spra3dng  with  an  arsenical  will  destroy  the 
larvae  when  such  treatment  becomes  necessary. 


CHAPTER   XV. 
INSECTICIDES. 

Those  insecticides  spra3"ed  or  dusted  are  generally 
divisible  into  two  classes:  (1)  poisons  which  kill  by  being 
eaten;  and  (2)  oils  or  dusts  which  kill  the  insect  by  pene- 
trating the  skin  or  by  clogging  the  breathing-pores. 
Poisons  are  used  for  insects  such  as  grasshop23ers,  cater- 
pillars, beetles,  etc.,  which  bite  jxnd  chew  their  food  (see 
page  12).  Contact  insecticides  are  used  against  insects, 
such  as  plant-lice,  scale-insects,  etc.,  which  suck  up  the 
juices  of  the  plant  through  a  slender  beak  (see  page  13) 
and  which  are  not  affected  by  poisons  applied  to  the  sur- 
face of  the  plant. 

Gases  are  used  against  certain  insects  which  cannot  be 
effectively  destroyed  by  sprays  or  other  uitJttiib.  They  kill 
by  suffocation  (see  page  18). 

Bordeavx  mixtnre  sometimes  acts  as  a  preventive  against 
insects  by  rendering  the  food-plant  distasteful  to  them.* 

*  Bordeau  Mixture  : 

Copper  sulphate  (bluestone) 4  pounds 

Fresh  lime  (unslaked) 6       " 

Water 40  gallons 

Dissolve  the  bluestone  in  a  half  barrel  of  water  by  hanging  in  a 
bag  over  night.  Slake  the  lime  and  add  to  a  half  barrel  of  water. 
Pour  the  two  half  barrels  of  bluestone  solution  and  lime  into  a  third 

284 


INSECTICIDES.  285 

poTsoj^s.     (for  biting  insects.) 

Most  of  the  poisons  used  as  insecticides  are  composed 
of  compounds  of  arsenic.  Formerly  only  Paris  green  and 
London  purple  were  used.  Now  several  substitutes  are 
cheaper  and  some  more  desirable.  Therefore,  where  the 
word  ar senile  has  been  used  above,  any  of  the  arsenites 
mentioned  below  may  be  used,  except  as  qualified. 

Remember  that  these  poisons  are  all  dangerous  to  human 
life.      Keep  them  well  labeled  and  locked  up. 

Arsenites. 

Unless  otherwise  directed  above,  the  arsenites  may  be 
either  sprayed  or  dusted.  Dusting  is  usually  desirable  on 
low-growing  j^lants  only  and  should  be  done  in  the  early 
morning  while  damp  with  dew.  "When  used  dry  tlie 
arsenite  is  usually  mixed  with  land  plaster  or  flour  and  is 
applied  with  a  bellows,  perforated  can,  or  powder-gun. 

When  adding  a  dry  arsenite  to  water  for  spraying,  first 
mix  it  in  a  small  quantity  of  water,  so  as  to  form  a  paste. 

Paris  Green. 

Paris  green . 1  pound 

Water 160-200  gallons 

Lime 2  pounds 

When  used  with  Bordeaux  mixture  use  4  ounces  of 
arsenite  to  50  gallons  of  the  mixture.  Keep  well  stirred 
while  spraying.     20  to  25  cents  per  pound. 

empty  barrel,  stirring  constantly.  A  "stock  solution"  of  copper 
sulphate,  in  which  40  pounds  is  dissolved  in  40  gallons  of  water,  is 
convenient  for  extensive  work.  Four  gallons  should  then  be  diluted 
with  one-half  barrel  of  water  and  mixed  with  lime  as  above. 


286  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

London  Purple. 

Used  in  the  same  proportions  as  Paris  green,  but  is 
much  more  caustic,  its  comj)Osition  being  variable,  and 
should  therefore  have  considerable  more  lime  added. 

Green  Arsenoid. 

"  Is  slightly  superior  to  Paris  green  in  composition  and 
a])pears  to  be  equally  safe  on  foliage  when  applied  at  the 
ordinary  strength.  The  powder  is  about  a  tliird  lighter 
than  Paris  green,  and  remains  correspondingly  longer  in 
suspension. ^^  Sold  by  manufacturers,  Adler  Color  and 
Chemical  "Works,  New  York,  at  15  cents  per  pound,  or 
13  cents  in  100-pound  kegs.  Rather  j^referable  to  Paris 
green.     Add  plenty  of  lime. 

Arsenite  of  Lead. 

Least  caustic  of  all  the  arsenites  in  its  effect  upon 
foliage.  Remains  in  suspension  and  adheres  to  foliage 
better  than  Paris  green.  Is  white  in  color.  Sells  at  15 
to  18  cents  per  pound.  Manufactured  by  Wm.  II.  Swift 
&  Co.,  Boston,  Mass.  Can  be  made  ''by  combining 
approximately  3  parts  of  the  arsenite  of  soda  with  7  parts 
of  the  acetate  of  lead  (white  sugar  of  lead)  in  water. 
These  substances  when  pulverized  unite  readily  and  form 
a  white  precipitate,  which  is  more  easily  kept  suspended 
in  water  than  any  of  the  other  poisons.  At  wholesale 
acetate  of  lead  costs  about  7^  cents  a  pound,  and  the 
arsenite  of  soda,  5  cents.  May  be  used  at  any  strength 
from  3  to  15  pounds  to  100  gallons  of  water  without  injury 
to  foliage,  and  is  much  safer  on  delicate  plants  than  any 
other  arsenical." 

"  Disparene,"  manufactured  by  the  Bowker  Chemical 


INSECTICIDES.  287 

Co.,  Boston,  Mass.,  is  practically  the  same  as  arsenite  of 
lead,  and  is  much  more  adhesive  than  the  other  arsenites, 
this  being  due,  we  understand,  to  its  containing  glucose. 

Arsenite  of  Lime. 
''This  has  the  threefold  advantage  of  being  (1)  cheap, 

(2)  the  amount  of  arsenic  is  under  perfect  control,   and 

(3)  it  does  not  burn  the  foliage.  It  is  made  by  boiling 
together  for  45  minutes : 

White  arsenic 1  pound 

Fresh  stone  lime 2  pounds 

^Vater 1  gallon 

''  This  may  be  kept  in  a  tight  vessel  (marked  -  Poison  I '} 
and  used  as  desired.  Thoroughly  stir  the  material  before 
usiug.  For  most  insects,  one  quart  of  the  above  per 
barrel  will  be  sufficient."  It  is  insoluble  in  water  and  will 
not  injure  foliage  at  this  strength.  The  cheapest  arsenite 
and  as  effective  as  any. 

Paragrene. 

''  Has  equal  insecticidal  value  with  Paris  green,  is  about 
as  likely  to  burn  the  foliage  and  remains  longer  in  suspen- 
sion. We  consider  it  an  excellent  substitute. "  Manufac- 
tured by  Fred  L.  Lavenburg,  Xew  York,  13  cents  per 
pound  in  1-4-pound  pails.  Add  1  pound  of  lime  per 
barrel. 

Resin-lime  Mixture. 

Pulverized  resin 5  pounds 

Concentrated  lye 1  pound 

Fish-oil,  or  any  cheap  animal-oil  except  tallow.   1  pint 

''  ^^^^' ' 5  gallons 

Place  oil,  resin,  and  a  gallon  of  water  in  an  iron  kettle 
and  heat  until  resin  is  softened;  add  lye  solution  made  as 


288  INSECTS    INJURIOUS   TO    STAPLE    CROPS. 

for  hard  soap;  stir  thoroughly;  add  remainder  of  water 
:iiid  boil  about  two  hours,  or  until  the  mixture  will  unite 
with  cold  water  making  a  clear,  amber-colored  liquid.  If 
the  mixture  has  boiled  away  too  much,  add  suliicient  boil- 
ing water  to  make  5  gallons. 

For  use,  dilute  1  gallon  of  this  stock  solution  with  16 
gallons  of  water,  add  3  gallons  of  milk  of  lime,  or  white- 
wash, and  'l  ]3ound  Paris  green  or  other  arsenite. 

Used  on  plants  with  a  very  smooth  foliage. 

Poisoned  Bran  Mash. 

Wheat  bran -iO  pounds 

Molasses  (cheapest) 2  quarts 

Arsenite  (dry) 1  pound 

Water Enough  to  make  a  thick  mash 

Mix  the  arsenite  with  the  dry  bran.  Stir  the  molasses 
into  about  a  gallon  of  warm  water,  and  pour  over  poisoned 
bran,  stirring  thoroughly,  then  adding  enough  Avater  to 
make  a  stiff  mash.  Apply  as  near  evening  as  possible,  a 
heaping  tablespoonful  near  each  plant.  Keep  poultry  out 
of  fields  thus  treated.  For  cutworms  apply  a  day  or  two 
before  setting  plants. 

CONTACT    INSECTICIDES.       (FOR    SUCKING    INSECTS.) 

Kerosene  Emulsion. 

Hard  soap ^  pound 

Boiling  water 1  gallon 

Kerosene 2  gallons 

Dissolve  the  soap  in  the  water,  add  the  kerosene  (away 
from  the  fire)  and  cliurn  with  a  pump  by  pumping  back 
and  forth  for  5  or  10  minutes.  Dilute  4  to  15  times  before 
applying.  Dilute  10  to  12  times  for  plant-lice  and  soft- 
bodied  bugs. 


INSECTICIDES.  289 

Kerosene-water  Mixture  (Kerowater). 
Kerosene  and  water  mixed  mechanically  may  be  used  in 
all  cases  where  kerosene  emulsion  is  advised  above.  The 
water  is  placed  in  one  tank,  and  the  kerosene  in  another, 
the  two  being  mixed  in  the  spray-nozzle.  Any  desired 
j^ercentage  of  kerosene  may  be  used.  Use  10  to  20  per 
cent  for  plant-lice.  Generally  much  preferable  to  kerosene 
emulsion,  but  the  latter  is  somewhat  safer  upon  tender 
foliage.  Can  be  aj)plied  only  with  a  special  pumj)  having 
a  kerosene  attachment  (same  pump  may  be  used  for 
other  purposes).  Pumps  mauufactured  b}^  Deming  Co., 
Salem,  0.,  Goulds  Co.,  Seneca  Falls,  N.  Y.,  Spray  Motor 
Co.,  London,  Ont. 

Tobacco. 

In  Water. — Place  old  stems  aud  leaves  in  a  tisfht  vessel, 
cover  with  hot  water,  and  allow  to  stand  several  hours. 
Dilute  3  to  5  times  and  apph^ 

Whale-oil  Soap. 
For  plant-lice,  1  pound  to  G  to  8  gallons  of  water. 
Costs  3  to  5  cents  per  pound.  Manufactured  by  James 
Good,  Philadelphia,  Pa.,  Leggett  &  Bro.,  301  Pearl  St., 
New  York,  and  W.  H.  Owen,  Catawba  Island,  Ohio. 
Mr.  Good  is  now  making  a  soap  containing  tobacco  which 
seems  superior  for  soft-l)odied  Jarv^. 

Pyrethrum  or  Insect-powder. 
N'ot  poisonous  to  man  in  ordinary  quantities,  and  there- 
fore used  against  household  pests,  used  either  as  powder 
or  spray.  Burn  in  room  to  destroy  mosquitoes.  Used  in 
water  at  a  rate  of  1  ounce  to  12  gallons,  wliich  should  stand 
a  day  before  using.  Use  in  hot  water  for  immediate 
application.     Keep  in  tight  cans — deteriorates  with  age. 


290  INSECTS    INJURIOUS    TO    STAPLE    CROPS. 

Sulphur. 
Apply  at  rate  of  1  ounce  to  a  gallon  of  water  for  red 
spiders  and  mites.  Often  used  to  rid  poultry -houses  of 
vermin.  May  be  mixed  with  lard  and  nibbed  on  skin 
for  lice  that  infest  animals.  Sprinkle  in  greenhouses, 
especially  over  steam  or  hot-water  pipes. 

GASES. 

Carbon  Bisulfide. 
Used  against  insects  affecting  stored  goods  and  grain. 
Is  a  clear  volatile  liquid,  giving  off  fumes  heavier  than  air. 
Sold  in  25-  to  100  pound  lots  at  10  to  12  cents  per  pound. 
May  be  thrown  directl}^  on  wheat  without  injury  to  it,  or 
may  be  placed  in  shallow  dishes.  For  wheat  in  store  apply 
1  to  3  pounds  to  every  100  bushels.  Make  the  enclosure  as 
tight  as  possible,  cover  grain  with  blankets  if  necessary. 
Leave  for  twenty -four  hours;  over  thirty-six  hours  will 
injure  germinating  qualities  of  grain.  Do  not  inhale  the 
fumes,  or  allow  any  light,  cigar,  or  pipe  around  building, 
as  gas  IS  exceedingly  explosive.  For  open  enclosure  use 
1  pound  to  every  1000  cubic  feet  of  space. 

Hydrocyanic  Acid  Gas. 

The  best  agent  for  the  disinfection  or  fumigation  of 
nursery-trees  and  plants,  certain  greenhouse  insects,  and 
pests  of  dwelling-houses,  store-houses,  mills,  etc.  Made 
by  combining  cyanide  of  potassium,  sulphuric  acid,  and 
water.  Diffuses  quickly,  is  lighter  than  air,  and  a  most 
deadly  poison.* 

*  See  "Fumigation  Methods"  by  W.  G.  Johnson,  Orange  .Tudd 
Co 


INDEX. 


(The  number  of  the  page  giving  complete  depciiption  is  in  blaelt-face  tj-pe.) 


Acrididce,  58 
Adalia  bipiinctata,  31 
Agriotes  mancus,  51 
Agropyriim,  111 
Agrotis  annexa,  196,  215,  259 
messoria,  258 
ypsilon,  215 
Aletia  xj^lina,  188 
Alimentary  canal,  17,  18 
American  acridium,  67,  71 
Angumois  grain-moth,  21,  162 
Anthomyia,  egg-parasite,  63 
Anthonomiis  grandis,  205 
Apliidte,  on  cotton,  197 
Aphis  gossypii,  197 

maidi-radicis,  134 

mali,  35 
Aphidius  granariaphis,  40,  116, 

118 
Army-worm,  3,  24,  79 
Beet,  262 
Fall,  84 
Aroecerus  fasciculatus,  200 
Arsenites,  285 
Arsenite  of  lead,  286 
Arsenite  of  lime,  287 
Asaphes  decoloratus,  51 
Ataxia  crypta,  197 

JSagworm,  196 
Bean  leaf-beetle,  240 
Beet  aphis,  255 

Army  worm,  262 
Beneficial  insects,  30 
Blissus  leucopterus,  52 


Blister-beetles,  251,  265 

Striped,  251 
Bordeaux  mixture.  284 
Brachymena  4-pustulat.a,  11 
Bran-mash,  poisoned,  78,  288 
Bryobia  pratensis,  179 
Burning,  24 

CacQ^cia  rosaceana,  196 
Cadelle,  159 
Calandria  granaria,  155 

oryzge,  155 
Calandridai,  141 
Calosoma  calidum,  37 

scrutator,  37 
Cambala  annulata,  239 
Camnula  pellucida,  68 
Carbon  bisulfide,  18,  168,  290 
Cathartus  ad  vena,  158 

gemellatus,  156,  158 
Cecidomyia  destructor,  100 

leguminicola,  182 
Cephus  pygm^eus,  97 
Cereals,  injury  to,  2 
Cerotoma  trifurcata,  240 
Cha?tocnema  confinis,  240 
ChalcididcT,  93 
Chalcis-flies,  43 
Chilocorus  bivulnerus,  33 
Chinch-bug,  3,  21,  24,  52 

False,  263 
Chrysopa,  118 
Cicada,  mouth -parts,  14 
Cigarette- beetle,  237 
Click-beetles,  49 

291 


292 


IXDEX. 


Clisiocampa  americana,  41 
Clover  bay-worm,  186 
Clover  insects,  172 

Leaf-weevil,  177 
-mite,  179 
Root-borer,  172 
Seed-caterpillar,  185 
Seed-midge,  182 
Stem-borer,  176 
Coccinella  novemnotata,  31 
Coccinellidse,  30 
Codling  motli,  21 
Coleoptera,  10 
Colorado    potato-beetle,   4,  21, 

243 
Comma  butterfly,  282 
Contact  insecticides,  18,  284 
Corn  bill-bugs,  24,  26,  141 
Ear- worm,  9,  24,  151 
Root-louse,  23,  134 
Root  webworm,  130 
Root- worm,  3,  21,  125 

Western,  125 
Southern,  129 
Stalk-borer,  32,  28,  146 
Crambus  caliginosellus,  130,  217 
Cotton  Boll- weevil,  4,  23,  25,  204 
Boll- worm,  27,  201 
Injury  to,  4 
Insects,  188 
-stainer,  199 
-worm,  4,  21,  188 
Cutworms,  21,  24,  28,  150,  195, 
214,  256 
Dingy,  150 
Granulated,  196, 215, 

259 
Greasy,  215 
Well-marked,  150 
Cyclocephala,  46 

Datura  stramonium,  236 

Deschampsis.  Ill 

Diabrotica  longicornis,  155 
12-punctata,  129 
vittata,  126,  253 

Diatrea  saccharalis,  146 

Dicvplius  minimus,  224 

Diph)sis  tritici,  122 

Diptera,  9,  10 

Disonycha  triangularis,  264 

xanthomeloiua,  264 


Dolerus  arvensis,  119 
collaris,  119 
Drainage,  26 

Drasterius  elegans,  49,  50 
Dysdercus  suturellus,  199 

Elateridae,  48 

Elynius,  111 

Empusa  aphidis,  182 

Ephestia  kuehniella,  159 

Epicauta  pennsylvanica,  267 
vittata,  65,  266 

Epidapus  scabies,  239 

Epitrix  cucumeris,  230,  240,  249 
fuscula,  230,  249 
parvula,  229,  240,  249 

Eristalis  tenax,  34 

Euplectrus  comstockii,  193 

Euscliistus  variolarius,  219 

Exorista  flavicauda,  65 
leucaniae,  65 

Fall  army-worm,  84,  196 

False  chinch-bug,  263 

Feltia  subgothica,  150 

Fertilizers,  26 

Flea-beetles,  23 

Beet,  264 
Potato,  249 
Sweet-potato,  240 
Tobacco,  229,  240 
Yellow-back,  264 

Flour-moths,  159 

Fumigation,  Grain,  169 

Fungus,  So.  African,  77 
Chinch  bug,  56 

Garden  webworm,  196,  260 

Gelechia  solanella,  227 

Grain  beetles,  157 

Foreign,  158 
Saw-toothed,  157 
Square-necked  ,158 

Grain,  stored.  Injury  to,  3 

Grain-weevils,  21,  155 

Granary,  167 

weevil,  155 

Grapholitha  interstinctana,  185 

Grasshoppers,   Cotton,  195 

Mouth  parts,  13 

Grass,  Injury  to,  3 

Root-iouse,  134 


INDEX. 


293 


Green  arsenoid,  286 

Green  dolphin,  182 

Ground -beetles,  36 

Fiery,  37 
jVIurky,  38,  39 

Gipsy  moth,  21 

Harlequin  cabbage-bug,  27 
Harpalus  caliginosus,  38,  247 
Harvest-mites,  7 
Hay,  Injury  to,  3 
Heart,  17,  18 

Heliothis  armi2:er,  9,  151,  201, 
220 
rhexice,  220 
Hemiptera  10 
Hessian   fly,    2,   21,    23,    28,  29, 

lOO 
Hippodamia  convergens,  31,  33 
Homalodisca  coagulata,  198 
Honey-bee,  7 
Hop  insects,  269 

-louse.  272 

-merchants,  278 

Plant-louse,  24 

Plant-borer,  269 

-vine  snout-moth,  276 
Horn-worm,  231 
Hydrocyanic  acid  gas,  18,  290 
Hydroecia  immanis,  269 
Hylastes  obscurus,  172 
Hymenoptera,  10 
Hypena  humuli   276 
rostralis,  278 

Ichneumon-flies,  39 

Indian  meal-moth,  161 

Insects,  How  they  breathe,  15 
How  they  feed,  11 
How  they  grow,  7 

Insecticides,  284 

Insect-powder,  289 

Irritants,  18 

Isosoma  grand e,  94 
tritici,  94 

Joint-worms,  93 

Kerosene  emulsion,  18,  288 

and   water    mixture, 
289 
Kerowater,  289 


Lachnosterna  arcuata,  45 

Ladybird-beetles,  30 

Convergent,  31 
Nine-spotted,  31,  33 
Two- spotted,  31 

Languria  mozardi,  176 

Laphygma  flavimaculata,  262 
frugiperda,  84,  196 

Lasioderma  serricorne,  237 

Lasius  niger  alienus,  135 

Leaf-roller,  196 

Leather-jackets,  90 

Lcbia  grandis,  38 

Lema  trilineata,  252 

Lepidoptera,  10 

Leptinotarsa  10-lineata,  243 

Leucania  unipuncta,  79 

Lime,  18 

Locusts,  21,  24,  58 

Devastating',  68 
Differential.  67,  70 
Lesser  migratory,  66 
Non-migratory,  66 
Pellucid,  68 
Red-lego-ed,     67,     68, 

230 
Rocky  Mountain,  58 
Two-striped,  67,  69 

London  purple.  286 

Loxostege  similalis,  196,  259 
sticticalis,  260 

Lydella  doryphorte,  246 

Lygus  pratensis,  263 

Macrobasis  unicolor,  266 

Mandibles,  12 

MaxilLT,  13 

Meadow-maggots,  90,  176 

Meal -moths,"  159 

Meal  snout-moth,  161 

Mediterranean  flour-moth,  159 

Megilla  maculata,  33 

Melanoplus  atlantis,  66 

bivittatus,  67,  69 
devastator.  68 
differentialis,  67,  70 
femur-rubrum,    68p 

67,  230 
spretus,  58 

Melanotus  cribulosis,  49 

Meloida^,  251,  265 

Meromyza  americana,  111 


294 


IXDEX. 


Metamorphosis,  Complete,  8 

Incomplete,  10 
Mexican  cotton  boll- weevil,  205 
Mouth-parts,  Biting,  12 

Sucking,  13 

Nectaraphora  avenge,  115 

pisi,  182,  183 
Noctua  clandestina,  150 
Noctuid«,  150 
Nysius  angustatus,  263 

Ophion,  41 

macrurum,  42 
Orthoptera,  10 
Oscinis  variabilis,  114 

Pach3'nematus  extensicornis,  119 
Pachyonerus  calcitrator,  98 
Pachj^rrhinis  sp.,  90 
Palpus,  13 

Panicum  glabrum,  135 
Paragrene,  287 
Parajulus  impressus,  239 
Parasites,  39 
Paris  green,  285 
Parthenogenesis,  136 
Pea-louse,  182 
Pemphigus  betae,  255 
Peridromia  saucia,  257 
Phorodon  humuli,  272 
Phragmites  communis,  143 
Phylfotreta  vittata,  264 
Phytononus  punctatus,  177 
Pimpla  conquisitor,  190 

inquisitor,  maggots,  41 
Pipiza  radicans,  35 
Planting,  Time  of,  28 
Plant-louse,  mouth-parts,  lo 
Plodia  interpunctella,  160,  161 
Plowing,  Deep  fall,  24 
Poa  pratensis.  111 
Poisons,  285 
Polygonia  comma,  282 

interrogationis,  279 
Polygonum  persicaria,  135 
Portulaca  solacea,  135 
Potato-beetle,  Colorado,  243 
Potatoes,  Injury  to,  4 
Potato  insects,  239 

Scab,  239 

Stalk- borer,  2,  24,  241 


I   Poultry,  26 
;   Predaceous  insects,  30 
I   Proctotrypida?,  43 
I   Protoparce  Carolina,  231 
celeus,  231 
Pyralida^,  260 
Pyralis  costalis,  186 

farinalis,  160,  161 
Pyrethrum,  18,  289 

Kesin-lime  mixture,  288 

Respiratory  system,  17 

Rice-weevil,  26,  155 

Root-louse,  Corn,  134 
Grass,  134 
Syrphus-fly,  35 

Rotation  of  crops,  28 

San  Jose  Scale,  21 

Sarcophaga  carnaria,  65 

Sawflies,  Wheat,  19 

Schizoneura  panicola,  134 

Schistocerca  americana,    12,   C7, 
71,  196 

Sciara  sp.  ?,  239 

Scirpus  fluviatilis,  143 

Semicolon  butterfly,  279 

Sesame  grass,  149 

Setaria  viridis.  111 

Sharpshooters,  198 

Silkworm,  Internal  anatomy,  18 

Silvanus  surinamensis,  156,  157 

Sitotroga  cerealella,  162 

Solanum  carolinense,  228 
datura,  245 

South  African  fungus,  77 

Sphenophorus  ochreus,  143 
obscurus,  141 
parvulus,  141 
pertinax,  144 
placid  us,  144 
robustus,  142 
scoparius,  144 
sculptilis,  144 

Spiracles,  15,  16 

Sporotrichum  globuliferum,  56 

Squash -bug.  24 

Structure  of  an  insect,  6 

Suck  fly,  Tobacco,  224 

Sugar-beet  insects,  252 

Web  worm,  260 


IXDEX. 


295 


Sugar-cane  borer,  21 
Sulphur,  290 
Syrphidse,  34 
Syrphus  americana,  35 

-flies,  34 

ribesii,  35 
Systena  hudsonias,  264 

taeniata,  264 
Systoechus  oreas,  63 

Tacliina-flies,  63 
Tarnished  plant- bug,  263 
Tenebriodes   mauritanicus,   158, 

159 
Tetranychidae,  179 
Three-lined  leaf-beetle,  252 
Thyridopterj'^x  ephemergeformis, 

196 
Tipula  bicornis,  90 
costalis,  90 
hebes,  91 
Tipulidae,  90 
Trachea,  16,  18 
Trap-crops,  26 
Trichobaris  trinotata,  24 
Trichogramma  pretiosa,  192 
Tripsacuin  dactyloides,  149 
Trombidiuni  locustarum,  63,  64 
Tobacco  bud -worms,  220 
-bug,  Spined,  219 


Tobacco  dust,  18 

Flea-beetle,  229 
Injury  to,  4 
Insecticide,  289 
Insects,  214 
Leaf-miner,  227 
Stalk-worm,  217 
-worm,  231 

Webworms,  Beet,  259 

Corn-root,  130 
AVeeds,  23 
"Weevil,  Grain,  155 
Western    Corn   root-worm,    29, 

125 
Whale-oil  soap,  18,  289 
Wheat  insects,  90 

Isosoma,  29 

Joint-worm,  22,  24,  93 

-louse,  115 

Plant-louse,  29 

-maggots.  111 

•midge,  122 

Saw-flies,  119 

Saw-fly  borer,  97 

Stem-maggot,  111 

Straw- worm,  96 
White  grubs,  28,  44,  252 
Wiuthemia  4-pustulata,  83 
Wireworms,  24,  28,  29,  48,  252 


SHORT-TITLE      CATALOGUE 

OF  THE 

PUBLICATIONS 

OP 

JOHN    WILEY    &    SONS, 

New  York. 
LoKDON^:    CHAPMAN  &  HALL,  Limited. 


ARRANGED  UNDER  SUBJECTS. 


Descriptive  circulars  sent  on  application.  Books  marked  with  an  asterisk  are 
sold  at  net  prices  only,  a  double  asterisk  (**)  books  sold  under  the  rules  o^  the 
American  Publishers'  Association  at  net  prices  subject  to  an  extra  charge  for 
postage.     All  books  are  boimd  in  cloth  unless  otherwise  stated. 


AGRICULTURE. 

Armsby's  Manual  of  Cattle-feeding i2mo,  $i  75 

Principles  of  Animal  Nutrition 8vo,  4  00 

Budd  and  Hansen's  American  Horticultural  Manual: 

Part  I. — Propagation,  Culture,  and  Improvement i2mo,  1  50 

Part  II. — Systematic  Pomology i2mo,  i  50 

Downing's  Fruits  and  Fruit-trees  of  America 8vo,  5  00 

Elliott's  Engineering  for  Land  Drainage i2mo,  i  50 

Practical  Farm  Drainage i2mo,  i  00 

Green's  Principles  of  American  Forestry i2mo,  i  50 

Grotenfelt's  Principles  of  Modern  Dairy  Practice.     (Well.) i2mo,  2  00 

Kemp's  Landscape  Gardening \. lamo,  2  50 

Maynard's  Landscape  Gardening  as  Applied  to  Home  Decoration i2mo,  1  50 

Sanderson's  Insects  Injurious  to  Staple  Crops i2mo,  i  50 

Insects  Injurious  to  Garden  Crops.     (In  preparation.) 

Insects  Injuring  Fruits.     (In  preparation.) 

Stockbridge's  Rocks  and  Soils 8vo,  2  50 

VVoll's  Handbook  for  Farmers  and  Dairymen i6mo,  i  50 

ARCHITECTURE. 

Baldwin's  Steam  Heating  for  Buildings i2mo,  2  50 

Berg's  Buildings  and  Structures  of  American  Railroads 4to,  5  00 

Birkmire's  Planning  and  Construction  of  American  Theatres Svo,  3  00 

Architectural  Iron  and  Steel Svo,  3  50 

Compound  Riveted  Girders  as  Applied  in  Buildings Svo,  2  00 

Planning  and  Construction  of  High  Office  Buildings Svo,  3  50 

Skeleton  Construction  in  Buildings Svo,  3  00 

Briggs's  Modern  American  School  Buildings Svo,  4  00 

Carpenter's  Heating  and  Ventilating  of  Buildings Svo,  4  00 

Freitag's  Architectiiral  Engineering.     2d  Edition,  Rewritten Svo,  3  50 

Fireproofing  of  Steel  Buildings Svo,  2  50 

French  and  Ives's  Stereotomy Svo,  2  50 

Gerhard's  Guide  to  Sanitary  House-inspection i6mo,  i  00 

Theatre  Fires  and  Panics , i2mo,  i  50 

Holly's  Carpenters*  and  Joiners'  Handbook iSmo,  o  75 

Johnson's  Statics  by  Algebraic  and  Graphic  Methods .• Svo,  2  00 

a 


Kidder's  Architect's  and  Builder's  Pocket-book.     Rewritten  Edition. 

1 6mo,  morocco, 

Merrill's  Stones  for  Building  and  Decoration 8vo, 

Monckton's  Stair-building 4to, 

Patton's  Practical  Treatise  on  Foundations 8vo, 

Peabody's  Naval  Architecture 8vo, 

2iebert  and  Biggin's  Modern  Stone-cutting  and  Masonry Svo, 

Snow's  Principal  Species  of  Wood Svo, 

Sondericker's  Graphic  Statics  with  Applications  to  Trusses,  Beams,  and  Arches. 

Svo, 

Wait's  Engineering  and  Architectural  Jurisprudence Svo, 

Sheep, 
Law  of  Operations  Preliminary  to  Construction  in  Engineering  and  Archi- 
tecture   Svo, 

Sheep, 

Law  of  Contracts Svo, 

Wood's  Rustless  Coatings:   Corrosion  and  Electrolysis  of  Iron  and  Steel . .  .Svo, 

Woodbury's  Fire  Protection  of  Mills Svo, 

Worcester  and  Atkinson's  Small  Hospitals,  Establishment  and  Maintenance, 
Suggestions  for  Hospital  Architecture,  with  Plans  for  a  Small  Hospital. 

i2mo. 
The  World's  Columbian  Exposition  of  1893 Large  4to, 

ARMY  AND  NAVY. 

Bernadou's  Smokeless  Powder,  Nitro-cellulose,  and  the  Theory  of  the  Cellulose 
Molecule i2mo, 

*  Bruflf's  Text-book  Ordnance  and  Gunnery Svo, 

Chase's  Screw  Propellers  and  Marine  Propulsion Svo, 

Craig's  Azimuth 4to, 

Crehore  and  Squire's  Polarizing  Photo-chronograph Svo, 

Cronkhite's  Gunnery  for  Non-commissioned  Officers 24mo,  morocco, 

♦  Davis's  Elements  of  Law Svo, 

•  Treatise  on  the  Military  Law  of  United  States Svo, 

Sheep, 

De  Brack's  Cavalry  Outpost  Duties.     (Carr.) 24mo  morocco, 

Dietz's  Soldier's  First  Aid  Handbook i6mo,  morocco, 

♦  Dredge's  Modern  French  Artillery 4to,  half  morocco, 

Durand's  Resistance  and  Propulsion  of  Ships Svo, 

*  Dyer's  Handbook  of  Light  Artillery i2mo, 

Eissler's  Modem  High  Explosives Svo, 

*  Fiebeger's  Text-book  on  Field  Fortification Small  Svo, 

Hamilton's  The  Gunner's  Catechism iSmo, 

♦  Hoflf's  Elementary  Naval  Tactics Svo, 

Ingalls's  Handbook  of  Problems  in  Direct  Fire Svo, 

♦  Ballistic  Tables Svo, 

*  Lyons's  Treatise  on  Electromagnetic  Phenomena.   Vols.  I.  and  II . .  Svo.  each, 

*  Mahan's  Permanent  Fortifications.     (Mercur.) Svo,  half  morocco, 

Manual  for  Courts-martial i6mOi  morocco, 

♦  Mercur's  Attack  of  Fortified  Places i2mo, 

♦  Elements  of  the  Art  of  War Svo, 

Metcalf 's  Cost  of  Manufactures — And  the  Administration  of  Workshops,  Public 

and  Private Svo, 

•  Ordnance  and  Gunnery.     2  vols i2mo, 

Murray's  Infantry  Drill  Regulations iSmo,  paper, 

Peabody's  Naval  Architecture Svo, 

•  Phelps's  Practical  Marine  Surveying Svo, 

Powell's  Army  Officer's  Examiner i2mo, 

Sharpe's  Art  of  Subsisting  Armies  in  War , i8mo,  morocco, 

2 


5 

00 

5 

00 

4 

00 

5 

00 

7 

50 

I 

50 

3 

50 

2 

00 

6 

00 

6 

50 

5 

00 

5 

50 

3 

00 

4 

00 

2 

50 

I 

25 

I 

00 

2 

50 

6 

00 

3 

00 

3 

50 

3 

00 

2 

00 

2 

50 

7 

00 

,  7 

50 

2 

00 

I 

25 

15 

00 

5 

00 

3 

00 

4 

CO 

2 

00 

I 

00 

I 

50 

4 

00 

I 

50 

6 

GO 

7 

50 

I 

50 

2 

CO 

4 

00 

5 

00 

5 

00 

10 

7 

50 

2 

50 

4 

00 

I 

5C 

*  Walke's  Lectures  on  Explosives 3vo  4  00 

*  Wheeler's  Siege  Operations  and  Military  Mining 8vo,  2  00 

Winthrop's  Abridgment  of  Military  Law i2mo.  2  50 

WoodhuU's  Notes  on  Military  Hygiene i6mo,  i  50 

Young's  Simple  Elements  of  Navigation i6mo  morocco,  i  00 

Second  Edition,  Enlarged  and  Revised i6mo,  morocco,  2  00 

ASSAYING. 

Fletcher's  Practical  Instructions  in  Quantitative  Assaying  with  the  Blowpipe. 

i2mo,  morocco, 

Furman's  Manual  of  Practical  Assaying 8vo, 

Miller's  Manual  of  Assaying i2mo, 

O'Driscoll's  Notes  on  the  Treatment  of  Gold  Ores 8vo, 

Ricketts  and  Miller's  Notes  on  Assaying Svo, 

Ulke's  Modern  Electrolytic  Copper  Refining Svo, 

Wilson's  Cyanide  Processes i2mo, 

Chlorination  Process i2mo. 


I 

50 

3 

00 

I 

00 

2 

00 

3 

00 

3 

00 

I 

50 

I 

50 

2 

50 

3 

50 

4 

00 

2 

50 

3 

00 

2 

50 

3 

00 

2 

00 

ASTRONOMY. 

Comstock's  Field  Astronomy  for  Engineers Svo, 

Craig's  Azimuth 4to, 

Doolittle's  Treatise  on  Practical  Astronomy Svo, 

Gore's  Elements  of  Geodesy Svo, 

Hayford's  Text-book  of  Geodetic  Astronomy Svo, 

Merriman's  Elements  of  Precise  Surveying  and  Geodesy Svo, 

*  Michie  and  Harlow's  Practical  Astronomy Svo, 

*  White's  Elements  of  Theoretical  and  Descriptive  Astronomy i2mo, 

BOTANY. 

Davenport's  Statistical  Methods,  with  Special  Reference  to  Biological  Variation. 

i6mo,  morocco,  i  25 

Thome  and  Bennett's  Structural  and  Physiological  Botany i6mo,  2  25 

Westermaier's  Compendium  of  General  Botany.     (Schneider.) Svo,  2  00 

CHEMISTRY. 

Adriance's  Laboratory  Calculations  and  Specific  Gravity  Tables i2mo,  i   25 

Allen's  Tables  for  Iron  Analysis Svo,  3  00 

Arnold's  Compendium  of  Chemistry.     (Mandel.) Smali  Svo.  3  50 

Austen's  Notes  for  Chemical  Students i2mo,  i   50 

*  Austen  and  Langworthy.      The    Occurrence    of   Aluminium    in    Vegetable 

Products,  Animal  Products,  and  Natural  Waters Svo,  2  00 

Bernadou's  Smokeless  Powder. — Nitro-cellulose,  and  Theory  of  the  Cellulose 

Molecule i2mo,  2  50 

Bolton's  Quantitative  Analysis Svo,  i  50 

*  Browning's  Introduction  to  the  Rarer  Elements ,  .8vo,  1  50 

Brush  and  Penfield's  Manual  of  Determinative  Mineralogy .Svo,  4  00 

Classen's  Quantitative  Chemical  Analysis  by  Electrolysis.  (Boltwood.)  , . .  .Svo,  3  00 

Conn's  Indicators  and  Test-papers i2mo,  2  00 

Tests  and  Reagents Svo,  3  00 

Copeland's  Manual  of  Bacteriology,     (in  preparation.) 

Craft's  Short  Course  in  Qualitative  Chemical  Analysis.  (SchaefiferJ.  .    .i2mo,  1   5© 

Dolezalek's  Theory    of    the    Lead    Accumulator    (Storage    Bactery).     (Von 

Ende) .    . i2mo-  2  50 

Drechsel's  Chemical  Reactions.     (Merrill.) . ....    i2mo,  i   25 

Duhem's  Thermodynamics  and  Chemistry.     (Burgess. ) Svo.  4  00 

Eissler's  Modern  High  Explosives. ...........    Svo,  4  00 

EfEront's  Enzymes  and  their  Apphcations.     (Prescott.) . .    Svo,  3  00 

Erdmann's  Introduction  to  Chemical  Preparations.     (Dunlap.) . ....... i2mo,  x  25 

3 


Fletcher's  Practical  Instructions  in  Quantitative  Assaying  with  the  Blowpipe 

i2nio,  morocco,    i  50 

Fowler's  Sewage  Works  Analyses i2mo,    2  00 

Presenius's  Manual  of  Qualitative  Chemical  Analysis.     (Wells.) 8vo,    5  00 

Manual  of  Qualitative  Chemical  Analysis.     Parti.    Descriptive.     (Wells.) 

8vo,    3  00 
System   of   Instruction   in    Quantitative    Chemical   Analysis.      (Cohn.) 

2  vols 8vo, 

Fuertes's  Water  and  Public  Health i2mo, 

Furman's  Manual  of  Practical  Assaying 8\  o, 

*Getman's  Exercises  in  Physical  Chemistry i2mo. 

Gill's  Gas  and  Fuel  Analysis  for  Engineers i2mo, 

Grotenfelt's  Principles  o/Modem  Dairy  Practice.     (WoU.) i2mo. 

Hammarsten's  Text-book  of  Physiological  Chemistry.     (Mandel.) 8vo, 

Helm's  Principles  of  Mathematical  Chemistry.     (Morgan.) i2mo, 

Hering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco, 

Hiads's  Inorganic  Chemistry 8vo, 

•  Laboratory  Manual  for  Students i2mo, 

Holleman's  Text-book  of  Inorganic  Chemistry.     (Cooper.) 8vo, 

Text-book  of  Organic  Chemistry.     (Walker  and  Mott.) 8vo, 

•  Laboratory  Manual  of  Organic  Chemistry.     (Walker.) i2mo, 

Hopkins's  Oil-chemists'  Handbook 8vo, 

Jackson's  Directions  for  Laboratory  Work  in  Physiological  Chemistry . .  8vo, 

Keep's  Cast  Iron 8vo, 

Ladd's  Manual  of  Quantitative  Chemical  Analysis i2mo, 

Landauer's  Spectrum  Analysis.     (Tingle.) 8vo, 

Lassar-Cohn's  Practical  Urinary  Analysis.     (Lorenz.) i2mo, 

Leach's  The  Inspection  and  Analysis  of  Food  with  Special  Reference  to  State 

Control.     (In  preparation.) 
Lob's  Electrolysis  and  Electrosynthesis  of  Organic  Compounds.  (Lorenz.)  i2mo, 
Mandel's  Handbook  for  Bio-chemical  Laboratory i2mo, 

•  Martin's  Laboratory  Guide  to  Qualitative  Analysis  with  the  Blowpipe.  .  i2mo, 
Mason's  Water-supply.     (Considered  Principally  from  a  Sanitary  Standpoint.) 

3d  Edition,  Rewritten 8vo, 

Examination  of  Water.     (Chemical  and  Bacteriological.) i2mo, 

Meyer's  Determination  of  Radicles  in  Carbon  Compounds.     (Tingle.).  .  i2mo, 

Miller's  Manual  of  Assaying i2mo, 

Mizter's  Elementary  Text-book  of  Chemistry i2mo, 

Morgan's  Outline  of  Theory  of  Solution  and  its  Results „ i2mo, 

Elements  of  Physical  Chemistry i2mo, 

Morse's  Calculations  used  in  Cane-sugar  Factories i6mo,  morocco, 

Mulliken's  General  Method  for  the  Identification  of  Pure  Organic  Compounds. 

Vol.  I Large  8vo,    5  00 

Nichols's  Water-supply.     (Considered  mainly  from  a  Chemical  and  Sanitary 

Standpoint,  1883.) 8vo,    2  50 

O'Brine's  Laboratory  Guide  in  Chemical  Analysis 8vo,    2  00 

O'DriscoU's  Notes  on  the  Treatment  of  Gold  Ores 8vo,    2  00 

Ost  and  Kolbeck's  Text-book  of  Chemical  Technology.     (Lorenz — Bozart.) 
(/n  preparation.) 
.  Ostwald's  School  of  Chemistry.     Part  One.     (Ramsey.)     (In  press.) 

•  Penfield's  Notes  on  Determinative  Mineralogy  and  Record  of  Mineral  Tests. 

8vo,  paper,        50 

Pictet's  The  Alkaloids  and  their  Chemical  Constitution.     (Biddle.) 8vo,    5  00 

Pinner's  Introduction  to  Organic  Chemistry.     (Austen.) i2mo„   i  50 

Poole's  Calorific  Power  of  Fuels 8vo,    3  00 

Prescott  and  Winslow's  Elements  of  WaterBacterlology,  with  Special  Refer- 
ence to  Sanitary  Water  Analysis i2mo,    i   2^ 

•  Reisig's  Guide  to  Piece-dyeing 8vo,  25  00 

4 


[2 

50 

I 

50 

3 

00 

2 

oo 

I 

^5 

2 

00 

4 

00 

I 

50 

2 

50 

3 

00 

75 

2 

50 

2 

50 

I 

00 

3 

00 

I 

25 

2 

50 

I 

00 

3 

00 

I 

00 

I 

00 

I 

50 

60 

4 

00 

I 

25 

I 

00 

I 

00 

I 

50 

I 

00 

2 

00 

I 

50 

Richards  and  Woodman's  Air  ,Water,  and  Food  from  a  Sanitary  Standpoint .  8vo, 

Richards's  Cost  of  Living  as  Modified  by  Sanitary  Science i2mo. 

Cost  of  Food  a  Study  in  Dietaries izmo, 

•  Richards  and  Williams's  The  Dietary  Computer 8vo, 

Ricketts  and  Russell's  Skeleton  Notes  upon  Inorganic  Chemistry.     (Part  I. — 

Non-metallic   Elements.) 8vo,  morocco, 

Ricketts  and  Miller's  Notes  on  Assaying ^ 8vo, 

Rideal's  Sewage  and  the  Bacterial  Purification  of  Sewage 8vo, 

Disinfection  and  the  Preservation  of  ^ood 8vo, 

Ruddiman's  Incompatibilities  in  Prescriptions 8vo, 

Sabin's  Industrial  and  Artistic  Technology  of  Paints  and  Varnish.     (In  press.) 

Sclkowski's  Physiological  and  Pathological  Chemistry.     (Orndorff.) 8vo, 

Sciiimpf's  Text-book  of  Volumetric  Analysis i2mo» 

Essentials  of  Volumetric  Analysis i2mo, 

Spencer's  Handbook  for  Chemists  of  Beet-sugar  Houses i6mo,  morocco. 

Handbook  for  Sugar  Manufacturers  and  their  Chemists.  .  i6mo,  morocco, 
Stockbridge's  Rocks  and  Soils 8vo, 

*  Tillman's  Elementary  Lessons  in  Seat 8vo, 

•  Descriptive  General  Chemistry 8vo, 

Treadwell's  Qualitative  Analysis.     (Hall.) 8vo, 

Quantitative  Analysis.     (HaU.) 8vo, 

Turneaure  and  Russell's  Public  Water-supplies 8vo, 

Van  Deventer's  Physical  Chemistry  /or  Beginners.     (Boltwood.) i2mo, 

*  Walke's  Lectures  on  Explosives 8vo, 

Wassermann's  Immune  Sera:  Haemolysins,  Cytotoxins,  and  Precipitins.     (Bol- 

duan.) i2mo, 

Wells's  Laboratory  Guide  in  Qualitative  Chemical  Analysis 8vo, 

Short  Course  ir  Inorganic  Qualitative  Chemical  Analysis  for  Engineering 

Students i2mo, 

Whipple's  Microscopy  of  Drinking-water 8vo, 

Wiechmann's  Sugar  Analysis Small  8vo. 

Wilson's  Cyanide  Processes i2mo, 

Chlorination  Process i2mo, 

Wulling's  Elementary  Course  in  Inorganic    harmaceutical  and  Medical  Chem- 
istry  i2mo,    2  oo 

CIVIL  ENGINEERING. 

BRIDGES  AND    ROOFS.       HYDRAULICS.      MATERIALS    OF    ENGINEERING 

RAILWAY   ENGINEERING. 

Baker's  Engineers'  Surveying  Instruments i2mo, 

Bixby's  Graphical  Computing  Table Paper  19^X24!  inches. 

♦*  Burr's  Ancient  and  Modern  Engineering  and  the  Isthmian  Canal.     (Postage, 

27  cents  additional.) 8vo,  net 

Comstock's  Field  Astronomy  for  Engineers 8vo, 

Davis's  Elevation  and  Stadia  Tables 8vo, 

Elliott's  Engineering  for  Land  Drainage i2mo. 

Practical  Farm  Drainage i2mo, 

Folwell's  Sewerage.     (Designing  and  Maintenance.) 8vo, 

Freitag's  Architectural  Engineering.     2d  Edition,  Rewritten 8vo, 

French  and  Ives's  Stereotomy 8vo, 

Goodhue's  Municipal  Improvements i2mo, 

Goodrich's  Economic  Disposal  of  Towns'  Refuse 8vo, 

Gore's  Elements  of  Geodesy 8vo, 

Hayford's  Text-book  of  Geodetic  Astronomy 8vo, 

Hering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco, 

Howe's  Retaining  Walls  for  Earth i2mo, 

Johnson's  Theory  and  Practice  of  Surveying Small  8vo, 

Statics  by  Algebraic  and  Graphic  Methods 8vo, 

5 


2 

00 

I 

00 

I 

00 

I 

50 

75 

3 

00 

3 

50 

4 

00 

2 

00 

2 

50 

2 

50 

X 

35 

3 

00 

2 

00 

2 

5« 

I 

50 

3 

00 

3 

00 

4 

00 

S 

00 

I 

50 

4 

00 

I 

00 

I 

50 

I 

50 

3 

50 

2 

50 

I 

50 

I 

50 

3 

oe 

35 

3 

so 

2 

50 

J 

00 

z 

SO 

z 

00 

3 

00 

3 

SO 

3 

SO 

Z 

7S 

3 

SO 

2 

50 

3 

eo 

2 

50 

I 

25 

4 

00 

2 

00 

I 

25 

2 

oo 

5 

oo 

I 

50 

2 

50 

2 

00 

2 

00 

3 

50 

2 

00 

7 

50 

5 

00 

3 

50 

I 

50 

2 

50 

2 

00 

5 

00 

6 

00 

6 

50 

5 

00 

5 

50 

3 

00 

2 

50 

I 

25 

4 

00 

3 

50 

Kiersted's  Sewage  Disposal i2mo, 

Laplace's  Philosophical  Essay  on  Probabilities.     (Truscott  and  Emory.)  i2ino, 
Mahan's  Treatise  on  Civil  Engineering.     (1873)     (Wood.) 8vo» 

•  Descriptive  Geometry 8vo, 

Merriman's  Elements  of  Precise  Surveying  and  Geodesy Svo, 

Elements  of  Sanitary  Engineering Svo, 

Merriman  and  Brooks's  Handbook  for  Surveyors i6mo,  morocco, 

Nugent's  Plane  Surveying .  =, Svo, 

Ogden's  Sewer  Design i2mo, 

Patton's  Treatise  on  Civil  Engineering Svo  half  leather. 

Reed's  Topographical  Drawing  and  Sketching 4to, 

Rideal's  Sewage  and  the  Bacterial  Purification  of  Sewage Svo, 

Siebert  and  Biggin's  Modem  Stone-cutting  and  Masonry * .Svo, 

Smith's  Manual  of  Topographical  Drawing.     (McMillan.) Svo, 

Sondericker's  Graphic   Statics,  witn   Applications   to   Trusses,  Beams,   and 
Arches Svo, 

•  Trautwine's  Civil  Engineer's  Pocket-book i6mo,  morocco, 

Wait's  Engineering  and  Architectural  Jurisprudence Svo, 

Sheep, 
Law  of  Operations  Preliminary  to  Construction  in  Engineering  and  Archi- 
tecture.   Svo, 

Sheep, 

Law  of  Contracts Svo, 

Warren's  Stereotomy — Problems  in  Stone-cutting Svo, 

Webb's  Problems  in  the  Use  and  Adjustment  of  Engineering  Instruments. 

i6mo,  morocco, 

•  Wheeler's  Elementary  Course  of  Civil  Engineering Svo, 

Wilson's  Topographic  Surveying Svo, 


BRIDGES  AND  ROOFS. 

Boiler's  Practical  Treatise  on  the  Construction  of  Iron  Highway  Bridges.  .Svo,  2  00 

*         Thames  River  Bridge 4to,  paper,  5  00 

Biirr's  Coiuse  on  the  Stresses  in  Bridges  and  Roof  Trusses,  Arched  Ribs,  and 

Suspension  Bridges ^ Svo,  3  50 

Du  Bois's  Mechanics  of  Engineering.     VoL  II Small  4to,    10  00 

Foster's  Treatise  on  Wooden  Trestle  Bridges 4to,  5  00 

Fowler's  Coffer-dam  Process  for  Piers Svo,  2  50 

Greene's  Roof  Trusses Svo,  i  25 

Bridge  Trusses Svo,  2  ^o 

Arches  in  Wood,  Iron,  and  Stone Svo,  2  50 

Howe's  Treatise  on  Arches Svo ,  4  00 

Design  of  Simple  Roof- trusses  in  Wood  and  Steel Svo,  2  00 

J#knson,  Bryan,  and  Tumeaure's  Theory  and  Practice  in  the  Designing  of 

Modern  Framed   Structures Small  4to,    10  00 

Merriman  and  Jacoby's  Text-book  on  Roofs  and  Bridges: 

Part  I. — Stresses  in  Simple  Trusses Svo,  2  50 

Part  n. — Graphic  Statics Svo,  2  50 

Part  in. — Bridge  Design.     4th  Edition,  Rewritten Svo,  2  50 

Part  IV. — Higher  Structures Svo,  2  50 

Morison's  Memphis  Bridge 4to,  10  00 

^addell's  De  Pontibus,  a  Pocket-book  for  Bridge  Engineers. .  .  i6mo,  morocco,  3  00 

Specifications  for  Steel  Bridges i2mo,  i  2s 

Wood's  Treatise  on  the  Theory  of  the  Construction  of  Bridges  and  Roofs. Svo,  2  00 
Wright's  Designing  of  Draw-spans: 

Part  L  — Plate-girder  Draws Svo,  2  50 

Part  II. — Riveted-truss  and  Pin-connected  Long-span  Draws Svo,  2  50 

Two  parts  in  one  volume 8vo,  3  50 


HYDRAULICS. 

Bazin's  Experiments  upon  the  Contraction  of  the  Liquid  Vein  Issuing  from  an 

Orifice.     (Trautwine.) 8vo,    2  00 

Bovey's  Treatise  on  Hydraulics 8vo,    5  00 

Church's  Mechanics  of  Engineering 8vo,    6  00 

Diagrams  of  Mean  Velocity  of  Water  in  Open  Channels paper,    1  50 

Coffin's  Graphical  Solution  of  Hydraulic  Problems i6mo,  morocco,    2  50 

Flather's  Dynamometers,  and  the  Measurement  of  Power i2mo,    3  00 

Folwell's  Water-supply  Engineering 8vo,    4  00 

Frizell's  Water-power 8vo,    5  00 

Fuertes's  Water  and  Public  Health i2mo,    i  50 

Water-filtration  Works i2mo,    2  50 

Ganguillet  and  Kutter's  General  Formula  for  the  Uniform  Flow  of  Water  in 

Rivers  and  Other  Channels.     (Hering  and  Trautwine.) 8vo,    4  00 

Hazen's  Filtration  of  Public  Water-supply 8vo,    3  00 

Hazlehurst's  Towers  and  Tanks  for  Water-works 8vo,    2  50 

Herschel's  115  Experiments  on  the  Carrying  Capacity  of  Large,  Riveted,  Metal 

Conduits 8vo,    2  00 

Mason's    Water-supply.     (Considered    PrincipaDy   from   a   Sanitary   Stand- 
point.)    3d  Edition,  Rewritten 8vo,  4  00 

Merriman's  Treatise  on  Hydraulics,     gth  Edition,  Rewritten 8vo,    5  00 

*  Michie's  Elements  of  Analytical  Mechanics 8vo,    4  00 

Schuyler's   Reservoirs  for  Irrigation,   Water-power,   and   Domestic   Water- 
supply Large  8vo,    5  00 

*♦  Thomas  and  Watt's  Improvement  of  Riyers.     (Post.,  44  c.  additional),  4to,    6  00 

Turneaure  and  Russell's  Public  Water-supplies 8vo,    5  00 

Wegmann's  Desiem  and  Construction  of  Dams 4to,    5  00 

Water-supply  of  the  City  of  New  York  from  1658  to  1895 4to,  10  00 

Weisbach's  Hydraulics  and  Hydraulic  Motors.     (Du  Bois.) 8vo,    5  00 

Wilson's  Manual  of  Irrigation  Engineering Small  8vo,    4  00 

Wolff's  Windmill  as  a  Prime  Mover 8vo,    3  00 

Wood's  Turbines 8vo,    3  50 

Elements  of  Analytical  Mechanics 8vo,    3  00 

MATERIALS  OF  ENGINEERING. 

Baker's  Treatise  on  Masonry  Construction 8vo,  5  00 

Roads  and  Pavements 8vo,  s  00 

Black's  United  States  Public  Works Oblong  4to,  5  00 

Bovey's  Strength  of  Materials  and  Theory  of  Structures 8vo,  7  50 

Burr's  Elasticity  and  Resistance  of  the  Materials  of  Engineering.     6th  Edi- 
tion, Rewritten . , : 8vo,  7  50 

Byrne's  Highway  Construction 8vo,  5  00 

Inspection  of  the  Materials  and  Workmanship  Employed  in  Construction. 

i6mo,  3  00 

Church's  Mechanics  of  Engineering 8vo,  6  00 

Du  Bois's  Mechanics  of  Engineering.     Vol.  I Small  4to,  7  50 

Johnson's  Materials  of  Construction Large  8vo,  6  00 

Keep's  Cast  Iron 8vo,  2  50 

Lanza's  Applied  Mechanics 8vo,  7  50 

Martens's  Handbook  on  Testing  Materials.     (Henning.)     2  vols 8vo,  750- 

Merrill's  Stones  for  Building  and  Decoration 8vo,  5  00 

Merriman's  Text-book  on  the  Mechanics  of  Materials 8vo,  4  00 

Strength  of  Materials lamo,  i  00 

Metcalf's  Steel.     A  Manual  for  Steel-users i2mo,  2  00 

Patton's  Practical  Treatise  on  Foundations 8vo,  5  00 

7 


' 

2r, 

I 

oo 

3 

50 

2 

oo 

2 

oo 

8 

oo 

2 

oo 

3 

50 

2 

SO 

5 

oo 

4 

oo 

3 

oo 

I 

25 

2 

oo 

3 

oo 

4 

oo 

Rockwell's  Roads  and  Pavements  in  France i2mo, 

Smith's  Materials  of  Machines i2mo, 

Suow's  Principal  Species  of  Wood 8vo, 

Spalding's  Hydraulic  Cement i2mo, 

Text-book  on  Roads  and  Pavements i2mo, 

Thurston's  Materials  of  Engineering.     3  Parts 8vo, 

art  I. — Non-metallic  Materials  of  Engineering  and  Metallurgy 8vo, 

Part  n. — Iron  and  Steel 8vo, 

Part  III. — A  Treatise  on  Brasses,  Bronzes,  and  Other  Alloys  and  their 

Constituents 8vo, 

Thurston's  Text-book  of  the  Materials  of  Construction Svo, 

Tillson's  Street  Pavements  and  Paving  Materials 8vo, 

^addell's  De  Pontibus.     (A  Pocket-book  for  Bridge  Engineers.) . .  i6mo,  mor. , 

Specifications  for  Steel  Bridges i2mo. 

Wood's  Treatise  on  the  Resistance  of  Materials,  and  an  Appendix  on  the  Pres- 
ervation of  Timber Svo, 

Elements  of  Analytical  Mechanics Svo, 

Wood's  Rustless  Coatings:  Corrosion  and  Electrolysis  of  Iron  and  Steel.  .  .Svo, 

RAILWAY  ENGINEERING. 

Andrews's  Handbook  for  Street  Railway  Engineers.     3X5  inches,  morocco,    i  25 

Berg's  Buildings  and  Structures  of  American  Railroads 4to,  5  00 

Brooks's  Handbook  of  Street  Railroad  Location i6mo.  morocco,    i  50 

Butts's  Civil  Engineer's  Field-book i6mo,  morocco,    2  50 

Crandall's  Transition  Curve i6mo,  morocco,    i  50 

Railway  and  Other  Earthwork  Tables Svo,    i  50 

Dawson's  "Engineering"  and  Electric  Traction  Pocket-book.    i6mo,  morocco,    5  00 
Dredge's  History  of  the  Pennsylvania  Railroad?    (1S79) Paper,    5  00 

•  Drinker's  Tunneling,  Explosive  Compounds,  and  Rock  Drills,  4to,  half  mor.,    25  00 

Fisher's  Table  of  Cubic  Yards Cardboard,        25 

Godwin's  Railroad  Engineers'  Field-book  and  Explorers'  Guide i6mo,  mor,,  2  50 

Howard's  Transition  Curve  Field-book i6mo,  morocco,    i  50 

Hudson's  Tables  for  Calculating  the  Cubic  Contents  of  Excavations  and  Em- 
bankments    Svo,    I  00 

Molitor  and  Beard's  Manual  for  Resident  Engineers i6mo,  i  00 

Nagle's  Field  Manual  for  Railroad  Engineers i6mo  morocco,  3  00 

Philbrick's  Field  Manual  for  Engineers i6mo,  morocco,  3  00 

Searles's  Field  Engineering i6mo,  morocco,  3  00 

Railroad  Spiral i6mo,  morocco,  i  50 

Taylor's  Prismoidal  Formulae  and  Earthwork Svo,  1   50 

•  Trautwine's  Method  of  Calculating  the  Cubic  Contents  of  Excavations  and 

Embankments  by  the  Aid  of  Diagrams Svo,  2  00 

The  Field  Practice  of  [Laying    Out    Circular    Curves    for    Railroads. 

i2mo,  morocco,  2  50 

Cross-section  Sheet Paper,  25 

Webb's  Railroad  Construction.     2d  Edition,  Rewritten i6mo.  morocco,  5  00 

Wellington's  Economic  Theory  of  the  Location  of  Railways Small  Svo,  5  00 

DRAWING. 

Barr's  Kinematics  of  Machinery Svo,    2  50 

•  Bartlett's  Mechanical  Drawing Svo,    3  oc 

•  •♦  *  "         Abridged  Ed Svo,    i  50 

Coolidge's  Manual  of  Drawing Svo,  paper,    i  00 

Coolidge  and  Freeman's  Elements  of  General  Drafting  for  Mechanical  Engi- 
neers.    (In  press.) 

Durley's  Kinematics  of  Machines Svo,   4  00 

8 


Hill's  Text-book  on  Shades  and  Shadows,  and  Perspective 8vo,    2  00 

Jamison's  Elements  of  Mechanical  Drawing.     (In  press.) 

/ones's  Machine  Design: 

Part  I. — Kinematics  of  Machinery 8vo, 

Part  II. — Form,  Strength,  and  Proportions  of  Parts 8vo, 

MacCord's  Elements  of  Descriptive  Geometrj    .        _ ,  * Svo, 

Kinematics;   or.  Practical  Mechanism , Svo, 

Mechanical  Drawing ,... 4to, 

Velocity  Diagrams Svo, 

•  Mahan's  Descriptive  Geometry  and  Stone-cutting Svo, 

Industrial  Drawing.    (Thompson.) Svo, 

Reed's  Topographical  Drawing  and  Sketching 4to, 

Reid's  Course  in  Mechanical  Drawing 8vo» 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design.  .Svo, 

Robinson's  Principles  of  Mechanism Svo, 

Smith's  Manual  of  Topographical  Drawing.     (McMillan.) Svo, 

Warren's  Elements  of  Plane  and  Solid  Free-hand  Geometrical  Drawing.  .  i2mo. 

Drafting  Instruments  and  Operations i2mo. 

Manual  of  Elementary  Projection  Drawing i2mo. 

Manual  of  Elementary  Problems  in  the  Linear  Perspective  of  Form  and  1 

Shadow i2mo, 

Plane  Problems  in  Elementary  Geometry i2mo. 

Primary  Geometry i2mo, 

Elements  of  Descriptive  Geometry,  Shadows,  and  Perspective Svo, 

General  Problems  of  Shades  and  Shadows Svo, 

Elements  of  Machine  Construction  and  Drawing Svo, 

Problems.  Theorems,  and  Examples  in  Descriptive  Geometrv Svo, 

Weisbach's  Kinematics  and  the  Power  of  Transmission.       (Hermann  and 
Klein.)  Svo. 

Whelpley's  Practical  Instruction  in  the  Art  of  Letter  Engraving i2mo, 

Wilson's  Topographic  Surveying Svo, 

Free-hand  Perspective Svo, 

Free-hand  Lettering Svo, 

Woolf's  Elementary  Course  in  Descriptive  Geometry Large  Svo, 

ELECTRICITY  AND   PHYSICS. 

Anthony  and  Brackett's  Text-book  of  Physics.     (Magie.) , . .  .Small  Svo,  3  00 

Anthony's  Lecture-notes  on  the  Theory  of  Electrical  Measurements i2mo,  i  00 

Benjamin's  History  of  Electricity Svo.  3  00 

Voltaic  Cell Svo,  3  00 

Classen's  Quantitative  Chemical  Analysis  by  Electrolysis.    (Boltwood.).  .Svo,  3  00 

Crehore  and  Squier's  Polarizing  Photo-chronograph Svo,  3  00 

Dawson's  "Eneineering"  and  Electric  Traction  Pocket-book. .  i6mOs  morocco,  5  00 
Dolezalek's    Theory  of    the    Lead    Acciunulator    (Storage    Battery).     (Von 

Ende.) i2mo,~2  50 

Duhem's  Thermodynamics  and  Chemistry.     (Burgess.) Svo ,  4  00 

Flather's  Dvnamometers,  and  the  Meastirement  of  Power i2mo,  3  00 

Gilbert's  De  Magnete.     (Mottelay.) Svo,  2  50 

Hanchett's  Alternating  Currents  Explained i2mo,  i  00 

Bering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco,  2  50 

Holman's  Precision  of  Measurements Svo,  2  00 

Telescopic  Mirror-scale  Method,  Adjustments,  and  Tests Large  Svo,  75 

Landauer's  Spectrum  Analysis.    (Tingle.) Svo,  3  00 

Le  ChateUer's  High-temperature  Measurements.  (Boudouard — Uurgess.)i2mo,  3  00 

Lob's  Electrolysis  and  Electrosynthesis  of  Organic  Compounds.  (Lorenz.)  i2mo.  i  00 

•  Lyons's  Treatise  on  Electromagnetic  Phenomena.     Vols.  I.  and  II.  Svo,  each.  6  00 

♦  Michie.     Elements  of  Wave  Motion  Relating  to  Sound  and  Light Svo,  4  00 

9 


I 

50 

3 

00 

3 

00 

5 

00 

4 

00 

I 

50 

I 

50 

3 

50 

5 

00 

2 

00 

3 

00 

3 

00 

2 

50 

I 

00 

I 

25 

I 
3 

50 

1 

I 

op 

I 

25 

75 

3 

50 

3 

oc 

7 

SO 

2 

50 

5 

00 

2 

00 

3 

50 

2 

50 

I 

00 

3 

00 

2 

50 

7 

oo 

7 

50 

I 

50 

6 

00 

6 

50 

5 

00 

5 

50 

3 

00 

2 

50 

Niaudet's  Elementary  Treatise  on  Electric  Batteries.     (Fishoack. ) lamo,  2  50 

•  Rosenberg's  Electrical  Engineering.    (Haldane  Gee — Kinzbrunner.) 8vo,  i   50 

Ryan,  Norris,  and  Hoxie's  Electrical  Machinery.     VoL  1 8vo,  2  50 

Thurston's  Stationary  Steam-engines 8vo,  2  50 

•  Tillman's  Elementary  Lessons  in  Heat ^ 8vo,  i  50 

Tory  and  Pitcher's  Manual  of  Laboratory  Physics Small  8vo,  2  00 

Ulke's  Modern  Electrolytic  Copper  Refining 8vo,  3  00 


LAW. 

♦  Davis's  Elements  of  Law 8vo, 

♦  Treatise  on  the  Military  Law  of  United  States 8vo, 

♦  Sheep, 

Manual  for  Courts-martial i6mo,  morocco. 

Wait's  Engineering  and  Architectural  Jurisprudence 8vo, 

Sheep, 
Law  of  Operations  Preliminary  to  Construction  in  Engineering  and  Archi- 
tecture      8vo, 

Sheep, 

Law  of  Contracts 8vo, 

Winthrop's  Abridgement  of  Military  Law i2mo, 

MANUFACTURES. 

Bemadou's  Smokeless  Powder — Nitro-cellulose  and  Theory  of  the  Cellulose 

Molecule i2mo, 

Bolland's  Iron  Founder i2mo, 

"  The  Iron  Founder,"  Supplement. i2mo. 

Encyclopedia  of  Founding  and  Dictionary  of  Foundry  Terms  Used  in  the 

Practice  of  Moulding i2mo, 

Eissler's  Modem  High  Explosives 8vo, 

Effront's  Enzymes  and  their  Applications.     (Prescott.) 8vo, 

Fitzgerald's  Boston  Machinist i8mo. 

Ford's  Boiler  Making  for  Boiler  Makers i8mo, 

Hopkins's  Oil-chemists'  Handbook 8vo, 

Keep's  Cast  Iron 8vo, 

Leach's  The  Inspection  and  Analysis  of  Food  with  Special  Reference  to  State 

ControL     (In  preparation.) 

Metcalf's  SteeL    A  Manual  for  Steel-users i2mo, 

Metcalfe's  Cost  of  Manufactures — And  the  Administration    of  Workshops, 

Public  and  Private Svo, 

Meyer's  Modern  Locomotive  Construction 4to, 

Morse's  Calculations  used  in  Cane-sugar  Factories i6mo,  morocco, 

♦  Reisig's  Guide  to  Piece-dyeing Svo, 

Smith's  Press-working  of  Metals Svo, 

Spalding's  Hydraulic  Cement i2rao, 

Spencer's  Handbook  for  Chemists  of  Beet-sugar  Houses i6mo,  morocco, 

HandbooK  tor  sugar  Manufacturers  and  their  Chemists.. .  i6mo,  morocco, 
Thurston's  Manual  of  Steam-boilers,  their  Designs,  Construction  and  Opera- 
tion   , Svo, 

♦  Walke's  Lectures  on  Explosives Svo, 

West's  American  Foundry  Practice i2mo, 

Moulder's  Text-book i2mo, 

Wiechmann's  Sugar  Analysis Small  Svo, 

Wolff's  Windmill  as  a  Prime  Mover Svo, 

Woodbury's  Fire  Protection  of  Mills Svo, 

Wood's  Rustless  Coatings:   Corrosion  and  Electrolysis  of  Iron  and  Steel.  .  .Svo, 

10 


2 

50 

2 

50 

2 

SO 

3 

00 

4 

00 

3 

00 

I 

00 

I 

00 

3 

00 

2 

50 

s 

00 

10 

00 

I 

50 

25 

00 

3 

00 

2 

00 

3 

00 

2 

00 

5 

00 

4 

00 

2 

50 

2 

50 

2 

50 

3 

00 

2 

50 

4 

00 

MATHEMATICS. 

Baker's  Elliptic  Functions 8vo, 

•  Bass's  Elements  of  Differential  Calculus i2mo, 

Briggs's  Elements  of  Plane  Analytic  Geometry i2mo, 

Compton's  Manual  of  Logarithmic  Computations i2mo, 

Daris's  Introduction  to  the  Logic  of  Algebra 8vo, 

♦  Dickson's  College  Algebra Large  i2mo, 

*  Answers  to  Dickson's  College  Algebra 8vo,  paper, 

♦  Introduction  to  the  Theory  of  Axgebraic  Equations   Large  i2mo, 

Halsted's  Elements  of  Geometry 8vo, 

Elementary  Synthetic  Geometry 8vo, 

Rational  Geometry i2mo, 

*  Johnson's  Three-place  Logarithmic  Tables :    Vest-pocket  size paper, 

loo  copies  for 

•  Mounted  on  heavy  cardboard,  8  X  lo  inches, 

10  copies  for 

Elementary  Treatise  on  the  Integral  Calculus Small  8vo, 

Curve  Tracing  in  Cartesian  Co-ordinates i2mo. 

Treatise  on  Ordinary  and  Partial  Differential  Equations Small  8vo, 

Theory  of  Errors  and  the  Method  of  Least  Squares i2mo, 

*  Theoretical  Mechanics i2mo, 

Laplace's  Philosophical  Essay  on  Probabilities.     (Truscott  and  Emory.)  i2mo, 

*  Ludlow  and  Bass.     Elements  of  Trigonometry  and  Logarithmic  and  Other 

Tables 8vo, 

Trigonometry  and  Tables  published  separately Each, 

*  Ludlow's  Logarithmic  and  Trigonometric  Tables 8vo, 

Maurer's  Technical  Mechanics 8vo, 

Merriman  and  Woodward's  Higher  Mathematics 8vo, 

Meniman's  Method  of  Least  Squares 8vo, 

Rice  and  Johnson's  Elementary  Treatise  on  the  Differential  Calculus. Sm.,  8vo, 

Differential  and  Integral  Calculus.     2  vols,  in  one Gmall  8vo, 

Sabin's  Industrial  and  Artistic  Technology  of  Paints  and  Varnish.  (7n  jyress.) 
Wood's  Elements  of  Co-ordinate  Geometry 8vo, 

Trigonometry:  Analytical,  Plane,  and  Spherical i2mo, 

MECHANICAL   ENGINEERING. 

MATERIALS  OF  ENGINEERING,  STEAM-ENGINES  AND  BOILERS. 

Baldwin's  Steam  Heating  for  Buildings i2mo, 

Barr's  Kinematics  of  Machinery 8vo, 

•  Bartlett's  Mechanical  Drawing 8vo, 

♦  "  "  "        Abridged  Ed 8vo. 

Benjamin's  Wrinkles  and  Recipes i2mo, 

Carpenter's  Experimental  Engineering 8vo, 

Heating  and  Ventilating  Buildings 8vo, 

Cary's  Smoke  Suppression  in  Plants  using  Bituminous  CoaL      (/n  prep- 
aration.) 

Clerk's  Gas  and  Oil  Engine Small  8vo, 

Coolidge's  Manual  of  Drawing 8vo,    paper, 

Coolidge  and  Freeman's  Elements  of  General  Drafting  for  Mechanical  En- 
gineers.    (In  press.) 
Cromwell's  Treatise  on  Toothed  Gearing i2mo. 

Treatise  on  Belts  and  PuLeys i2mo, 

Durley's  Kinematics  of  Machines 8vo, 

Flather's  Dynamometers  and  the  Measurement  of  Power i2mo. 

Rope  Driving i2mo, 

u 


50 

00 

00 

50 

50 

50 

25 

25 

75 

50 

75 

IS 

5 

00 

25 

2 

00 

I 

50 

I 

00 

3 

50 

I 

50 

3 

00 

2 

00 

3 

00 

2 

00 

I 

00 

4 

00 

5 

00 

2 

00 

3 

00 

2 

50 

2 

00 

I 

00 

2 

50 

2 

50 

3 

00 

I 

50 

2 

00 

6 

00 

4 

oc 

4 

00 

I 

00 

I 

50 

I 

50 

4 

00 

3 

00 

2 

00 

I 

25 

I 

oo 

2 

SO 

5 

oo 

T 

50 

3 

oo 

5 

oo 

2 

oo 

5 

oo 

4 

oo 

I 

50 

3 

50 

3 

00 

2 

00 

3 

00 

I 

50 

3 

00 

3 

00 

3 

00 

I 

00 

7 

50 

5 

00 

5 

00 

5 

00 

3 

00 

2 

50 

Gill's  Gas  and  Fuel  Analysis  for  Engineers ^ i2mo, 

Hall's  Car  Lubrication i2ino, 

Bering's  Ready  Reference  Tables  (Conversion  Factors) i6mo,  morocco, 

Hutton's  The  Gas  Engine 8vo, 

Jones's  Machine  Design: 

Part   I. — Kinematics  of  Machinery 8vo, 

Part  II. — Form,  Strength,  and  Proportions  of  Parts 8vo, 

Kent's  Mechanical  Engineer's  Pocket-book i6mo,    morocco, 

Kerr's  Power  and  Power  Transmission Syo, 

MacCord's  Kinematics ;  or.  Practical  Mechanism Svo, 

Mechanical  Drawing 4to, 

Velocity  Diagrams Svo, 

Mahaa's  Industrial  Drawing.    (Thompson.) Svo, 

Poole's  Calorific  Power  of  Fuels Svo, 

Reid's  Course  in  Mechanical  Drawing , Svo. 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design.  .Svo, 

Richards's  Compressed  Air i2mo, 

Robinson's  Principles  of  Mechanism Svo, 

Smith's  Press-working  of  Metals Svo, 

Thurston's  Treatise  on   Friction  and    Lost  Work  in   Machinery   and   Mill 

Work Svo, 

Animal  as  a  Machine  and  Prime  Motor,  and  the  Laws  of  Energetics.  i2mo, 

Warren's  Elements  of  Machine  Construction  and  Drawing Stro, 

Weisbach's  Kinematics  and  the  Power  of  Transmission.      Herrmann — 

Klein.) Svo, 

Machinery  of  Transmission  and  Governors.     (Herrmann — Klein.).  .Svo, 

Hydraul.cs  and  Hydraulic  Motors.     (Du  Bois.) Svo, 

Wolfif's  Windmill  as  a  Prime  Mover Svo, 

Wood's  Turbines Svo, 

MATERIALS  OF  ENGINEERING. 

Bovey's  Strength  of  Materials  and  Theory  of  Structures Svo,    7  50 

Burr's  Elasticity  and  Resistance  of  the  Materials  of  Engineering.     6th  Edition, 

Reset Svo, 

Church's  Mechanics  of  Engineering Svo, 

Johnson's  Materials  of  Construction Large  Svo, 

Keep's  Cast  Iron Svo, 

Lanza's  Applied  Mechanics Svo, 

Martens's  Handbook  on  Testing  Materials.     (Henning.) Svo, 

Merriman's  Text-book  on  the  Mechanics  of  Materials Svo, 

Strength  of  Mater»als i2mo, 

Metcalf's  Steel.     A  Manual  for  Steel-users i2mo, 

Smith's  Materials  of  Machines i2mo 

Thurston's  Materials  of  Engineering 3  vols.,  Svo, 

Part   11.— Iron  and  Steel Svo, 

Part  in. — A  Treatise  on  Brasses,  Bronzes,  and  Other  Alloys  and  their 
Constituents Svo 

Text-book  of  the  Materials  of  Construction Svo, 

Wood's  Treatise  on  the  Resistance  of  Materials  and  an  Appendix  on  the 
Preservation  of  Timber Svo, 

Elements  of  Analytical  Mechanics Svo, 

Wood's  Rustless  Coatings:  Corrosion  and  Electrolysis  of  Iron  and  Steel. .  .Svo, 

STEAM-ENGINES  AND   BOILERS. 

Carnot's  Reflections  on  the  Motive  Power  of  Heat.     (Thurston.) i2mo, 

Dawson's  "Engineering"  and  Electric  Traction  Pocket-book,  .i6mo,  mor.. 

Ford's  Boiler  Making  for  Boiler  Makers iSmo, 

13 


7 

50 

6 

00 

6 

00 

2 

50 

7 

50 

7 

50 

4 

00 

I 

00 

2 

00 

I 

00 

S 

00 

3 

50 

2 

50 

5 

00 

2 

00 

3 

00 

4 

00 

X 

50 

5 

CO 

I 

00 

Goss's  Locomotive  Sparks 8vo,  2  00 

Hemenway's  Indicator  Practice  and  Steam-engine  Economy i2mo,  2  00 

Button's  Mechanical  Engineering  of  Power  Plants 8vo,  5  00 

Heat  and  Heat-engines 8vo,  5  00 

Kent's  Steam-boiler  Economy 8vo,  4  00 

Kneass's  Practice  and  Theory  of  the  Injector 8vo  i  50 

MacCord's  Slide-valves 8vo,  2  00 

Meyer's  Modem  Locomotive  Construction 4to,  10  00 

Peabody's  Manual  of  the  Steam-engine  Indicator i2mo,  i  50 

Tables  of  the  Properties  of  Saturated  Steam  and  Other  Vapors 8vo,  i  00 

Thermodynamics  of  the  Steam-engine  and  Other  Heat-engines 8vo,  5  00 

Valve-gears  for  Steam-engines 8vo,  2  50 

Peabody  and  Miller's  Steam-boilers 8vo,  4  00 

Pray'g  Twenty  Years  with  the  Indicator , Large  8vo,  2  50 

Pupln's  Thermodynamics  of  Reversible  Cycles  in  Gases  and  Saturated  Vapors. 

(Osterberg.) i2mo,  i  25 

Reagan's  Locomotives :  Simple,  Compotmd,  and  Electric i2mo,  2  50 

Rontgen's  Principles  of  Thermodynamics.     (Du  Bois.) 8vo,  5  00 

Sinclair's  Locomotive  Engine  Running  and  Management i2mo,  2  00 

Smart's  Handbook  of  Engineering  Laboratory  Practice i2mo,  2  50 

Snow's  Steam-boiler  Practice 8vo,  3  00 

Spangler's  Valve-gears 8vo,  2  50 

Notes  on  Thermodynamics i2mo,  i  00 

Spangler,  Greene,  and  Marshall's  Elements  of  Steam-engineering 8vo,  3  00 

Thurston's  Handy  Tables 8vo,  i   50 

Manual  of  the  Steam-engine 2  vols..  8vo,  10  00 

Part  I. — History,  Structuce,  and  Theory Svo,  6  00 

Part  n. — Design,  Construction,  and  Operation Svo,  6  00 

Handbook  of  Engine  and  Boiler  Trials,  and  the  Use  of  the  Indicator  and 

the  Prony  Brake Svo  s  00 

Stationary  Steam-engines Svo,  2  50 

Steam-boiler  Explosions  in  Theory  and  in  Practice i2mo  i  50 

Manual  of  Steam-boiler? ,  Their  Designs,  Construction,  and  Operation .  Svo ,  5  00 

Weisbach's  Heat,  Steam,  and  Steam-engines.     (Du  Bois.) Svo,  5  00 

Whitham's  Steam-engine  Design Svo,  5  00 

Wilson's  Treatise  on  Steam-boilers.     (Flather.) i6mo,  2  50 

Wood's  Thermodynamics   Heat  Motors,  and  Refrigerating  Machines. . .  .8vo,  4  00 


MECHANICS    AND  MACHINERY. 


Barr's  Kinematics  of  Machinery Svo, 

Bovey's  Strength  of  Materials  and  Theory  of  Structures Svo, 

Chase's  The  Art  of  Pattern-making i2mo, 

Chordal. — Extracts  from  Letters i2mo, 

Chiirch's  Mechanics  of  Engineering .8vo, 

Notes  and  Examples  in  Mechanics Svo, 

Compton's  First  Lessons  in  Metal- working i2mo, 

Compton  and  De  Groodt's  The  Speed  Lathe i2mo, 

Cromwell's  Treatise  on  Toothed  Gearing i2mo, 

Treatise  on  Belts  and  Pulleys i2mo, 

Dana's  Text-book  of  Elementary  Mechanics  for  the  Use  of  Colleges  and 

Schools i2mo. 

Dingey's  Machinery  Pattern  Making i2mo. 

Dredge's  Record  of  the   Transportation   Exhibits  Building  of  the   World's 

Columbian  Exposition  of  1893 4to,  half  morocco,    5  00 

13 


2 

50 

7 

50 

2 

50 

2 

00 

6 

00 

2 

00 

I 

50 

I 

SO 

I 

SO 

I 

SO 

I 

50 

2 

OD 

Du  Bo  s's  Elementary  Principles  of  Mechanics: 

Vol.     I. — Kinematics 8vo, 

Vol     II.— Statics 8vo, 

Vol.  III.— Kinetics 8vo, 

Mechanics  of  Engineering.     Vol.    I Small  4to, 

Vol.  II SmaU  4to, 

Durley's  Kinematics  of  Machines   8vo, 

Fitzgerald's  Boston  Machinist i6mo, 

Flather's  Dynamometers,  and  the  Measurement  of  Power i2mo. 

Rope  Driving i2mo, 

Goss's  Locomotive  Sparks 8vo 

Hail's  Car  Lubrication i2mo. 

Holly's  Art  of  Saw  Filing i8mo, 

*  Johnson's  Theoretical  Mechanics i2mo« 

Statics  by  Graphic  and  Algebraic  Methods 8vo, 

Jones's  Machine  Design: 

Part   I. — Kinematics  of  Machinery 8vo, 

Part  II. — Form,  Strength,  and  Proportions  of  Parts Svo, 

Kerr's  Power  and  Power  Transmission Svo, 

Lanza's  Applied  Mechanics Svo, 

MacCord's  Kinematics;  or.  Practical  Mechanism. Svo, 

Velocity  Diagrams Svo, 

Maurer's  Technical  Mechanics Svo, 

Merriman's  Text-book  on  the  Mechanics  of  Materials Svo, 

•  Michie's  Elements  of  Analirtical  Mechanics Svo, 

Reagan's  Locomotives:  Simple,  Compound,  and  Electric i2mo, 

Reid's  Course  in  Mechanical  Drawing Svo, 

Text-book  of  Mechanical  Drawing  and  Elementary  Machine  Design.  .Svo, 

Richards's  Compressed  Air i2mo, 

Robinson's  Principles  of  Mechanism Svo, 

Ryan,  Norris,  and  Hoxie's  Electrical  Machinery.     Vol.  I Svo, 

Sinclair's  Locomotive-engine  Running  and  Management i2mo. 

Smith's  Press-working  of  Metals Svo, 

Materials  of  Machines i2mo, 

Spangler,  Greene,  and  Marshall's  Elements  of  Steam-engineering Svo, 

Thurston's  Treatise  on  Friction  and  Lost  Work  in  Machinery  and  Mill 
Work Svo, 

Animal  as  a  Machine  and  Prime  Motor,  and  the  Laws  of  Energetics.  i2mo, 

Warren's  Elements  of  Machine  Construction  and  Drawing Svo, 

Weisbach's    Kinematics    and    the  Power  of    Transmission.     (Herrmann — 
Klein.) Svo, 

Machinery  of  Transmission  and  Governors.     (Herrmann — Klein.). Svo, 
Wood's  Elements  of  Analytical  Mechanics Svo, 

Principles  of  Elementary  Mechanics i2mo. 

Turbines Svo, 

The  World's  Columbian  Exposition  of  1S93 4to, 

METALLURGY. 

Egleston's  Metallurgy  of  Silver,  Gold,  and  Mercury: 

VoL   I.— Silver Svo,  7  5o 

VoL   II. — Gold  and  Mercury Svo,  7  50 

*♦  Iles's  Lead-smelting,     (Postage  9  cents  additionaL) i2mo,  2  50 

Keep's  Cast  Iron Svo,  2  50 

Kunhardt's  Practice  of  Ore  Dressing  in  Europe Svo,  i  50 

Le  Chatelier's  High-temperature  Measurements.   (Boudouard — Burgess.) .  i2mo,  3  00 

Metcalf's  Steel.     A  Manual  for  Steel-users i2mo,  2  00 

Smith's  Materials  of  Machines i2mo,  i  00 

14 


3 

50 

4 

00 

3 

50 

7 

50 

10 

00 

4 

00 

I 

00 

3 

00 

2 

00 

2 

00 

I 

00 

75 

3 

00 

2 

00 

I 

SO 

3 

00 

2 

00 

7 

50 

5 

00 

z 

SO 

4 

00 

4 

00 

4 

00 

2 

50 

2 

00 

3 

00 

X 

SO 

3 

00 

2 

SO 

2 

00 

3 

00 

Z 

00 

3 

00 

3 

00 

z 

00 

7 

50 

5 

00 

5 

00 

3 

00 

z 

25 

2 

50 

z 

00 

Thurston's  Materials  of  Engineering.     In  Three  Parts 8vo,  8  oo 

Part   II, — Iron  and  Steel 8vo,  3  50 

Part  III. — A  Treatise  on  Brasses^  Bronzes,  and  Other  Alloys  and   their 

Constituents 8vo,  2  50 

Ulke's  Modem  Electrolytic  Copper  Refining 8vo,  3  00 

MINERALOGY. 

Barringer*s  Description  of  Minerals  of  Commercial  Value.     Oblong,  morocco,  2  50 

Boyd's  Resources  of  Southwest  Virginia 8vo,  3  00 

Map  of  Southwest  Virginia Pocket-book  form,  2  00 

Brush's  Manual  of  Determinative  Mineralogy.     (Penfield.) 8vo,  4  00 

Chester's  Catalogue  of  Minerals Svo,  paper,  i  00 

Cloth,  I  25 

Dictionary  of  the  Names  of  Minerals Svo,  3  50 

Dana's  System  of  Mineralogy Large  8vo,  half  leather,    12  50 

First  Appendix  to  Dana's  New  "Ssrstem  of  Mineralogy." Large  Svo,  i  00 

Text-book  of  Mineralogy Svo,  4  00 

Minerals  and  How  to  Study  Them. i2mo,  i  50 

Catalogue  of  American  Localities  of  Minerals Large  Svo,  i  00 

Manual  of  Mineralogy  and  Petrography i2mo,  2  00 

Eakle's  Mineral  Tables Svo,  i  25 

Egleston's  Catalogue  of  Minerals  and  Synonyms Svo,  2  50 

Hussak's  The  Determination  of  Rock-forming  Minerals.     (Smith.)  Small  Svo,  2  00 

Merrill's  Non-metallic  Minerals:  Their  Occurrence  and  Uses Svo,  4  00 

•  Penfield's  Notes  on  Determinative  Mineralogy  and  Record  of  Mineral  Tests. 

Svo,  paper,  o  50 
Rosenbusch's  Microscopical  Physiography   of   the   Rock-making   Minerals. 

(Iddings.) Svo,  5  00 

•  Tillman's  Text-book  of  Important  Minerals  and  Docks Svo,  2  00 

Williams's  Manual  of  Lithology Svo,  3  00 

MnnNG. 

Beard's  Ventilation  of  Mines i2mo,  2  50 

Boyd's  Resources  of  Southwest  Virginia Svo,  3  00 

Map  of  Southwest  Virginia Pocket-book  form,  2  00 

•  Drinker's  Tunneling,  Explosive  Compounds,  and  Rock  Drills. 

4to,  half  morocco,    25  00 

Eissler's  Modem  High  Explosives Svo, 

Fowler's  Sewage  Works  Analyses i2mo, 

Goodyear's  Coal-mines  of  the  Westem  Coast  of  the  United  States i2mo, 

Ihlseng's  Manual  of  Mining Svo, 

**  Iles's  Lead-smelting.     (Postage  gc.  additionaL) i2mo, 

Kunhardt's  Practice  of  Ore  Dressing  in  Europe Svo, 

O'Driscoll's  Notes  on  the  Treatment  of  Gold  Ores Svo, 

•  Walke's  Lectures  on  Explosives Svo, 

Wilson's  Cyanide  Processes i2mo, 

Chlorination  Process i2mo. 

Hydraulic  and  Placer  Mining i2mo. 

Treatise  on  Practical  and  Theoretical  Mine  Ventilation i2mo 

SANITARY  SCIENCE. 

Copeland's  Manual  of  Bacteriology.     {In  preparation.) 

Folwell's  Sewerage.     (Designing,  Construction  and  Maintenance.; Svo,  3  00 

Water-supply  Engineering Svo,  4  00 

Fuertes's  Water  and  Public  Health i2mo,  i  50 

Water-filtration  Works Z2ino»  2  50 

15 


4 

00 

2 

00 

2 

SO 

4 

00 

2 

50 

I 

50 

2 

00 

4 

00 

I 

50 

I 

50 

2 

00 

I 

25 

4 

oo 

I 

25 

2 

oo 

2 

so 

2 

oo 

I 

25 

I 

50 

I 

00 

I 

00 

a 

00 

I 

50 

3 

so 

5 

00 

3 

50 

z 

50 

Gerhard's  Guide  to  Sanitary  House-inspection i6mo,    i  00 

Goodrich's  Economical  Disposal  of  Town's  Refuse Demy  8vo,    3  50 

Hazen's  Filtration  of  Public  Water-supplies 8vo,    3  00 

Kiersted's  Sewage  Disposal i2mo,    i  25 

Leach's  The  Inspection  and  Analysis  of  Food  with  Special  Reference  to  State 

Control.     (In  preparation.) 
Mason's   Water-supply.     (Considered   Principally   from   a   Sanitary   Stand- 
point.)    3d  Edition,  Rewritten 8vo, 

Examination  of  Water.     (Chemical  and  BacteriologicaL ) i2mo, 

Merriman's  Elements  of  Sanitary  Engineering 8vo, 

Nichols's  Water-supply.     (Considered  Mainly  from  a  Chemical  and  Sanitary 

Standpoint.)     (1883.) 8vo, 

Ogden's  Sewer  Design i2mo, 

Prescott  and  Winslow's  Elements  of  Water  Bacteriology,  with  Special  Reference 
to  Sanitary  Water  Analysis.  ,    lamo, 

♦  Price's  Handbook  on  Sanitation i2mo, 

Richards'.  Cost  of  Food.     A  Study  in  Dietaries i2mo. 

Cost  of  Living  as  Modified  by  Sanitary  Science i2mo. 

Richards  and  Woodman's  Air,  Water,  and  Food  from  a  Sanitary  Stand- 
point  8vo, 

*  Richards  and  Williams's  The  Dietary  Computer 8vo, 

Rideal's  Sewage  and  Bacterial  Purification  of  Sewage 8vo, 

Turneaure  and  Russell's  Public  Water-suppUes 8vo, 

Whipple's  Microscopy  of  Drinking-water 8vo, 

Woodhull's  Notes  and  Military  Hygiene i6mo, 


MISCELLANEOUS. 

Barker's  Deep-sea  Soundings 8vo,    2  00 

Emmons's  Geological  Guide-book  of  the  Rocky  Mountain  Excursion  of  the 

International  Congress  of  Geologists , Large  8vo 

Ferrel's  Popular  Treatise  on  the  Winds 8vo 

Haines's  American  Railway  Management i2mo^ 

Mott's  Composition,  Digestibility .  and  Nutritive  Value  of  Food.   Mounted  chart. 

Fallacy  of  the  Present  Theory  of  Sound i6mo 

Ricketts's  History  of  Rensselaer  Polytechnic  Institute,  1824-1894.  Small  8vo, 

Rotherham's  Emphasized  New  Testament Large  8vo, 

Steel's,  Treatise  on  the  Diseases  of  the  Dog 8vo, 

Totten's  Important  Question  in  Metrology 8vo 

The  World's  Columbian  Exposition  ot  1893 4to, 

Worcester  and  Atkinson.     Small  Hospitals,  Establishment  and  Maintenance, 

and  Suggestions  for  Hospital  Architecture,  with  Plans  for  a  Small  . 

Hospital i2mo,    i  25 


HEBREW  AND  CHALDEE  TEXT-BOOKS. 

Green's  Grammar  of  the  Hebrew  Language 8vo,  3  00 

Elementary  Hebrew  Grammar i2mo,  i  25 

Hebrew  Chrestomathy 8vo,  2  00 

Gesenius's  Hebrew  and  Chaldee  Lexicon  to  the  Old  Testament  Scriptures. 

(Tregelles.) Small  4to,  half  morocco,  5  00 

Lett»  ris's  Hebrew  Bible 8vo,  2  25 

16 


I 

SO 

4 

00 

2 

50 

I 

25 

I 

00 

3 

00 

2 

00 

3 

SO 

3 

50 

r 

00