MARYLAND.

ovigultural E speriment Station,

oe 7

of the M
BULLETIN. No. 2s.

‘
adie:

INJURIOUS INSECTS

OF

MARYLAND.

U /
ent Otation/ .

/

COLLEGE “PARK; MD:

December, 1898.

MARYLAND

gricultural seperiment Station,

ADVISORY COMMITTEE OF BOARD OF TRUSTEES.

GOVERNOR FRANK BROWN......... Reise. Annapolis.

THE Hon. MARION DE KALB SmITH.....Chestertown.
THE Hon. SPENCER C. JONES..t........... Rockville.

THE Hon. MURRAY VANDIVER...........- Havre de Grace.
Tun Hon, DAVID: SEIBERT:...295/.2..---=-- Clear Spring.
OLAYTON J. PURNELL ...... Renee oe Ae Snow Hill.

OFFICERS OF THE STATION.

Rospert H. MILLER............ Director.

Harry J. PATTERSON, B.S..Chemzst.

JASS Oe HOBINSONets: -Sc-0 27-3 Horticulturist.

CAVs) RIGENG © iy De cers. 7 o's: Entomologist and Physiologist.
MILTON WHITNEY...-..-....... Physicist.

ERNEST H. BRINKLEY......... Assistant Agriculturist.
Jos. Re OWENS, MD; -....2.- Treasurer.

P. B. Hassprouck, B. 6.......Stenographer.
hLoeated on the B. &O.R.R., 8 miles N. of Washington, D.C.

DA ee |

ad
The bulletins of the Station will be mailed free to any citizen of Mary-
lan 1 who sends his name and address to the Station for that purpose.

Correspondents will please notify the Director of changes in their post-
office address, or of any failure to receive the bulletins.

ADDRESS,
MARYLAND AGRICULTURAL EXPERIMENT STATION,

COLLEGE PARK, MARYLAND.

ce,

LETTER OF SUBMITTAL.

MARYLAND AGRICULTURAL EXPERIMENT STATION,
DEPARTMENT OF ZOOLOGY AND ECONOMIC ENTOMOLOGY,

COLLEGE PARK, MD.

DECEMBER IsT, 1893.
SIR:

In accordance with your wishes, I take pleasure in submitting
herewith a bulletin on some of the injurious insects of Maryland, with
a treatment of the best methods of counteracting their injuries. It is my
intention to follow this up from time to time with other bulletins of like
nature, the particular subjects to be dealt with depending somewhat upon
the inquiries received in the current correspondence of the Station, and
upon the insect peculiarities of any particular year.

Respectfully yours,
C. V. RILEY.
Robert H. Miller, Esq.,

Director, Maryland Agricultural Experiment Station.

THE MARYLAND

AGRICULTURAL EXPERIMENT STATION.

Bulletin No. 23. December, 1893.

*

SOME INJURIOUS INSECTS OF MARYLAND.

Bs Cove RGH Yer. 2D:

INTRODUCTION.

This is the first of a series of bulletins which I hope to issue from
time to time upon the insects of Maryland. In my governmental work it
is my object to avoid threshing over old straw and republishing anything
that has been published before, as I conceive itto be the chief function
of the Department of Agriculture and its various Divisions, to prosecute
original research and to investigate those problems which yet remain to
be solved. To a certain extent this I hope to do, as an officer of the
Station, for the entomology of Maryland; but for the present I feel that
it will be more productive of good to devote these bulletins primarily to
those insects which are most important to the farmers and fruit growers
of the State, by giving summaries of all the more important facts in refer-
ence to them, and dwelling more particularly on the methods of counter-
acting their injuries. The average farmer has little use for detailed
descriptions of the forms of the minute life with which he has to deal,
and for their recognition it will be better to depend upon good illustra-
tions, with the barest indication of the colors and other salient character-
istics. The figures in this bulletin, unless otherwise stated, are from my

own drawings, or else from those made under my supervision.

THE CODLING MOTH.

(Carpocapsa pomonella L.)

LIFE HISTORY.

Wormy apples are fully as abundant in Maryland as in other states
of the Union, and this worminess is due almost entirely to the larve of
the Codling Meth. A little mass of brown excremental grains about the

valyx end of the apple, or more rarely issuing from a small hole in its

side, indicates the presence of this insect. Upon cutting the apple open
these holes are seen to lead to rapidly broadening tunnels reaching to
the core, which is often eaten through or surrounded by the nauseous
brown cavities.

The perfect insect is, as shown at Fig. 1, a small grayish moth,
> which issues from its cocoon about
the time the trees are in full bloom,

and soon thereafter lays its eggs in

the forming fruit, choosing the
calyx cavity or its immediate vicin-
ity for this purpose. The eggs
hatch and the young larve gnaw
their way through the skin and into
the fruit, moving up and down free-
ly in their burrows and enlarging
the entrance holes to push out their
excrement. Inabout a month they
become full-grown. By this time
the infested apples have begun to
fall to the ground; but whether
they fall or not, the larve bore to

Fig. 1.—Carpocapsa pomonella; a, apple the sides and issue through a round
showing the work of the larva; b, point of hole. If issuing from a fallen apple,
moth: h head of larva icacoon. *® they crawl back to the tree trunk
and mount it until some convenient crevice or piece of loose bark is found,
and here they spin their cocoons and transform to the pupa state. If
issuing from an apple which has not fallen, however, they crawl down
the branches until they reach the rough bark of the trunk, on which, as
in the other case, they spin their cocoons.

A few days after completing the cocoon, the larva in this first or
summer generation changes to the chrysalis state, and in about two weeks,
on the average, from the time of leaving the apple, issues as a moth. The
female soon begins to oviposit, at this season not so uniformly in the
calyx end as was the case with the preceding generation in the spring.
This summer generation of moths issues quite irregularly, covering a

im)

72 MARYLAND AGRICULTURAL EXPERIMENT STATION.

period of several weeks, and egg-laying thus extends into the late summer,
so that larve of different sizes will be found in the apples during the
late summer and autumn, and even well into the winter. The cocoons
of these late individuals are usually spun in the crevices of the barrels
in which the apples are packed for storage.

REMEDIAL MEASURES,

The damage which this insect wrought to the apple crop all over the
country down to within the last eight or ten years was very great,
and is still very serious in sections where intelligent measures are not
taken to prevent it. Anywhere from 50 to 100 per cent. of wormy
apples was common ; and the effect of the alternate seasons of heavy and
light setting of fruit was intensified to such a degree that in seasons of
light setting, the crop was almost entirely destroyed.

In a few localities the old plan of bandaging or encircling the trunks
of the trees with paper or rag bandages was systematically carried on,
with the result of greatly reducing the proportion of wormy fruit, as the
larve are very fond of spinning up in the shelter afforded by such ban-
dages, and where these are systematically removed every two weeks and
scalded, (or in the case of paper bandages burned) this method of check-
ing the injury of the insect is well worth adopting. The efforts of the
State Horticultural Societies of Michigan, Illinois and Kansas in the use
of these bandages were particularly productive of good results, as there
was co-operation. At the present time, however, this method has been
almost entirely superseded by one which is, on the whole, better and
simpler, viz: spraying with arsenical poisons. The use of arsenical
poisons against this insect practically dates from 1878, though they had
been employed on apple treesas early as 1872, against Canker Worms.
It was in fact, their use against Canker Worms that led to the discovery
that they were available as preventives of the Apple Worm. They are
now very generally employed among the most advanced apple growers of
the North and West, especially where a sufficient number of trees is
grown to justify providing the proper machinery. This method is not
confined to the United States, but has been introduced with profit into
New Zealand, Australia and Tasmania, where the insect prevails as it
does with us. Spraying with arsenicals was longer in making its way in
Europe, but even in England and in parts of the continent apple growers
are beginning to appreciate its value, though prejudiced against the use
of poisons. Many of our apple growers, particularly in the South, have
so far failed to appreciate its importance, and this is to a large extent
true of the State of Maryland.

As some of our orchardists may yet fancy that the time and means
required to spray effectively are wasted, let me quote a single instance of
the value of spraying from a correspondent in the vicinity who is an ex-
tensive grower, and then giye briefly some of the best and latest methods.
nae years ago Mr. John 8. Lupton of Winchester, Va., wrote me as
ollows:

BULLETIN NUMBER 23, DECEMBER, 1893. 73

“Please allow me to acknowledge my very great obligation to youfor bringing to my
attention, through your official publications, the use of arsenical poisons for destroying
Codling Moth and other noxious insects.

“T have a fine young apple orchard of fifty acres, all Newtown Pippins, immediately

adjoining which on the north is an older and much neglected orchard belonging toa
neighbor.

“The old orchard has been badly infested with worms for many years, and until the
present season the north half of my orchard has been practically worthless, the trees
shedding most of their fruit in May and early part of June, the little which remained
being so wormy as to be largely unfit for market, while the south half has borne fair
crops, comparatively free from worms.

“Soil, drainage and other conditions being similar throughout, lam constrained to
the belief that the near proximity of the old and worm-infested trees to the north side of
my orchard is the cause of the difference above noted.

“Acting upon information obtained from one of your pamphlets, I bought last spring
a full spraying outfit, using the Climax preparation of London purple sold by the Nixon
Company.

“Soon after the blossoms fell I began spraying on the side nearest the old orchard,the
machine working perfectly, the Climax nozzle breaking up the solution into a fine mist
which completely enveloped the trees.

“After working a day anda half and applying the poison to about one-third of the
trees, I suspended operations on account of the weather becoming so windy as to make
the work exceedingly disagreeable, one of the men having been made sick by having
the poison blown into his face.

“Influenced to some extent by the skepticism of my neighbors, most of whom regard-
ed the experiment as highly dangerous, and confessing to no small lack of faith myself,
IT regret to say that I allowed other work on the farm to interfere, and never finished the
work of spraying.

“With the mental reservation that should the heretofore barren north side where the
poison had been applied do as wellas the south half, I would spray more thoroughly
next year, I waited the outcome with an indifference born of unbelief. Please note
the result. From the sprayed trees, not quite one-third the whole number, I gathered
1,000 barrels of Al merchantable fruit so entirely free from worms that sorting was
almost unnecessary, while the remaining two-thirds of the orchard yielded 883 barrels of
good fruit, quite one-fifth of the apples on the unsprayed trees being wormy and unfit
for sale. The market price of apples in this section the past season was from 60 to 75 cents
per barrel, one or two choice lots of Ben Davis and York Imperial bringing $1 per barrel,
while my fruit sold in the orchard nearly a month before picking at $2.55 per barrel.

“T estimate the cost of failure to spray the whole orchard at $2,500, but consider the
lesson cheap at the price, as I shall never have it to learn again, and feel confident that
with ordinary care no harmful results will follow spraying.”

THE USE OF ARSENICAL SPRAYS.

Substances to be used.—Two arsenical poisons are commonly used in
spraying orchard trees for the Codling Moth, namely, Paris green and
London purple. Of the two, Paris green still holds the vantage ground
by virtue of the fact that it is insoluble in cold water and contains a
more constant proportion of arsenic. London purple, on the other hand,
is somewhat cheaper, and the slightly purplish hue which it imparts to
the treated foliage possesses some value as indicating more clearly the
efficacy of the spraying, for it permits us to see whether or not the appli-
cation has been uniformly made and has taken a firm and uniform place
upon the leaves, which the Paris green does not show to the same extent.
The slight solubility of the purple in cold water renders it more apt to

©

74. MARYLAND AGRICULTURAL EXPERIMENT STATION.

burn the foliage, but this difficulty is easily overcome by the addition of
a small quantity of lime water to the mixture, thus transforming the sol-
uble arsenic into insoluble calcic arsenite,

The use of ordinary white arsenic is not advised because of its in-
solubility and its color, which renders it indistinguishable from some
harmless substances for which it is apt to be mistaken, so that it is more
dangerous to have about the farm in quantities.

Kither London purple or Paris green, then, should be thoroughly
mixed with water in the proportion of one pound of the poison to 150
gallons of water, and this mixture should be thrown in a fine spray
through the trees, so as to thoroughly moisten all parts of the leaves and
fruit. I cannot too strongly urge the advantage of careful spraying
which shall cause a uniform fall in the form of a mist, and not drench the
tree, and thus cause the concentration of the poison in particular spots.
The spray should be forced from the center of the tree and then all
around it, in an even mist, which will settle uniformly on all parts.

The first application should be made about a week after the blossoms.

fall and before any of the larvee have hatched or entered the fruit, as the
efficacy of the spraying depends upon the larve taking a small quantity
of the poison with their first meal in eating through the calyx of the
young apple. Unless a heavy fall of rain should follow this first appli-
cation, the spraying will not have to be repeated. A small quantity of
flour or starch mixed in at the time of stirring the poison in the water
will tend to make the spray adhere better and more uniformly, but these
sticky substances should not be mixed with London purple as they pre-
cipitate the poisoh and rather increase the inequality of its distribution.

One great advantage of such spraying is that in addition to greatly
lessening, if not practically checking, the work of the Codling Moth, it
also destroys a great number of insects which feed upon the leaves of the
apple tree, and in a measure will also serve as a protection against certain
fungus diseases. Where orchards are seriously affected with rust or scab,
it is desirable even to combine with the arsenical spray a certain amount
of Bordeaux mixture, and a good formula for this last is, 7 poumes of
unslaked lime, 6 pounds of copper sulphate (or blue stone), 3 pound of
London purple, and 75 gallons of water.

Apparatus for Spraying. —For orchard use, the knapsack pumps or
bucket pumps are practically unavailable, however useful for a few trees
by means of ladders. I shall therefore not consider them in this connec-
tion, but refer to a few of the more important tank or barrel pumps and
state the requisites of a good orchard spraying apparatus.

The following firms manufacture Spray pumps of several styles*and
are always glad to send circulars to fruit growers:

Nixon Nozzle & Machine Co., Day ton, Ohio.

Field Force Pump Co., Loc ‘kport, N. Y.

Deming Manufacturing Co., Salem, Ohio.

W. & B. Douglass, Middletown, Conn.

The Gould’s s Company, Seneca Falls, N. Y.

BULLETIN NUMBER 23, DECEMBER, 1893. 75

A good, strong double-acting force pump should be purchased and
mounted on a large stout barrel with the supply tube reaching well down
to the bottom. It has become the custom to mount the pump in the end
of the barrel, but except in the case of the Nixon Tripod, it will be al-
most as easy to mount it on the side of the barrel, which is easily held in
place by a skid near either end, and is then more compact and stable
than when standing on the end, while the handle of the pump comes
lower and is more easily worked.

It will be well to buy the pump without attachments. About 25
feet of + inch cloth insertion rubber tubing is attached to the discharge
orifice, or to each of the orifices in case there are two. To the end of the
tube is fitted one of the modifications of the Cyclone or Riley nozzle and
the outer 8 or 10 feet are clamped or wired to a light pole or bamboo fishing
rod for convenience in elevating the nozzle into the larger trees, The
tank or barrel is mounted on a cart or sled and driven between the tree
rows, one man driving and pumping and the other holding and directing
the extension pole and nozzle.

T have mentioned the cyclone nozzle for the reason that, all things

ah vinaszett
HH }
‘ i}
Wt
Mil

ured and sold by the Nixon
Nozzle & Machine Co. is also
a good nozzle, but it is rather
“large and clumsy, its spray
hardly so fine, and it will not
answer for fungicides contain-
ing lime, since it clogs easily.
The Vermorel modifi¢ation of
the Cyclone nozzle (Fig. 2) pos-

B ‘
eae ome Are, Modification of uhe Cy- sesses a little attachment which
clone Nozzle—natural size (Original).

A, entire; B, in section; c, removable cap; d, end quickly unclo Se sule orifice
of cleaning rod; e, rubber casket to prevent back- when once stopped up, and is
ward escape of liquid; f, cap to hold liquid when ,; ft ; cian : ;
cleaning rod is pushed forward. therefore preferable. More-
over, neither the Cyclone nor the Vermorel modification is patented,
which, other things being equal, is in their favor. Both are manufact-
ured by Thomas Somerville & Sons, Washington, D. C., and Robert
Leitch & Sons, also of Washington, or may be made by any brass and iron
worker from the descriptions in my official reports* or from the accom-
panying figures.

NATURAL ENEMIES,

While ordinarily little can be done to encourage the natural enemies
of the Codling Moth, there are nevertheless a few which it is well worth
while for the orchardist to become familiar with. Those of its own
class which he will most often meet with in sheltered situations, about
the trees or under the bandages used to trap the worms are the followin g:

“INSECT LIFE, Vol. I. p 243-244: Fifth Report U. 8. Entomological Commission, p 45.

76 MARYLAND AGRICULTURAL EXPERIMENT STATION.

THE PENNSYLVANIA SOLDIER BEETLE.—(Chaultognathus pennsyl-
vanicus De Geer.) This is a little yellowish beetle (Fig. 3, 2) with
‘. £ inore or less black upon its
~‘y’,; Wing-covers and upon the thorax, ~
mm abundanton almost all pollen-bear-

7- ing flowers; but while the beetle is
Pe ~ pollinivorous, the larva is carnivor-

6 ous and devours the apple worm

. / ¢ ™ either within the apple or while it
Fig 3—Chauliognathus pennsylranicus: a,is getting ready to spin up. The
larva, natural size: P, Read and Sst seement -companying figure (3) shows this

leg: 7, left maxilla: g. antenna: h, left man-jynzp ; =
a ng insect in the larva state at @ and

the adult at ¢, the other figures indicating details of the larval structure.

i
«

es yO

ae

hae

rg)

COREL ET)

‘

THE TWO-LINED SOLDIER BEETLE.--This is an allied species belonging —

x to another genus and known entomologi- —
cally as TZelephorus bilineatus Say. Here
alsoitis the larva which preys upon the
apple worm. Figure 4, shows it in natural
= size at a, its head and two thoracic segments
-® at 4, enlarged, and the beetle natural size

Fig. 4.—Telephorus bilineatus. a.at c. The larva, like the preceding, is of a -
anlareed image OF S8™€ rich, velvety-brown and black color, the
beetle having brown and black wing covers and reddish-yellow thorax, the
latter having two short black longitudinal marks, from which the insect
takes its name.

In the Fourth Report on the Insects of Missouri, 1871, I called at-
tention to the fact that the principal bird enemies of the Codling Moth
are the Creepers, Black-capped Titmouse, the Downy Woodpecker, the
Blue Bird and the Crow Black Bird. In the Fifth Report of the same
series I described and figured
two true parasites. The Ring-
legged Pimpla (Pimpla annu-
Ziges, Br.) and the Delicate
Long Sting, ( Macrocentrus deli-
catus Cress.,) and there men- —
tioned the fact that a species
of Hair-snake or Hair-worm, -
(Mermis acuminata), also in-
fests the larva. All of these
an =. insects are found in Matyland. -
Fig. 5.—Tenebrioides corticalis: a. larva; ¢, its man- I have also found a peculiar =

dible: d. antenna: ¢é. under side of head: 7, the two-

horned anal plate: b. the beetle: h, its antenna: i. larva of another Beetle, ( Zene-
mandible; g. labium and its palpi: j. one of the - - - ee =
maxilla and its palpus. i orioides corticahs, Fig D)s prey-s
ing upon the larve, while Dr. LeBaron, (Fourth Report as Illinois State __
Entomologist, p. 64), records the same habit of the same species and Mr. _
C. D. Zimmermann records a similar habit, on the part of the larva of
LT. laticollis, (Canadian Entomologist, 1878, p- 60). In Europe three

BULLETIN NUMBER 23, DECEMBER, 1893. TT

Ichneumon flies prey upon the Codling Moth. These are Phygadeuon
brevis, Pachymerus vulnerator and Campoplex pomorum Rtz. On the
Pacific Coast the Ring-legged Pimpla, (Pimpla annulipes Br.,) is an im-
portant parasite of the Codling Moth, as ascertained by Mr. Albert Koe-
bele who has also found several new enemies of this insect there. Two

Dermestic beetles also feed upon the pupa in California. These are
Trogoderma tarsale and Perimegatoma variegatum as shown in my Annual
Report as U. 8. Entomologist, for 1887. Mr. Koebele has also found a
species of the Chalcidid genus Trichogramma, which infests the eggs of
the Codling Moth and has further observed that the larva of a species of
the very peculiar Neuropterous genus Rhaphidia runs up and down the
ree trunks, searching for Codling Moth larve and pup (see Bulletin
22, Division of Entomology, Wigs: Department of Agriculture, pp. 90-92).

Mr. Koebele has also reared a parasite of the genus Pteromalus, but this
may be a secondary parasite on the Pimpla above mentioned or upon one
of two other primary parasites of the genera Cryptus and Phygadeuon
which he has also reared from Codling Moth cocoons.

Some of these California insects were sent by me through Mr.
Koebele to New Zealand and Australia, for the purpose of introducing
them into the apple orchards of those countries, and they as well as the
European parasites, are mentioned in this connection, as it may be
desirable in special cases to introduce them into apple orchards in the
eastern United States.

THE GREEN JUNE. BEETLE.

(Allorhina nitida L.)

This is an insect which has become more and more noticeable during
recent years and has at times proved exceedingly destructive, especially to
lawns in the vicinity of Washington. It is very common in Maryland,
where it is known ordinarily as the June Beetle or the June Bug, a term
which has, however, been very loosely applied to several insects and par-
ticularly to the common May Beetle (Lachnosterna fusca). These May
Beetles, or June Bugs as they are called in the northern states, of the
genus Lachnosterna, are brown beetles which begin to fly in the month of
May, though they continue into June and even later, in the latitude of
W ashington. Under the circumstances it will be w ell to designate the
insect Iam now treating by the name indicated in the title. The larve
of this insect and those of the May Beetles, havea similar general appearance
and are known popularly among farmers by the rather comprehensive
name of White Grubs. The ‘leprae of the true May Beetles are, as a rule,
smooth and naked in appearance, though when examined under a strong
lens, minute stiff hairs or bristles may be found on different portions of
the body. But the larva of our Green June Beetle is clothed with min-
ute yellowish hairs in sufficient numbers to make them easily observable
with the naked eye. The two kinds of White Grubs may be further dis-
tinguished by the fact that when the larva of Allorhina is placed on a
smooth surface it will immediately turn over on its back and rapidly
move away by the alternate expansion and contraction of the body seg-

78 MARYLAND AGRICULTURAL EXPERIMENT STATION.

ments, while the White Grubs proper, the larve of Lachnosterna, will
lie in a half-coil on their sides, or make awkward efforts to use their feet,
being essentially burrowers. It is for these reasons that I have figured
the larva of Allorhina on its back, as shown in the accompanying illustra~
tion, (Figure 6).

Fig. 6.—Allorhina nitida; a, larva; 5, pupa, ¢, imago: d,g, mouthparts of larva; d, man-
dible;e, antenna; f, maxillary palpus; y, maxilla.

The larve of the Green June Beetle attract more attention than the
others, partly because they are somewhat larger in size, and partly because
they occur abundantly every year and are more easily brought by disturb-
ances and by irrigation to the surface of the ground. The parent beet-
les begin to fly the latter part of June, increase somewhat in numbers
during July and August, and disappear in September. Like the other
species of its sub-family this Green June Bug does not devour the leaves,
like the true May Beetles, but feeds upon over-ripe fruit and vegetables.
It is fond of clustering in numbers upon anything that is over-ripe or
half decayed, especially half decayed melons, and does in this way more
or less damage to ripe peaches hanging on the tree. It will swarm
around the flowing sap of fruit trees or even of young oaks and maples,
wherever there is a braise inducing such flow, and I have noticed that
they are particularly fond of feeding at the moisture that frequently re-
sults from the attacks of borers. <A closely allied species, Auryomda me/-
ancholica is commonly known as the Fig-eater from its similar habit of
attacking fully ripe or over-ripe figs. Nevertheless the damage which
the parent beetle does is slight compared with the injury which the
species often does in the larva state.

Although so common, the readers of this bulletin will be surprised to
learn that there is a great deal yet to learn in reference to it, and that its
full life-history has not been traced. This is largely due to the fact that
the larva works under ground and out of sight, and to the further fact
that it is somewhat difficult to rear in confinement. I received two spec-
imens of this larva in November; 1868, from Mr. G. D. Baker, of South
Pass, Ills., who found them in his strawberry beds in company with one of
the May Beetle larve, and it was at once noticeable that this Green June
Bug differed from all I had up to that time studied in its peculiar habit
of crawling on its back, traveling with the same motion and quite as
yvapidly as an ordinary caterpillar, and invariably turning on its back to
move or to burrow. ‘I'hese larvee remained alive in-doors, feeding greed-

BULLETIN NUMBER 23, DECEMBER, 1893. 79

ily on roots of wheat which I grew for them. In April, 1869, they
formed tough, hard cells of earth, and by the middle of May had changed
to pupae (Fi igure 6, 4), the adult beetles i issuing in June.

Around Washington these larvee are observed almost every autumn,
and are not infrequently brought to me by persons who find them crawl-
ing in large numbers on the eround, This is particularly the case on the
sidewalks” adjoining the lawns of the Capitol grounds, where they are
sometimes so numerous that bushels of them may be swept together.

The beetles lay their eggs, unquestionably, underground, and though
the egg has not yet been observed or described, there is no question in my
own mind that the beetles are attracted to any soil which is heavily
mulched and where there is manure or decomposing vegetation. I have
seen them swarming and buzzing lazily over the ground on the New Jer-
sey coast wherever the sand was covered with sea-weed or marsh grass,
settling down ever y once ina while to enter the ground or get beneath
the mulching. There is every reason to believe from the size of the larve
and the habits of the beetles, that the eggs are laid during any of the
summer months, and even during September. The early life- -history of
the larva has not been studied, but it is well-known that as it attains full
growth it injures the roots of vegetation. Yet my own impression is that
during most of their growth these larve are comparatively harmless,
feeding largely on vegetable humus and deriving the greater part of
their nourishment in this way. The contents of ‘the very large alimen-
tary canal in color and consistence, would indicate this habit.

The exact length of the insect’s life in the larva state is also not accu-
rately known, and this is one of the points which is now being investi-
gated at the Station. In late autumn two distinct sizes are noticeable,
though larve of almost every size may be found. The prevalence of
these two sizes would indicate that the larva requires perhaps two years
for full development, yet I am more inclined to attribute the difference in
size to differences in the period of egg-laying and hatching and to believe
that the insect may go through all its transformations in a single year.

It will thus be seen that there are many points yet to be ascert tained in
the life-history of this insect, common as it is, and that some of these,
when ascertained, may give us a clue to a better management of it.

REMEDIES AND PREVENTIVES.

Undoubtedly one of the best available remedies which we have, and one
which is by no means extravagant in cost in a strawberry bed where
plenty of water is convenient, is the application of a dilute kerosene emul-
sion. ‘The experiments which I had tried a few years ago on the lawn in
front of the east wing of the Capitol at Washington, (see Insect Life, Vol.
IL, No. 2, pages 48-50, Aug., 1888), showed that one part of the standard
kerosene emulsion diluted with fifteen parts of water, and subsequently
well washed down into the soil by copious applications of water, will kill
all the grubs which it touches, and at the same time will penetrate suffi-
ciently “deep into the ground to reach those grubs which are furthest
down, Moreover it is found that even at a strength of one part of the
emulsion to eight parts of water, the grass is not injured. In addition to

80 MARYLAND AGRICULTURAL EXPERIMENT STATION.

this it was found that heavy watering will cause these grubs torise to the
surface of the ground. We have, then, simply to pour an abundance of
water upon the affected soil and when the grubs begin to appear upon the
surface of the ground, to treat them thoroughly with the emulsion at one
part to fifteen of water. Then, after say “bw enty-four hours, pour on
more water to carry the insecticide further down into the soil. The
economy of this plan may be shown by the following facts: One barrel
of kerosene cos sting $4. 50, and a sufficient quantity of : soap to make half a
barrel of strong soapsuds, co sting, say, twenty-five cents, will make a bar-
rel and a-half of standard emulsion or twenty-two and-a-half barrels of
the dilute emulsion. This will be amply sufficient to treat an acre of
strawberries and even more upon a porous soil. Upon large field crops
this process would prove too expensive, but as a matter of fact, this insect
is always most abundant upon small, choice, heavily manured or mulched
crops, and there is seldom any occasion for treating field crops.

A most interesting case was reported ‘to me the present season by Col.
Wright Rives, of Rives Station, Md., near the College. An acre of choice
celery y upon his place was found to be fairly teeming with these grubs.
They did not seem to injure the celery by attacking the roots, but dam-
aged it by carrying dirt into the heart’ and inducing rot by contact with
‘ici acid excrement. U pon investigation I felt quite certain that the
heavy mulching and large masses of rotting straw which had been accu-
mulated in the neighborhood, had served to attract the parent beetles,
and thus induce their concentration upon the celery beds. The experi-
ments which Mr. Lull has recently made upon Col. Rives’ place prove
that the application of the standard kerosene emulsion, as above recom-
mended, or at the rate of one part to fifteen of water, does not injure the
celery in the slightest, while it kills the larva when they are at or near
the surface of the ground. Experience this autumn with these larve
shows that in addition to the food-habits already indicated, they are, on
occasions, quite inclined to be carnivorous, so that when several are
placed together in a breeding-cage or jar they invariably feed to some ex-
tent upon each other.

As this larva has not yet been fully described, I close this article
with a technical description, which will have some ‘entomological value,
though descriptions of these Lamellicorn larve are necessarily unsatis-
factory except by comparison with other allied forms.

Allorhina nitida.—Full grown larva.—Length, 40 millimetres,
somewhat largest posteriorly, “sub- cylindrical, broader at thorax and
eighth and ninth abdominal segments, which are materially swollen.
More flattened ventrally, with a ‘distinct swollen lateral ridge just below
the stigmata, which rather increases the flattened aspect of the venter.
General color, glassy yellowish white, inclining to green or blue towards
the extremity. Head, rather small, flattened, well inserted into the
prothoracic segment, chestnut brown in color. Dorsal surface of the
body strongly transy ersely corrugate or wrinkled, each of the chief seg-
ments having three distinct ridges, the whole body studded with short,
thick yellowish bristles, which are most dense on the dorsal ridges and

BULLETIN NUMBER 23, DECEMBER, 1893. 81

more sparse, but longer,on the ventral and anal segments. Dorsally
these stiff hairs are directed posteriorly and materially assist in the dorsal
locomotion. ‘The legs are honey yellow, covered with similar stiff bristles
without definite tarsal claw. ‘They are short, compared with the larve
of Lachnosterna, generally. Prothoracic segment with a honey yellow
horny plate in front of the spiracle, which, as usual, is rather larger
than the abdominal spiracles. Mandibles short, stout, dark brown, with
the left (looking from the dorsum), 4-dentate and the right, 3—dentate.
Antenne short, 4-jointed, joints sub-equal in length, diminishing in
width, from 1 to 4, maxillary palpi, 3—jointed, joints sub-equal in length,
terminal narrowest at tip. Labial palpi, 2—jointed, joint 1 longest,
somewhat swollen at tip and bearing a short poiuted joint 2, on the inner
side of its tip. Labium covered with short stout bristles. Maxille with
long, stiff bristles on the inner surface and with two long, sharp, black
teeth near the tip.
The half-grown larva does not differ in structure or coloration.
CABBAGE WORMS.
Six different species of caterpillars or worms, affect the Cabbage
very commonly, in the state of Maryland. All feed upon the outer leaves,
fr) often boring well into the head. They are known
by the following names: The Imported Cabbage-worm
(larva of Pieris rape L.), the Cabbage Plusia, ( Péusza
brassice Riley), the Cabbage Mamestra, (JZamestra
trifolii Rott.), the Zebra Caterpillar, (larva of MJamestra
picta Harvr.), the Cabbage Evergestis, (Zvergestes rimosalts
Gn.), and the Cabbage Plutella or Diamond-back Moth,
(Plutella cructferarum \.). All of the insects will be
found treated at some length in my annual report, as
Entomologist to the U. S. Department of Agriculture,
for 1883, to which I would refer those who care to go
into the details of the subject. For the purpose of
ae Peer suis bulletin, it is my desire to dwell principally on

pw: d,larva:b,chry- the facts of practical value.
salis,

THe ImporTED CABBAGE WorM (Pieris rape), is a pale green
vaterpillar, about 32mm. (one and a quarter inch) long when full-grown,
(Fig. 7, a). It is very finely dotted with black, has a faint yellowish
line down its back and a row of. yellow dots along each side. It

Fig. 8.—Picris rape, male Fig. 9.—Pieris rape, female:

52 MARYLAND AGRICULTURAL EXPERIMENT STATION.

hatches from a minute yellowish, ribbed egg and transforms to a pale
green cbrysalis, covered with small black k dots, Giee ye d). The adult
butterfly is the common white or yellowish white species, with black
spots, as at Figures 8 and 9, seen flying about cabbage patches.

THE CABBAGE PLUSIA (Plu-

sta brassicé) is also a green
caterpillar but is larger “than

the preceding and lighter in
color. It is marked with
lighter longitudinal — stripes
and is very soft bodied and
tender. It measures 2 inches
in length when full-grown,
(Fig. 10, a.)

The egg from which it
hatches is pale greenish yel-
low in color, convex in shape
and two-hundredths of an
inch in diameter. In trans-
forming to pupa the caterpil-

Fig. 10 —Plusia brassicw; a, caterpillar; b, chry- lar spins a delicate semi-trans-
Salis in cocoon; ¢, moth, male. parent web usually partly or
entirely wrapping itself in a leaf, (Fig. 10, .) The adult insect is a
dark gray moth with a wing spread of about 14 inches and marked with
a bright silvery dot and V-shaped mark near the center of each front
wing, (Fig. 10, c.)

THE CABBAGE MAMESTRA (Mam-
estra trifolit) is a variable caterpil-
lar in color, some being bright
green above and some nearly brow n,
but all are marked by a rather
broad pink stripe down each side,
(Fig. 11, 4 c.) It transforms to
pupa in an oval cavity about two
inches below the surface of the
ground. The parent moth is some-
what variable in size and color,
ranging from a pale yellowish-gray
to a dark brownish-gray but mottled
as in the figure, (Fig. 11, 2. dP ae
is readily “distinguished from the
moth of the Plusia by lacking the
silvery spot on the front wing. This
insect is more common in Maryland
iMag cabbage-fields than I have known it
* Fig. 11.—Mamestra trifolii; a, b, larvee: ¢, elsewhere.

pupa; d, moth; e, wing Or same (enlarged):
f, anal segment of pupa.
\

.

ne oe a ee, ee Premera

BULLETIN NUMBER 23, DECEMBER, 1893. 83

THE ZEBRA CATERPILLAR (larva of Mamestra picta) is a
very easily distinguished in-
sect. When first hatched it is
almost black but soon becomes
pale and green. When full-
grown it is 2 inches long,
velvety black, with tawny red
head, ‘legs and belly and two
narrow yellow lines along the
side between which are many
white irregular zebra-like finer
lines. The pupa is found, like
that of the preceding species,
S—~ beneath the surface of the
\. ground. The front wings of
the adult moth are rich pur-
ple-brown and the hind wings

; are white, faintly edged w ith
Fig. 12.—Mamestra picta; a, caterpillar; b, moth. brown, (Fig. 12).

THE ee EVERGESTIS OR CABBAGE PRONE as it used to
be called (Z£vergestis rimosalis) is a small purplish-brown or bluish-
brown worm w ait a greenish-yellow head and green venter. When full-
grown it is a little over half an inch in length and
transforms to pupa at the surface of the ground i in
a slight oval cocoou covered with earth. The moth
% is pale ochre-vellow in color, the front wings dark-
ening towards the tip, with the hind wings semi-
transparent near base, (Pigal3;. 2). has a wing
Fig. 13.—Evergestis rim- Spread of about 1 conve This caterpillar is rather
ei Py nee pupa: ¢ fond of boring into the cabbage heads w hich ren-
(enlarged). ders it more destructive and harder to treat than
if it confined itself to the outside leaves.

THE CABBAGE PLUTELLA
(Pluitella cruciferarum) 18 a
little, active pale green worm,
something over a quarter of
an inch in Jength. It pupates
within a delicate gauze-like
cocoon resembling lace. The
parent moth has narrow wings
—expanding five-eighths of
an inch, and is of an ash-
gray color, usually with an
undnlate pale streak along

e Fig. 14.—Plutellacruciferarum; a, larva (enlarged); the inner border of the front
»,dorsum of a single /oint (greatly enlarged); a eee aie ae =. er
side view of same; d, pupa (enlarged); e, aeons Wwilgs, (Fig. 14.: f. &); W hich
(enlarged); f, moth (enlarged); g, Wing of derk va- o1ves a ser 1es of cdiamond-
riety (enlarg ged); h,moth at rest (enlarged);i, cre- © ri Q
master of pupa (greatly eularged). shaped marks when the wings

84 MARYLAND AGRICULTURAL EXPERIMENT STATION.

are closed. This worm feeds only on the outer leaves of the cabbage.
REMEDIES FOR CABBAGE WORMS.

All of the above-mentioned cabbage worms are amenable to “about
the same treatment. In my 1883 Report, already referred to, I recom-
mend hot water (ata temper ature of about 130° F. apy ethrum powder,
200 grains to 2 gallons of water, and kerosene emulsion. I also mentioned
the fact ‘that dr y applications of lime, salt, pepper, bran, buckwheat
flour, road-dust, soot, or of any other fine pow “der are efficacious against
the young worms and quoted Mr. P.'T, Quinn’s remedy of sawdust, im-
pregnated with carbolic acid as wellas an anonymous remedy from the
N.Y. Tribune of 20 parts superphosphate of lime, 3 parts shell or fresh
air-slaked lime and 1 part of carbolic powder. I also mentioned the fact
of the efficacy of the arsenical poisons, but stated that few persons would
use them for fear of their poisonous effects.

Since that time little has been suggested that is new, but many ex-
periments have been made with the remedies mentioned above. Prof.
Lawrence Bruner of Nebraska claims that corn meal dusted on the cab-
bages causes the worms to fall off and protects the crop until washed off
by rain. It should be applied in the morning while the dew is on.

The best results, however have been reached by a careful, intelligent
and sparing use of Paris green and London purple. Many successful
cabbage growers are today using these poisons. JI am very loath to ree-
ommend them, for there is d: anger unless the greatest care be had. When
Paris green is thoroughly and evenly mixed with flour at the rate of one
ounce of the green to 100-ounces of flour and dusted through a cloth bag
so as to just make a slight show of dust upon the leaves, the worms will
all be killed in the course of 2 or 3 days. Prof. C. P. Gillette has shown
that, applied in this w ay, the average amount of poison on each head will
be about one-seventh of a grain. ( ‘onsidering that fully one half of the
powder will fall upon the outside leaves or upon the ground he concludes
that a person will have to eat about 28 heads of cabbage in order to con-
sume a poisonous dose of arsenic even if most of the poison remained
upon the cabbage after cooking, which of course it does not.

In spite of this encouraging reasoning, however, and in spite of the
fact that no cases of poisoning have been reported, although the remedy
is in more or less general use, I hesitate to recommend it except while the
plants are young. At this time its use is advisable, where necessary, as

none of the poison can per manently lodge in the heart or head w hich is
yet unformed.

From the present outlook pyrethrum mixed with water, as above
described, or dry mixed with flour, is the safest remedy. Prof. James
Fletcher of Canada, a careful and reliable experimenter, says concerning
this remedy :

“In the treatment of cabbage caterpillars, pyrethrum diluted with
four times its weight of common flour, and then kept tightly closed for

BULLETIN NUMBER 23, DECEMBER, 1893. 85

24 hours, leaves nothing to be desired, and thousands of dollars are
yearly saved to small growers who most need the assistance.” (Zzsect
Life IV, 13.)
HARLEQUIN CABBAGE BUG.
(Murgantia histrionica Hahn.)

This I haye found to be one of the most destructive insects to cabbages
in certain parts of Maryland, and it has been particularly abundant dur-
ing the last two or three years. Known in the Southern States as the
Harlequin Cabbage Bug or the Calico Back,this insect has been gradually
spreading from the extreme Southwest to the North and East for the
past twenty years, and has only recently become a serious trouble in
Maryland. The adult bugs (Figure 15,) hibernate under old grass,
stones, logs, and other rubbish, and upon the advent of spring take to
the first cruciferous plants that put ferth
leaf, and lay their little barrel-shaped
eggs. (Figure 16 c) in small clusters on
the undersides of the leaves. There are
several geuerations in the course of the

Fig. 15.—Murgantia histrionica, im- F suey : aAnMeS
ago with wings closed and ‘with Summer and wherever the insect becomes

VUES SS IRIE abundant the crop is generally ruined.
The insect feeds upon the cabbage in all stages of growth, not by gnaw-
ing the leaves, but by puncturing them with its beak, causing the leaves
to wilt by exhaustion of the juices.

This is a very difficult insect to deal with, as the older remedies have
not proved efficacious. My early recommendations in treating of this in-
sect, of clean culture, raking up and burning all rubbish in autumn and
hand-picking the bugs on the first opportunity in spring, were, on the
whole, the most available remedies in our possession up to last spring.
In 1892, however, Prof. H. E. Weed, of the Mississippi Agricultural Ex-
periment Station, who has had excellent opportunities of studying and
experimenting with this insect, bécause of its great abundance in his
locality, found that the following plan was satisfactory, and it may well
be adopted by Maryland cabbage growers. Wild Mustard is one of the
earliest cruciferous plants to appear in spring, and the hibernated bugs
take their first spring meals on this plant. ‘They seem to prefer it, in
fact, when young and tender,to cabbage. Mr. Weed at first (1891) killed

é the bugs upon the mustard when-
ever he found them, by sprinkling
them with pure kerosene, but the
following year he decided to sow a
row or two of mustard between the
prospective rows of cabbages. It re-

Fig. 16.—Murgantia histrionica; a,larva sulted from this that the great me-
pena o CEE e eggsenlarged,sideviews jority of the hibernated bugs of the
vicinity clustered upon these early Mustard plants, and were killed by the
application of pure kerosene, to the almost perfect protection of the cab-

56 MARYLAND AGRICULTURAL EXPERIMENT STATION.

bage crop. Istrongly recommend this course as one of the most prom-
ising, and where mustard plants are not available or have not been pro-
vided, the best remedy to be applied is to spray with a pretty strong kero-
sene emulsion,

APPLE-TREE BORERS.

There are two borers which seriously effect the apple tree in Maryland,
as they do, in fact, in almost all great apple-growing regions in the coun-
try east of the Rocky Mountains. These are, the Round-headed Apple-
tree Borer (Saperda candida 1.) and the Flat-headed Borer (Chrysobothris
femorata F). The former is i far the most frequent and injurious.
Both affect the trunk and usually the lower part, but they differ in their
mode of work and in their life-habits.

Tbe Round-headed Borer is the larva of a rather handsome long-horned
beetle with a number of grayish-white longitudinal stripes ( (Figure 17 ¢.)
The female lays her eggs in the month of June, in the trunks of not only

Fig. 17.—Saperda candida; a, larva; b, pupa; ¢, imago. :

the cultivated apple, but of wild crab apple, haw, pear and quince. As I
pointed out in 1877 she makes with her jaws \an incision in thé bark,
causing it to split open from one-third to half an inch in length, and
thrusts the egg between the bark and the liber at right angles to the side
of the slit, accompanying the ess with a gummy fluid which covers it and
Secures it in place (Fig. 18 c). The egg (Fig. 18 d,) is pale rust
brown in color, elongate ovoid, somewhat flattened and three millimetres
long. The young larva hatches in about two weeks and for the first year
and-a-half of its life lives in the sap wood, excavating shallow cavities,
visible only by a slight discoloration of the bark and by a small quantity
of sawdust-like ec astings, which issue from the original hole of entrance
or from cracks in the bark. During the third summer it generally com-
mences to cut cylindrical passages up into the wood of the tree, not in-
frequently perforating it. It then rests in its burrow through the third
winter and transforms to pupa (Fig. 17 4,18 g,) in the spring, issuing
as a beetle during the late spring or early summer.

BULLETIN NUMBER 23, DECEMBER,

Fig. 18.—Saperda candida; a, piece of apple eit: Son! ing scar made in oviposition
and hole of exit of beetle; b, f, section of same thr ough line a, e; c,section of bark, showing
slitand egg natural size; d, egg enlarged; g, showing pupa, witu packing betw een it
and bark.

This is a summary of its larval habit, based upon the observations
of Dr. Asa Fitch, who gave the subject perhaps more close attention than
any other previous or subsequent writer. ‘The actual length of the larval
life, has, so far as I know, not been proved by any consecutive following
of any one individual larva, and there is room here for further experi-
mentation and observation.

This species affects more particularly the base of the tree, and ne-
glected trees, (particularly those where the grass has been allowed to
grow up to the base), suffer most.

The Flat-headed Borer, (Chrysobothris femorata,) isthe larva of a
beetle entirely different in appearance. The shape of this
last is indicated in the figure, (Fig. 19), and its color is
greenish black, with brassy “lines and | spots above, instead of
being copper color. While the Saperda is essentially noc-
turnal, this Chrysobothris 1s diurnal, being found flying
about in the hot sunlight. The female lays her eggs under
bark scales and in the cracks and crevices of the trunk of

Fig. 19.— many different kinds of trees, including the ash, beech, elm,
Eres maple, oak, peach, etc., as well as the apple. The eggs are
ago. yellow, irregularly ribbed, and less than a millimetre in
length. The larva hatching from this egg, is at once distinguished from
that of the Round-headed Borer, by its flattened form and by its
ae broad flattened head, from which feature it derives its
popular name, (Fig. 20). It feeds upon the sap wood
during most of the summer, and there excavates broad,
rather flat channels, a single individual sometimes com-
pletely girdling a small tree. Upon approaching full
growth it usually eats into the more solid wood and works
back to the bark, when ready to transform to the pupa

Fig. 20.--Chrys-
obothris femorata,

larva. state. The pupa stage lasts about three weeks, when the

)

(

88 MARYLAND AGRICULTURAL EXPERIMENT STATION.

beetle cuts through the bark and emerges. The burrow made in the
solid wood by this insect, is always flattened or elongate-ovoid in shape.

This beetle produces but one annual generation, the larva requiring
but one season for full growth. I have known it to become full-grown
and to kill young trees, between the first week in June and the last of
September, and only the last year had absolute proof of this limitation
of the larval life of the insect, by losing a young sycamore tree, which
was planted from the nursery as late as the first of June, and which was
carefully inspected and showed no evidence of the borer, at the time of
planting. This tree was killed by the girdling of the borer by the end
of September.

While the Round-headed Borer is found in older treesand frequently
in trees that otherwise seem to be vigorous, yet it prefers trees of feeble
growth or those which are newly transplanted, and those growing upon
ridge lands or in plowed orchards, are more liable to attack, than those
growing on low lands or in orchards seeded to grass. With the Flat-
headed Borer, however, a great predilection is shown for trees that have
been injured in any way, and newly transplanted trees from a nursery
should be particularly watched. ‘The injury is most apt to take place on
the south-west side, which is most subject to the so-called “sun scald.”
In fact, it is doubtful if the young larve or the eggs can withstand the
strong flowing sap of a vigorous tree, and in almost every case in my ex-
perience, where this borer has done any damage, it has been as a conse-
quence of some prior injury.

REMEDIAL MEASURES.

A slight discoloration of the tree, a flattening of the bark, a slight
exudation of the sap or an extrusion of fresh, sawdust-like excrement or
gnawings, will often indicate the presence of these borers, in which case
they may frequently be cut out and destroyed, if the work is detected in
time, or if they have entered the solid wood, a wire may be used as a
probe to follow and kill the borer, or a little hot water or kerosene may
be poured into the hole.

Prevention, however, is to be preferred in both cases, and alkaline
washes applied to the trunk, have been found by experience to have a de-
terring effect upon the female beetles and to prevent their laying their
eggs upon the trees so treated. I generally take a bar of hard soap and
rub it wp and down the trunks of young trees, and place a piece in the
principal crotch, allowing the rains to gradually wash it down over the
trunk. This isa simple preventive method, which Dr. Fitch, many years
ago found to be satisfactory, and which I have proved to be so in my
own experience. If soft soap is used, the trunk and larger branches may
be painted by means of a white-wash brush, the soft soap being reduced
to the consistency of thick paint, by the addition of a strong solution of
washing soda in water. A certain proportion of either of the arsenical
poisons in ordinary use, if mixed with such soap-wash, will serve to
render the same more permanent and effective, while a good fish-oil soap

a ee ae

et es

_

BULLETIN NUMBER 23, DECEMBER, 1893, 89

would be preferable to the ordinary soft soap. A good formula is as
follows: :

Potash lye, 1 pound; fish oil, 3 pints; soft water, 2 gallons. The
lye is dissolved in the water, and when brought to the boiling point, the
oil is added and the batch is boiled about two hours. Water is filled in
to make up the evaporation by boiling, and the result will be about 25
pounds of soap, which will make from 50 to 100 gallons of trunk wash.

INSECTS PARTIALLY STUDIED AT THE STATION,
DURING THE PRESENT YEAR.

Since the firstof July Mr. R. S. Lull, one of my assistants, has for
the most part made his headquarters at the station, with a view to study-
ing and experimenting on such insects as presented themselves in injur-
ious numbers or attracted particular attention at the station, Most of
his investigations are yet incomplete, but the following notes, which are
based upon Mr. Lull’s observations, are worth recording.

THE TOBACCO FLEA-BEETLE.

This little beetle (Zpitrix parvula Fab.) did considerable damage
to the tobacco plants grown at the station by eating small holes in the
leaves, giving them an unsightly appearance. Anything affecting the
appearance of the leaf of tobacco naturally reduces materially its value
asacrop. The beetle is yellowish-brown in color and but 1.9 milli-
metres (about .06 of an inch) in length. Itis one of the few insects of
economic importance the life-history of which has not been followed out,
but this I hopeto do in the near future. In the meanwhile, without
knowing anything of the habits of the larva, it will be difficult to protect
the tobacco crop from itsinjuries, since the ordinary poisonous insecti-
cides must not be used. Mr. Lull found that pyrethrum in powder, di-
luted with flour or road dust destroyed a large proportion of those beetles
which it touched, but the trouble is, as in the case of the Rose Chafer
and a number of other insects, other individuais quickly take the place
of those which are killed, and some other preventive must be found
with which to check the injuries of this particular species.

THE TOBACCO SPHINX, OR HORN WORM.

m=" This well known insect (Protoparce celeus Hbn.) was also quite abun-
dant in the tobacco fields at the station, and did considerable damage,
as it generally does in all parts of the country to the tomato. The life-
history of this species is well known, and there is nothing new to be as-
certained in reference to it. The eggs are about the size of a pin-head,
green in color, and laid singly on the undersides of the leaves. The larva
develops rapidly, is an enormous feeder, and late in the summer descends
into the ground, where it transforms to the pupa state, in which it re-
mains through the winter. Hand-picking is chiefly resorted to, especially
in tobacco fields, to keep this species in check, and a more rapid way of
working is to go through the field with a pair of shears and clip each
worm in two as fast as detected. Those which bear on their backs or

90 MARYLAND AGRICULTURAL EXPERIMENT STATION.

bodies clusters of white, oval, egg-like cocoons should be left alone, as
the cocoons are those of the Microgaster parasite, which should be given
every opportunity to multiply. Late fall ploughing results in the de-
struction of many of the pupx, and a large number of the parent moths
may be poisoned by pouring a little liquid cobalt into the flowers of the
“Jimpson” weed (Datura stramoniun ) The moths are strongly attracted
to the flowers, and readily suck up the poisonous dose. This method
has been so effective at the Louisiana Station that a row of Jamestown
weeds has been purposely planted around the tobacco field, while a patent
has been granted for an imitation of the Jamestown weed flower in por-
celain, to be used for the same purpose.
THE MELON PLANT-LOUSE.

This insect (4pA¢s cucumerts Forbes) was observed in great numbers on
the undersides of the leaves of the canteloupe vines during the latter part
of July. No new observations of any importance were made, but it was
noticed that, contrary to the ordinary published statements, the lice re-
mained quite numerous beyond the time of ripening of the fr uit, a winged
brood appearing during the first week in August. Under-spraying of the
leaves with a dilute kerosene emulsion is recommended for this insect,
and the spraying is done by fitting to the hose of a knapsack or bucket
pump an upturned Cyclone nozzle, the hose being clamped or wired to a
three-foot cane, so that the nozzle may be readily thrust beneath the
leaves. This is probably the most convenient method where a large num-
ber of vines have to be treated. Mr. H. Garman, of the Kentucky Experi-
ment Station, uses bisulphide of carbon in a very effective way against
this insect, Gland his method is advisable for smaller patches. One entire
vine is well gathered up into a bunch and a large sized wash-tub is in-
verted over it. A table spoonful of bisulphide of carbon in a saucer is
then placed under the tub and the edge of the latter is pressed down into
the earth. The bisulphide ev aporates rapidly and its fumes kill the lice
without injury to the plant.

THE ASPARAGUS BEETLE.

This is a handsome black, yellow and red beetle, known by the scien-
tific name of Criocerts asparugt, Lu. It is a well-known species, passes the
winter in the beetle state, and lays small, black, ovoid eggs on the young
asparagus shoots in spring. The larve hatching from these eggs “reach
full growth in about two weeks and descend into “the ground to “undergo
transformation into pupe and beetles. The second generation of beetles
appear ten days after the descent into the earth, and lay their eggs for a
second generation of larve on the more mature plants. The actual num-
ber of generations during the year has not been definitely ascertained and
we may assume that it will vary according to the latitude. There is in
Maryland, without much doubt, a third generation of beetles which go
into winter quarters rather early. The fact that Mr. Lull found eggs,
larve and beetles rather abundant on old asparagus plants as late as
August 31, would indicate that there may be even four generations in
this latitude.

BULLETIN NUMBER 23, DECEMBER, 1893. QI

This insect has long been quite destructive in the vicinity of Baltimore
and Washington, and - yet itis not difficult to handle. A very light dust-
ing of pyrethr um powder mixed with spoiled flour in the proportion of
one to ten, is the cleanest and best way to treat the first larvee observed,
and even without insecticide substances, the daily cutting off of all shoots
upon which eggs are observed will serve to effectively check the work of
the first brood. As it is the neglected later broods which rapidly multi-
ply after the market season is over, which supply the hibernating beeties-
that damage the young shoots the following spring, it is quite important
to treat these later broods. All voluntary asparagus in the neighborhood
of the beds should be rooted up and destroyed and only a few plants should
be allowed to grow. These will attract the beetles that are in the immediate
neighbor hood, and their larva may be killed in the manner already indi-
dicated or by the use of kerosene emulsion, which, if repeated two or
three times during July and August will serve materially to prevent in-
jury the following spring.

BLISTER BEETLES.

The Striped Blister-beetle (Zpccauta vittata F.) and the Black Blister-
beetle (2. pennsylvanica DeG.) were very abundant the latter part of the
season, the former feeding upon potato plants in early August and upon
beets in early September, ‘and the latter upon carrots in September. A
little later a number of complaints were received of damage to chrysan-
themums by the black species. ‘The abundance of these insects may, to
a certain extent, be traced to the abundance of locusts or grasshoppers
the previous year, since in their larval state both these species are par-
tially parasitic in the egg masses of these locusts. During the present
year these locusts have been extremely abundant, and there is therefore
, every reason to expect large numbers of the blister beetles to-
wards the close of next summer. The experiments which
Mr. Lull made with the arsenical sprays were remarkable suc-
cessful. On August 5th he sprayed a potato patch infested
with the Striped “Blister Beetle pretty thoroughly with Paris
green, it being well known that the foliage of the potato plant
will stand without injury London purple or Paris green in
the proportion of one pound of the poison to 75 gallons of
emia vit water. The carrot patch was similarly sprayed for the black
tata, imago. species. The beetles rapidly dis appeared from the plants
thus treated. In regions where the beetles make earlier inroads into
the fields, experience has not been so satisfactory with the arsenical
sprays. This is due to the fact that the poisoned - beetles fly away and
die, and their places are taken by later-issuing individuals, thus neutral-
izing the treatment. In the extensive beet fields of the west it is the cus-
tom, when these insects are abundant, to send men or boys through the
field, working with the wind, and driving the beetles before Aen by
short flights. On the leeward side of the field windrows of hay or straw
have been previously placed, and into these the beetles are driven and then
burned. This is an old remedy that has been successfully used in large
potato fields. The damage done to chrysanthemums, and especially to

92 MARYLAND AGRICULTURAL EXPERIMENT STATION.

clematis vines, by these insects, is often quite serious, and there is no
perfectly satisfactory way of protecting these plants under such cir-
cumstances, other than by covering them with gauze or netting.

The following is a condensed account of the very peculiar life-history
of the Striped Blister-beetle which may be taken as a type of the life-his-
tories of the other blister-beetles here mentioned. Those who are inter-
ested in the subject will find full details in a paper in the Transactions

\ of the Academy of Sciences
of St. Louis, volume IIT., and
in the First Report of the U.
S. Entomological Commission,
pages 293-301.

From July to the middle of
October the female lays her
eggs in the ground in loose,
irregular masses of about 130,
on the average. Each female
lays from 400 to 500 eggs,
choosing locations which are
apt to be used for the same
purpose by locusts. In about.
ten days the eggs hatch and
the first larva, known as the
triungulin, emerges (Fig.
oot 22.—Epicauta vittata, a, egg-pod of Caloptenus 22, c.) This little larva is at

ifferentialis with the mouth torn open, exposing pp ~ ;

the newly hatched larva of Epicauta eating into an first feeble and perfectly
SBE; fe; c, Urat larva. or Griungulln, (greatly en; white, but soon turns brown
view (greatly enlarged). and becomes very active when
warmed by the sun, running about over the surface of the ground and
searching for egg pods. When one of these is found, the triungulin
bores through the neck of the pod and begins to eat it away (Fig. 22,
a.) After absorbing the substance of one or two eggs, this triungulin
moults and produces the second larva, known as the carabeoid stage (Fig.
22, d). In this stage it lies in a curved position within the pod, as
shown ate. During the growth of the larva, which is rapid, several
other moults take place, the second one producing the scarabeoid stage
(Fig. 23, z@) in which the larva looks very much like an ordinary white
1 : grub. <A third moult results in lt-

tle change structurally, but the
larva attains full size, and gener-
ally leaves the egg pod which it
has by this time gutted. After
the fourth moult, a still greater
change takes place and the larva
becomes shrunken, rigid and hard-
Fig. 23.—Epicauta vittata: a, full grown ened, with the legs and mouth-
Sin of seonas ata; portion of thedorsal parts reduced to mere tubercles,
larva, lateral view; d, same, dorsal view. This is known as the coarctate lar-

s

J

A es Ons

—, Ore ee -

ee ae a we

ee ee eee ee

ae os

BULLETIN NUMBER 23, DECEMBER, 1893. 93

val stage (Fig. 23, c. a.) The fifth moult causes this hardened shell
to split open and from it there issues the ultimate larva, which resembles
the scaraboid stage in appearance, except that the larva is more active
and moves about—without feeding, however. It burrows a short distance
into the soil, where it forms a cavity within which, in the course of a few
days, it transforms with the sixth moult to the true pupa, (Fig. 24.)
Iti is in the Stevens larva stage that the insect generally passes the win-

Fig. 24.-—Epicauta
vittata; a, true pupa,
side view; b, same,
ventral view.

ter, the true pupa state being assumed only in early
summer just before the perfect beetles issue from the
ground.

These curious larval changes are designated as
hypermetamorphoses by entomologists, and it will
be seen from the figures and from the brief descrip-
tions, that with each moult until the coarctate larval
stage is assumed, there is a rapid reduction in the
size of the legs and mouth- -parts, and the animal be-
comes more and more helpless. The habit of feeding
on Jocust or grasshopper eggs to a certain degree off

sets the destructive habits of the perfect beetles.

“ne

ee a

Sed

a

TABI Ky OF (CON PEEREES. a

‘
ee ee, ae ee eee

PAGE :

LETTER OF SUBMITTAL, - - - - - - - - 3
INTRODUCTION, - - - - - - - - - 4
THE CopLING Morn:

Life history; abundance in Maryland; remedial measures; effi- "

cacy of the old plan of bandaging and instances of the value of

spraying; substances used in spraying; apparatus for spraying ; 2

natural enemies ; predaceous beetles; true parasites, - - 5 |
THE GREEN JUNE-BEETLE: 5

Differences between this insect and the 'May beetles or June a

beetles of the North; habits of the adult; damage done by the i

larve ; life history not fully known; abundance of the larvee in

celery beds; remedies and preventives; technical description

of the larva, : - = > = 5 : 5 11
CABBAGE-WORMS:

Imported Cabbage worm; Cabbage Plusia; Cabbage Mamestra

Zebra Caterpillar; Cabbage Evergestis or Pionea; Cabbage

Plutella; remedies, - - - - . - - = le
HARLEQUIN CABBAGE-BUG:

Distribution; difficulty of fighting; older remedies; H. E. Weed’s

plan recommended, - - - - - - - - “We
APPLE-TREE BoRERS: .

The Round-headed Apple-tree Borer; life history, including ac-

count of oviposition; Flat-headed Borer; account of life his-

tory; remedial measures for both species, - - - - 20
INSECTS PARTIALLY STUDIED AT THE STATION:

Tobacco Flea-beetle; Tobacco Sphinx, or Horn Worm; Melon

Plant-louse; Asparagus Beetle; Blister Beetles, - - - 23

HLA

9088 01270 9895