(Ephestia kuehniella Zell.)

IN

i EUROPE AND AMERICA.
APP RN Dex |
neteenth Report of the State Eee eer a
OF ILLINOIS. |
i
fe 2 By WG JOHNSON. & M. ae
i ee ENTOMOLOGIST.
SPRINGFIELD, ILL.,
£p. F. Harrman, State Printer. Ea
1896. -

eo Ee D Tex

TO THE

ON THE

MEDITERRANEAN FLOUR MOTH

(Ephestia kuehniella Zell.)

By W. G. JOHNSON,

ASSISTANT ENTOMOLOGIST.

BOI Nis

Prefatory Note..
Introductory . Salbgents
Zoblogical Position.

_ Specific Characters.....
General Review..

Distribution and Diseemination Ui Sie daha aloes
Character and Extent of tees Dee Oe ae hehe ahe « « SMT ot ieee le teins otis ool etinaie

Development.. 5c
History of Gaiticanit Oren 3

DISCOVERY ANNO YW) MONK. LALO sac ccte ars rcs! areca eaten ant ais.$°2atay/ayore cia tlc «vie e'eos elats a's aiatpla ejeinieyaleles ateco
MiswuCiToreacin: CANAG EE: i satabe ec calcicacrniaieseraticten's sierctaleiale@icle «Avcleic' oaumtolsin) wisie sleieia impel teis et mrefslenes

SST OT EEA SRB Seer DRC DDO SED GO SOCTEO SOLA: DOCS CITED o GCECEoSOBEIERE OSNC nae OGreT re erence a

Birds . aieaisiales
eatin :
Predaceous eceee

Flour Weevils (‘Fribolium ‘Canfas ‘and T. ‘ferrugineum) .
Cadelle (Tenebrioides mauritanica)..
GOCLOCEI USE COUMULIUB T: oivicls atvie!e.<\ 6x7 cctetaetowieete siias wie) acrs/cizal cis) siecvielsiale of olzisia} ejelcin'=\'s/oieloyebpieialelytalesets

POC Oe eee eee wee te tees eats eee ree wee ee eee Oe eee

ALC UUNIBE CUS tis ace lctnelelolaels oan store crcis setatetteneioneioie cielo etctbiaiviciacs ale laremueesiMeial eithid’c.cutsalsleicarene sl areas

BV ECOTU-OTEVICOTIUES: « occas ee ee cin sie cece
CHEMCUULUS TUL DZOSTUORDES oon icra c/o valels\c.'s <i etstutatotetinte’ slaiie's claves \e cits) als (aletalemesstetetiotat wrote oh ais athe lo'taleiste facta ctaie ste

Bracon hebetor .

Preventive and Remedial Swcnatr a aaa iWacnararer maviceee

Cleanliness .

Fumigation Box..

Metal Spouts.. :
Attachment of raehen to peltae
See of Carbon........
Sulphur.,.

Steam.

Steam ad Sapna

Miscellaneous iepodientas: Matetetatslcine eicisietatetats

Bibliographical List. ...... ......

PREFATORY NOTE.

The following article by Mr. Johnson, one of the entomological
assistants of the State Laboratory of Natural History, detailed for
service in the office of the State Entomologist, contains in part
results of work done by him as a graduate student of Stanford
University before his connection with this institution, and written
up as a thesis for the master’s degree. Much of his time has been
given to the subject, however, since his engagement here, and a
large part of the present paper is based upon results of this
later work.

Although the Mediterranean flour moth has not yet been found
to infest any mills in this State, its distribution in our vicinity
makes it practically certain that it will eventually appear within
our limits, and a comprehensive article on it is consequently even
more timely than it would be if withheld until after the threatened
invasion were an accomplished fact.

It is of great consequence to every miller that he should be not
only forewarned of his liability to serious annoyance and heavy
loss by the work of this worst of the pests of the flouring mill,
but that he should also be thoroughly forearmed with informa-
tion as to the signs of its presence, the characteristics by which it
may be unmistakably recognized, and the measures of prevention
and destruction to be used against it.

I have gladly availed myself, therefore, of this opportunity to
put the millers of this State and of the country in possession of
the esserttial facts, and to have compiled for the benefit of the
working entomologist a complete review of the history and results

of previous studies of this insect pest.
S. A. ForBes.

THE MEDITERRANEAN FLOUR MOTH (Ephestia kuehniella
Zeller) IN EUROPE AND AMERICA.

By WILLIS GRANT JOHNSON, A. M.

INTRODUCTORY.

Insect injuries in flouring-mills have been known from time
- immemorial, but not until recent years have they attracted public
attention. The mild and equable temperature which is maintained
in the modern mill is highly favorable to the development and
multiplication of those pests commonly called ‘mill insects.” The
most formidable enemy in this group is the Mediterranean flour
moth, Hphestia kuehniella Zell., an insect unknown to American
millers less than seven years ago. ‘The discovery of this terrible
scourge in Canada in 1889, in California in 1892, and in New
York and Pennsylvania in 1895, has awakened a keen interest in
the subject among millers and scientifiic workers.

Its discovery in California in March, 1892, led me to a careful
examination of all available literature on the subject. I found
this material so scattered that I have deemed it advisable to bring
it together and to embody it substantially in this paper which
covers my own observations and experimental work on this insect.
Most of these observations were made in California, where also a
large part of my experimental work on life history and. methods
of destruction was carried on. Much additional information has,
however, been gained by experimentation and correspondence
since my connection with the Illinois State Laboratory of Natural
History.

I wish to express here my thanks to Mr. L. O. Howard, U. S.
Entomologist, Washington, D. C., through whose’ kindness I ob-
tained Figures 1, 2, 3, and 5 from the U. 8S. Department of Ag-
riculture. I also beg to acknowledge, with thanks, the kindness
of Mr. James Fletcher, of the Department of Agriculture of
Ottawa, Canada, in furnishing me with his exhaustive reports con-
taining articles on this subject, and the courtesy of Dr. P. H. Bryce,
Secretary of the Provincial Board of Health of Ontario, Canada,
in sending me his excellent Bulletin and circular letter on the
flour moth. I am also indebted to Miss E. A. Ormerod, late Consult-
ing Entomologist of the Royal Agricultural Society of England,
for her complete accounts of the moth in England; and to Mr. J.
Danysz, Director of the Laboratory of Parasitology and of the Cham-

8

ber of Commerce, Paris, France, for his exhaustive and most impor-
tant paper on this subject. I desire also to acknowledge here,
with thanks, the help and codperation I have received from the
millers of California, New York, Pennsylvania, and Canada; and,
finally, to express my appreciation of the favors received from Pro-
fessor 8S. A. Forbes, Director of the Illinois State Laboratory of
Natural History and State Entomologist, through whose kindness
I am able to publish this article in its present form.

The names of all individuals and of firms on whose premises
this pest is known to exist, have been omitted by special request,
and I have carefully kept the confidence reposed in me. Such
suggestions are offered as my experience warrants, and I trust
this paper will enable all those interested to become better ac-
quainted with this ravenous pest, and with measures for its con-
trol. In discussing the latter I have confined myself to methods
which have been tested in large mills.

Before taking up my subject in a formal way it may be well
to give, in a paragraph, a brief summary of the life history and
habits of this insect.

The small gray moth, with a wing expanse of about seven
eighths of an inch, is a sluggish insect, often remaining for hours
in one position. The female usually deposits her eggs in spouts
and elevators, or on piles of flour in bags, but they may be found
in every conceivable place about a mill where there is sufficient
food for the larve. The eggs hatch in about nine days, and the
larvee feed from five to seven weeks. It is during this period
that the mischief is done. The larve have a peculiar habit of
trailing a silken thread wherever they go, and this waste silk,
mixed with flour and dust, often clogs the spouts to such an ex-
tent as to stop the machinery. About nine weeks are required
for the transformations of the insect, reckoning from the time of
the deposition of the egg to the emergence of the adult. It
breeds continuously in warm mills, where the temperature is con-
stant, and from four to six broods appear annually. It is usually
disseminated in manufactured products, or on empty bags and
second-hand machinery. It is comparatively fres from the attacks
of natural enemies, and when once established in a mill can be
checked only by absolute cleanliness and the free use of bisul-
phide of carbon, sulphur, or steam.

ZOOLOGICAL POSITION.

There has been much dispute among systematists regarding the -
zodlogical position of this little moth, and its name has conse-
quently been the subject of much discussion. It belongs to the
family of moths known as Phycitide, and was first given a scien-
tific name in 1879, since which time it has been known as Ephes-
tia kuehniella—a name given it by Prof. Zeller in honor of Prof.
Kihn, Director of the Agricultural Institute of the University of
Halle, Germany.

9

Mr. W. H. Patton, of Hartford, Conn., is responsible for the
statement* that Dr. F. Karsch has shown that kuehniella and in-
terpunctella are only dimorphic forms of one species. In 1884,
Dr. Karsch gave it as his opinion} that Tinea zew of Fitch might
prove to be a variety of kuwehniella; and in an article in “Insect
Life” for November, 1890,t under the caption ‘‘Notes upon Ephes-
tia interpunctella (Hibn.) Zeller,” Mr. Patton gives both H. kueh-
niella and T. zece as synonyms of FE. interpunctella. Under the
head of “Special Notes,” the editors of “Insect Life” (1. ¢ p. 134)
strongly dissent from Mr. Patton’s conclusions, stating that they
long since adopted zece as a synonym of inlerpunctella, but that
they now fully believe in the distinctness of kuehniella, though
inclined earlier to a different opinion.

Mr. Geo. D. Hulst, in his monograph of the Phycitide of North
America,® has placed interpunctella in the genus Plodia, and left
kuehniella under Ephestia. The main difference between the two
genera, as indicated by Mr. Hulst, is that in Hphestia the palpi
are erect, while in Plodia they are porrect.

Mr. Ragonvt has shown§ that Mr. A. W. Scott's Hyphantidiwm
sericarium evidently belongs to the genus Ephestia and, accord-
ing to the description, closely resembles kuehniella; and he is of
the opinion that the former will prove identical with the latter
species, since its larval habits are precisely the same. For the
present, however, Mr. Ragonot is content to let the species remain
as Hphestia sericaria (Scott).

Mr. Hulst says (1. c, p. 199) that he has specimens from New
Mexico which connect Hphestia fuscofaciella Ragonot with £.
kuehniella, and he is of the opinion that the former may prove only
a variety of the latter.

SPECIFIC CHARACTERS.

Ephestia kuehmel-
la (Fig. 1, a and b) is
a delicate moth, from
10 to 14 mm. in length,
with a wing expanse
varying from 18 to 22
mm.** (about seven
eighths of an inch).
The females are, as
a rule, larger than the

Fie.1. Hphestia kuehniella:—a. moth; 0. female moth, from males, but the general

side, resting; ¢. larva; d. pupa; e. abdominal joint of larva,— s
all enlarged, the hair lines 1epresenting the natural size. (0d, C, es color and markings on

from ‘Insect life; @ and d after Chittenden). the wings are the same
in both sexes. Labial palpi blackish gray; head and thorax some-

*Insect Life, Vol IIT., p. 158.

+Hntomologische Nachrichten, May, 1884.

tVol. [II, p. 158.

{Trans. Am. Ent. Soc., Vol. XVIL., pp. 938-228.

g§Ann. Ent. Soc. France (Bull.), 1892, p. CCLXXIV. ‘
**Mr, Hulst gives 24-26 mm. (Trans. Am. Ent. Soc., Vol. XVII., p. 198 )

10

what lighter; abdomen the same color, with an;
ocher shade. Front wings medium gray, eprinkled (SE a
with blackish scales, crossed near the tips by ~~

two wavy angular blackish lines; a W-shaped
transverse line about one third the way from
the base; a black dot in the center, which is
sometimes double. (See Fig. 2, g.) The hind,
wings are semi-transparent, of a silvery luster, with \,
a darker border. Both pairs of wings are heavily ©
fringed. (See Fig 1, a.)

The egg, plainly visible to the naked eye, is
elongated oval in outline; greasy whitish in color SS
when first laid, becoming darker as the embryo oe oe
matures within; and varies considerably in length oem
and breadth, as shown by the following measure- meckingd and Senet
ments made from four different lots of eggs: aga: (After Snell-

First lot, laid April 12, 1895—Length, 0.482 mm.; breadth,0.204 mm,

Second lot, laid April 17, 1895—Length, 0.480 mm.; breadth,0.240 mm.

Third lot, laid May 5, 1895—Length, 0.408 mm.; breadth,0.228 mm,
Fourth lot, laid June 19, 1895—Length, 0.444 mm. ; breadth,0.216 mm.

This variation in size occurs also in eggs of the same lot. The
general average length is 0.441 mm., and the breadth 0.222 mm.
The surface is irregular and has a crumpled appearance.

The larva (Fig. 1, c) when first hatched is very small, being
only 1.083 mm. long, with a body diameter of 0.19 mm; head
slightly larger, measuring 0.247 mm.; flesh-colored, varying from
a whitish to a pinkish tint; head reddish brown; legs and pro-
legs a little lighter colored than body; body sparsely hairy, hairs
longest on the posterior segments, often measuring there 0.342
mm., but about 0.114 mm. on the other segments. When full
grown the larva varies from 12 to 14mm. in length; form cylin-
drical, somewhat slender, with a rather uniform diameter of about
2mm.; color as earlier, the pinkish tint more pronounced in
some than in others. Three pairs of true legs, and a well-developed
caudal pair; abdominal legs long, cylindrical, with a circular fringe
of hooklets at the crown. Piliferous warts black or brown, rather
minute but prominent; lateral ones more conspicuous in front of
the first spiracle, the subdorsal ones, one each side of the meso-
thorax, almost completely encircled by a narrow black ring inter-
rupted only at its upper margin. Each segment has six bristle-
bearing dots, four of which are conspicuous and two smaller; a
transverse reddish-brown patch on the segment next the head,
divided, from front to back, by a faint central line; surface of body
rather smooth.

The chrysalis (Fig. 1, d) varies from 9 to 10.5 mm. in length,
and from 2.5 to 3 mm. in width. Reddish brown above, the head
and thorax being darker than the rest of the body, much lighter
below, the shade becoming lighter from the head back, approach-
ing a yellowish tint on the wing-pads and abdomen; posterior
part slightly curved and cylindrical; tip of the last segment con-
siderably darker than the rest of the body and furnished with 9

11

ory 10 stout brownish bristles, with their points curved, encircling
the margin of the upper surface. Eyes prominent, usually of the
same color as the head buat sometimes darker; spiracles distinct.

The cocoon (Fig. 3, a and
b) varies in length from 10
fee to 14 mm., and from 4 to 6

fmm. in width. It is com-
posed of very delicate whit-
@ ish silk spun by the larva,
fm and is often intermingled
# with particles of meal, flour,
® dirt, or other material. It is
| perfectly smooth within, and
is usually attached to some
surface by a very thin layer
of silk, so that the pupa can
be plainly seen when the
cocoon is removed from its
place of attachment, as rep-
resented in the accompany-

Fig. 3.—a, cocoon from below, showing pupathrongh INDY illustration.
the thin silk attaching the cocoon toa beam; }, same

from above. Enlarged. (From ‘Insect Life **)

GENERAL REVIEW.

Although this moth was first discovered in a flouring-mill in’
Germany in 1877, it was not made known to science until 1879,
when Prof. Zeller noted the outbreak and described and named
the species (1)* from specimens from the infested mill, sent him
by Prof. Kiihn, Director of the Agricultural Institute, University
of Halle, Germany. Prof. P. C. T. Snellen refers to this paper
of Zeller’s in 1881 (2).

The insect was next observed in a noodle factory in Belgium
in 1884, and was reported by Mr. Alfred Preudhomme de Borre,
July 5 of the same year (5). He supposed it to have been in-
troduced into that country with American cereals. Many sub-
stances were used to rid the mill of the infestation, but they
proved useless. The most noticeable improvement in the situa-
tion resulted from scrupulous cleanliness.

In May, 1884, Mr. Maurice Girard read a paper before the
Entomological Society of France (3) on the ravages of the flour
moth, which had appeared in a flouring-mill at Lodelinsarte,
Belgium, and gave a short description of the adult insect and
Jacva. In the discussion which followed this paper Mr. E. L.
Ragonot said that he had in his collection specimens of H’phestia
huwehniella from North Carolina,. Mexico, and Chili. In this same
vear Dr. F. Karsch, in an article entitled “Hphestia kuehniella,
Zeller: Eine Nord Amerikanische Phycide am Rhein,” (4) notes
the appearance of this moth at several places along the lower

* The full-face parenthetical figures in this paper refer to the bibliographical list appended.

12

Rhine. The ground color of the front wings of the typical speci- |
mens bred by Zeller was pure yellow or nearly brownish, while
those bred by Karsch were glossy lead-giay, but Karsch considers —
them one species, The only moth he found in American litera-
ture that approached kuehniella was Fitch’s Tinea zew, which is
the same as Plodia interpunctella; but Fitch’s description of the
latter species did not agree with that of Zeller’s species. Dr.
Karsch thought, nevertheless, that zew might prove to be a vari-
ety of kwehmella.

In an editorial note in the Hntomologische Nachrichten for
1885 (pp. 46, 47), the statement is made that this pest had ap-
peared in some mills near Bremworde. The burning of sulphur
and the application of bisulphide of carbon were found useless,
and the mills were stopped and thoroughly cleaned. It is asserted
that the insect, in that locality, is of American origin, and was
introduced with American wheat. The same periodical, for the
same year (pp. 239, 240), contains another note, reviewing a com-
munication from Prof. Landois to the Braunschweiger Tage-
blatt, in which the statement is made that this pest is by far the
most annoying and dangerous insect affecting wheat or flour.

_ Professor P. C. T. Snellen published in 1885 (7) an illustrated
article of considerable importance on this insect, which included
a summary of Prof. Zeller’s article already referred to, and a
comparison of kwehniella with other European species of Ephestia.

Mr. A. Seige], German Consul-General at New York City, be-
ing asked by some of bis countrymen to find out what he could
regarding Hphestia kuehniella in this country, and to ascertain if
possible the means employed for its destruction, addressed a letter
on the subject to Dr. J. A. Lintner, State Entomologist of New
York, under date of February 2, 1885, who replied that he had
no knowledge of the pest as an American insect, and that if
it existed in the United States it was as yet unknown, as no such
habits had been manifested in any of our flouring-mills by any
species akin to Hphestia kuehniella. He refers to Plodia inter-
punclella, and suggests several remedies for the destruction of
the flour moth; viz., bisulphide of carbon, sulphur, and trapping.
This, I believe, is the first published statement in American liter-
ature (8) regarding this pest.

The next note I find on this insect is by Mr. W. Thompson, of
Stoney Stratford, Bucks, England (9). Larve found feeding on
rice cones were given him by a friend in October, 1886, from
which moths emerged during November and December, At first
the insect was thought to be Myelois ceratonie and was so re-
ported; but specimens sent to Mr. Barrett in April, 1887, were
identified by him as Ephestia kuehniella. In the same volume
of the same journal (10) Mr. J. W. Tutt gives a short account
of the feeding habits of this insect, and records the breeding of
the adult moth from larve given him by Prof. T. D. A. Cock-
erell, collected originally from. a cargo of flour at the London
docks. In June, 1887, larve from this same source were exhibited
by Prof. Cockerell at a meeting of the South London Ento-

13

mological Society. In the first published account of this exhibi-
tion (If) it is stated that the larve were in flour shipped from
America to Trieste, and thence to London; but later (20) Prof.
Cockerell states that although the larve just referred to were
in flour from America, they were supposed to have come from
some badly infested Trieste flour stored in the same warehouse.

In the same year Mr. C. G. Barrett (12) reports breeding
moths of Hphestia kuehniella from larve sent him by Prof.
Zeller in 1879; refers to the moths of this species sent him by
Mr. Thompson for determination, noted above; and briefly de-
scribes the moth, noting ready means of distinguishing it from
that of other species of Ephestia and from Myelois ceratonia.

November 2, 1887, Mr. Sidney T. Klein read notes of his ob-
servations on the habits of Hphestia kuehniella, at a meeting of
the Entomological Society of London (13). He discovered in
May a colony of these larve in some large warehouses in the
east end of London, where the insect spread rapidly in spite of
the fact that the building was fumigated with sulphur and the
ceilings, walls, and floors were hot-limed. One entire warehouse
was “literally smothered with larvee, and several hundred pounds’
worth of damage was done.” Chickens introduced into the ware-
house gorged themselves with the larve. Some interesting ob-
servations are reported concerning the habits of the larva, and it
is said that a small hymenopterous parasite (Bracon brevicornis
Wesm.) destroyed the pest by September. The same author
gives elsewhere (14) full details concerning a lot of flour from
Trieste infested with larve of the flour moth, referring again to
the parasite, and in another connection (15) has an item con-
cerning the introduction of the flour moth into England. The
County of Middlesex Natural History and Science Society pub-
lished a note by Mr. Archibald Geikie (17), in which he reported
the complete destruction of Ephestia kuehniella by the same
little braconid mentioned by Mr. Klein, figuring the male and
female. He said, in substance, that he had noticed a black spot -
on the back of the flour moth larve which he had not observed
before, but paid no attention to it, thinking it a normal phenom-
enon in the development of the insect. Some weeks later he was
astonished to find on the sacks of flour, which had been covered
with Ephestia larvee, a great number of little black insects, and he
was of the opinion that the black spots he had seen were noth-
ing else than the eggs of Bracon brevicornis.

I will not call in question the correctness of this inference, as I
know nothing about the life history of the European braconids,
but will simply say in this connection that our two American
species, Bracon gelechie Ashm. and PB. hebetor Say, do not lay
their eggs within the body of their host. I have made many
observations on this point, and have always found the egg either
on the body of the larva or attached to some material very near
it. Mr. E. B. Poulton, of London, England, has, however, shown
by experiment (2!) that these black spots are simply testicles
in the process of evolution. Mr. J. Danysz, of Paris, France,
who seems to have overlooked Mr. Poulton’s paper, has arrived

lt

at the same conclusion (55). In my own work I have found
this a very convenient method for separating the sexes of the
larvee, and in no case has it been misleading.

In 1887, Mr. R. Adkin, of London, made two contributions to
the literature of the flour moth (18, 19) which I have not.
seen. In an article published in 1592 (45) he states that the
pest is still present in England, and that it is of sufficiently fre-
quent occurrence in granaries, mills, bakeries, etc., to be regarded
as an established insect pest.

In 1889, Miss E. A. Ormerod reports the appearance of the flour
moth in very destructive numbers in England (23) and refers
(24) to a new outbreak in a mill in the north of England in
1888, the larve getting into the spouts and machinery and, by
their webs, stopping the flow of the flour. Some of this infested
flour was found, on examination, to be little more than a webbed
mass full of living larve, chrysalids, and dead moths. The mill
was stopped and thoroughly cleaned, steam was introduced into
every part of the place, and the walls and flcor beneath were
washed with “paraffine”’ (kerosene). The owner of this infested
mill thought the insect came to him in empty sacks returned from
some baker, perhaps coming originally from London in this way.
In 1890 (32) Miss Ormerod reports the pest as still present in
England, in one instance being kept in check by frequent
fumigation, sulphur being the chief substance used. She gives
the results of some inquiries regarding the presence of this
insect in other countries, with a short abstract of matter in
her Twelfth Report concerning the nature of the attack. Several
paragraphs are quoted from Mr. Fletcher’s Report for 18:9 (29) and
from a Bulletin by Dr. Bryce (26), both of which are referred
to on another page of this article. In her Fourteenth Report
(38) Miss Ormerod says that the flour moth may be regarded
as thoroughly established in England ard quietly extending itself,
and that it is still doing serious damage in the mills from which
it was first reported, although expensive preventive measures have
been taken to keep it in check. The fact that this insect is
present in widely distant parts of England is evidence of the
root the insect has taken in that country.

There is no record of damage by this pest in North America
prior to 1889, at which time it appeared in destructive numbers
in a large flouring-mill in Ontario, Canada. The owner tried
every means known to him to destroy the insect, but every effort
failed, and he finally appealed to Mr. James Fletcher, Dominion
Entomologist, for help. The matter was then brought officially
before the notice of the Ontario Government, and the investiga-
tion was placed in the hands of Dr. P. H. Bryce, Secretary of
the Provincial Board of Health of Ontario, who published the re-
sults of his investigation (26) in October, 1889.

The manager of the mill suspended work, and took down the ma-
chinery and subjected it to steaming. The whole mill was then
thoroughly cleaned and fumigated with sulphur; the walls and
ceilings were scraped and swept; elevator spouts, loose wooden

15

work, paper bags, and many hundred dollars’ worth of goods were
burned; elevator cups and belts were boiled for hours in water;
and those parts of the machinery not easily accessible, were
flamed by means of a kerosene torch. All this was not sufficient,
and September 19 the Local Government passed an Order in
Council, compelling the manager of the mill to take more strin-
gent steps for the suppression of the pest. In compliance with
an order from Dr. Bryce, the miller constructed a tight steam
- box and subjected every piece of machinery, even millstones and
iron rollers, to a thorough steaming. After two months’ loss of
time, and loss of fixtures and machinery, the mill started up
again.

In hig Bulletin (26), Dr. Bryce gives details concerning the habits
and appearance of this insect in its various stages, and adds an
account of its depredations in the past, drawing largely from
Miss Ormerod’s Twelfth Report. He suggests preventive and
remedial measures in case the moth appears again in other mills.

Mr. Fletcher accompanied Dr. Bryce a part of the time during
these investigations. They visited many stores and mills to find
out whether the moth had spread, but in one case only was the
insect found, and here, only such quantities of farinaceous foods
were kept as would be sold out during the week to consumers.
In his Report for 1889 (29), Mr. Fletcher says, “There was a gen-
eral opinion among all those visited, that this insect was only the
ordinary meal worm, Asopia farinalis, which may generally be
found in small numbers in neglected meal or flour barrels, but
which seldom does sufficient harm to be classed as an injurious
insect.’ He further adds that “the present species may be con-
sidered a much more formidable enemy, and if allowed to multiply
and spread through our large American flouring-mills, will be a
calamity of enormous magnitude.” A few months later the state
of affairs in the infested mill was found to be very serious. Mr.
Fletcher gives a brief summary of recent literature on this insect,
with Dr. Riley’s excellent figures of Plodia interpunctella and
Ephestia kuehniella and comparison of the two species, adding
information suggested by his own notes and observations.

In spite of the measures taken the year previous, the moth
spread to other mills, and many local dealers in flour and grain
had the pest on their premises. A printed circular letter was
issued by Dr. Bryce, October 15, 1890 (33), offering to millers
and produce men the codperation of the Board of Health for the
eradication of the pest A copy of the Provincial Act (47 Vic,
chap. 38, sec. 39 and 40) is_ printed in this circular, according to
which, among other provisions, any medical officer or sanitary in-
spector may at any reasonable time inspect a mill and examine
the goods being manufactured for sale as food, and may condemn
and order to be destroyed any food-products which may be found
unfit for use. In addition to this, the person exposing them for
sale shall be liable to a penalty not exceeding one hundred dol-
lars for each parcel of grain, bread, or flour. In conclusion, Dr.
Bryce reprints, from his former Bulletin, the remedies to be
used in combating the pest.

16

In his Report for 1890 (37) Mr. Fletcher reviews his previous —
account of Hphestia kuehniella, and quotes several important let-
ters from the manager of the first infested mill. The indifference
on the part of those most interested is very noticeable, for one
would naturally suppose that millers and produce dealers would
have taken a little trouble to understand this matter, and to assist
in carrying out measures which would be for their special benefit.
A great many millers suffered severely for thinking there was
nothing to fear when the moths first appeared on their premises.
Mr.:Fletcher says, “the steps taken by the Provincial Board of
Health, and the milling company on whose premises the moth
worked such havoc in 1889, have proved very satisfactory and
were entirely successful. A few straggling moths were seen in
the mill during the summer of 1890, but constant watching and
scrupulous cleanliness finally rid the mill of the infestation.” Mr.
Fletcher gave an earlier account of this outbreak in Canada in a
Report of the Entomological Society of Ontario (30).

The appearance of this moth in North America in 1889 in such
destructive numbers called forth a timely article by- Dr. C. Y.
Riley and Mr. L. O. Howard (27), in which the known facts
regarding this pest are brought together in a condensed form.*
Mr. Howard visited the Canadian mills the latter part of August,
1889, and accompanied Mr. Fletcher on a tour of inspection to
the worst-infested establishment. The entire building was still
completely overrun by this insect, notwithstanding the thorough-
going measures which had been taken for its destruction. The
principal studies on kwehniella mentioned in this article were,
however, made upon material brought to Dr. Riley by Professor
Panton, of the Guelph Agricultural College, during the summer
of 1889; on material in the National Museum, containing speci-
mens from Eufaula, Ala.; on five specimens from Europe sent by
Mr. Ragonot; and on others from Germany, forwarded by Pro-
fessor Zeller in 1883. The various stages of Hphestia interpunc-
tella are figured in comparison with those of kuehniella, in order
that both may be readily recognized, the early stages being quite
similar.

In his excellent monograph of the North American Phycitidee
(36) Mr. G. D. Hulst cites some of the literature of Hphestia
kuehniella and a short description of the species, indicates its
distribution, and says that his specimens from New Mexico were
taken in August and September. He refers to GZeller’s original
description and to Dr. Bryce’s pamphlet, and quotes several par-
agraphs from the latter.

In August, 1892, Prof. T. D. A. Cockerell, then of the In-
stitute of Jamaica, reported the appearance of this insect in Kings-
ton, Jamaica. He found some oatmeal badly infested with larve
which he sapposed to be those of the Mediterranean flour moth,
and accordingly issued a circular letter giving a short history of
this pest, which was afterwards published in several daily papers
in Kingston (40). April 1, 18938, Prof. Cockerell wrote me as

_* Ihave made liberal use of the reviews contained in this paper, although I have carefully ex-
amined all the articles mentioned in it.

17

follows: “I hasten to make a correction on Ephestia. I wrote
you October 27, { 1892] that we had found larve sof H. kuehniella
here, but, although the larve seemed to be indeed that species,
when the moths emerged they appeared different. So I sent some
to M Ragonot, in Paris, and I have just heard from him that they
are Eiphestia desuetella Walker.”

Several articles on this pest have appeared in French publica-
tions. The first, by P. Brocchi (22), in 1688. It contains a
brief summary of the past history of this insect, and gives several
methods, both preventive and remedial, for its arrest and destruc-
tion. Several papers on this subject have been written by Dr.
C. Decaux, of France, referred to in the bibliography appended
(41, 42, 43).

Mr. K. L. Ragonot (49) refers to the question of the origin
of Ephestia kuehniella, calling attention to the fact that a species
of the family Phycitide, discovered in the district of Wollombi,
New South Wales, and described by Mr. A. W. Scott, in the Pro-
ceedings of the Z logical Society of London, 1859, under the name
of Hyphantidium sericarium, belongs evidently to the genus
Ephestia, and, according to the description, closely resembles L.
kuehniella, but the plate shows two supplementary lines in the
basillary space and another in the middle of the space, the im-
perfect crossing being replaced by a round dot. This slight differ-
ence he is inclined to lay at the door of the artist, and thinks
that the species may prove to be identical with Hphestia kueh-
niella, the more pirticulacly as its larval habits are precisely the
same For the present, however, he is content to let the species
remain as LH. sericaria (Scott).

The most important publication that has yet appeared on this
subject is by Mr. J. Danysz, of Paris, France, Director of the
Laboratory of Parasitology and of the Chamber of Commerce. It
is an illustrated article (54) of about sixty pages, and was pub-
lished in 1893. It contains a summary of the more important
articles previously published on this subject, a careful review of
what has been said in regard to the origin and spread of the
moth observations on its life history, and a discussion of the
remedies used in various places for its suppression. As noted in
the articles to which reference has already been made, Euro-
pean authors, excepting Miss Ormerod, have hitherto regard-
ed this insect as of American origin, having been imported
into Europe with American cereals. It will also be remem-
membered that Dr. Riley and Mr.- Howard, in their article on this
moth which was published in ‘Insect Life” (Vol. IL, pp. 166-171),
protested against this haphazard conclusion, but with little effect
upon the European authors who have since discussed this matter.
Mr. Danysz concludes, after a careful review of the arguments
brought forth by European writers, that it is unsafe to point to
any one country as the original home of this insect. He is in-
clined to think that it was originally a very widespread species,
and that it comes into prominence as a pest in flouring-mills at in-

—A. 2

18

tervals when circumstances favor. He places no reliance upon the
idea that it is being, or has been, imported in numbers from
America into Europe.

Mr Duinysz has also written an interesting article (55) upon the
pigment +pots (embryonic testicles) of the larva of Hphestia kuehni-
ella. While searching for the natural enemies of this insect, his
attention was drawn to the published note of Mr. Archibald
‘Geikie (17), referred to on p. 13. Mr. Danysz then segregated
a number of Ephestia larve with the black spots upon their backs
in the hope of securing some of the parasites, but his expectations
were disappointed, for they all transformed successively to chrysa-
lids and adults without presenting any abnormal features, while of
the parasites he did not secure a single specimen. His close watch
of the black spot, however, furnished him with a very interesting
observation. By dissectim he found that the pigment spot in
question consisted of two reddish brown reniform corpuscles placed
in the cellular tissue above the digestive tube, and that these same
organs, a little modified, were easily recognizable in both the
chrysalis and adult, so united in the latter, however, as to form a
single ovoid body, connected by two long canals with the genital
armature. The fact that larve with black spots always produce
males, left no doubt that these organs were testicles in the process
of developmeat—a conclusion already reached by Mr. E. B. Poul-
ton in the fall of 1888. (See p L..)

In this same year (1895) Dr. F. Decaux published (56) a short
illustrated article on Hphestia kuehniella in which he reviews
its habits and suggests means for its destruction; and Prof. Law-
rence Bruner, of the University of Nebraska, published a_ short
illustrated article (61), which is principally a compilation from
pub ished reports on this insect, and was intended as a timely
warning to millers and dealers to be on the lookout for it. In
January, 1894, Mr Gerald McCarthy published (62) a notice of
the Mediterranean flour moth’s presence in North Carolina, saying
that it is likely to become a serious pest in that state.

In D-cember, 1892, I sent out a circular letter regarding the
flour moth, calling attention to its appearance in destructive num-
bers on the Pacific coast. This is, I believe, the first authentic
record of its occurrence in the United States. The notice natur-
ally interested the general public and several California papers
(46) printed it. During the same month another newspaper
(47) printed a reporter’s account of an interview with me con-
cerning this insect, and I published myself (48) a short account
of its past history aud appearance iu California, with a review of
the remedies used elsewhere for its suppression. I furnished an
article of the same general character, for the January (1893)
issue of “Milling”, which was reprinted in another monthly
journal (50) devoted to the same interest. The most import-
aut articles I have contributed on this subject appeared in
the “American Miller” io 1895 (67, 68, 72, 73). In the March
number (67) I gave a brief summary of former publications,
a short skeich of the insect’s life history, a preliminary account
of my experiments, a review of the remedies used in various

19

places, especially in California, and quotations from a large num-
ber of correspondents on this subject. In the May number (68) I
anvounced the discovery of the pest in New York State, which is the
first record of is occurrence in destruc ive numbers in mills in
the United States east of the Rocky Mountains. In the October
number (72) [ gave a brief account of the methods now used in Cali-
fornia and New York for keeping the flour m th in check, tog -ther
with other notes and observations. In the November issue (73) I
announced the discovery of a new parasite (Bracon hebetor Say)
of this insect, and added a new locality. The facts which led to
the discovery of the parasite are discussed somewhat in detail,
suggestions are made for its colonization, and extensive notes re-
garding the new Canadian outbreak are given.

Mr. F. H. Chittenden, As-istant Entomologist to the United
States Department of Agriculture, in an article entitled “The
more Important [sects Injurious to Stored Grain,” gives a short,
somewhat popular account (71) of the Mediterranean flour moth.
The article is illustrated, and contains the most perfect represen-
tation of the adalt moth ever published. It is reproduced by per-
mission on p. 9 of this paper. Mr. Chittenden also contributed
some valuable notes previonsly unpublished.

In December, 1895 (74) I called attention to the fact that I had
discovered Bracon hebetor Say: feeding upon the larve of the
Mediterranean flour moth, and further stated that I had bred a
single specimen, a male, from the same lot of larvee, which differed
in many respects from typical specimens of hebetor, but was
thought by Mr. Ashmead to be a small variety of the same
species. 6. gelechice, although not found on the flour moth, is
mentioned, as it is closely related to B hebetor; and reference is
also make to the European parasites of this insect, B. brevicornis
and Chrymelus rubiginosus.

I note next a comiau ication from a Pennsylvania miller, Mr.
EK. Burns, who states (75) that he has been troubled with the
flour moth in his mill for the last three years. He has been
fizhting it, principally, by keeping an extra sweeper, which adds
about $500 per year to the running expenses of the mill. He
says he tried sweeping his mill with steam some years ago, and
found it worked well in the summer, when all the doors and win-
dows were open, but as soon as cold weather set in he could not
use this method, as the “steam on the cloths of the purifiers
makes all good middlings run over the tail ed of the machine.”
This information adds a new locality for the flour moth, as it has
not heretofore been record-d from Pennsyl!vania.

Comments upon this outbreak and a few notes eoncerning the
flour moth, wich illustrations were published (76) by me in
January, 1896; and in Fe»ruary I replied (78) to a query from
a milling firm in Melbourne, Australia, who tad forwarded me
for examination a sample of flour matted together in a way to sug-
gest the: work of the flour moth. No insects were found in it.
An illustration accompanying my reply shows a sample of wheat
flour felted together by the flour moth.

20

Prof. William Trelease, of the Shaw School of Botany, St. Louis, -
exhibited at the February (1896) meeting of the Academy of Sci-
ence of St. Louis (79) specimens of a curious silk fabric taken
from the ceiling of a corn-storing loft in San Luis Potosi, Mexico,
by Dr. Francis Eschauzier. Although specimens of the insect re-
sponsible for the silk were not secured, it was presumed that it.
was made by larve of the Mediterranean flour moth.

Besides the articles already mentioned, several reviews and
notices have appeared in other publications, principally in “Insect
Life,” all of which are mentioned in the list at the end of this

paper.
DISTRIBUTION AND DISSEMINATION.

As has been already stated, Hphestia kuehniella was first
brought to the attention of scientists in 1877. Prof. Zeller, two
years later, when he described it, stated on insufficient grounds
that in all probability the insect came from North America. It was
supposed to have been introduced in Belgium, in 1884, on American
cereals. Regarding its appearance in mills near Bremworde in
1885, it is stated positively that the insect was introduced in
that locality on American wheat. This being in the Belgium and
Bremworde mills at the time of the outbreak, seemed to suggest
to those concerned that the pest must be of American origin.
The fact of the case is, that the pest was not known in North
America in destructive numbers prior to 1889, at which time it
appeared in Canada. The moth has been known much longer in
Europe than in America, but the extreme readiness with which
Europeans attribute new pests to this country, has been exhibited
more than once.

Miss Ormerod did not find Hphestia kuehniella listed in Grote’s
check list of the moths of North America for 1882, and was there-
fore of the opinion that the pest came to England from Europe
or the Hast, rather than from America. Mr. Sydney Klein, in
the ‘Mark Lane Express,” 14th Novemher, 1887, in speaking of
the English outbreak, says the pest was introduced into the Lon-
don warehouse where he carried on his observations, in some
meal shipped from Fiume, on the Adriatic, in 1885. I might
state here, that Mr. Klein mentions this pest as the scourge of
the Mediterranean ports, but does not give any date as to its first
appearance there.

In 1890 Miss Ormerod made inquiries regarding the distribu-
tion of the moth, and received a letter from Dr. Lindeman, of
Moscow, stating that he was not aware of its being present
in Southern Russia, and that it had not been observed in Central
Russia up to that time. :

Mr. J. Danysz, of Paris, has made a careful study of the out-
break in France, and states that its first occurrence there is re-
corded prior to its first appearance in England. He does not
think it safe to point to any one country as the original home of
the pest, and places no reliance upon the idea that the insect was

21

introduced into Europe from America. He calls attention to the
fact that Halle, Germany, where the pest was first observed in
1877, is an inland town, as is also the place where the moth was
first observed in France, and concludes that circumstances will
not sustain the theory of the original importation of the insect into
either Germany or France. A _ practical miller assures Mr.
Danysz that he has known of the pest in the neighborhood of
Paris for the last fifty years, and that he remembers a case of
serious damage as early as 1840. Another miller asserts that he
knew of a serious outbreak of this insect in a flouring-mill in Con-
stantinople in 1872; that it was very troublesome for two.years,
and then disappeared.

Dr. Selmar Schonland, Curator of the Albany Museum, Gra-
hamstown, Cape Colony, wrote Miss Ormerod in 1890, that in-
quiry had been made regarding a moth, or rather, larva, which
was doing considerable damage in flouring-mills in King Wil-
lhamstown. I do not know whether this was Hphestia kuehniella
or not, but judging from the account of the damage done, [ am
inclined to think it was.

Regarding the introduction of the pest into Canada, Mr. Fletcher
says there is some doubt as to the time when the first specimens
came, and also concerning their origin; but evidence seems
to point to a consignment of goods imported from Mediterranean
ports in 1887. Mr. Geo. P. Hulst, in his monograph of the
Phycitide of North America, in speaking of the flour moth,
says: “I do not know that it has given trouble in California, if
indeed it exists there (1890). It has, however, developed very
rapidly in Europe, becoming a very great evil. The ‘Ontario
Bulletin’ speaks of its having come from Europe, though there is
no reason why it should not have come from the Pacific coast.”
With reference to the present Canadian outbreak, so far as I can
learn, the pest seems to have been in local mills for some time
past, and as these mills are in an inland town, it would be a
difficult matter to trace the moth to its original source.

Notwithstanding the fact that this insect was not noticed in
North America until 1889, evidence seems to point to its presence
in this country some years earlier. Mr. Danysz has traced its
occurence in America as far back as 1880. As stated by Dr.
Riley and Mr. Howard, specimens from Alabama, indistinguish-
able from Ephestia kuehniella, were in the Natural Museum col-
lection at the time of the Canadian outbreak. Dr. Riley states
also that he had seen specimens from North Carolina in Mr.
Ragonot’s collection in Paris. It is also recorded from Colorado
and New Mexico, and was found in a Mexican exhibit at the
World’s Fair in Chicago; and it has been found in Chili and prob-
ably occurs in Australia and South Africa. However long the
pest may have existed in North America, no record of any dam-
age is recorded prior to 1889; and the California outbreak, first
observed by me, is positively the first record of any destruction
by this pest in the United States.

22

The moth seems to have appeared in great numbers in certain
localities for a time, and thea disappeared. Prof. Zeller wrote
Dr. Riley in 1883 that the insect had apparently died out at
Grinhof; and, as stated above, Mr. Danysz wesintormed by a prac!ical
miller that it appeared in destructive numbers in a flouring-mill
in Constantinople in 1872, and disappeared after two years. This
mizht seem to indicate that the insect is a passive creature, and
if not disturbed, and allowed to multiply for a time, would finally
disappear altogether; but so far as I can learn, it has never disap-
peared from a given locality or mill only after the most energetic
fighting.

There is not much doubt but that the moth existed in widely
separated places a long time before 18/7. As stated above, Mr.
Danysz has collected some important information on this point
from practical millers in France. I have been informed by a
thoroughly reliable miller in San Francisco, whose name I with-
hold by request, that he came in contact with this pest in 1858.
At that time he was employed in a large flouring mill at Rast-
dorf, near Kiel, Schleswig Holstein, Germany, where the moth
was very abundant during the month of June. He is positive
about his identification of the insect, having had much experience
fighting it in his California mills since 1889.

The foregoing facts inlicate that Hphestia kuehniella was
cboroughly established in Germany twenty years or more before it
fame into Prof. Zeller’s hands for description, and it is there-
ore unlikely that the pest was introduced into that country from
North America. From all I have been able to gather on this
point I am of the opinion that its original home, if ever ascertained, |
will not be North America.

It has been recently discovered that this moth lives in the nests
of a wild bumblebee in California, and Mr. D. W. Coquillett, of
the U. S. Department of Agriculture, is reported by Mr. F. H.
Chittenden as having stated that it also occurs in the hives of
the honey-bee. The question naturally presents itself, bas the
moth found that it can perpetuate its species in a bumblebee’s
nest or a beehive, and transferred its attack from the mill to
these more natural and primitive food houses, or vice versa? The
theory that the transfer has been from the bumblebee’s nest and
the beehive to the mill would afford a plausible explanation of
the appearance of the moth in mills in isolated places, and at
times when it was least expected. The origin of the California
outbreak might be thus explained; but [ have myself no faith in
this theory concerning the present infestation, and will not discuss
the matter further from this standpoint.

I will now state as briefly as possible the facts I have gathered
regarding its occurrence on the Pacific coast. I have been told by
prominent millers in California, that it has been less than fifteen
years since oatmeal was bought in the Eastern States, shipped to
California, and sold cheaper than it could be manufactured there,
I do not infer from this that the moth came through this chan_
nel, but simply introduce the statement to indicate the commercia,

23

relations that existed a short time ago between the Pacific coast
and the Eastern States. Had we known positively that the moth
existed in the United States east of the Rocky Mountains during
this period, we might have been a little hasty in accounting for
its presence in California. I am reported as having stated * that
the pest was probably introduced into California on second-hand
machinery brought from a Chicago mill which was in communication
with the Ontario mills. JI had been informed that the ma-
chinery in question came direct from Chicago to San Francisco,
being stored in the mill where the pest soon afterwards appeared
in great numbers, flying in and out of cylinders connected with
the apparatus. I have since ascertained that the machinery, al-
though purchased in Chicago by a California firm, changed hands
several times in San Francisco before it reached the mill where
my first observations were made, being in the meantime in a
mill—since burned down—where the pest was known to exist.
This seems to indicate that the moth was introduced into the
former mill from a neighboring one and not from Chicago.

A prominent miller in San Francisco informs me that his mill
was overrun by this pest in the early part of 1889, soon after the
introduction of a large quantity of rice from Sicily. He is of the
opinion that the moth came to him with this rice. This is not
certain, since it was observed about the same time in neighboring
mills in which rice was not kept. After interviewing the owners
of many larger mills in California, I found that the pest, in all
cases, was first noticed during the early months of 1 89. This in-
dicates that the introduction must have been a general one, as the
outbreak occurred at the same time in widely separated mills.

The manager of the mill which has been the principal seat of
my observations, tells me that he purchased the machinery men-
tioned above from an oatmeal company in San Francisco, which
has since discontinued business, and transferred them to his
premises. They were bought in the spring of 1890, and were
stored in the attic of his mill. About three months later he
noticed some moths flying in and out of cylinders connected with
the apparatus, and fearing they might be the same pest that had
appeared in Canada, he took immediate steps for their extermina-
tion, closing the end of the cylinders and burning sulphur inside.
He says, regarding this outbreak: ‘This entirely destroyed the
moths in the cylinders, but about six months later a more ener-
getic fight was required, the mill being then thoroughly swept and
fumigated with sulphurous fumes, with good results.”

I have positive proof that the moth is established in mills in
the following California localities: San Francisco, Oakland, Sac-
ramento, Port Costa, Stockton, and Woodland. It is only a matter
of time-—unless millers keep the pest in check more effectually
than at present—before every miller in that state will have Hphes-
tia kuehniella to combat.

There is a good deal of uncertainty about the origin of the
flour moth in New York State. From what I can ascertain by
correspondence, the pest is pretty generally distributed throughout

* “San Francisco Call,’’ Dec. 6, 1892.

24

the southwestern part of that State. It seems to have been first
observed in the early part of 1893, and has been spreading from
mill to mill until it is now established in mills in several counties.
I cannot find any printed account of its presence there previous
to my own announcement of it in March, 1895.

Dr. J. A. Lintner, the State Entomologist, stated, in a letter
written in February, 1885, that he had no knowledge of the flour
moth as an American insect, and that if it existed in the United
States it was unknown to him. I cannot venture even the slight-
est hint as to the source of this outbreak in New York. Suffice ©
it to say that the pest is well established in several interior coun-
ties in the southwestern part of the State, and, from present ac-
counts, is spreading to others. The latest information I have
on this subject is contained in a communication to the “Ameri-
can Miller’ for December, 1895, (p. 910) from a Pennsylvania
miller living in the vicinity of the New York outbreak.
| Considering the ease with which the flour moth is carried from
place to place, it is not surprising that we hear so much concern-
ing its ravages. The eggs, Jarve, and pup are transferred long
distances in manufactured products, and the conveyances themselves
very often become sources of infestation. Ships, canal boats,
freight cars, or even wagons that carry large quantities of grain, -
flour, or other farinaceous products, afford excellent breeding
beds for this pest, which is usually transferred to the warehouse,
mill, store, or private residence with the material. The fact that
the adult moth is capable of living from seven to nine days after
maturity, seems to indicate that it may fly a considerable distance;
and in large cities where many mills are operated, it is quite pos-
sible that the parent insect often finds lodgment in such places
after long flights. The moth, however, is not a rapid flyer, and
alights quite often, the distance between flights depending on the
surroundings. In a California mill I have seen the adults fly the
full length of the building (a hundred and ten feet) before light-
ing. In the open air no doubt the flight would be much longer.

Owing to the minuteness of the eggs, and to the fact that the
larve are almost always concealed, these two stages are the most
readily transferable. Eggs deposited on sacks of flour and on
other manufactured products in the mill, are carried away un-
noticed with the material, and the pest is thus given a large local
distribution, finding lodgement in warehouses, grocery stores, livery
and feed stables, hotels, and private dwellings. Mills in the vicinity
of such places are liable to become infested from them, by the
returo of old bags or barrels.

The pest is sometimes transferred long distances in second-hand
machinery. In April, 1894, a Stockton, Cal., miller wrote me as
follows: ‘Referring to yours of the 3d inst., relative to the Medi-
terranean flour moth, would state that I have known of it for some
years, and for the past eighteen months we have had it with
us here. Although its presence is not at all desirable, still we
have suffered no damage or inconvenience from it, unless, per-
haps, we have had to exercise a little more vigilance in keeping
the mill thoroughly clean, We introduced it here by purchas-

25
.

ing a machine that was for a short time in one of the San Fran-
cisco mills. We have not used sulphur nor done anything to
eradicate it, excepting to increase our endeavor towards clean-
liness.” An instance of this same nature is given on p. 28, the
moth being introduced on some apparatus bought from a local
firm in whose mill the pest had a firm foothold.

As a rule, the moth is transported carelessly on bags and
machinery. The former is, however, the commonest and greatest
source of danger, and extreme care should be taken lest the pest
is introduced in this manner. All bags which have been used for
transporting grain, flour, or meal should have no entry to a mill
until subjected to a thorough fumigation with bisulphide of car-
bon or with steam. Preventive measures are treated in detail
on subsequent pages of this paper.

CHARACTER AND EXTENT OF INJURIES.

The larve of the Mediterranean flour moth would not be such
a pest to millers were it not for the strange peculiarity they have
of trailing little silken threads as soon as they begin to crawl.
This silk is usually mixed with flour and dust, and looks and feels
like a handful of cobwebs rolled loosely together in a flour bin.
The mass of flour and web
represented in Fig. 4 gives
a fairly good idea of its
condition. This _ particular
material was taken from a
spout in a New York mill
last April, from which a
photograph was made and
reproduced. It is this waste
silk that troubles millers
most. When hundreds and
thousands of these larve are
at work in a spout, elevator,
or other portions of machin-
ery, this silk accumulates
rapidly, piles up in tangled
masses, clogs’ the machinery,
and very soon stops it en-
tirely. Then the whole plant
must be taken apart and
cleaned.

One of my California cor-
respondents sent me the fol-
lowing note on this subject:

“We find more trouble
with the pest in the spouts
and elevator legs than in
any other portion of the
mill, since these parts of the
machinery are kept closed

Fic. 4.—A mass of flour webbed together by the flour
moth larve. (Original). and the moth can breed there

26

without being disturbed. Some of the elevator legs have been so
closed up that there was scarcely room for the elevator to travel,
and many of the spouts have been so completely choked up that
it was necessary to take them down and remove the web, larve,
and pup before the stream of stuff could pass through them.”

The magnitude of the attack depends somewhat on the time of
the year and upon the nature of the products manufactured. In
the eastern states, and also in California, the larve are most
abundant during the summer months, but in California the climate
is so even that but little variation is noticed at different times of
the year.

The larvz are particularly found of products manufactured from
rice, and in mills where this is the principal cereal handled that
department is worse infested than others. Buckwheat flour is
also a favorite, and the larve will pass over oatmeal and wheat
flour in order to get to this product; but in mills where rice and
buckwheat are not handled, they attack any cereal product. The
parent insect may deposit her eggs in any part of the mill where
the young larvee can find food, but in the great majority of cases
the eggs are laid where the conditions are most favorable for the
development of the\young larve. The spouts and elevators are
therefore worse infested than other parts of a mill. In a mill
where flour is stored in sacks, the female pushes her ovipositor
through the meshes of the sacks and places her eggs within the
flour. I have carefully observed this point, and have found that
three fourths of the eggs are deposited in this way, when such
places are chosen for their deposition. Such flour may be per-
fectly free from larve when sent out from the mill, but in a few
days the young creatures hatch from the eggs within it, and the
flour is soon matted together and is unfit for use. The larve get
into most mannfactured products in this manner, the eggs of the
moth being usually packed with the material.

It has been reported by some European writers that the larve
attack the bolting-cloth, but I have made no similar observations.
I have found many larve on and about the screens in mills, but
have never seen one attack the cloth. In my breeding. cage ex-
periments I have no difficulty whatever in this direction. .All my
cages are covered with fine Swiss muslin, and I have no trouble
in keeping the larve within. To see whether, in confinement,
they would attack bolting cloth, I procured some of this material from
a miller in California, and covered two cages with it. The larve
matured, and pupated in most cases in the top of the cage,
usually forming their cocoons on the under surface of the cloth,
but in no case was it punctured by them. I am of the opinion
that in the cases reported the injury to the bolting-cloth was due.
to that cosmopolitan creature, the cadelle (Ten brioides mauri-
tanica). I have seen both larva and adult of this insect cutting
bolting-cloth, and. have found it in every mill I have inspected.
In California it is known as the “bolting-cloth beetle.”

The Ephestia larvee thrive best on the more glutinous cereals,
but they infest all manufactured foods prepared from wheat,
oats, rice, Indian corn, and buckwheat, and will attack the grain

27

itself, to a limited extent, when the manufactured products
are not available. While a resident of California, being sus-
picious of all breakfast foods purchased for my table, I
closely inspected every package, and found flour-moth larve
in oatmeal, corn meal, rolled wheat, and germea bought at
a local grocery store. They also feed on crackers, and have
been found in bumblebees’ nests and in beehives, feeding
probably upon the wax and bee-bread. Mills in which several
kin ls of cereals are prepared for food are not troubled equally in
all departments. For instance, where wheat flour, oatmeal, and
buckwheat flour are manufactured, the oatmeal is more infestd
than the wheat flour, and the buckwheat worse than the oatmeal.
The manager of a California mill wrote me with reference to this
subject as follows: “I have observed that they seem to thrive best
in buckwheat flour. I have never been able to understand why
they should prefer this flour, but we have to be exceedingly care-
ful of this food, or in a short time it will become full of webs
spun by the larve.” The manager of a Canadian mill wrote Mr.
Fletcher the following: “If this insect strikes a mill where a
variety of cereal products are manufactured, it will work its way
into every product, though it likes glutinous substances best. It
attacked every thing we made, from pot-barley to fine farina and
milk food in tins” In a mill, where rice foods are the principal
product manufactured, the manager tells me the rice is more at-
tacked than any other cereal. He said they were much troubled
with the larve in food put up in tin cans lined with tissue paper,
very often having the goods returned, marked ‘“‘wormy.”

DEVELOPMENT.

By a long series of experiments, conducted in California and
Illinois, I have ascertained that the life cycle of Hphestia kuehni-
ella under the most favorable conditions, from the time the egg
is deposited until the adult moth emerges, is about nine weeks.

Mr. Danysz has found that the period of development in France
is about the same, insects in his experiments having completed
the life cycle in from two to two and a half months. Professor
Landois is of the opinion that during warm weather, in Germany,
the larva of the flour moth develops into the adult within four
weeks. In speaking of the outbreak in warehouses in London,
Mr. Kiein says: ‘I'he larve, which were full-fed in about three
weeks, then made their way to the surface.” It is hardly safe to
assume that this represents the full life cycle of the larvee, as the
exact date of hatching was not recorded.

In connection with the Canadian outbreak, Mr. Fletcher says:
“There are probably two normal broods of the flour moth, one
emerging in the spring, and another in the autumn; but in a jar
kept constantly under observation in my office, which was heated
during the winter, there have been, I judge, three distinct broods;
although from the fact that some retarded individuals have been
emerging the whole time, and no special study made of them, it
is very difficult to keep track of the separate broods.”

28

Mr. F. H. Chittenden has estimated, from experiments re-
-cently conducted by him in Washington, that in the warmest
weather the life cycle is about five weeks. In my experimental
work during midsummer, under the most favorable conditions,
in California and Illinois, I have been unable to get a full grown
larva in less than five weeks from the time it emerged from the egg.

The number of annual broods of this insect depends largely
upon the geographical location and upon the condition of the
mill. In California, where the climate is even, the amount of
damage done and inconvenience caused varies but little with the
time of year. In the Eastern States, however, the insect is most
troublesome during the summer months; although in exceptionally
warm mills it is very annoying even in midwinter. I have shown
by a series of carefully planned experiments that there are from
five to six annual broods in California, and probably the same
number in some of the Southern States and in Eastern States where
the mills are well heated during the winter months. In most
cases, however, in the East, four broods seem to be the average,
appearing most abundantly from April to December. Brood after
brood have appeared successively in my cages for the past two
years.

From a long series of experiments, I have selected five repre-
senting the life cycle of this insect, the eggs heing deposited in
April, August, and October. The results are given in the follow-
ing table:

29

“""**"G68T'gg OUNL JO WOON] ** “GEST ‘ZI UNL Jo SuraI0W|** “GEgT ‘SI OUNL Jo SuyusOW| ****** ““gEgt‘T ‘WEP JO WOON|***-Z6gI'6 100 Jo Sutusoy| poSzewe Tour INpe ysI1g

ie 2s GBBT Se ABN Treeeesesesees sonar ton adag|pejo[dmoo 3 undeq 10090;)

ee eene SIRI Tits alte | eune se eee eeenes "*°*GgQT Ye Avy eo ad “PEBT ‘06 ‘00

“F681 'SI 99g JO TOOUDIOg| 2691 ‘2e “Ideg Jo MOOTOIOg | BAIR] poingeU A[[NJ jst

“C68 ‘ZT euNL JO ToOUeIO,g| “*cggt ‘oz AB FO MOOUIIZY| “*aggt‘gz ABI_ JO UOOUSeIOY

“c6gt', Let JO nooasonsy “*"""a681 ‘1g [Tidy JO WOON] “CERI ‘TZ [lady Jo WcoueI04|"" “PERT ‘g ‘AON JO WOOUEIOW| **gEQI'g ‘Suny Jo noonsaiy| see eeees NoTOIBY 8590 ISI

OS OE Spe Ra MEd Yr FOOTE CE Ndi ef OTRO a cr Pee ee ee or ae ee eee ewes e es SSE" (oe eee eee tees a eee So SINT YF peyrsodep ssdo jo ‘ON 1810,
ee ee Fe cai ee ee O_O | Be oe BO a ee
“*"""G68T'6S Id V JO JUSTIN] **** “G6SI‘TL dV FO IUSIN| "°° “G6RT TT adv Jo INSIN| ****** HEBT'Ge “200 JO IUTIN| "*****-eeQt't “Say Jo IWSIN|"* ~*'*poysodap sB¥e sity
pee eS ES ee ee eS eee ee ee eae ae a oe ee a eee
Same vsee soe == = aR OTe pe [udy SAO OTIS Teh Voy eG qudy Sele vies ee cee eRe «pT qTudy eee e reer seers PERT ‘Sz 490 se eee eee eee so eeOT fT “sny se eens suriied punoj siupy
a Bg a el | ee

SOB CCAR OOIIET Foy jf cea og esters re* SSTOu(e] OAT IGE ORDSCTT aT eG GH ft seseeeeeeenereengpgngty 2770080" qaHOptE9 “ar peyonpuos quoutiedxg

TreteceecereceeesTOR MON [TTT HOR MON] TTT ttt eso KR MON] Tete tees erTOTTED tree eeeeee ss seesepimzogTTR| ***'** '[RIeeU Jo eoINOg

re a Ee ee a ee Se ee ee ee es ees ee eee

“‘QON “*p ON ‘ON "SON ‘TON *yuousiodxg

pis SE ee Rate ee eS Ee a ee Lg ea :
‘“ATOAO HAIT NO SNOILVAURSAO JO LICIHXG

30

From the above table we see (1) that the period of incubation
for the eggs varies from seven to nine and a half days, with an
average of eight and two fifths days; (2) that the feeding stage
of the Jarve varies from thirty-five to forty-nine and a half days,
with an average of forty days; (3) that usually from one to two
days elapse after the larve are full grown before the cocoon is
spun; (4) that the chrysalid stage lasts from ten and a half to
fifteen days, with an average of thirteen days; and (5) that the
. period from the time the eggs are deposited to the emergence of
the moths varies from fifty-nine and a half to sixty eight and a
half days, with an average of sixty-three and three fifths days, or
about nine weeks.

Copulation takes place, in most cases, the same day the adult
emerges, usually in the early morning, lasting from four to five
hours, but oftentimes extending over a period of eight to ten
hours. A single female will pair several times, and a male that
was seen pairing on two different occasions on two successive days,
on being removed to another cage, in which a freshly emerged
female was placed April 11, 1895, paired again the same after-
noon. The eggs deposited by this female that same night, hatched
just ten days later, thus proving their fertility. The female has a
peculiar habit of resting with the anterior end of her body some-
what elevated, the wings slightly spread, between which she pro-
jects the tip of her abdomen, as shown in the illustration at b on
page 9. Oftentimes she also extends her ovipositor from an
eighth to a quarter of an inch (not represented in the figure),
giving the abdomen the appearance of ending in a long spike.
The female will assume this attitude for several days, or until
copulation takes place. I have had as many as twenty five
females in a cage at a time, where they often remained five or six
days in this characteristic position before any males emerged.
They are rather sluggish while pairing, and can be easily trans-
ferred from one cage to another without being separated.

The female usually deposits her first lot of eggs the night after
the first copulation, and so far as my observations and experiments
go, they are laid at night only. The egg-laying period of a sinyzle
individual lasts five or six days, during which time an average of
about two hundred and forty eggs are deposited. In mills
they are usually deposited singly, but may often be found in
chains of eight to ten. The largest number I have succeeded in
getting from a single female is two hundred and seventy-one, and
the smallest one hundred and twenty. The total number de-
posited by each individual in the above experiments is listed in
the table. The female lives only two or three days after the eggs
have been deposited; and the average life of the male after
pairing is from six to seven days.

Professor H. Landois, of Minster, Germany, ascertained by an
anatomical examination that the eight ovaries of an Hphestia
kuehnie'la contained respectively, 66, 79, 80, 84, 85, 87, 92, 95 eggs,
an aggregate of 668.

31

I have dissected a great many fully matured females, some im-
mediately after pairing and others just before, but have not ob-
tained any such results as those tabulated by Prefessor Landois The
greatest number of eggs I have obtained by dissection is 342, and
the least number 187. I have also carefully exami: ed a series of
females after death, immediately after the eggs had been deposited,
to see if any undeveloped eggs were left, in the ovaries, and in
five cases found they were completely spent, while I found seven
eggs each in three others, fourteen in another, and twenty-six in
another. This would seem to indicate that the total number of
eggs in the ovaries does not represent in all cases the total num-
ber that may be laid by a single individual. As stated above,
the greatest number of eggs I have yet obtained from a single
female is 271 (No. 3), and an examination of the parent insect
later showed that the ovaries were spent.

A correspondent of mine in California was asked by me to con-
duct a series of experiments in his mill during the month of
November, 18')2, to ascertain the exact time required for the in-
cubation of the flour-moth eggs, and on December 5 I received
the following reply: “The eggs hatch in my mill, under the most
favorable conditions, in a trifle less than nine days.” This is in
accordance with my own experiments. Mr. James Fletcher says
that caterpillars emerged in December, in a warm office, about
nineteen days after the eggs were laid. I cannot account for this
difference in time, as eggs deposited December 4, 1894, kept in
my office where the temperature ranged from 38° to 72° Fah.
hatched in exactly nine days. As has been shown by Mr. Danysz
the development of the embryo is greatly retarded by a continuous
low temperature, and it is possible that the eggs in Mr. Fletcher's
office may have been exposed to a lower temperature than 38° Fah.
for a considerable length of time, which would, possibly, explain
the difference in the period of development. Another point to be
taken into consideration is the fact, that the female is from five
to six days in depositing her eggs, and that there is a difference
of as many days in the hatching of the first-laid and the last-laid
eggs of the same generation.

‘he active or feeuing stage of the larva depends upon the tem-
perature of its surroundings, and upon the kind and amount of food.
Larvee hatched from eggs October 9, 1894, were divided into two
lots and placed in breeding-cages with wheat flour for food. One
cage was placed in the insectary where the temperature varied
from 28° to 78° Fah., and the other was kept in a warm office at a
temperature of 48° to 82° Fah. Larvae in the former lot were
fully matured November 26, or in about seven weeks, and in the
latter November 13, or just five weeks from the time they emerged
from the eggs. In other experiments conducted to test the effect
of the amount and kind of food on the larve, I have had varied
results. Larvze feeding on coarse corn meal, for example, did not
mature as quickly as those in the same room fed on wheat or
buckwheat flour. As already stated the average active period of
the larva is about forty days; but under the most favorable cir-

32

cumstances this stage is reduced to about five weeks. Mr. James
Fletcher writes that moths kept in a breeding cage in his study,
continued to emerge and lay eggs until December 15. He then
adds in a foot-note, that larve from these eggs were full grown
March 21. This makes a period of ninety-five days, and woull
seem to indicate that in Canada the development of the larva is
very much slower than in California, or in Illinois and New
York, during the winter months, as in no case have I observed
the larval period to last longer than forty-nine and a half days.

When the larve reach maturity they have the peculiar habit of
migrating to some isolated corner for pupation, and will then
leave their feeding quarters provided an outlet is afforded. It is
difficult to confine them in a breeding-cage at this period, and in
my cages many larve have escaped by working their way out un-
derneath the stout rubber bands which held the muslin over the
cage. After maturity the larva will often crawl about for one or
two days, without taking any food, before finding a suitable place
for its quiescent stage. The cocoon, in which the chrysalid rests,
is made of fine silk, often intermingled with particles of flour or
meal. These cocoons are sometimes found in great masses in the
most remote parts of a mill. The adult moths emerge in about
two weeks, and deposit their eggs for succeeding generations.

Mr. Sidney T. Klein, in a paper read before the Entomological
Society of London, refers to the peculiar migratory habits of the
flour moth as follows: {

“Their migratory habits, when full-fed, were very extraordinary;
nothing seemed to keep them within bounds. I had a colony of
some thousands in my house, in order to make experiments how
to exterminate them; but I found that my breeding-cages, with
the finest meshed wire, were useless to restrain them. I then
placed them under a large glass shade on a polished surface with
no perceptible outlet; but it was no use; the corners and ceiling
of my room were within a week studded with their cocoons, and
every day specimens of the larve were discovered in different
parts of the house, from top to bottom; in fact, they increased
and wandered to such an alarming extent that I had to give up
keeping them.”

In the same paper, speaking of the creatures in the warehouse
where he made his observations, Mr. Klein says:

“When full-fed the larve made their way to the surface, and
could be seen in myriads crawling along the floor and up the
walls of the warehouse, till they reached the angle where the roof
met the walls. There they spun compact silken cocoons, in which
they turned to the pupa state.”

HISTORY OF THE CALIFORNIA OUTBREAK.

In March, 1892, the president of one the largest milling firms
on the Pacific coast invited me to visit one of his mills which, he
said, was literally overrun with worms and moths. I inspected
the mill the latter part of March, and procured a large number

ere:

33

of the moths and larve which were responsible for the annoyance,
I recognized the insect as the. Mediterranean flour moth, and gave
the proprietor the necessary warning; but to make sure that my
determination was correct I sent specimens of both larva and
adult to Prof. J. H. Comstock, of Cornell University, Ithaca, New
York, for identification, and at the same time forwarded speci-
mens to Dr. C. V. Riley, United State Entomologist, at Wash-
ington, D. C., for comparison with those in the National Museum.
The material sent to Prof. Comstock was referred to Mr. M. V.
Slingerland, Entomologist to the Cornell University Experiment
Station, who replied that there was no doubt about the insects’
being that terrible pest, the Mediterranean flour moth. In the
absence of Dr. Riley from Washington, my letter was acknowl-
edged by Mr. L. O. Howard, Acting Entomologist; who wrote in
reply that my determination was unquestionably correct, further
stating that the Department had received no prior information
regarding the occurrence of this species on the Pacific coast.

I made frequent visits to the mill during the summer, and each
time found the insect more abundant than on my previous exam-
ination. After considerable correspondence with the the propri-
etor, who had become greatly alarmed, I deemed it advisable to
send out an emergency circular to various papers on the Pacific
coast, in which due warning should be given to millers and deal-
ers of the presence of this formidable enemy. Accordingly, De-
cember 1, 1892, I sent out from the Department of Entomology,
Leland Stanford, Jr., University, Palo Alto, California, the follow-
ing circular, which is the first authentic record of the presence
of this pest in mills in the United States:

‘“‘Notes on the Mediterranean Flour Moth, EHphestia kuehniella Zeller.

(Hmergency Circular. )

“This moth was first found in a flouring-mill in Germany during 1877,
and was brought to the attention of Prof. Kuehn, of the Agricultural
Institute of the University of Halle, who sent specimens to Prof. Zeller,
of Gruenhof, for determination. The insect proved to be new to science,
and was described and named kuehniella by Professor Zeller, in honor of
Dr. Kuehn. ;

“The moth was little known until 1884 and 1885, when it appeared in
some mills in Belgium and did much damage. Several articles appeared
in English periodicals in 1887, concerning its ravages in Europe. It
caused a great deal of trouble, and in many instances mills were closed.
Very little was known about the pest in this country until 1889, when
it appeared in Ontario, Canada. Much damage was done; mills were
closed, and in one case the loss was estimated at one thousand pounds.

“The fact that such an unwelcome pest has established itself on the
Pacific coast is to be regretted. The announcement that it is in our
midst should be a signal of alarm to every miller and grain dealer in
this region. Notwithstanding its comparatively recent appearance, it
has caused much trouble to millers and flour dealers. Every possible
means should be taken to eradicate this ravenous pest from our midst.
Not only are our mills in danger, but our commerce is at stake, and
public health imperiled.’

After the publication of this note, I received many letters of
inquiry from various parts of the country regarding this pest. I
pushed my experimental work in the laboratory, and made good
my opportunity of studying this creature in the mill. I endeay-

3

34

ored to trace it to its original source, but the more material and |
facts I gathered on this point, the wore complicated the matter
became, and i finally concluded it was unsafe to assume that the
moth came at any stated time from any given locality.

My first correspondent, on whose premises the moth was first
discovered, has given me much valuable information on this
subject, and if all millers on the Pacific coast had taken as firm
a stand, and fought as persistently as he has for the past three
years, the Mediterranean flour moth would not now be so widely
distributed. May 24, 1892, he wrote me as follows: “I desire to
say that you are correct regarding the moth, and I know that it
is a great pest. We have endeavored to exterminate it, and have
succeeded in keeping it in check somewhat by constant sweeping
and cleaning, and by burning sulphur in the building; but we
must now adopt some other means, as it seems to be gaining
during this warm weather.”

I visited the mill again June 4, 1892; making a thorough in-
spection, and found a frightful state of affairs. Only a few moths
were seen in the basement, but on the other floors I found a
very different state of things. In some parts the moths were
found upon every piece of machinery and apparatus, and could be
seen in great numbers upon the sacks in which large quantities
of flour, meal, and grain were stored. Hundreds were clinging to
the sides of the mill and about the windows. An occasional
moth would take wing when disturbed, but as a rule they were
quiet. They were even in the dark chambers of the reels. The
larve were found in every crack and angle about the ma-
chines and wood-work, around bolt-heads, in nail holes, and in
every crevice where masses of flour had collected. They were
particularly abundant in the spouts and elevator legs. I scooped
down a handful of the dust that had accumulated in one of the
spouts, and upon careful examination found thirty-five larve,
varying trom one eighth to one half inch in length. All the
spouts and elevators carrying the more glutinous cereals were in
a similar condition. The larve were also seen on piles of boxes
containing breakfast foods. Jn fact, in the most isolated places
I could find eggs, larvee, pupse, and adults.

I made frequent visits to the infested mills during the summer
of 1893, and each time found the insect on the increase, and
spreading from mill to mill. In April, 1894, I wrote the manager
of the mill where I made my first observations, inquiring about
the present condition of the place, as compared with one year
ago, and received the following reply: ‘Following up my previous
letter to you regarding the flour moth, and in answer to your
specific questions in the letter just received from you, I would
state that our mill is still infested to some extent, and we are
still fighting it, keeping one man constantly employed for that
purpose. The condition of the mill, however, as compared with a
year ago, is very much improved. We have the pest so in sub-
jection that we are really not suffering any inconvenience from it,
nor any loss, with the exception of the wages of the man em-

30

ployed to fight it, and the cost of the material used in the war-
fare, which is immaterial.” During the same month I made a
tour of inspection to the worst-infested mills in the State and
found that the moth had generally a firmer foothold, and was more
troublesome, than the year previous. In answer to a query of
August 16, 1895, the president of the firm in whose mill I made
my first observations, says: “The flour moth is still with us. It
is hardly equal to death, but discoun!s taxes in the inconvenience
it gives us. The outlook, as compared with a year ago, is about
the same as regards the probability of becoming entirely rid of
it; but it affords me great pleasure to tell you that I have it in
subjection, and that it is not now injuring us nearly so much as
formerly.” As regards the present distribution of the pest, he
says in the same letter: ‘The insect is increasing in this State.
I believe that every mill in California, and in all probability
every mill on the Pacific coast, unless it may be some very new
mill, is infested by these moths. One of the newest mills in
this State, which is now shut down, was more afflicted with these
moths than any other mill we have with us. They were so numer-
ous they choked up every spout and elevator, and before the mill
had run six months it was necessary to shut down and employ a
force of men to take down all the spouts and elevators and clear
away the accumulations from them.”

My recent discovery of a hymenopterous parasite of the larva,
Bracon hebetor Say, gives encouragement that the pest may be
at least somewhat checked by this little insect. This is the first
reported case of parasitism of this insect in this country, and is
treated in detail on a subsequent page. Judging from the wide
distribution of the flour moth on the Pacific coast, it is safe to
predict that the worst has not yet been recorded. It is only by
the most persistent and energetic fighting that the pest can be
kept in check in any locality; but in California the climate is so
equable and so mild that the propagation of the species goes on
continuously, and I am in doubt if it ever can be entirely eradi-
cated there. Here is what one of my. correspondents says on the
subject: “I think I see in this little insect a very serious pest,
and that it will be only a question of time when it will be im-
. possible to obtain a barrel of flour that does not contain either
the eggs or larvee of this insect. This would not, however, mili-
tate so much against the manufacture of flour as it would against
cereals or breakfast foods, or meals, as they are called in millers’
parlance. The moth cannot live very long in a sack of flour,
owing to its being so densely packed that there is no room for it
to move about, and it thus soon dies; but in coarse meals and
coarser grain, the moth and larva can move, spin their web, lay
their eggs, and multiply; and this I fear will eventually destroy
the popularity of breakfast foods, and ruin to a great extent a
large trade that has been built up in this country.” Millers
throughout California have become very much alarmed, and agree
with my correspondent, that if something, either natural or arti-

36

ficial, does not check this advancing enemf very econ, the successful
operation of large mills will be seriously, if not permanently, in-
jured.

DISCOVERY IN NEW YORK STATE.

In response to my article on the flour moth in the March (1895)
number of the “American Miller,” I received several interesting
letters pertaining to the same subject. One of these revealed a
new locality for the pest; the first positive record of its appear-
ance in mills in the United States east of the Rocky Mountains.
The letter, dated March 10, 1895, came from the head miller
(name and the exact locality omitted by request) of a firm in
southwestern New York, and reads as follows:

“Your article which appeared in the ‘American Miller’ of this
month has no doubt been read with a great deal of interest. Of
course it'can only be appreciated by those who have been afflicted
with the flour moth in their mills. I have had charge of some of
the best and largest mills in this country, and have never had
any trouble with this insect until about a year ago, at which time
it took possession of the entire plant in about two weeks’ time.
I was forced to shut down and take out elevator spoute. The
covers were removed from the spouts, and the birds’ nests, as we
call them, were taken out by the bushel. I would not have be-
lieved it had any one informed me, but such was actually the
case. I have been a contributor to the milling press now and
then, but have not dared to say anything about it on account of
being scored by tiose who have been fortunate enough to escape
their presence. I have tried everything to get rid of them, and I
think I have succeeded fairly well by using metal spouts through-
out the mill.”

Upon receipt of this interesting communication, I immediately
wrote the miller asking for samples of the material containing
the larve, and March 20 I received two packages of flour literally
filled with the worms, pupx, and several dead adult moths. The
material was placed in a _breeding-cage, and the following day
(March 21) three adult females emerged, leaving no doubt about
the identity of the species. Two more females emerged the 25th;
and the first male appeared April 10. With this material I con-
ducted a series of experiments, mentioned later in this paper. The
letter Sean e this material is of general interest, and I quote
it in full:

“Your favor of the 13th instant is received and noted. I mail
you two samples of the webs, as per request, one taken from an
elevator leg, and the other from a hopper in a porcelain roller
mill, grinding fine purified middlings. I will answer your ques-
tion as to how they originated in this mill, as near as I can.
This mill has been run by the [—— | Milling Company for
years on a system as nearly perfect as any mill can be run.
About eighteen months ago this firm surrendered to the First
National Bank of this city, and one of the stockholders became
office manager. This gentleman, not being acquainted with the

37

art of manufacturing flour, attempted to cut down expenses. He
looked upon the sweeper in a mill as a sort of luxury and dis-
pensed with his services. The mill run night and day and soon
became filthy. In about four months’ time the moths made their
appearance; in fact they got so bad the head miller was forced to
resign. I was then engaged, by correspondence, for one year.
Had I known the condition the mill was in at that time, I should
not have accepted; but, as it is, I have done the best I could. I
have succeeded fairly well in getting rid of the pest, and I expect
to drive them out entirely.”

The remainder of this interesting letter is quoted under the
heads of remedies and distribution.

I made the first public announcement of this pest in New York,
in a short article in the “American Miller’ for May, and special
editorial mention of it was made in the same issue, warning mil-

lers to be on their guard in that and adjoining states.

reo. ee

i made an especial effort to account for the presence of the flour-
moth pest in this mill; but, after a large amount of correspondence,
I only ascertained that it had been established for some years in
mills at several places in southwestern New York, and, possibly,
in parts of Pennsylvania. Some mills in this region were forced
to shut down and clean out spouts and elevators nearly two years
before the pest came to my attention. The infested district in
New York is inland, and to say that the moth came originally
from Canada, or from any other specified source, would be pure
assumption. The moth is still present in New York; but the head
miller who first made known its presence to me assures me, in a
letter dated September 14, 1595, that it is not nearly so abundant
in his mill as formerly, and that he has it under control.

NEW OUTBREAK IN CANADA.

It will be rem2mbered that the Mediterranean flour moth ap-
peared in destructive numbers in Ontario, Canada, in the year
1889, and after encountering a determined and energetic fight,
practically disappeared, little or nothing having been heard of dt
since in that region. In the November (1895) number of the
“American Miller” I recorded its occurrence in the Province of
Quebec, Canada, and gave other notes concerning it. My atten-
tion was called to this outbreak by Mr. Edward R. Taylor, manu-
facturing chemist, Cleveland, Ohio, who wrote me September 23,
1895, as follows: “I take the liberty to forward you a letter and
sample of flour infested with what appears to me to suit the de-
scription of the Mediterranean flour moth. If you will kindly
examine the material and report to the party concerned it will be
greatly appreciated.’ The letter was from a Canadian miller, dated
September 19, 1895, and read as follows: “I mail you to-day a
sample of flour containing a little pest that has appeared in our
mill this year for the first time, and is consequently a stranger
to me. You will find in the sample several small flies, with their
young in the mat enclosed. They are to be found in great quanti-
ties in our spouts, in every conceivable corner, and so abundant

38

in purifiers and bolts that it is becoming a serious matter. Any
information you can give me, publicly or privately, will be thank-
fully received.”

A careful examination of the material left no douot as to the
species’ being Ephestia kuehniella. In my reply I asked for addi-
tional information regarding the pest, and for a fresh lot of
material, as the sample sent was in bad condition when received,
having been crushed during transit. I received the following
answer, dated October 2: ‘Replying to your favor of the 26th ult.,
would say that the pest came into our mill from a neighboring
mill during the past summer. We have made no particular attempt
to exterminate it. Our mill is a new one, put in only a year ago,
and consequently the moth is a new thing with us; but we learn
that it was in the neighborhood last year. With thanks for your
kind attention we will await the ‘American Miller’ for further par-
ticulars.” The sample of infested flour accompanying this letter
was placed in a breeding-cage, from which I took two adult females
October 15. The specimens did not vary in any particular from
typical specimens from California and New York. As to the source
of this infestation I have nothing to say. The whole subject of
the distribution of this pest is in such an unsettled state that I
will not venture to give an explanation of its origin in apy given
locality.

NATURAL ENEMIES.

In the struggle for existence the flour moth is not entirely free
from the attacks of natural enemies, but has many pronounced
advantages in the fact that it is entirely concealed in silken tun-
nels during its larval or feeding state. There are two weak points,
however, in its life history; namely, the quiescent or pupal state,
and the period immediately after the larva has reached maturity,
when its migratory instincts are so strong that it will expose its
delicate body for several hours as it crawls about hunting a suitable
place for pupation. Nature has taken advantage of these vulner-
able points, but, on the whole, interposes but feeble checks on the
multiplication of the species.

*The reducing agents of the flour moth fall naturally under two
heads, predaceous enemies and parasitic enemies, the former in-
cluding insects, birds, and mammals; and the latter, insects alone.
Such data as we have are presented here chiefly as an indication
of the practical inefficiency of the natural enemies of this species.

Birds.—Mr. Sidney T. Klein delivered a colony of the larve of
the flour moth, which he had been keeping in his room for ex-
perimental purposes, over to the tender mercies of about fifty game
and Plymouth-rock hens kept in his garden, and the greediness with
which these larve were eaten by the fowls suggested a ready means.
for the extermination of myriads of those in the warehouse where
he had been making observations. Mr. Klein says: “A great.
number of hens was therefore requisitioned from the neighbor-.
hood in the east end, and it was encouraging to see the enormous:
quantities co simed. But the hens began to flag after ten minutes:
of gorging, and, although they were kept in the warehouse for

Se LP

39

‘several weeks, the insects still continued to increase and spread

to other granaries.” An outbreak of this pest very rarely occurs
where chickens could be utilized for its destruction, and they are
therefore of little practical value in this connection.

Mammals.—tl have here to relate a curious instance where a com-
mon house mouse, Mus musculus, devoured several hundred pure of
the flour moth in one evening. April 11, 1895, I removed a male
and a female flour moth, still pairing, from a stock cage, and placed
them in a separate cage in order to obtain the eggs for experi-
mental purposes. The eggs were laid and hatched in due season,
the first young appearing April 21, and the larvze were supplied
with an abundance of wheat flour and catmeal for food. The larvee
matured and were all pupated by June 5, the brown chrysalids
being plainly seen through the sides of the glass cage. By actual
count there were two hundred and fifty-four pupzx in the cage at
this time. A mouse discovered this cage sometime during the
night of June 12, cut through the Swiss muslin that covered it,
and devoured every pupa within. Little or none of the flour and
meal in the cage had been eaten. Of course, millers and dealers
can turn mice to no good account as enemies of the flour moth,
and this instance is introduced simply as a record of the evident
relish of one mouse for insect pupe,

PredaceousInsects.
—Those insec's pop-
ularly known as
“flour weevils” are

-¢ foremost in this
Hi group. They are

- Tribolium ferrugine-
um* and T. con-
jusum. The two spe-
cies are so closely
esac that they can
| with difficulty be sep-
arated, and, to the
ordinary observer,

Fie. 5.—Tribolium eaurrsumns Gd. adult beatles b, joryast cuppa they are one and the
all enlarged; d, lateral lobe of abdomen of pupa; ¢, head of beetle. . o
showing Baca: f; same of 7. ferrugineum,—all greatly enlarged. same thing. Their

(After Chittenden.) habits are sjmiliar,
and the injuries occasioned by them far outnumber those of any
other insect that attacks grains and farinaceous foods. Both spe-
cies are cosmopolitan, and have a wide geographical distribution.

© In speaking of the flour moth larve Professor Zeller says: “Simultaneously with these
larve [ received the little beetle Tribolium ferrugineum, which multiplied so rapidly that during
the summer [ sometimes found large masses of its yellowish larvee. I eagerly destroyed them, fear-
ing they would, at least, be disadvantageous to the larve and pup of the flour moth. Now, it
seems to me that this beetle was unjustly held in suspicion by me, and tbat it and its larvie, at
mos, would help to devour the moths reared for propagation, and dying soon after mating.” From
this it appears that Prof. Zeller did not observe the weevil feeding upon the larve or pup of the
flour moth. In the same paragraph, however, he says: ‘I rather suspicion the Ephestia larvie of
devouring little by little, not only their dead parents, but also the pup which have fallen out of
the web.”” I have myself seen the flour-moth larve attack and deyour pupw of their own kind ina
breeding-cage where the pup: had been uncovered.

40

They have long been known to infest meal, flour, grain, and veg-
etable stores in Europe, and in the past few years have become
very troublesome in this country, occasioning considerable alarm ~
among millers, flour and feed dealers, grocers, and dealers in
patent foods. It is not an uncommon pest in our museum collec-
tions, feeding on the dead bodies of insects. The adult insects
are small, flat, reddish-brown beetles, about three sixteenths of an
inch in length. Our most common species, T. confusum, is represented
in its different stages in Fig. 5 (p. 39). The eggs are deposited in
the flour, from which the young hatch a little later. There are four
or five broods during the year. They are offensive creatures, and
impart a disagreeable odor to the infested material. Their carniv-
orous habits, however, make some amends for the mischief they do. I
have frequently seen the adults of both weevils preying upon the
larvee and pupz of the flour moth in mills in California. In one
reel, where a great number of the flour-moth larvee had pupated,
it was rather difficult to find a single cocoon which did not con-
tain an adult of either confuswm or ferrugineum, the former spe-
cies being, however, most abundant. The flour-moth chrysalids,
in most cases, had been completely devoured.

August 18, 1895, I placed a hundred adult beetles of confusum,
received August 16 in flour from Toledo, Ohio, in a breeding-cage
in which several hundred larve of the flour moth had just pupated,
and left them undisturbed for several days. August 26, [ made
a careful examination and found that the weevils had penetrated
two thirds of the cocoons and destroyed the chrysalids within
them. August 30, two flour moths emerged from this cage, but
no others issued at any time later. There was an abundance of
wheat flour and corn meal in the cage, which fact alone would
seem to suggest that the weevil prefers insect food when it is
available. These weevils were left in the cage undisturbed, where
they have been breeding continuously ever since, and there are
now in the cage thousands of adults and larve.

One enthusiastic miller in San Francisco, California, who ob-
served the flour weevil feeding upon the Jarva of the flour moth,
made artificial breeding beds for the formar and distributed them
about his mill in the hope of reducing the flour moth, which was
everywhere present in his mill. August 23, 1895, he wrote me
the following letter on this subject: “I had hopes of some as-
‘sistance from the little weevil, having observed them feasting on
the larve of the flour moth. I cultivated colonies of them and
distributed them through the mill, and watched them very closely
for some weeks. I found that while they did attack the larve to
some extent, it was still not enough to be of any particular benefit.
The little beetles are themselves a pest, as they get into the
meals and flour and make trouble there, so I have abandoned any
hope in that direction.”

I have seen the notorious cadelle (Tenebrioides mauritanica),
‘known. sometimes as the “bolting-cloth beetle” in California, at-
‘tacking both the larva and pupa of the flour moth and devouring
both the larva and adult of the flour weevil, 7. confusuwm, in my

=

breeding: cages. I have also seen Gnathocerus cornutus, another

mill pest, attack and devour the flour-moth larve in mills in

California.

Parasitic Insects.—The larva of the flour moth is attacked by
several species of very small hymenopterous parasites. They are deli-
cate wasp-like creatures, which take advantage of the full-grown
larva of the flour moth during its migratory period just prior to
its pupation. While the delicate larva is thus exposed the winged
parasite lays her eggs, usually upon its body. In one instance at
least, that of Bracon hebetor Say*, the parent insect paralyzes the
larva, reducing it to a helpless condition before the eggs are de-
posited.

The first true parasite of the flour-moth observed, Bracon bre-
vicornis Wesm., was discovered by Mr. Sidney T. Klein in
August, 1887, in-a London warehouse. He describes the attack
as follows: “I held an inspection in August, and brought away

_ several of the full fed larvee for examination, as I noted some
irregular markings which had not been noticed before. These
larve seemed to pupate quite regularly, and I did not suspect the
state of the case until 1 went down again at the beginning of

September. No sooner had I entered the warehouse than I

noticed a most extraordinary change in the appearance of the

large piles of flour. On closer examination I found this appear-

ance was caused by enormous numbers of a small black fly * * *;
and, upon examiniog several of the larve, the majority of which
had markings on their backs, the startling fact was established
that nature had come to the rescue and provided a remedy her-
self. It is very rarely that such a striking example of nature’s
wonderful counterbalancing powers is discovered.”

Mr. Wm. H. Ashmead, of Washington, D. C., who is our best
authority on this group, informs me that Bracon brevicornis is
not found in North America so far as he knows.

Specimens of Chremylus rubiginosus were bred from Ephestia
kuehniella and sent to Mr. J. B. Bridgman, of Norwich, England,
who records the fact in a communication to the editors of ‘Insect
Life” (Vol. IL, p. 260). In a letter from Mr. Ashmead, dated
September 21, 1895, he says: “I know this species only by Euro-
pean specimens. It is not yet recorded from North America.”

- The present economic relationship of Bracon hebetor Say

to the flour moth was discovered by me September 2, 1895.

The insect was first described by Thomas Say in February, 1835,, and

is therefore an old-time species. Mr. Ashmead, who kindly de-
termined it for me, says: “I have seen specimens from California,

Indiana, Ohio, Illinois, District of Columbia, Virginia, New York,

Massachusetts, and other New England States. [t is therefore a

widely distributed species. It comes very close to my Bracon
gelechic, reared by yourself from Canarsia hammondi, in color and
general facies, but differs in sculpture and antennal characters.”

4]

* Belongs to Mr. Ashmead’s new subgenus Habrobracon.
Best. Jour. Nat. Hist., Vol. 1, 1835, p. 252.

42

I bred another specimen, a male, from the same lot of flour-
moth larve, which, although certainly different from typical males
of Bracon hebetor, is probably only a small variety of this species.
Mr. Ashmeaa characterizes it as follows: “It differs markedly in
several particulars—number of joints in antennz, its more elon-
gated shape, much smaller size, and in color; but until the oppo-
site sex is bred, it would be better to consider it only as a vari-
ety of hebetor.” This little braconid has been bred from the In-
dian meal moth, Plodia interpunctella, in Massachusetts. I have
reason to believe that we may expect some good results from it
in this country. Out of: several hundred flour-moth larve sent
me by the California miller, only one moth emerged, all the oth-
ers having been destroyed by the little parasites, of which I re-
moved twenty-seven specimens from my breeding-cage. It is
surprising how easily these little creatures can be colonized. It -
is only necessary to collect a quantity of the webbed flour con-
taining the flour-moth larve and place it in a breeding-cage, into
which the parasites are afterward introduced. Here they multiply
rapidly, and can be liberated at will in the worst-infested parts
of the mill. I have suggested this expedient to the president of
the milling firm from whom I received the larve.

I will now give, somewhat in detail, notes of my own observa-
tions on Bracon hebetor. When I discovered this little parasite,
I noticed that several of the flour-moth larve were lying in the
bottom of the cage in a helpless condition, although presenting
the fresh and plump appearance characteristic of living larve.
Upon examination I found that they were not dead, but in a state
of lethargy. Two larve in this condition were removed from the
cage and placed in a glass tube, where they remained perfectly
motionless, but still gave on the fifth day evident signs of life by a
slight movement of the thoracic segments when touched with a
needle point. This movement was not noticeable on the sixth
day, and the larve were dried up and shriveled two days later.
It is quite probable that this paralysis is caused by the adult
parasite, but in what way has not yet been worked out
satisfactorily. I have now several experiments in progress to
determine this point if possible. I have observed the same
paralytic state in larve of Canarsia hammondi, and in nearly
every case have found the eggs of Bracon gelechiw either
on the body of the larve or on the silk or web imme-
diately over them. In this latter case it is very important.
that the larve should not move after the eggs of the par-
asite have b2en deposited, as the little grubs hatching from them
are legless, and could not crawl far in search of food. I am of
the opinion that B. hebetor deposits its eggs in much the same
way. I have not seen the eggs of this species, but have found
grubs just hatched attached to the external surface of the flour-
moth larve. In one instance, September 18, 1895, I removed a
larva from a cage with five grubs, just emerged, feeding upon it,
two of which were removed and placed in alcohol, and the others
were left for development. The following morning, at 8 o'clock,

_ they had left the larva and were forming cocoons on the side of
the tube. The cocoons were completed by 8 o’clock, September
20, and were whitish in color. The fully developed chrysalids
could be plainly seen by the 23d, in which condition they re-
mained until October 7, when the adult parasites emerged. From
this one observation it appears that the grubs reach maturity in
one or two days; that one day is required for the construction of
the cocoon; and that a little over two weeks is passed in the
pupa stage, making about three weeks for the complete life cycle
of the parasite. It will be remembered that about nine weeks
are required for the complete evolution of the flour moth, so that
there would be three generations of the parasite during a like
period.

PREVENTIVE AND REMEDIAL MEASURES AND MECHANICAL DEVICES.

It is now a well-known fact that this moth is carried from mill
to mill in the greater number of cases through carelessness.
Millers who have never been trqubled with insect pests think there
is nothing to fear, and carelessly permit all sorts of material, such
as empty bags, barrels, boxes, and second-hand machinery, to enter
their premises without even suspecting the presence of their worst
enemy. The indifference displayed by most millers who have been
fortunate enough to escape the ravages of insect pests in their
mills, is truly lamentable. All preventive measures are ignored,
the mills are often dirty through neglect, and unconcern prevails.
These very people, sooner or later, will suffer severe mental anxiety
and heavy financial loss for their negligence. Other firms- neglect
their mills simply because they are new, thinking they have noth-
ing to fear from outside foes. Some of the worst flour-moth out-
breaks recorded in this country have occurred in newly con-
structed mills. One of the newest mills in California was obliged
to shut down before it had run six months, and employed a
torce of men to take down all spouts and elevators and clean out
the accumulations from them. The Canadian outbreak at Val-
leyfield, Quebec, is another instance. The mill was constructed
about a year ago, and has been obliged to shut down several
times during the past season in order to clean out the webs
from spouts and elevators. When a mill is clean and new it
would certainly be good policy on the part of the owners to keep
it fresh and clean. In this day of common insect pests, a sweeper
or duster is indispensable to the successful operation of a mill.
He should be thoroughly acquainted with all insects injurious to
mills, mill products, and stored grain, and competent to apply
such measures as may be requisite for their arrest and destruc-
tion. He should be responsible for the inspection of all incom-
ing material, of whatever sort, where there is the slightest ques-
tion as to its freedom from insect pests.

Where the flour moth has established itself in a mill, it canbe
_ kept in subjection only by the most persistent and energetic fight-
ing. The standard remedies are steam, sulphur, and bisulphide
of carbon, all of which are soon to be considered in detail. I shalh

44

‘discuss here only such remedial measures as have been used suc-
cessfully by milling firms, including suggestions warranted by my
own experimental work.

Cleanliness.—The only safeguard against insect pests in mills
is scrupulous cleanliness. This can be attained by constant sweep-
ing and dusting; but a much more effective method has been per-
fected and used by one of my San Francisco correspondents,
whose procedure is as follows: ‘I am now employing,” he writes,
“a scheme for cleaning our mill which I find the most efficacious,
taking it all around, of anything I have tried. I have run a half-
inch pipe under each ceiling of every story in the mill, and
every twenty-five feet I have a steam-cock, so that I can attach
a steam hose, on which I use a nozzle (the same as that used on
any garden hose). With this arrangement I thoroughly steam all
the spouts, corners, garners, walls, posts, in fact every part of the
mill. It is the best cleaning apparatus for a mill that I have
seen. One man in one day with this hose will sweep the mill
cleaner of dust, dirt, and other accumulations, than twenty men
could do with broom and brush. In fact it is impossible to
clean out dust with broom and brush as well as it can be done
with steam. I recommend this scheme to all those with whom I
talk, and you can safely recommend it to all your correspondents
as being an excellent thing. There is no other apparatus that
will cleanse a mill so thoroughly.” This is by far the most
practical method known to me, and I commend these steam pipes
to millers as a most necessary part of the equipment of a mill.
No new mill should be contemplated without incorporating the
“steam sweeper’ in its plans and specifications. Such an equip-
ment will pay for itself in a short time, and a clean well-kept
mill certainly commends itself to public favor. The cautions to
be observed when steam is used in mills are discussed on p. 54.
‘Great care should be taken not to allow loose material, empty
bags, boxes, and the like, to accumulate about a mill. All such
rubbish should be burned if it has no commercial value.

Fumigation Box.—Every well-equipped mill should have a
tight wooden box, large enough to hold all the bags, boxes, or
barrels that usually come and go from the mill, or are in circula-
tion among local customers. Such material should be thoroughly
‘steamed, or subjected to the fumes of sulphur or bisulphide of car-
‘bon, before being permitted to re-enter the mill. Any second-
‘hand machinery that may be bought should be treated in the
same manner. Instances where the flour moth and other insect
pests have been carelessly introduced on old bags and _ second-
hand machinery have already been given.

Metal Spouts.—Any substitution of-one piece of apparatus for
another that will in any way make it more difficult for insects to
find lodgement in a mill, will certainly be productive of good
and lessen the chances of infestation. It is a well-known fact
that the flour moth finds spouts and elevator legs its most favor-
able quartere. The wooden spouts are so arranged that the larve
have no difficulty whatever in clinging to them, and consequently
great quantities of flour are matted together and cause the trouble

in such places. This liability
may be removed by the sub-
stitution of metal for wooden
spouts. The metal spout
was first used for this pur-
pose by the inventor, Mr. L.
C. Schroeder, of Olean, New
York, and is protected by a
patent. These spouts are
perfectly smooth and there
is no chance for an insect to:
find lodgement within them.
The inventor claims that they
can be made for less money
than the lumber costs for
wooden ones, and that a mill-
wright is not needed to put
them in position. (See Fig. 6. ):
I might say in this connec-
tion that Mr. Schrceder has.
also applied for a patent for
a metal elevator leg, which,
when on the market, will
afford another useful piece of
apparatus for preventing the
establishment of injurious insects in these parts of a mill.

Where metal spouts have been resorted to in mills overrun with
this scourge, the results have been very satisfactory. In March, 1895,
a New York miller wrote me the following letter on this subject:
“T have discontinued the use of wooden spouts and have substi-
tuted metal ones. Since I adopted this spout I have had no
trouble with the moth in the plant, but it has drifted from
here to the flour department, and seems to be most abundant in
the purifiers and rollers. I am now removing all the wooden
spouts as fast as I can in the flour depertment, and I hope to be
sble to get rid of the pest before warm weather comes on.”

This letter was followed by another communication from the same
miller, dated August 14, which I quote in full, and which needs no
comment: “The Mediterranean flour moth is a thing of the past,
or nearly so, in our mill. When I wrote you last [March 17]
this mil] was alive with them; but I have rooted them out by
degrees. I was confident I could do it. As I said before, they
shifted about from the meal department to the buckwheat depart-
ment and then to the flour department, all three plants being
located under one and the same roof. The latter part of May I
shut down four days for the sole purpose of cleaning out this
pest. I ran down the stock as close as possible and then had the
mill swept from top to bottom. I then took down all wooden
spouts and replaced them with metal spouts. I have metal spouts
here which were put in nearly twelve months ago in our meal
department, and during that time not a moth has been seen in

Fic. 6— Adjustable metal spout.

46

them; in fact, they cannot locate in them, for they are perfectly
round and smooth inside. It is in the corners of a wooden spout
that the worms locate and spin their webs. It would bea hard
matter for me to find a sample of stock in this mill, at present,
that contains either the worms or moths.” ,

Attachment of Brushes to Belts—The fact that the larve of
the flour moth cause most trouble in spouts and elevator legs
has suggested the attachment of several brushes to the belts, so
arranged that they constantly clean the sides and corners of the
spouts and the elevator legs. Where it is necessary to retain the
wooden spouts in an infested mill, this device is highly recom-
mended and should be kept in constant use. It has been success-
‘ful in France, and one of my California correspondents who is
using the brushes says: ‘Our spouts were continually choking up,
so that we had to employ one or two extra men in operating
the mili in order to take care of the choke-ups that occurred. Now
we have no difficulty whatever. The elevators and spouts are en-
tirely clean, and we have no trouble with worms in our mill; in
fact, we hardly notice the existence of the pest at all, but we
realize that we must keep up a constant warfare on them or they
will immediately increase to such an extent that we shall be
in as great trouble as before.”

The ‘American Miller’ for December, 1895, contains a com-
munication from a practical miller bearing directly upon this
‘subject, and I quote it here in full:

“Hditor American Miller: Millers are often troubled with ele-
vators sweating and dust settling in them, which becomes musty
and moldy. More or less of this is bolted into flour, and as a
result musty flour comes back to the mill. I have designed an
elevator brush to prevent this trouble, a drawing of which is pre-
sented in the accompanying illustration. [See Fig. 7. |

“To make the brush take a
piece of 14-inch plank of the

il Ny | Wa Yy same dimensions as_ the elevator
A Zz gO cups, and fasten bristles to three
|& sides. The side A is fastened

6 a eae to the elevator belt with flat-

r —= headed bolts running «through
A == PD the plank, as shown at B, B,
i ! AE.) the bolts being + or 2 of an

—= inch. The bristles on the sides C,
= C, should be ? of an inch long, but
a vat
AV; Nh} \ i

Fig. 7.—El:vator Brush.

that they will give a good brush-
ing to the outer side of the ele-
vator. The brush is easily made,
and the miller can make it of any
size to fit his elevators.”

AN those at D should be longer, so

I will now consider, in the order of their effectiveness, sub-

stances which have been used with the most satisfactory results
in combating the flour moth. Bisulphide of carbon stands first,
followed by steam, sulphur, and steam and sulphur combined.

47

Bisulphide of Carbon.-—The simplest, most effective, and least
expensive remedy for all mill pests is bisulphide of carbon, a

very inflammable, volatile, foul-smelling liquid, as clear as water.
Its vapor is heavier than air, and will penetrate every crack and
crevice in a mill or warehouse when used in sufficient quantities.
It can be thrown directly upon grain without injuring its edible
qualities, and will not affect its vitality in the least. In mills it
can be used about the machinery, spouts, and elevators with per-
fect assurance that the manufactured products will not be dam-
aged. It is a powerful insecticide, the atmosphere produced by its
vapors being sure death to insects, as well as to rats and mice. I
know of no instance, however, where the slightest deleterious effect
has been realized by persons applying it in mills, although they
unavoidably inhale some of the fumes,

The amount of liquid to be used depends (1) on the size of
the buildivg, (2) on its tightness, and (3) on the magnitude of
the attack. Where the building is reasonably tight and but slightly
infested, one pound of bisulphide is sufficient for every thousand
cubic feet of air space. If it is somewhat open or badly infested
the amount should be doubled. When applied to bins containing
stored grain, one pound of the liquid to every hundred bushels
of grain is commonly used; but if the insects are very abundant
the amount of. bisulphide shouid ba doubled.

A number of methods for the application of bisulphide of car-
bon have been suggested and tested, but the most effective man-
ner of applying it in mills consists in simply pouring the liquid
into shallow dishes, such as soup plates, or pans, and distributing
them about the building. Bits of cotton-waste saturated with the
liquid should also be thrust into spouts, elevator legs, machines,
and other places where the pests usually congregate in great num-
bers. Spraying or throwing the liquid broadcast into badly in-
fested corners, on machines, and other pieces of apparatus where
the pests are particularly abundant, has been attended with very
good results.

Saturday afternoon is the best time for fumigating a mill. After
sweeping it from top to bottom, using a “steam sweeper” where it
is practicable, all fires about the premises should be extinguished
and the mill closed as tightly as possible. Thedishes and cotton-
waste should be previously distributed, so that there will be no
unnecessary delay in the application of the foul-smelling fluid.
The distribution of .these vessels must of course depend, as
alréady stated, upon the condition of the mill and the severity of
the attack. It is best to begin with the lowest story and work
up, as the operators can then keep above the settling gas. When
the bisulphide has been applied throughout the mill it should be
locked and kept closed until the following Monday morning. All
windows and doors should then be thrown wide open and the
building allowed to air an hour before any fire is started. Where
the buildixrg is large and a great quantity of bisulphide has been
used, it would be wise to observe the extra precaution of station-
ing a watchman without to prevent any one from entering the
building during fumigation.

48

As a guide to millers who may use this method for exterminat-
ing insect pests in mills, I will quote several letters from practi-
cal millers who have used bisulphide of carbon successfully. The
superintendent of a large Pennsylvania milling company, whose
name is withheld by request, under date of July 12, 1895, wrote
me the following letter, which is a valuable contribution to this
subject, and should be read by every wide-awake miller and grain
dealer:

“We have delayed answering your valued favor of May
last until we were able to report the result of our efforts to de-
stroy the weevils in our mill. Following in the line of your ad-
vice, we ran our stock down and thoroughly renovated our mill
from top to bottom, cleaning all reels and purifiers. We then
fumigated the whole mill with bisulphide of carbon. We distrib-
uted 300 soup plates about half filled with bisulphide through
the mill, and saturated balls of cotton with the same material
and placed them in all the reels and purifiers. This we did on
Saturday night and closed the mill tight and Jeft the weevils to
their destruction.

“We opened the mill Monday morning and thoroughly venti-
lated it before starting. We found that we had destroyed thou-
sands, and in the reels and purifiers we had killed them all. In
the course of 1 few days, however, they began to show up in the
cracks in the floors all over the mill, and in dark corners. Two-
weeks later we repeated the dose of bisulphide in the same man-
ner and obtained about the same results. In the meantime, how-
ever, we whitewashed the mill from top to bottom, that is, every
place that could be covered, putting on a good heavy coat. We
have not destroyed them all by any means; but we have reduced
their forces to a very small number. Eternal vigilance is the
orcer cf the day. ;

“We are still fighting them. Our plan is to keep a stock of
bisulphide on hand outside of the mill building, as we do not
think it advisable to store it in the mill on account of its in-
flammable nature. Wherever we find a place infested by the wee-
vil we use it freely, taking care to do it when the mill is shut
down and closed up tight. We find the best results from the use
of bisulphide of carbon can be obtained by spraying it on the floors.
and infested places. We think when placed in plates it does not.
evaporate quick enough to produce the death atmosphere required.
Before closing let us return our sincere thanks to you for the
interest you have taken in the matter, and assure you that we
appreciate your valuable advice.”

The “American Miller” for July, 1895, contains another inter-
esting and valuable communication on this subject, from Mr. H.
J. Laurie, of Norwalk, Ohio, and I quote it here in full:

“As the season is now upon us when a large majority of the flouring-
mills of the country are being troubled with insects of various.
kinds, such as weevils, worms, moths, etc., I thought it might not.
be out of place to give our experience here with bisulphide of
carbon, which we have been using for several seasons with very
satisfactory results.

49

“I have reason to believe that a number of millers have used
this remedy with very indifferent results, owing, in my opinion, to
the manner in which it was applied. In the first place, the mill
should be thoroughly swept (as every mill should be daily), and
if there are any broken panes of glass in the windows they should
be replaced, the object being to make the mill as tight as pos-
sible. Then have a number of shallow tin pans, say, about fifty
to every 100 pounds of the compound used. Begin at the top
[bottom] of the mill, and place the pans where the insects are
the thickest. 1t is best for two to go together, one placing the
pans, the other filling them, using a watering-can or something
of the kind having a spout.

“I apply it to the bolting reels and flour garners as follows:
I get ready, beforehand, a number of medium-sized bunches of
cotton-waste, two for each reel, with a string attached to each. I
dip these bunches into the bucket of compound, pressing out
with a paddle so they will not drip too much; then throw them
under the reel and down on the conveyor, leaving the string on
the outside su they can be recovered, then close the doors of the
bolting chest tightly. I suspend one or two bunches in like man-
ner in the flour garners and screening bins. In applying it to the
wheat bins we level off the grain and place the pans on it filled
with the liquid. By applying it in this way to wheat bins and tak-
ing proper care to have the bins emptied and swept out oc-
casionally, no one need be troubled with weevils in their grain
elevators. ‘There is one thing that we have discovered, and that is
that the compound must be reasonably fresh when used. If kept
for any great length of time it loses its strength, consequently it
should be used as soon as practicable after receiving it, and no
more should be ordered than it is intended to use.

“Before commencing the use of bisulphide of carbon this mill
was badly infested with weevils and other insects. Now we are
nearly free from the pests. Ido not say that this remedy will kill
every insect in a mill. I do not think there is an insecticide made
powerful enough to reach every nook and crevice, such as we
have in mills; but we do know that by a judicious use of bisul-
‘phide of carbon in warm weather, when the insects are in full
force, and by a due regard to cleanliness all over the mill, any mill
can be rid of the pests.

“The compound being highly inflammable, there should be no
fire or lights used in the mill at the time it is applied. The best
time to apply it is Saturday evening, and the mill should be kept
closed till Monday morning.”

There have been so many exaggerated reports about the nature
of this chemical compound that it is necessary to give a few notes
regarding it in this place. In this connection I can do no greater
service than to quote a letter from Mr. Edward R. Taylor, of Cleve-
land, Ohio, the leading manufacturer of bisulphide of carbon in
this country. It appeared in the “American Miller” for Septem-
ber, 1895, and reads as follows: .

—A 4

50

“Editor American Miller: I have seen a great many very rar-
dom statements on the subject of the inflammability of bisulphice
of carbon. One says, ‘Use the same care as with gunpowder.’
Another says ‘It is a very explosive liquid.’ These are both very
misleading statements with reference to the properties of bisul-
phide of carbon. I have quoted the statements, however, in my
printed matter for the reason that farmers and many others use
the goods, and will be sufficiently startled by such statements to
be careful and have no light or fire about.

“Nearly everybody is now familiar with gasoline. The proper-
ties of that liquid and bisulphide are practically identical in
that both are inflammable but neither of them explosive. The
vapor of either of them mixed with air is explosive, but the
liquids are not explosive. I have shipped thousands of pounds of
bisulphide to millers, elevator operators, and farmers in the last
few years, and I have yet to have the first report of any disaster,
even of the most trivial character, from a single one of them.
Need I say more? My directions are explicit: Do the work
Saturday afternoon by daylight. Absolutely have no light or fire
of any kind about. Close the mill and leave the bugs to their
destruction till Monday morning. Then open doors and windows,
and thoroughly ventilate before going to work.”

Some of the insurance companies have commenced to feel a
little uneasy lest they should suffer Joss by fire originating from
the use of bisulphide of carbon in mills. The “American Miller”
has investigated this subject by sending letters of inquiry to
all the more important millers’ insurance companies in the United
States and Canada, and so far has not learned of a single fire
which is known to have been caused by the.use of bisulphide of
carbon. The properties of the fluid have been fully described re-
peatedly, and millers have been warned to keep lights and fire
away from the vapor, lest an explosion should occur. The fact
that it has been used so long without fires being traceable to it,
gives strength to the opinion that millers, out of consideration for
their own lives, have heeded the warning and have been exceed-
ingly careful in applying it. When they become more familiar
with its use they may grow careless, but we hope such will not
be the case. It should not be stored near the mill, as this in-
creases the fire risk. A break in the can might unexpectedly re-
lease fumes which would soon fill the mill.

Bisulphide of carbon is sold at drug stores at from 20 to 30
cents a pound, but can be bought much cheaper at wholesale,
directly from the manufacturer. A grade known as “Fuma Bisul-
phide of Carbon” can be obtained directly from its manufacturer,
Mr. Edward R. Taylor, Cleveland, Ohio, in fifty- or hundred-pound
cans at ten cents a pound, and is as effective as the ordinary
grades on the market. A carefully prepared circular containing
full information for its use and the necessary precautions to be
heeeded during its application is sent with each order sold. .

Sulphur.—From a practical standpoint sulphur ranks next to
bisulphide of carbon, as an effective remedial measure, but it

51

must be handled with great care. The burning of sulphur
in infested mills has been attended with both good and evil results.
The experience of th» millers cited below, should be sufficient
warning for all those who may resort to this method for the sup-
pression of insect pests. The experience of an English miller, as
related by Miss Ormerod in her Fourteenth Report (p. 58), is
given in ths following paragraph: “But we found that sulphuring
has an effect which we did not anticipate or wish. We had stand-
ing in the mill when the fumigation was carried on, some eighty
or a hundred sacks of flour, and we find to our dismay that the
sulphur has penetrated right into these, and acted on the gluten
of the flour in such a manner as to apparently break up all
soluble albuminoids, and render the dough made from it more
like a lot of weak putty than the strong, tough dough our customers
require.”

In May, 1892, the manager of a San Francisco mill, who tried
the burning of sulphur in his mill for the destruction of the
flour moth, wrote me as follows: “The fumes of the sulphur
acting on the different cereals, destroys certain properties of the:
grain and flour, rendering both useless for bread-making purpo-
ses. Onour first application of the sulphur fumes we nearly destroyed
about a thousand barrels of flour. This was very discouraging.
and has since prevented us from applying that gas in so exten-
sive a manner as is necessary to fully exterminate the moths.”

Even after this sad experience, the same miller is of the opinion
that sulphur is the best remedy for keeping the pest in check
when used in the proper manner.

Another California miller, who has had much experience fighting
the moth, writes me as follows: “We cannot use sulphur in the
mill any more without taking out all the flour and grain that we
usually carry in stock. We find that the fumes of sulphur de-
stroy the vitality of the flour by some chemical action rendering
the flour worthless for bread-making purposes. They also destroy
the value of the wheat for flour-making purposes, as the flour
made from fumigated wheat makes no better bread than the fumi-
gated flour.” BAM seis:

Other instances of this nature might be given, but these will
suffice. In preparing to sulphur a mill the stock should be
run down as low as possible, and all flour and wheat removed
before the sulphur is ignited. Care should be taken also to see
that all windows, doors, and other openings are closed. Various.
ways have been suggested and tried for burning sulphur. A.
California miller outlines his method as follows: “Our method
of using the fumes of sulphur is to take an iron pot, set the:
same in a can of water, put in a quantity of sulphur, or pulverized
brimstone, pour over it some alcohol and set the same on fire.
Then close up everything tight, so that the fumes cannot escape.
This will kill every living thing with which the gas comes in con-
tact. We have frequently found dead mice on the floor after hay-
ing fumigated the place. We use this sulphur in parts of the
mill which can be tightly closed so as to prevent the escape of.
the fumes.”

52

Dr. Bryce, speaking of destroying the flour moth in Canada,
says: “This can be done by closing the windows, doors, or other
apertures of the building, and, night after night, until all evi-
dences of moths have disappeared, burning sulphur by placing it in
shallow pans, upon a number of heated stoves, say, small coal-oil
stoves, in different parts of the building and putting a match
to it.”

The following method is also given by Dr. Bryce:

“To prepare sulphur fumes: Place a metallic dish containing
hot ashes on some support in a pan of water, or place in an old
pan or other vessel a bed of ashes at least 6 inches deep, and
about 15 inches in diameter, and place the sulphur and saltpetre
in a slight depression in the centre and ignite. The proper pro-
portions are 3 lbs. of sulphur and 3 oz. of saltpetre per 1,000 cubic
feet of air space. All doors, windows, and other openings should
be tightly closed before the sulphur and saltpetre are ignited.”

There are cartain necessary precautions to be carefully ob-
‘garved in burning sulphur in mills, which may be given briefly
as follows: (1) Remove all grain, flour, or other manufactured
products from the mill; (2) see that all external openings are
closed before the sulphur is ignited; (3) have the vessels con-
taining sulphur so arranged and situated, that there will be no
danger of fire from that source; and (4) thoroughly air and clean
the mill again before resuming work. Particular attention should
be given to the cleansing of the machines, especially those used
for manufacturing flour and other farinaceous foods, as the sul-
phur compounds will continue to act on the manufactured products
some days after disinfection unless this caution is heeded.

Steam.—Steam has been used in mills for the suppression of
insect pests with considerable success. Miss Ormerod suggested
the possibility of destroying the larve of the flour moth by turn-
ing ‘on steam from the boiler—a plan which had ben entirely
successful in clearing a cheese factory of maggots which had
spread to every nook and corner. This method was tried by an
English miller at Miss Ormerod’s suggestion, and he outlines his
method of procedure as follows: “The way I applied the steam
was by carrying about forty yaras of half-inch piping into the
mill from the boilers, and attaching an india-rubber hose to it
for the men to work about on the walls, floors, spouts, and ma-
chines, blowing the steam into all the crevices and holes. I stopped
the mill for a week while this was being done. It has rusted all
the shafting, etc., but this is quite a secondary matter as it can
soon be cleaned again. After blowing the steam, which took two
or three days, I set the men to work to wash the walls (and every
other surface that they could without fear of affecting the flour)
with paraftine [kerosene]. The inside of the machines I had
‘washed with a strong solution of boiling water and soda.”

In Canada the Local Government compelled the miller, on whose
premises the pest was first found, to take down all the machinery

53

and apparatus in his mill and subject it to a thorough steaming.
The sad experience of this miller is related by himself and is
quoted here in full from Dr. Bryce’s bulletin (26): a
“In the meantime we took down our machinery and subjected it
to steaming. Every part was thoroughly steamed. ‘The mill was
swept down, and subjected to sulphur fumes. The walls, ceilings,
etc., were cleaned, and elevator spouts and loose wooden work
burnt up. Paper bags and hundreds of dollars’ worth of goods
were burnt in the furnace, while the other bags, elevator belts,
and cups were boiled for hours in a cauldron of water. The ma-
chines and all parts that were not destroyed were then burnt by
means of a kerosene torch, which flamed and smoked through and
around every part of them until we considered we had everything
clean and ready for putting together again.

“But on the 19th of September, the Local Government passed
an Order in Council compelling us to take more stringent steps,
aud on the 20th of September, we received an order from Dr.
Bryce, which stated that before placing our machinery in position
we should subject it to a thorough disinfecting process in a strong
room, so arranged that steam under pressure might be drawn or
driven into it.

‘In compliance with this order we at once constructed a tight
steam box 6 feet wide, 6 feet high, and 12 feet long, and attached
a steam pipe to it from the boiler. In this box we put every ma-
chine, and even our mill stones and iron rollers. This process
was very expensive, and took up considerable time, as we were
over a week at the process and were delayed in the placing of
our machinery. The Board of Health visited us in a body during
the time this process was going on, and pronounced it a_ success.
This was all done not only in our own interests, as was pointed
out in the letter of the 20th of September from Dr. Bryce, but in
tle interests. of the public health and commerce of the country.

“Having now got in a position to go to work again, after two
months’ loss of time, and loss of machinery, fixtures, and stock, at-
‘ended with much expense, we have arranged for remedial meas-
ures to prevent the reappearance of the pest or to destroy it if
we should ever again be attacked. We have erected a steam
stand-pipe with hose or other connection on each flat of the mill
building. By shutting up all the doors and windows of each flat
and turning on the steam simultaneously to each floor, the whole
building can be filled with hot live steam sufficient to kill any-
thing. This will rust all bright parts of the machinery, but to
remedy this we intend using oil on them, should we ever be
under the necessity of resorting to the measure.

“Another purpose of this steam stand-pipe will be in cold
weather to let on sufficient steam to moisten everything and every
part of the building at night, and then throw open the windows for
the night and let the frost penetrate so as to kill any eggs or
insects that may have become lodged in unseen parts.

54

“By these measures, with plenty of light, thorough cleanliness,
a cold mill, and caution in taking in stock and old bags, we hope
to keep free of the pest which has occasioned us so much trouble
and loss.”

One of my California correspondents, who is now using steam
for the destruction of this pest, says: “By the use of this sys-
tem I am now keeping the flour moth in check, but I am com-
pelled to go over the mill, from top to bottom, at least once a
week. If I let it go longer than that I observe a decided increase
of the moths in the mill and worms in the goods. On the whole,
I find this the most efficacious method I have tried since the
moths have been with us.”

The most satisfactory method for equipping a mill with appa-
ratus for steaming purposes, now known to me, is that described
on page 44, and used by a San Francisco miller.

There are several points about this method of destroying in-
sects that should be carefully considered.

1. Any grain, flour, or other manufactured product left in a
mill during the steaming process is liable to become damp and
seriously injured. All such material should therefore be removed
before the steam is turned on.

2. The bright parts of machinery and other apparatus are liable
to become rusty if not wiped thoroughly dry immediately after
the operation, or oiled before the steam is turned on.

3. The “steam sweeper” or steam introduced by means of a
hose and nozzle, is certainly more advantageous than steam intrc-
duced through other pipes where the entire mill is filled at one
time, as in the former case it can be directed into corners, spouts,
machines, or other places where the attack is severest, with less
liability to the injuries specified under 1 and 2.

4. Steam can be used to best advantage during the summer
months, as the windows and doors can be thrown open at’ this
time. In cold weather, or during the winter months, when the
mill is tightly closed, the steam on the cloths of the purifiers
often causes trouble, the middlings running the wrong way. Steam
sweeping, on the whole, is most successful in the summer months,
except in California and some of the Southern States where there
is a mild and equable temperature.

Steam and Sulphur.—The use of steam and sulphur combined has
been attended by very satisfactory results. My California correspond-
ent, after his bitter experience with the sulphur, writes again: “I
think that there is no doubt but that the moth can be extermi-
nated from any one mill by sufliciently long-continued applica-
tions of sulphur fumes and steam. This, however, necessi-
tates a great expense in moving all the stock out of the mill, and
also loss of time that would result in shutting down the mill to
make the applicatior. I do not believe that all ‘the eggs, larve,
pupz and adults could be destroyed in less than one week’s con- —
stant application of the gas and steam. This process would leave
the mill in such a condition that unless the acid which is de-
posited by the gas could be neutralized by some agent it would

55

be impossible to make any flour that could be used for bread-
making until all the acid deposited should have been absorbed
and carried away, which would result in enormous waste of ma-
terial. I find, however, that the acid could be neutralized to a
great extent by ammonia, and this, or some other equally power-
ful agent, would have to be used before turning the mill on to
making flour again after the application of the gas.”

In dealing with the Mediterranean flour moth eternal vigilance
should be the order of the day, and if the above methods are
faithfully employed, I think that we shall, in a few years, hear
little or nothing about the insect in the mills of this country.

MISCELLANEOUS EXPEDIENTS.

Many ineffective expedients have been resorted to in the war-
fare with the flour moth, but they deserve only passing notice,
and are mentioned here mainly for the benefit of experimenters.

Kerosene.—We have used this substance for washing walls, ap-
paratus, and the inside of machines, but find it slow and tedious,
and I would suggest its use only in extreme cases, where it is
necessary to take a machine or other piece of apparatus apart.

Solution of Soda and Water.—A strong solution of soda and
water has been used to good advantage for washing the inside of
machines, and is very effectual in destroying larvee when it comes
in actual contact with them.

Soap and Lime.—A mixture of soft lye-soap and lime has
been used for washing elevators and bolting-reels. This, like
the above washes, is used mainly for cleansing the machines, and
is of very little value unless the washing is kept up at regular
and frequent intervals.

Buhach.—This substance(also called pyrethrum, insect-powder,
etc.) was burned in a single mill with slight success. It is not
as effective as bisulphide of carbon or sulphur fumes, and is more
expensive. Mr. Danysz has given quite a lengthy account of his
experimental work with this substance in his paper.

Ammonia.—Ammonia has been tried without success.

Hydrocyanic Gas.—I have some hopes from the use of hydro-
eyanic gas, but have not carried my experiments far enough to be
certain of its safety or of the feasibility of its application in mills.

Corrosive Sublimate.—A solution of this substance has been
used in mills for spraying walls, floors, and ceilings, but on ac-
count of its poisonous nature I would not recommend it.

Lime.—Very many millers after thoroughly cleaning and then
‘whitewashing their mills have found that the pest was more easily
kept in check. If the ceilings and walls of the mill are not tight,
I would suggest that a little glue be added to the whitewash be-
fore being applied. Various methods have been used for apply-'
ing this substance. Some paint the ceilings, walls, and | floors,
using a brush; while others use a pump and sprayer, forcing the
lime into every crack and crevice. Ordinary whitewash, as com-
monly used, rubs off easily and often becomes a source of annoy-

56

ance. This can be overcome by adding a handful of commo:
salt and about half a teacupful of lard to each gallon of the wash,
which should then be thoroughly stirred before ‘being applied.
One of my California correspondents, in a letter dated August
27, 1895, says: “When making the whitewash I put in all the
sulphuric acid that can be used without burning the pipe through
which the wash is sprayed on the walls. I believe this acid is a
good thing.”

Sulphuric Acid.—A strong solution of sulphuric acid has been
used to wash machinery, elevators, and spouts with good results,
the acid being afterwards washed off with water.

Tobacco.—The burning of tobacco in mills is not effective on a
large scale, but has given fairly good results in small, tight rooms
and bins. Tobacco infusion has also been used for washing and
cleansing apparatus, but, on the whole, it is not a satisfactory
substance for general use.

Flour Paste-——The value of this material is summed up in the
following letter from one of my California correspondents: “Ia
answer to your question, ‘What led you to try the flour paste ex-
periment? I would state that we use flour paste for putting up
packages of small goode. This paste is made, as needed, by one
of our workmen, and is composed of flour, water, and vinegar,
and is boiled by steam. I pay particular attention, in a general
way, to all the work going on in the mill, visiting it every morn-
ing and going through every department. On one or two morn-
ings I noticed that during the night the moths had seemed to
congregate about this paste, many of them having fallen into it,
and as it is of a tenacious nature they could not get away, and
had perished. This seemed to be a curious kind of a thing to
me and I made some investigation—had some of the paste put
out in shallow pans, and I discovered that it had an attraction
for the moth. I found, however, that it must be in a certain
stage of fermentation in order to be of any value as an extermi-
nator. I then commenced a series of experiments on a large
scale, and in a short time had so reduced the number of moths.
in the mill that I was very much delighted with the result. At
the same time I ‘carried on experiments with other materials,
the cost of the paste being a considerable item, since it had to
be renewed every few days in order to be of any service.”

Vinegar and Water.—This experiment was suggested by the
one immediately preceding, and is outlined by the same miller in
a letter dated August 23, 1895, which I quote in full: “I have’
tried numerous ways of getting rid of the pest, and, if I remem-
ber rightly, when I saw you last I was experimenting with flour
paste. My experiments in that direction gave some promise of
success, but I eventually abandoned the flour paste for a mixture
of vinegar and water—about one fourth vinegar to three fourths
water. This seemed to attract them as much as the paste did,
and was not nearly so inconvenient, for the pans did not need to

: 57
be replenished nearly so often as with the paste. The paste seemed
to attract them only in a certain stage of its fermentation—after
that stage was passed they did not appear to care anything for it.
The vinegar, however, attracted them until it had evaporated; but
the acid contained in the mixture soon ate the pans up, and I
had to abandon its use.”

Molasses’ amd Vinegar.—We have found that a mixture of
molasses and vinegar—three parts of the former to one of the
latter—can be used to good advantage for the destruction of the
moths. The materials should be well stirred and placed about
the mill in shallow pans or dishes in the evening just before
closing. This substance lasts longer than either the flour
paste or the vinegar and water, and does not require as much at-
tention. The moths are attracted to it and are caught in the
sticky substance. |

Fly-paper.—This paper, known also as “tangle-foot,” is rather
expensive for use in mills, but we have used it with very good
results, catching from fifty to a hundred moths on a single sheet
in one night. Care should be taken to place the paper in such
places as are likely to be visited by the moths for the deposition
of their eggs; for example, on piles of flour in bags.

Coal-tar.—This substance has been used to good advantage by
smearing it over large pieces of heavy paper and placing them
about the mill. The tar dries out rapidly, and must be renewed
at least every twenty-four hours. Coal-tar has also been used,
with surprisingly good results, for painting rough walls and other
places about a mill, thus stopping up cracks where insects
would find lodgement and escape unnoticed.

Coal-tar and Vaseline.-—We have tried an equal mixture of
these two substances with no better results than with coal-tar
alone, except that paper smeared with this mixture, not drying
out so rapidly, does not need to be renewed so often.

Hand picking.—Many millers whose premises have been over-
run with the flour moth, have kept it,in check somewhat by
“hand-picking.” For this purpose extra help was employed, which
added materially to the operating expenses of the plant. One firm
in California kept several boys and one man at work several
months killing moths in this manner. This method was, however,
finally abandoned, and the mill was fitted up with steam pipes;
and now one man does the entire work of sweeping, cleaning, and
inspecting all incoming material, of whatever kind, and the moth
is kept in such subjection that it gives them little or no in-
convenience.

Hay Ropes.—I have already referred to the outbreak in Ger-
many in 1858 on page 22. The miller who told me of this
instance said the moth was most abundant during the month of
June. This, he says, was the haying season, and long ropes of
newly mown hay were made and placed about the mill in coils.
He says the moths collected in great numbers in these coils,
which were gathered up and burned each week.

58

High and Low Temperatures.—It has been ascertained by ex-
periment that a temperature of 120° to 130° Fah., continued for
two or three hours, is fatal to the larve in flour or other manu-
factured products, and if continued five or six hours is destructive
to the eggs. In case whole grain is found infested, a very much
greater heat is permissible. Wheat has been subjected to a
temperature of 150° Fah. for a short time without destroying its
germinating power.

As before mentioned, infested mills in Canada have been filled with
steam and then thrown open, the cold winter air, as it penetrated
every part of the mill, destroying many larve and pupex. Cold
weather, however, has little or no effect on the larve when left
undisturbed in their silken tunnels.

The following references to the places of publication of the
more important articles that have been written on the Mediter-
ranean flour moth are given below in convenient, compact form,
usually with an indication of the character of the contribution.
The articles marked with an asterisk I have not seen.

BIBLIOGRAPHICAL LIST.

1879:

1. Zetuer, P. C.—Stett. Ent. Zeit., 1879, pp. 466-471.
Original description of species, with notes on outbreak.

1881.

2. SNELLEN, P. C. T.—Tijdschr. voor Ent., 1881, pp. 20-22.
Mention of Prof. Zeller’s paper (1879).

1884.
3. Grrarp, Mavurice.—Bull. Soc. Ent. France, 1884, pp. Ixxiii,
lxxiy.
Note on ravages of the moth at Lodelinsarte, Belgium.
4. Karson, F.—Ent. Nachr., May, 1884.
Record of the appearance of the moth on the lower Rhine.

5. PREUDHOMME DE Borre, A.—Compt. Rend. Soc. Ent. Belgique,
July 5, 1884.

An account of injury done in a noodle factory in Belgium.

1885.

6. ENromoLoGIscHE NACHRICHTEN, 1885, pp. 46, 47, 239, 240.

Editorial mention of the appearance of the flour moth at
Bremworde,

Review of a communication by Prof. Landois to the Braun-
schweiger Tageblatt.

59

“7. SNELLEN, P. C. T.—Tijdschr. voor Ent., 1885, v. 28, pp.
237-251,

An illustrated article of considerable importance.

1887.
8. Lintner, J. A.—Thirty-ninth Ann. Rep. N. Y. State Mus.
Nat. Hist., pp. 99, 100.

Reply to a letter from Mr. A. Seigel, German Consul-General
at New York City, asking information regarding the flour moth.
9. THomprson, W.—The Entomologist, 1887, v. 20, pp. 66, 189.

Finds this insect—first recorded (p. 66) as taal ceratonice—
feeding on rice cones.

10. Tort, J. W.—The Entomologist, 1887, v. 20, p. 212.

Records breeding of the adult from larve found feeding in a
cargo of flour at the London docks, and gives short account of
larval feeding habits.

11. CockerreE.t, T. D. A.—Proc. 8S. Lond. Ent. Soc., 1887, p. 58.

Exhibition of larvee, with statement that they lived in flour
which had been shipped from America to Trieste, and thence to
London. (See No. 20.)

12. Barrett, C. G.—Ent. Month. Mag. 1887, v. 23, p. 255.

Account of breeding experiments, with brief description of moth
and note of distinctive characters.

13. Kuen, 8S. T.—Trans. Ent. Soc. Lond., 1887, pp. lii-liv.
Record of observations made in a large warehouse in the east
end of London, in which the discovery of a flour-moth parasite
(Bracon brevicornis) is mentioned.
*14, The Miller (London) 18387, p. 446.
Full details concerning a lot of flour from Trieste infested with
larve. Reference also made to the parasite noted above.
*15. Mark Lane Express (London) Noy. 14, 1887.
A note regarding the introduction of the flour moth into England.

16. Enromoxtoaist’s MonrHty MaAGazing, 1887, p. 163.
Editorial notice of paper read by Mr. Klein before the En-
tomological Society of London. (See No. 13.) '
17. Getxtz, A.—Proc. County of Middlesex Nat! Hist, and Sci.
Soc. for Nov. 8, 1887.
Note on the destruction of the flour moth by a parasite (Bra
con brevicornis ).
#18. Apxin, R.—Field, 1887, p. 829.

*19. Proc. 8. Lond. Ent. Soc., 1887, p. 20.

60
1888. |

20. CockerELL, T. D. A.—The Entomologist, Nov. L888, p. 279.

States that the larve exhibited before the South London Ento-
mological Society in June, 1887 (see No. 11), although found in
flour which came from America, are supposed to have come from
some infested Trieste flour which was in the same warehouse.

21. Povuutton, E. B.—Trans. Ent. Soc. Lond., Dec., 1888, pp.
598, 599.

Under the caption ‘“‘The Determination of Sex in certain Lepi-
dopterous Larvee,” gives an interesting item concerning the larva
of Ephestia kwehniella. Demonstrated by observation and experi-
ment that larve with dark spots on the dorsal surface of the
fifth abdominal segment always developed as males, and that the
spots are embryonic testicles.

22. Brocout, P.—Bull. du Ministére de l’Agriculture, 1888.

A brief summary of the past history of the pest, with mention
of remedies.

1889.

23. Ormerop, E. A.—Insect Life, Mar., 1889, v. 1, p. 314.

A letter to Dr. C. V. Riley regarding this pest in England.
24. ——-—— Twelfth Rep. Inj. Ins. 1888, pp. 66-72.

An interesting account of the outbreak of the flour moth in
England.

25. Ritey, C. V., & Howarp, L. O.—Insect Life, May, 1889,
¥. 1, D. ood.
Mention of Ephestia kuehniella in connection with a review of
Miss Ormerod’s Twelfth Report.
26. Brycr, P. H.—Bull. L, Provincia! Bd. Health, Ont. (Issued
by Ont. Dept. Agr., Oct., 1889.)
An important article concerning the Canadian outbreak.
2%. Riuey, C. V., & Howarp, L. O.—Insect Life, Dec., 1889, v. 2,
pp. 166-171.
Summary of history and literature, with original notes and ob-
servations.
28. F.LercHer, JAMES.—Insect Life, Dec., 1889, v. 2, pp. 187-189.
A letter to Dr. Riley regarding the Canadian outbreak.
1890,
29. FuLercure, James.—Rep. Minister Agr. [ Ottawa ], 1889, App.,
pp. 73-79.

A review of Dr. Bryce’s Bulletin (see No. 26), with much ad-
ditional information regarding the Canadian outbreak.

61

30. Fuercuer, James.—Rep. Oat. Ent. Soc., 1889, pp. 95-100.
A general review of the history of the flour moth in Canada.
$1. Rivzy, C. V., & Howarp, L. O.—Insect Life, Jan.—Feb.,,

1890, v. 2, p. 260.

Mention of the rearing of Chremylus rubiginosus from Ephestia
kuehniella.
32. Onrmerop, E. A.—Thirteenth Rep. Inj. Ins., 1889, pp. 49-54.

A partial review of matter in her Twelfth Report concerning
the flour moth, with many other notes upon it.

33. Brycr, P. H.—App. Bull. I., Provincial Bd. Health, Ont.
Oct. 15, 1890.

A circular letter urging millers and dealers to take active steps
to eradicate the flour moth.

34. Patron, W. H.—Insect Life, Nov. 1890, v. 3, pp. 158, 159.
Under caption “Notes upon Ephestia interpunctella (Hibn)
Zaller,” both H. kuehniella and Timea zee are listed as synonyms
of E. interpunctella.
35. Ruey, C. V., & Howarp, L. O.—Insect Life, Nov. 1890, v. 3, -
p. 134.

Dissent from Patton’s views (See No. 34) believing Hphestia

kuehniella to be a distinct species.

1891.
36. Hvtst, G. D.—Trans. Am. Ent. Soc., 1890, v. 17, pp. 198-200.
Some notes on Ephestia kuehniella in monograph of North
American Phycitide.
37. Fieroner, James.—Rep. Minister Agr. [Ottawa], 1890, App.,
pp. 168-171.
General summary concerning the Canadian outbreak.

38. Onrmerop, E. A.—Fourteenth Rep. Inj. Ins., 1890, pp. 49-54.
A general review of the English outbreak, for the year 1890,

with much additional information on the subject.

39, Ruiey, C. V., & Howarp, L. O.—Insect Life, Apr. 1891, v. 3,

p. 333.
Mention of a sp2cies of Ephestia (either kuehniella or tnter-
punctella) in corn from Venezuela.

1892.
*40. CocKkERELL, T. D. A—Daily Gleaner, Aug. 11, 1892; Tri-
Weekly Budget, Aug. 11, 1892; Jamaica Post, Aug. 13, 1892.

Reprint by the above Jamaica newspapers of a circular letter
announcing the appearance in Jamaica of what was at first sup-
posed to be the flour moth, but which proved to be Ephestia

desuetella.

62 a

*41. Decaux, C.—Arch. de Med. et de Pharm. Militaire (France, }
No. 8, 1892.

Notes and record of experiments with Hphestia kuehniella.

*42, Ann. Soc. Ent. France, v. 62 (Bull.), pp. ccii, cciii.
A communication concerning E’phestia kuehniella to the Congrés

des Sociétés Savantes, notice of which is published in the Annales

above cited.

*43. Ann. Soc. Ent. France, v. 62 (Bull.), pp. ceii, ccili.

A communication to the Académie des Sciences (France), con-
cerning Ephestia kuehniella, referred to in the above Annales.
44, Riuey, C. V., & Howarp, L. O.—Insect Life, Nov. 1892, v. 5,

p. 141.

Reference to the appearance of H’phestia kuehniella in Jamaica
(erroneously reported; see No. 40) and in flouring-mills in San
Francisco, Cal.

45. Apxin, R—The Entomologist, 1892, v. 25, pp. 53, 54.

A short article on the English outbreak, and original notes.

46. Jonnson, W. G.—Sacramento Record Union, Dec. 5, 1892;

Santa Cruz Surf, Dec. 5, 1892; Los Angeles Times, Dec.
5, 1892; Santa Barbara Morning Press, Dec. 8, 1892.

An “emergency circular” (for copy see p. 39.) reprinted in the
California newspapers. .
4%. San Francisco Call, Dec. 6, 1892.

Matter furnished a reporter in an interview concerning Epheshia
kuehniella.
48. Stockton [ Cal. ] Mail, Dec. 12, 1892.

A short accourt of the flour moth with reterence to its occur-
rence in California.
49. Raaonot, E. L.—Ann. Soc. Ent. France (Bull.) Dec. 28,

1892, p. cclxxiv.

Remarks on the origin of EHphestia kwehniella and on _ its
zoological position.

1893.

50. Jonnson, W. G.—Milling (Indianapolis,: Ind.) Jan., 1893, v.
2. pp. 177-180; reprinted in American Miller (Chicago)
Feb.; 0895, 0y..2aaee1 19:

z ines summary of past history, and notes on the California out-
reak.

51. Dercaux, F.—Ann. Soc. Ent. France (Bull.) 1893, p. xii.

Remarks upon the distribution of Hphestia kuehniella and upon
the experimental work of Dr. ©. Decaux.

63

62. Racgonot, E. L.—Ann. Soc. Ent. France (Bull.), 1898, pp.
MD, Sil!
General remarks upon the habits of Hphestia kuehniella and on
means for its destruction.
53. Rivey, C. V., anv Howarp, L. O.—-Insect Life, Apr., 1893,
v. 5, p. 276.

Mention of the article by W. G. Johnson in “American Miller,”
for February, 1893 (see No. 50), and notice of Mr. Danysz’s pre-
liminary studies on the flour moth.

64. Danysz, J.—Mém. du Lab. de Parasitologie Végétale de la
Bourse de Commerce, v. 1, 60 pp.
_This is perhaps the most important article that has been pub-
lished on the flour moth.
55. Ann. Soc. Ent. France, (Bull.), 1893, pp. clxxviii,
elxxix.
Note on the pigment spots of the larva.
56. Dercaux, F.—Rev. Sci. Nat. Apliquées, Ist Semestre, 1893,
pp. 220-225.
An article with illustrations, treating of the habits of the flour
moth and of means for its destruction.
57. Ruizzy, C. V., & Howarp, L. O.—Insect Life, July, 1893,
v. 5, pp. 290, 291.
A review of Mr. Danysz’s pamphlet, mentioned above.
58. — Insect Life, July, 1833, v. 5, p. 350.
Announcement that the insect reported from Jamaica as E’phestia
kuehniella (see No. 44) proved to be EH. desuetella Walker.
59. — Insect Life, July, 1893, v. 5, p. 353.
Mention of Mr. Ragonot’s views concerning the origin of
Ephestia kuehniella.
60. ——— Insect Life, Nov., 1893, v. 6, pp. 44, 46.
Note concerning Mr. Danysz’s observations on the pigment
spots of Ephestia kuehniella.
61. Bruner, Lawrence.—Rep. Neb. State Bd. Agr. 1893, p. 401.
A short, compiled, illustrated article.

1894,

62. McCarrny, G.—Bull. 96, N. C. Agr. Exper. Station, Jap.
1894, p. 64.
A notice regarding Hphestia kuehniella in which it is said to
be present in North Carolina. |
63. Ruizey, C. V., & Howarv, L. O.—Insect Life, Feb., 1894,
v. 6p. 221.

64

Ephestia kuehniella listed as having been found ‘in meal, bran, -
and cakes in the Mexican exhibit at the World’s Fair (Chicago).

64. Ruiuey, C. V., & Howarp, L. O.—Insect Life, May, 1894, v.
6, p. 355.

Reference to Mr. E. B. Poulton’s paper on the embryonic testi-
cles of the larvee of E'phestia kwehniella. (See No. 21.)

1895.

65. Jounson, W. G.—Am. Miller, Jan., 1895, v. 23, p. 33.
Mentions finding Tribolium ferrugineum feeding upon the
larvee of H’phestia kuehniella in a California mill.
66. AmeERIcAN MILLER, Jan., 1895, v. 23, p. 50.
Editorial notice of the proposed work on the fiour moth in
Eastern United States.
67. Jonnson, W. G.—Am. Miller, Mar. 1895, v. 22, p. 198. .
A preliminary account of experiments with the flour moth, with
notes on observations.
68. Am. Miller, May, 1895, v. 23, p. 347.
Announcement of the appearance of the flour moth in New
York State.
69. AMERICAN MILLER, May, 1895, v. 28, pp. 367, 368.

Editorial comments on the New York outbreak mentioned above,
and (p. 3868) a note on the flour moth quoted from Prof. Lan-
dois.

70. Rivny, C. V., & Howarp, L. O.—Insect Life, July, 1895, v.
7, p. 416.

Reference made to the article (see No. 68) announcing the ap-
pearance of the moth in New York State, and recommendations
made to millers.

41. Cuirrenpen, F. H.—Year-book of the U. 8. Dept. of Agr.
for 1894, pp. 283-285.

A short, illustrated, somewhat popular account of the flour
moth, with notes.

72. Jounson, W. G.—Am. Miller, Oct. 1895, v. 23, pp. 738, 739.
Brief account of the methods used in New York and California

in fighting the flour moth.

13. Am. Miller, Nov., 1895, v. 23, p. 810.

Notes on the discovery of Bracon hebetor Say, a new parasite
of HK phestia kuehniella,—the first observed in America,—and on a
new locality for the moth in Canada.

74. int. News, Dec., 1895, v. 6, p. 324.

A preliminary note on the discovery of Bracon hebetor Say
preying upon larve of Hphe stia kuehniella.

65
75. Burns, E.— Am. Miller, Dec., 1895, v. 23, p. 910.

A communication from a Pennsylvania miller, giving an account
of his three years’ experience in fighting the flour moth.

1896.

76. Jounson, W. G.—Am. Miller, Jan., 1896, v. 24, p. 32.

- A few notes on the flour moth with reference to the new out-
break in Pennsylvania. TIllustrated.

77. Can. Ent. Jan., 1896, v. 28, p. 13.
‘Note on the new outbreak of the flour moth in Canada.

78. Am. Miller, Feb., 1896, v. 24, p. 114.
Answer to a query from a milling firm in Melbourne, Australia.

79. Trevease, WILLIAM.—Science, Feb. 14, 1896, v. 3 (n. 5.), p.
252; Can. Ent., March, 1896, v. 28, p. 61; Am. Nat. v. 30,
p. 298.
Reports that he exhibited at a meeting of the St. Louis Academy
of Science, a silk fabric from Mexico, supposed to be the work of
the Mediterranean flour moth.

Norg.—I am in receipt (March 5, 1896) of a package of infested flour from a mill in Saltillo,
Mexico, which has been forwarded to me by the editor of the ‘‘American Miller.”’ The flour is one
mass of web, and contains hundreds of larve, pups, and dead moths of the Mediterranean flour
moth Hphestia kuehniella. The material was taken from a flouring-mill, where the moth is doing
much mischief.

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