Papers on cereal and forage insects

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Title:
Papers on cereal and forage insects
Series Title:
Bulletin / U.S. Dept. of Agriculture, Bureau of Entomology ;
Physical Description:
7 v. : ill. ; 23 cm.
Language:
English
Creator:
United States -- Bureau of Entomology
Publisher:
U.S. Dept. of Agriculture, Bureau of Entomology
Place of Publication:
Washington, D.C
Publication Date:

Subjects

Subjects / Keywords:
Forage plants -- Diseases and pests   ( lcsh )
Grain -- Diseases and pests   ( lcsh )
Genre:
federal government publication   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )

Notes

Bibliography:
Includes bibliographical references and index.

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Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029637351
oclc - 22577538
Classification:
lcc - SB818 .B85 no.95, 1913
System ID:
AA00018926:00006

Full Text



-/


U. S. DEPARTMENT


OF AGRICULTURE,


BUREAU OF ENTOMOLOGY-BULLETIN No. 95, Part VII.


L 0. HOWARD, Entomaologt and Chief of Bureau.


PAPERS ON CEREAL AND FORAGE INSECTS.


THE


ALFALFA LOOPER.


BY


JAMES A. HYSLOP,

Agent and Expert.


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OCTOBER 16, 1912.


WASHINGTON:.
GOVflNMINT PRINTING OFFICE.
1i12


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BUREAU OF ENTOMOLOGY.

L. 0. HOWARD, Entomologist and Chief of Bureau.
C. L. MArLATT, Entomologist and Acting Chief in Absence of Chief.
R. S. CLIFTON, Executive Assistant.
W. F. TASTET, Chief Clerk.

F. H. CHITTENDEN, in charge of truck crop and stored product insect InvesttisUM4l^
A. D. HOPKINS, in charge of forest insect investigations. .. ..
W. D. HUNTER, in charge of southern field crop insect investigations. ..
F. M. WEBSTER, in charge of cereal and forage insect investigations.
A. L. QUAINTANCE, in charge of deciduous fruit insect investigations. ..
E. F. PHILLIPS, in charge of bee culture. -!
D. M. RoGERs, in charge of preventing spread of moths, field work.
ROLLA P. CuRnIE, in charge of editorial work.
MABEL COLCORD, in charge of library.

CEREAL AND FORAGE INSECT INVESTIGATIONS. i
: .:. .......
F. M. WEBSTER, in charge. ..

GEo. I. REEVES, W. J. PHILLIPS, C. N. AINSLIE, E. 0. G. KELLY, T. D. Unann, :"m::.:
HARRY S. SMITH, GEo. G. AINSLIE, J. A. HYSLOP, W. R. WALTON, J. T. Moax h ..
J. J. DAVIS, T. H. PARKxs, .R. A. VxcIKERY, HENRY Fox, V. L. WiLnmns,"i:1,
R. W. MCCONNELL, E. G. SMYTH, HERBERT T. OSBORN, PHILIP LirGenuinsl
C. W. CREEL, E. J. VOSLER, R. N. WILSON, VERNON KING, GEo. I. SMhTH :M .
E. H. GIBSON, L. P. ROCKWOOD, IRVING CBAWFORD, entomological assistant. .
NTrrIE S. KLOPFER, ELLEN DASHIELL, preparators. L;|
MIRIAM WELLES REEVES, collaborator. ...::i

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CONTENTS

Page.
Introduction .............................................................. 109
Distribution .............................................................. 110
Seasonal history----------------------------10
Seasonal history ............................................................ 110
Food plants ................---......................--.........-----............--...-. -112
Descriptions--------..............--..-------------...-------..................--..-----..---------- 112
The egg --------------------------------------------------------------- 112
The larva .............................................................. 112
The pupa .............................................................. 113
The adult ....................--.............--............................. 113
Parasites ---------------------------------------------............................................... .................... 114
Diseases .................................................................. 118
Remedies and preventive .................................................. 118





ILLUSTRATIONS.

PLATES.
Page.
PLATE XI. The alfalfa looper and its parasites. Fig. 1.-Cocoon cluster of
Apantles hyslopi. Fig. 2.-Cocoon of alfalfa looper (Autographa
gamma californica). Fig. 3.-Larva of alfalfa looper with
cocoon of Microplitis alaskensis. Fig. 4.-Pupa of alfalfa looper.
Fig. 5.-Adult alfalfa looper. Fig. 6.-Adult alfalfa looper at
rest ......................................................... 112
TEXT FIGURES.

FxG. 45. The alfalfa looper (Autographa gamma californica): Larva, dorsal and
lateral aspect s.................................................. 113
46. Rhogas autographs, a parasite of the alfalfa looper ..................... 115
47. Larval skin of alfalfa looper from which Rhogas autographs has issued. 115
48. Cocoons of alfalfa looper parasites: Microplitis sp., Sargaritis w'ebsteri,
Microplitis alaskenasis. --------------------------------------- 116
49. Apanteles hyslopi, a parasite of the alfalfa looper -.------------------............ 116
50. Plagia americana, a parasite of the alfalfa looper --....---................... 117
51. Phorocera aaundersii, a parasite of the alfalfa looper .................... 117
510960-Bull. 95, pt 7-12





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U7. S. D. A., B. B. Bul. 95, Part VII. Issued October 16, 1912.

S* PAPERS ON CEREAL AND FORAGE -INSECTS.


THE ALFALFA LOOPER IN THE PACIFIC NORTHWEST.
(Autographa gamma californica Speyer.)
By J. A. HYSLOP,
Agent and Expert.
INTRODUCTION.
The first record of this moth of economic importance is an un-
published note by Mr. Theodore Pergande1 made June 29, 1895,
wherein he records having received from Mr. E. W. Baker, of Grand
Junction, Colo., a few specimens of the larvae of a Plusia, determined
on the note as "Plusia gamma (?)," with the statement that the larvae
do much damage to the leaves and blossoms of alfalfa. Material was
not preserved, so actual specific determination is impossible. As
Plusia gamma L. is a European species, presumably it was P. gamma
californica Speyer, now known as Autographa gamma californica.
The depredations of this species have not as yet been sufficiently
serious to cause damage in the Palouse region of Washington and
Idaho, although its attacks on alfalfa and clover have attracted the
attention of many ranchers. The larvae are usually very numerous in
the early spring and gradually increase in numbers until the first
hay cutting, when they appear to reach the maximum. They do not
seem to be inconvenienced by the removal of the hay crop, but imme-
diately turn their attention to the young second growth, on which
larvae are to be found throughout the summer until the early frosts.
The alfalfa looper in this locality has been held in check by a
number of parasites and a disease, but any change in environmental
conditions which might tend to reduce the efficiency of these natural
checks or accelerate the reproduction of these moths would undoubt-
edly cause a serious outbreak, such as occurs periodically with the
highly parasitized white-marked tussock moth, Hemerocampa leu-
costigma S. & A. It does, however, offer an excellent illustration
of the statement, so often made, that many injurious insects are held
in check by their parasites. Such cases as the above justify the arti-


1Bureau of Entomology Notes, No. 6692.


109






ficial introduction of parasites as one of the efficient me i=
taken in the control of a serious pest.
That Autographa gamma californica may appear in
numbers is evidenced by one of the earliest biological reno
this species. A note in the Bureau of Entomology files,
Mr. Koebele1 in 1886, states that on the morning of April.
examined a mass of material collected from within an electric|
globe at Los Angeles, Cal. Of 4,161 moths examined, 2,011W::
Autographauz gamma californica. He further states that the
were- numerous on a variety of plants. In anticipation of'"
outbreak the biological notes and other data at hand in this offli
herewith published. *ii
DISTRIBUTION.
Specimens of this moth (Autographa gamma califmoai) i:n
United States National Museum were collected in Los Ani
County, Kern County, Placer, Alameda, and Fresno, Cal.; ..:
rado; Nevada; Seattle, Pullman, and Easton, Wash.; and ..j
Kaslo Creek, in British Columbia. Mr. T. H. Parks, of this :
has collected larva of this species at Cokeville, Wyo., and.:
Falls and Blackfoot, Idaho, in all cases feeding on alfalfa. 4

SEASONAL HISTORY. 1

This insect, in the Palouse region of Washington, passes the i
as hibernating pupa and probably also as the adult moth, `4
much-battered adults are to be seen early in the spring. Late it
and throughout June the adults are to be seen in the alfalfa a
clover, darting rapidly away when disturbed. They are actitl
bright sunlight, feeding on the nectar from the clover and ait
blossoms. The flight, though short, is very direct and so rapiP
to render the insect almost invisible. ""3
May 2, 1887, Mr. Koebele1 records observing one of these mnoth,
Alameda, Cal., ovipositing on Malva rotundifolia at 3 o'clock "i.d
afternoon. Definite data relative to the length of the egg stapi'
this species have not been obtained, though several female
were confined for that purpose. They fed greedily on sugar4
but refused to oviposit. However, Mr. E. 0. G. Kelly, o
bureau, captured a female of Autographa brassicce Riley in anna
field at Wellington, Kans., on October 27, 1909. This mofth
the following day, after laying eight eggs. These began hate
November 2 and were all hatched the next day. This li
egg stage of Autographa brassicew to seven days, and this is '"l
the time of incubation of the other species of this genus. ...
SBureau of Entomology Notes No. 95 K. Xii.


CEREAL





STHE ALFALFA LOOPER IN PACIFIC NORTHWEST. 111

Early in June the young larvae become numerous in the fields,
S walking very much as do geometrid larvae or "measuring worms."
This is due to the fact that the larvae have prolegs on only.the fifth,
sixth, and ninth abdominal segments. If disturbed they curl up
and drop to the ground, the older larvae lying there tightly curled
up and refusing to move when irritated, but larvae of the second and
third instars when touched alternately straighten out and curl up
very suddenly, thus jumping about spasmodically. The larvae while
young feed upon the epidermis of the leaves, skeletonizing them and
giving to the attacked plant a brownish appearance. The older
larvam-that is, after the third molt-eat from the edge of the leaf
toward the midrib, entirely consuming the leaves. The larval period
lasts about two weeks, there being five molts with periods of about
S three days elapsing between each. When ready to pupate the larva
spins a loose white silken cocoon (Pl. XI, fig. 2) among a number of
leaves, usually well up in the plants, incorporating two or three
leaves in its structure. The larva completes the cocoon in about half
a day and, at least in the case of specimens reared in our insectary,
pupates the day following that on which the cocoon is completed.
The length of the pupal stage of specimens reared in our laboratory
was very uniformly 10 or 11 days. Dr. H. G. Dyar1 gives 12 days
as the length of this period, and Mr. Koebele2 records the length of
the pupal stage as from 10 to 15 days. He gives an exact rearing
record wherein he mentions a larva collected at Piedmont, Cal.,
February 24, 1888, which pupated on March 5, the moth emerging
March 22, making a pupal period of 17 days. Dr. F. H. Chittenden,
of this bureau, gives from 6 to 22 days as the pupal period of a
closely related species, Autographa bra8siew.
Thus the time elapsing from egg laying until the adult emerges
covers a period of from 26 to 48 days, probably being about 30 days
in the Palouse country of Washington.
The first adults of the second generation appear in early July,
and adults continue quite numerous throughout this month, belated
individuals having been collected as late as August 3. There are
two generations, and probably three in the case of the earlier ap-
pearing individuals, and larva in all instars are to be found in the
field as late as the end of August, but these very late larvae probably
succumb during the winter.
Mr. T. H. Parks,.of this office, records finding the larvae of this
species about half grown in the alfalfa fields about Salt Lake City,
Utah, as early as May 22, in 1911. Larvae were found throughout
S June. The first pupa found in this locality was obtained on June 5
1 Entomologica Americana, vol. 6p. 14, 1890.
Bureau of Entomology Notes, No. 95 K.
SBureau of Entomology Notes, No. 389 K. -

V.....









ing an adult in his cages on July 7, and observed i hw,
alfalfa fields near the Salt Lake City Field .
On August 23 one of these moths was..: fond bnder :i4A
along a fencerow adjoining an alfalfa field near Salt L

FOOD PLANST&S ;
:: .. :..-* ; :. .,:iij

Mr. Koebele1 records the larva of this species as ...B"
bage, barley, and elder (Sambucus sp.) at Los
dock (Rumew sp.) at Piedmont,'2 Ca., and records l
female while ovipositing and also larvae while feedings:
rotundifolia at Alameda, Cal. We have collected the ^
reared adults from red clover, alfalfa, and garden peasW'at1
W ash ..,..

DESCRIPTIONS. 4

THE W O: A.. U: : . "
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Egg hemispherical, rounded at the base, the apex with a rou9va4
Finely creased vertically; color pale yellow." :, ;.
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THE LARVA.

First instar (?).-Body slender, pale creamy white, with long
head conspicuously large, shining black; thoracic legs blaekhh;; .......
of prolegs, situated on abdominal segments 5, 6, and 9, prolpgs oneoiw o
body. Length, 1.8 mm. . ......".
Second minstar.-Body segments 7 and 8 enlarged, 9 small; C iorit0i
marked with cream-colored longitudinal lines as follows: A dubdr4
very fine and wavy; a stigmatal line, broader, straight, sharply de .e. 1
and fading out ventrally; segments ornamented with traznverse" ow,, '
papillae bearing black hairs; head cream-color; thoracic legs su4
tips of claws ferruguinous. Length, 3 am. to 5 mm. :
Third instar.-Body papillae white, with black dots at base of hel
longitudinal lines in subdorsal space, the more dorsal one fine, el ...
and wavy, the middle one broad and indistinct, and the third oe*::1!.
fine as the first but less wavy; stigmata on first thoacic and f ,
abdominal segments, pale, with oval black margins, that on eighthk
segment much larger than others; mandibles pale reddish b .ron,;.'i.
series of six black dots arranged in a ventrally directed selr*'i^
base of the antennae. Length, 6 mm. to 9 mm. I : ....'. =
Fourth instar.-Body darker green, papilse In two." tanuiete
papillMa of one row alternating with those of te o other; headt giw:d
body, mandibles and palpi brownish; thoracic legs infubeate;.ii
of prolegs ferruginous-brown. Length, 10. mm. to 14 am.=
-------------------------------------------------- --- ,,.. ,, .. .. .... M I^
Bureau of Entomology Note, No. ...W5X :::::
'Bureau of Entomolog Notes, No. 463 1. X .
'E* ntomologina Anerifsna, vol.6,P. 14, L8b.
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Bul. 95, Part VII, Bureau of Entomology, U. S. Dept. of Agriculture.


4

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N.


a.m


THE ALFALFA LOOPER AND ITS PARASITES.
Fig. 1.-Cocoon cluster of Apanteles hyslopi. Fig. 2.-Cocoon of alfalfa looper (Autographa gamma
californica). Fig. 3.-Larva of alfalfa looper with cocoon of Microplitis alaskensis. Fig. 4.-Pupa
of alfalfa looper. Fig. 5.-Adult alfalfa looper. Fig. 6.-Adult alfalfa looper at rest. All enlarged.
(Original.)


PLATE X1.



















7









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4 !tsr, (fig. 45).-Body dark olive-green, dorsal edge of stigmatal line
ha1. a. almost black line which fades into the general body color dorsally;
l at green, mandibles and palpi brown, a black oblong patch on
:itrn of eye extending from near median line almost to base of
in-aecc legs almost black. Length, 21 mm. to 28 mm.
..' : THE PUPA.
ti p r o
7 n (Pl. XI, fig. 4.)
.:ij? "::: :*- : .... *" .. **..
id
S...depressed somewhat above the wing cases at back of the thorax, the
inent, the tongue case projecting below the wing cases, forming a round
over the first abdominal segment. The cremaster is short and blunt,
T::hooks.with which it is furnished are fastened in the silk of the cocoon.
seeos slightly creased. Color brownish-black, but paler at the joining of
e..V and between the abdominal joints. In occasional instances the whole
4K Psie."
isabove description of the larval stages of. this moth agrees in
i e with that published by Dr. H. G. Dyar1 for this species
allifornia. The larvae, however, are not constant in the matter
riMtolration. Adult
K4.::w.. were found with- ,
I the characters istic
markings, while
-l]ad. i .. the entire
sad black. Some
itiwere of the same i
I1-trTewn colorinthe- e-
Adngstar as in the
(PI WI. while others
i'"" .almost white. Fia. 45.-The alfalfa looper (Autographs gamma cali.-
ri hat we had the first fori.): a, Larva, dorsal aspect; b, same, lateral
ol g ioya as t aspect. Enlarged 21 diameters. (Original.)
.r is- only an as-
mption from the number of subsequent molts obtained. Dr. Dyar's
idieMWsiption of the pupa is used, as it agrees identically with those
kunad in the Northwest. The pupa is dark olive-green, with brown
k ings and pale intersegmental bands when first formed, but soon




^ j', l^,i:-:" . i^':"^ .. ... ;:.
Thi I es uniformly brown.
14<"' THE ADULT.2
..... *i, "(P l. XI, figs. 5, 6.)

following is a translation of Speyer's original description:
o. California males from Moschler's collections differ from the European
| "~p (which I can, however, only compare with native specimens) in the fol-
Potinuts" The color of the dorsal surface of the forewings is a clear,
s.a. gy, except the punctuation which is rose colored or rust colored;
10 ei. f0.1 t i.n all-the gwnma found here by me, and also in several dis-
N: 5 ::'.:.ii f t idA M W. .... ...
\1Val.. e, p. 14, 1S89.
.... t. t. t. p.4 1876 ; i : teaes Hy Edwards.
.. ... r : .. ... .. ... ... ...: ...
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The gamma mark is somewhat differently shaped: Both it. '|..
verge, thus cutting off a broader equilateral triangle, thriuWt.,
median border, between them. The outer arm of this figure form...
side an obtuse angle and is directed parallel with the hind edge (a.t..
while in the European species it is more basally directed. The lowi*k'
the gamma sign runs nearly horizontal. In this direction the bglek{& 0.
part, supported by the two outer arms, is more snout-shaped while in q.th
man forms this form is approximately a rectangular space, rounded
apex. The ring spot is surrounded by a whitish margin, elongate, and :
very obliquely basally. The posterior diagonal band runs from the
to the inner branch of the median (branch 2), not in a smooth curmf.t
gamma but in an unbroken straight line and is not so strongly curved :MK:|
opposite the lower arm of the gamma sign as in the latter. On th,.*
surface, as in the French forms, the wings are clear white with, s...
the forewings, sharp black mottlings. The remainder of the border at0
underside, as is also the color of the hind wings, is lighter colored tla
European forms. This form may be easily separated from moderately .'..;:
varieties in color and design by these important distinctions-the gamm i
and the posterior diagonal band. r|
Whether we have to do with a distinct species, a local variety, or *ii.....
an accidental variety, must be proved by more extensive comparishnL. : -
Specimens of gamma from the Atlantic States, where they are said to tbe fi.!
-enous by Ruhordem, Koch, and Grote, I have not yet seen. They aft,|
the californ4ica form is considered with them, spread over the whole notuka
hemisphere from Greenland to Abyssinia. They should be found even in: Nli
Holland [Australia], cf., my Geographical Distribution of the Butterfl4.:es<|
Germany, etc., Volume II, page 219. .:
. .. ... ... ,
PARASITES. 1
!, *.. '|.

This moth is severely parasitized. At the field laboratory i.
Pullman, Wash., we obtained five hymenopterous and two dipte i
parasites and observed a disease during the seasons of 1909 and ..1
On July 12, 1909, two small larvae of the alfalfa looper, meaurin i
about 14 mm. in length, had contracted to 8 anm., became turgid, qu4
hard, and changed to a rich ferruginous brown. On July 2: r
the same year two specimens of Rhogas autographia Vier. (fig. i4)
emerged. On close examination of this improvised puparium it 1
found to be almost entirely made up of the abdominal segments 7 to $
of the lepidopterous larva (see fig. 47). The thoracic and anterior- -iA
dominal segments 1 to 6 contract to form an almost black anna
cap over one end of the puparium, with the transparent head .
terminating this cap. Segment 13, bearing the anal prolegs,
nates the other end of the puparium and is also transparent
ments 9 and 10 each bear the transparent skin of their res .....
prolegs. The hair papillae on segments 7 to 10 are pale and".
elected in a darker elevated band around the middle of their rest,
segments. The adult in emerging gnaws a smooth, circular lh
through the dorsum of the eleventh and twelfth segments.





THE ALFALFA LOOPER IN PACIFIC NORTHWEST.


r On July 29, 1909, a larva was observed with a cocoon fastened
:Ixtwen the middle and anal prolegs (PI. XI, fig. 3). The moth
I8 larva was still alive, though unable to move from the cocoon, and died
Sthe following day. On August 1 an adult hymenopteron, Micro-



i.r


















Fl ae. 46.-Rhogas autographtr, a hymenopterous parasite of the pupal stage of the alfalfa
looper. Greatly enlarged. (Original.)
i:":..' ..: "









Splitia aas/ke nis Ashm., emerged from this cocoon. The cocoon
of this parasite (fig. 48, c) is pale green, 5 mm. long, cylindri-
p cally ovoid, and slightly pointed at the anterior end. In emerging

Soften remaining fastened to the co-
coon by a few threads. On August
12 another larva was found bearing
one of these cocoons, and on August A
14 adl adult parasite emerged.
i Microplitis n. sp., determined by
Mr. H. L. Viereck, was reared from
:the larvae of these moths on June 28, FIG. 47.-Larval skin of alfalfa looper
1910. This parasite spins a tan- from which Rhogas autographed has
-issued: a, Dorsal aspect; b, lateral
W.lored cocoon which measures 3.53 aspect. Enlarged 6 diameters. (Orig-
m,'im. tin length (fig. 48, a). ginl 5
9i18&rgaryiti webateri Vier. is one of the most numerous parasites of
I the alfalfa looper at Pullman, Wash. The first specimen obtained
Oxerged pn August 14,1909. The following year specimens emerged
Lf 1 ...........


115






116 PAPERS ON O-RUAL AND FORAGE IFSOl :.aK'ix

which is bluntly oval, mottled with brown, and 2xieaB ":'
in length.
On August 27 a dead larva of the alfalfa looper with:. ::
hymenopterous cocoons fastened to it (PL XI, fig. 1) w
in an alfalfa field in Puima .... il
The cocoons were enveloped
1"- white, silken ball 18 mm. in
.On August 29, 34 specimens of
I hys8lopi Vier. (fig. 49) emerged
U :,a a. mass.
lAmeloctonus n. sp., determined&: i
H. L. Viereck, was reared from iK.
$1 of this moth at Salt Lake City, .......
a 6 c 1911, by Mr. T. LH. Parks, of th"'
Fir.. 48.---Cocoons of alfalfa looper The cocoon of the parasite was .P.I
parasites: aL, MicropUtis ap.;
b, Srgaritis websteri,; M&sro- August 17, and the adult parasite m2uin0M1
plitis alaskensi. Enlarged 5 on August 23. "".
diameters. (Original.) .....
One of the alfalfa looper larvne il,
insectary rearing cages started to spin a cocoon on January U',
On examining the cocoon two days later it was found to
puparia of Plagia americana Van der Wulp, one entirely and ........
partly within the dried larval skin. On July 23 one adult engm

















Fie. 49.--Apastelea hyalopf, a hymenopterons' parasite of the alfalfa looper. ,'iM
..:r-c...--J-







enlarged. (Original.).

*L




and on either July 24 or 25 another -emerged (fig. 50). ezajBi
of these flies were reared, and the number that would ieg fc|
larva was always directly associated with the size. 6f.lielfimJ
very small larva in our cages produced one fly:-a n.edi...... .... .
two,, aJ
enlarged.: (OriginaL)






two, and a full-grown larva produced five of these parasitK:
*:*. .":: i i~l





THE ALFALFA LOOPER IN PACIFIC NORTHWEST.


i* wo specimens of a dipterous fly, Phorocera saundersii Will. (fig.
:;...-), were reared from a larva of the alfalfa looper on May 18, 1910.
k /


Cr


.. w. 50.-Plagia americana, a dipterous parasite of the alfalfa looper. Greatly enlarged.
(Original.)
S Mr. Koebele1 records having reared 14 parasitic flies from a single
; larva of this moth at Los Angeles; but as the material is not now
available, determination is impossible. These were probably not
flies but Hymenoptera and very likely Apanteles hyslopi Vier. On
"! !(


K


TNT ^


i@ Io. 51.-Phorocera saundersii a dipterous parasite of the alfalfa looper. Greatly
i. enlarged. (Original.)
":the same note he also records rearing two flies from a larva of this
a--noth at Alameda, Cal.
.'On. July 8, 1909, two ants (Formica rufa obs8curipes Forel) were
hmd at Pullman, Wash., dragging a young larva of this insect that
W alive and struggling.
SBureau of Entomology Notes, No. 95 K.


117




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118 PAPERS ON CEREAL ND FORAGB I SE....Bf 1'

Mr. T. H. Parks, of this office, also made a similar recoi t
Lake City, Utah, on August 16, 1911, wherein he observed 17al_
of large ants (Formica subpolita Mayr) dragging one of
grown larvae to their nest in a field of alfalfa. The larvi'
to free itself but was finally overcome and killed by the ante"J,
DISEASES.
Early in July, 1909, many of the larvae in our rearing...:....
Pullman, Wash., were killed by a disease. First, they b a
gish and contracted, and then turned dark brown, often being..'
to a black purulent mass. In other cases they became m.
Specimens of these diseased larvae were sent to Dr. Flora W.
son, Mycologist of the Bureau of Plant Industry, who rep q
that while she could find no fungi, the specimens were swar.ming w ,'"
bacteria. '
A note 'made by Mr. Theodore Pergande1 February 21, 4i
records a fungous disease (Botrytis rileyi), having been found p0"
sitic on Plu8ias brassiwe, by Mr. W. G. Farlow, of Cambridge,
REMEDIES AND PREVENTIVES...
ii ,, "I: "i:::: ; ,
Attention has already been called to the fact that in this spto
we have an illustration of the influence of natural enemies of ai
in protecting the interests of farmers by keeping the insect so Awl
duced in numbers as to prevent injury to his crops. So effetui
was this being done in the case of the present species as actually tu
prevent the conducting of experiments for warding off such injuries;
hence no recommendations can be given. The time may come, how-'
ever, when these natural enemies may themselves suffer reverses ad
temporarily fail to hold the pest in check; then the information hs@
given will become of the utmost importance as a basis for ex eri
ments with restraining measures.
1LBureau of Entomology Notes, No. 294. ....,,
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