Papers on insects affecting vegetable and truck crops

MISSING IMAGE

Material Information

Title:
Papers on insects affecting vegetable and truck crops
Physical Description:
Unknown
Creator:
Chittenden, F. H ( Frank Hurlbut ), 1858-1929
Marsh, H. O ( Harold Oscar ), 1885-1918
Publisher:
U.S. Dept. of Agriculture, Bureau of Entomology ( Washington, D.C )
Publication Date:

Record Information

Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029623034
oclc - 22539527
System ID:
AA00018915:00002

Full Text




4 9.6 ( !/2Vp'/
U. S. DEPARTMENT OF AGRICULTURE,
BUREAU OF ENTOMOLOGY- BULLETIN No. 127, Part I.
L. 0. HOWARD. Entomologist and Chief of Bureau


S PAPERS ON INSECTS AFFECTING VEGETABLES
AND TRUCK CROPS.


THE SPOTTED BEET WEBWORM.





BY

F. H. CHITTENDEN, Sc. D.,
In Charge of Truck ('rop and Stored Product ifnset Iivtestigalioats.


ISSUED MAY 31, 1913.


WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1913.





















BUREAU OF EVTOIOLOGY.


L. 0. HOWARD, Enlomologist and Chief of Iurcray.
C. L. MARLATT, Entmolrgiu i ami .4Atrling Chihf in .4b.qeuce of Chief;
R. S. CLIFTON, Exceitti'e A.ssi.itunl.
W. F. TASTET, Chief Clerrk.

F. H. CHITTENDEN, iii ch rifge of ruck crop and .torc d product in.er-l inrr.diafiowna.
A. D. HOPKINS, in chaige of forr-sl in.ert inrcstigatiois..
W. D. HUNTER, ini charge of southern field crop iniecl iremxligations.
F. M. WEBSTER, in chfirfir oif crreafl tinI forag, insect intre/sligations.
A. L. Qt'A.INrANCE. i l (tiagfgC uf Iccitlitotin fruit inse,! i-reCStigtlion..
E. F. PHILLIPS. in (harg(i of bcr culture.
D. M. ROGERS, ii ehltlge of pr.r'',vatig .spreud of imothl, field work.
ROLLA P. CURRI:, ii chirg" of rditori/a iarlork.
MABEL COLCORD, in r-lhatrgr of liiraarli.

TRUCK CROP ANDL STORI.ED PIROItrT INSECT INVI.STI'ATIONS.
F. H. CHITTENDEN. ih cI'ht!/.
C. H. POPENOF. WMi. B. PARK:R, M1. M. HI;H, It. O. .MARSH. JOHN E. GRAF,.
FRiD A. JOIINSTON. D. E. FINK. C. F. STAHiL, A. B. DU'CKETI, cuitoiiioogiwal
assistants.
I. 3. CONDIT, B. S. V'AILE, collaborators in Califoraiit.
HENRY N. ORD, collaborator in Oregon.
THOS. H. JONES. rollaborettor in Poj to Rico.
IA.RION T. VAN HORN. I'A.UTLINE M. JOIHNON, ANITA .31. BALLINUEB. CE'CILIA
Sism O, paii'pirator.s.
II-















CONTENTS.

Page.
Introductclory........................................................ ....-------------------------------------------------------.. 1
D e.,c.ripti e ................................................................ 1
The moth.................................-------------......................... -----------------------------------------.. 1
The e-g. .............................................................. 2
The larva .................... ......................................... 3
D isTrib iuti n .............................................................. 3
Notes on occutirrence .............. ......................................... 4
Attack o(in beets and ('hard ..........................................------ 4
Injury to ornamental plants ............................................. 5
Other record-, and notes .......-..................-.....--..........--........ 6
Associated insects ......................................................... 7
The yellow-necked flea-beetle (TDisonyc7a melli:olits Sayi .................--------------- 7
The spinach flea-beetle (Disonychaxantthoinel-tna Dalm.) ................. 8
The Hawaiian beet webworm (Hymeniafasciais Cram.)---------------.................. 9
Natural enem ie ................................- ............................ 9
Control ........................................---..-.......................... 10
Bibliography. ..........................-- ...-....-..... ......................... 11





I L L UST R A TIONS.


PLATES.
Page.
PLATE I. Swiss chard injured by the spotted beet webworm (TTiqimeria pr.rsper-
talis) ............................. ............. ................. 4
II Sugar beets showing injury from combined attack of spotted beet
webworm and spinach flea-beetle ............................... 4
Ill. Swiss chard in same row as shown in Plate I, not attacked by the
spotted beer webworm. but showing mild attack by the spinach
flea-beetle ...................-................----............ 4
IV. Fig I.-Male arid female moths of the spotted beet webworm. Fig.
2.-Moth of the Hawaiian beet webworm (Jlymi ia f'ascialis) ....... 8

TEXT F I;URE:..

Fii.. I The spotted beet webworm i llymenia perspecaolsi: .Moth, larva and
details .......................................................... 2
2. The Hawaiian beet webworm i'llyme n ia.fasrialis i: Wingvenation, show-
ing characters of genius; head and antenna ....................... 3
3. The spotted beet webworm i lqmenia perspatalis': External male
characters ....................................................... 3
78051--13 III













































Digitized b) Ie Inileinei Archive
in 2012 wilh lunding Irom
University ol Florida. Geoige A. Smalhers Libiaries wilh .uppoil from LYRASIS and lhe Sloan FouLindalnon


hllp. archiv.e.org deliails. riseI4unLii











T'. S P. A., B. E. But. 127. Part I.


T. C. & S. P. I. I., Mny 31, 1913.


PAPERS ON INSECTS AFFECTING VEGETABLE AND
TRUCK CROPS.


THE SPOTTED BEET WEBWORM.
(1tt lmciia p<'i: s'pe'<.tai.bi Hiilin.)
By F. H. CHITTF.NDEN. Sc. D.,
In ClniirqI" vof i1t,'l, ('ro ii nll l ifi I'Oll. Prodlcft Insect Iii r'lifluli j .

INTRODUCTORY.

The spotted beet webworm (H/neni;i, perspectalis Hiibn.) has at-
tracted the writer'. attention on two occasions from its occurrence on
beets in the District of Columbiai. It is a singular fact that it was
fir-t observed in 1905 and that its presence d(lid not again become no-
ticeaiible until after a lapse of seven years, or until 1912, when it became
a veritable pest. It may be classified both as an enemy to sugar beet,
because of its occurrence on that plant normally, and as an insect
injirio.us to ornamental plants in both the garden and greenhouse.
The lariva is at first sight rather plain, but on closer examination it is
seen to be distinctly and beautifully marked. The moth is also a
most beautiful creature and has often been found flying about the
Di.-trict of Columbia. The food plants which will be mentioned in
the pre-ent pa per probably do not by any means exhaust the list.

DESCRIPTIVE.

THE MOTH.

Hyi,,i-an perspectalis is a member of the family Pyralidse and sub-
faminilv Pyraustinw. according to Dr. Dyar'sclis, inflation. Ithasbeen
described under various synonyin, as follows: Spoladia animals
Guen.. .S. e.rportalis Guen., Zincken;a priiWorddia.s Ze7l., D,,.'mi
rhitif /i tis' Walw.. and Hymer ina piar'sh.sa'.;s Walk.
The genus (under the name Zinckenia) is characterized by Sir
George Hampson as follows:
Pallii upturned, the 2nd joint broadly scaled in front and not re;chuine vertex
of head, the 3rd well developed and acuni;ite; wauixillary ialp|ii long and fill-
formn ; frons rounded: .;i'tenn;e of male nearly simple. the base of shaft excieild,
1







INSECTS AFFECTING VEGETABLE AND TRUCK CHOPS.


1and a tuft if hair [risiugl fromu basil joint : tibiie with thle spurs long and nearly
equal. Fore wing with veins 3, 4. 5 from angle of cell; 7 well separated from
Q. s, t<4 which 1) is approximated. Hind wing with vein 3 from angle of cell;
-I. 5 aplJ'prosimated for a short distance; 6. 7 from upper angle, 7 anastomosing
with 8.
THlE EGG.

The egg was not seen by the writer owing to the lateness of the
.-eason when continuous work was begun. We therefore have to
depend upon the description furnished by Mr. Davis. He writes,
in substance, that the female deposits her eggs flat and singly on the
-tern of the plant near thle base. The egg is oval. 0.57 mm. by 0.82
mm., and being transparent pale green is quite conspicuous on the
plant. Its surface is slightly convex and covered with microscopical,
irregular polygonal areas appearing a., a netlike sculpture on the
Su rface.
Walker's description of the specie. under the name phrasibsalia
follw-v :
Female. Brown rather slender, whitish beneath. Palpi vertical, slightly


-;. ,r^
'**^- e
4 1'
e


6


FTG. 1.-Thb spotted heet wel-worm iHyncnva per.
*pc talii: u, MoTh b: b. larva. lateral view: r,
larva, rdon al view, bowingg characteristic mark
infs on head and juoini; d, abdominal jnint; c,
anal joint. o-(, Enlarge-d 1, e, more enlarged.
i(irig nal i


curved, rising higher than the
head: second joint slightly
fringed ; third lanceolate,
about half the length of the
second. Peitus pure white in
front. Abdomen extending a
little beyond the hind wings;
hind borders of the segments
white. Fore legs with brown
bands. Wings modern tely
broad, with a cupreous tinge;
markings white; fringe here
and there white. Fore wings
with the interior line slender,
nearly straight; exterior line
much interrupted, broad and
regular in front; reniform
nIairk represented by a tnians-
verse siihqunadrnte spot. Hind
wings with the exterior line


librnid. i-onplete, arttenuated hindward. Length of the body 4 lines: of the
wings 9 lilie .

Lems tecliiically. this moth may be described, in comparison with
the related HyIjl/ n:i f,.st-/;lis Cram..' as of very similar form and
having a similar pattern. The color is paler brown, inclining to
cinnatnon. Thlie white fasciae or bands are much less conspicuous,
especially the second band on the fore wing two-thirds from the
apex. The fascia on the hind wings is of different shape, not more
than half as wide as in the other species, and more irregular. The

See Bul. 100. I't. I, Buin. Ent.. I'. S. DIpt. Agr.. November 6, 1912.






THE SPOTTED BEET WEBWORM.


pattern i-, about as illustrated in figure 1, a. Tlie average wing ex-
panse is 20 mm.. while the :ody is S mni. long. The venation is as
shown in figure 2, and the external male character. are illustrated
in figure 3.
THE I.ARVA..

The larva f this species is, when nearly mature, subcylindrical
and somewhat depress-ed. When contracted it is about ten times as
long as it is wide. and when extended still longer. Thlie general
color i, green, brighter in the younger
individuals and paler just before "-
transfoin'nmtion. The head is prettily7
marked within purplishl dots, leaving a
white, longitudinal center thrioiugh
each half. The head is well divided,
thle two lubes meeting sonmewliat nar- ,.
rowlv. TIThe thoracic plate is of about -
thle same widtli as the head. having a
F IG. 2.-Venation of Hymenia fas-
black border with conspicuous tuber- ialis, showing characters of the
tle, clothlied witli rather long hairs, genus; head and antenna, lateral
view, at right. (After Hampson.)
Of these tubercles there are two con-
spicious pairs oi the first thoracic segment. with two others on each
side. The second tihiracic 'egnient is very similarly niuarkedl. Tlhe
abdominal .-eginieiits are marked with four tubercles on the dorsuin
and larger ones each side. The arrangement of the spots on the
anal segmentt is well shown in figure 1 at e. Th- location of all
tliese tubercles is well illustrated in figure 1,
1 the arlrangenient from above being shown at c
,land the lateral arrangement at b. The length
Eff ? of this larva when extended is about 20 mm.
When at rest, or retracted, it is considerably
Less. The width at the widest portion is about
2. -_. mm.
The pupa, unfortunately, was not pre-erved.
Fl:. 1.-E x t e r n n I
iI.hihc clial'rnCt'rlS of DISTRIBUTION.
illit ih of !ilhiI lia
pr-oiifefliili. GJreat.
I.* rnlarsd. lOi-ig- The d(listribuit i n accorded this species I)y Hamp-
inal 1 son is Nearctic. Neotropical,-Ethiopian, and Aus-
trailian regions." Nothing is known of the origin of the ,pecies,
and it is uncertain whether it comes from the Old or the New
Worhl, but it is obviously exotic and introduced into the United
States. As the known species are from Africa, this may indicate
the original habitat. The species is not known in Europe, but it
wil probably in time become cosmopolitan.







4 INSECTS AFFECTING VEGETABLE AND TRUCK CROPS.

The record of injurious occurrences includes only Brooklyn, N. Y.,
and Washington, D. C. Undoubtedly the species occurs in troubl-
some numbers in many localities, but no records are available.
Through the kindness of Dr. H. G. Dyar and from other sources
I alm enabled to furnish the following distribution:
W.isliiiingoii. D. C.. October 1. 1S179. (;ren;dla. British West Indies.
Kans;is. September. 1S72. St. Lucia. British West Indies
Oh io. Guatemala I Cockerell).
(;eorgia. Apifl. 1.ST7I. Costa Itica (Schaus).
litirricaue Mills, Tenn. (G. t;. Ainslie). Panama (Busck).
P.rownsville. Tex. I M1cMilhl). Venezuela.
Tryon. N. C., July 3, 1904 iW'. F. French Guiana.
Fiske 1. P'eru.
D.illas. Tex. iBolli. Rio de Janeiro. Brazil.
Texas tBelfrage). Newark. N. J.
Miami. Fla. ( Schalusi. Cub:i.
Pernambuco. Brazil i Koehelep. Sarawak. Borneo.
Oaxaca. Mexico. Central America.

NOTES ON OCCURRENCE.

.ATT.\( K ON REETS AN) CIARM).
October 1. 1905. the writer first observed this species in a small
colony on sugar beets, growing in the insectary, garden connected
with the Bureau of Entomology. The insect was studied at that time
with sufficient care to enable a drawing of the larva to be made, which
is presented herewith. The moth, however, was not reared because of
an acc ident which occurred to thlie rearing jar in the writer's absence.
September 30. 1912. after a lapse of seven years, this same species
w.,s again detected by the writer and readily recognized from the
drawing previously made. It was first noticed and caused consider-
ablet injury on Swist chard growing in the grounds of the Bureau of
Entomology. The infestation covered one-half of a row of chard,
where the damage wa, practically complete. Injury. however, was
oIIl)lic;itetl by another insect within which it was associated, the spin-
ach or beet flea-beetle (Donmrha xanthontimelrrwai Dalm.), which had
been injuriou-, to the same plants in an earlier and a later generation
'Ind wa, .s-,till at work throughout the time that the lepidopterous
l.arva was ob.-erved, and even later. The work of both species is illus-
trated in Plates I and II, while Plate III shows, for comparison, a
vihard plant which has been slightly infested but not injured. The
laIrge holes were made chiefly by the beetles earlier in the season, and
the blacker portions show where the larvme or caterpillars did their
grea test damage.
From the outset of attack it was noticed that larva were rarely
seen during the daytime and evidently were nocturnal or practically













*II'.


S
>1


SWISS CHARD INJURED BY THE SPOTTED BEET WEBWORM (HYMENIA PERSPECTALIS).
[Note complete breaking down of plant, its compared wit h ordinarAy injur bIy r by i' spinach flea-beetle ( )i.so'inye .r utoHof / l1.v ).
shOWIn in Plate IT.] (Original.)


NV P *1I




















03
-0











C





C


,'.






















S3
r-


3>

























SUGAR BEETS SHOWING INJURY FROM COMBINED ATTACK OF SPOTTED BEET WEBWORM AND SPINACH FLEA-BEETLEE. i ORIGINAL.)















"0















low %o
-o




















Ph





SWISS CHARD IN SAME Row AS SHOWN IN PLATE I, NOT ATTACKED BY THE SPOTTED BEET WEBWORM BUT SHOWING
MILD ATTACK BY THE SPINACH FLEA-BEETLE. (ORIGINAL.)








THE SPOTTED BEET WEBWORM.


so. and that they concealed tlieiu,,elves about the bases of the plants
near the roots and under portions of leaves or petioles which rested
on tlhe grouLind. This was especially noticeable at the time when the
larvr- were attaining their full growth.
Subhieqii.ntly, October 3. the writer, with Mr. A. B. Diuckett, found
larvae of this species at work on table and sugar beets. On tlhe sugar
beets similar injury to that on Swiss chard had been done, blut for
some reason the larval were scarce. The work was quite apparent.
however. On the table beets the larve looked considerably darker,
due to the darker food plant on which they fed. They were ob-
s-erved at this time in all stages of growth from the fir.,t tagss of the
larva to the last stage. The location of the chard and table and sugar
beets had much to do with the growth of the larva., the sun playing
an important part.
On a single leaf of sugar beet taken October 4 the larvae remained
in thle same position for about -24 hours. The leaf was small, and
after this period, a after capture. only v slight growth of the larvw could
be observed, especially in the caie of the .oillnger stages.
These latter were probably in the second stage. They were very
nearly white. shlOwin-r very feeble nmarking-.. They measure about
3.5 >mm. in length. In what appears to be the third stage the larvae
i,siumne decided marking.. lihut are not nearly so dark as in the next
stage. They are l,'ih'dlYv green in color, and measure about 10 mm.
in length.
In the la-t t;1jc thle l:1ir\;. jI. before pulpating. turn pale ;mnild
solinewhai Yellowi-li.
Thlie coc01)on l-, forlled inll difi'reLit ways-on the plant and on the
grLunild-ani id coverdl with iiiire or less welbing, and sometimes
with an abundlance (of biick ,,xcrulnent which naturally soon grows
dr\'.
IN J I RY TO ( IICN A MENTAL PLANTS.

On October (i. 1!912. the writer r observed at Iowa (Circle, Washing-
ton. D. C.. severe injiiry to foliage plants of the order Aimaranthacc-ii'.
The mobt seriously injured area was a large circle in one of the beds
at the west end of the park. The plants were practically ruined,
merely hanging together in .-hreds. Opportunity did not offer to ob-
tain the larva' because of the crowd of pedestrian., and others seated
in the immediate vicinity. On another plat wlher,- the plants did not
receive nearly so full sunlight the larve were found in more abun-
dance. but only half as much injury had been accomplished. It
is plain that thle first lot had motly matured and the second lot
were near maturity. The plant in question, on which the insects were
mo-t abundant, was Telaonthera cer.,icolo, or the Alternanthera of
florists.






INSECTS AFFECTING VEGETABLE AND TRUCK CROPS.


There were also bed. of the .Arhyranthes armniuatu of florists,
known botanically as fi'resine linden, which were slightly injured by
this pest. It wa-i noticed that the larvae, as in the case of attack to
otl her low-growing plants, rest chiefly during the daytime on the lower
leaves and near the roots.
()-tobler 7 the writer observed much injury to several plats of Alter-
nantliera onl the grounds of the Department of Agriculture, but larva.
were difficult to obtain until the much injured lower leaves were
noticed: thenn no trouble was experienced, Mr. Duckett easily taking
about a dozen. In this case, as in others, with the. exception of that
ait Iowa Circle. colonies of thle spinach flea-beetle (Disonyc/ha xantho-
',lIrna Dalni.) were present aniid had been responsible for the early
injury. When first collected the two species were in thlie proportion of
five of the flea-beetle to two of the webworm. but later the lepidop-
terous larvaw were found to be doing the greatest damage. A few
young larva? were observed at this time.
Cuit leaves of beets and refuse stems were placed near the affected
Swiss chard as decoys, with the result that many larvae were found,
oniome within the stems and some of them on the side nearest the
aroundd. Many were also found on and utinder leaves' which had
withered.
Larvae which transformed to pupa' October emerged as moths
October 25, or in 21 days. Larvae which transformed to pupae Octo-
ber 1-2 emerged on October 30, or in 18' days. One which pupated
October 16 emerged October 31, or in 15 days. showing the length of
the last generation of the season to vary between 15 and 21 days, ac-
cording to temperature. None of the moths which were kept for the
purpose deposited eggs. nor did any remain over as larvae, as in the
case of many related species in hibernation. Hence it is doubtful if
thi-, specie.-, really hibernates in the District of Columbia, and it may
be that the region is reached by moths which fly from more southern
places in warm days in spring or early summer. At any rate injury
lias., never been noticed until the autumn. One moth was captured by
the writer as late a-, December 10 in the insectary. It might have
emiergied from the plants there or obtained accee-s to the building from
the out.ide.
OTHER RECORDS AND NOTES.
The foregoing records have been made from the writer's personal
ob.servationu-. In looking over the notes of the Bureau of Ento-
iology a much earlier record was found, dated April 1, 1896, when
Mr. Theodore Pergande noticed large numbers of the moth flitting
about in the propagating house of the Department of Agriculture
tThis habiit of concealment on tho dried Iave- is a very common one among both beetles
;iiid ';Ittrpilli'-. Ius#. i'lii hit i inti ouin'la'na was observed in similar locations, even on
dried ,av'.-, growing high on the plants.





THE SPOTTED BEET WEBWORM.


anld was told by the gardener that thi, miotlli evident ly belonged to a
.siall larva which was doing great damage to the leave-, of several
varieties of Alternanthera grown in boxes and pot., in thle green-
house. It was also observed that the larvae worked mainly at night
and that they concealed themselves during the daytime between the
roots of these plants at thlie bottom of (lie pot.
November 27, 1909, Dr. II. T. Fernald sent specimen, of this .pe-
cies for identification that had been received from Cuba.
November 15. 1910. Mr. D. K. McMillan, while working under the
writer', direction at Brownsville. Tex.. collected the larvae of this
species on Amaranthus and beets in that vicinity. The larvae were
attacking the leaves and flowers of both plants and webbing the
leaves and stems. Moths were very numerous on December I of the
same year. a few larva: still being found on the food plants, men-
tioned. Parasites were reared from larva' taken November 15.
April 11. 1912., Prof. Glenn W. Herrick. of Cornell University,
Ithaca. N. Y.. sent specimens of the moth with report that they were
reared from larva' found very abundantly in a greenhouse in Brook-
lyn. N. Y.. and that they were especially bad on Alternanthera.
Mr. John June Davis has forestalled the writer in publishing an
article on this same species, which hlie term-n, the Alternanthera worm.
He records that in 1910 this specie, was found eating the foliage of
the variegated border plant Alternanthera. and state-, what the writer
has also noted, that if the larva, are numerous enough to attract at-
tention they usually defoliate the plant repeatedly as new shoots
and leaves put forth, thus ruining it for ornamental purposes and
sometimes killing it. The article includes descriptive matter, notes
on habits, and suggestions as to remedial measure-, among which
arsenicals, hand picking, and light traps are especially mentioned.

ASSOCIATED INSECTS.

THE YELLIW_--NECKED ELI.EA-BEETLE.'
( Di.on'I! ha n i'irllhit lli. S.ay.)

October 8. 1912. the writer observed, in a badly infested plat not
previously examined in Iowa Circle, Washington City. about 20 indi-
viduals of the yellow-necked flea-beetle (D;ot,'n-yt/t meri,'o/i.s- Say)
congregated in a space of less than a square foot. They were in a
warm place, the sunlight was strong, and hence they could all have
escaped, though they could have been captured that evening. The
writer captured enough specimens to be sure of the species,. although
this insect can be readily separated from .ra,1,/0ia1nri 11, in life some-
1 Set' also Bil. 82, Pt. II. Rut. Ent.. 1'. R. Dept .zr pp '9-:12, 1U09.






8 INSECTS AFFECTING VEGETABLE AND TRUCK CROPS.

what better than in dried specimens. It is singular that this park
should have been so badly infested by this species, while only one
individual could be found in a long search on thile grounds of the
Department of Agriculture. The difference in distance is not more
than 14 miles.
THE SPINACH FLEA-BEETLE.

(Di.sonyrha .raanthiiiiilana D ilm.)

During thle year 1912 beets as well as spinach grew very rapidly
in the District of Columbia during rainy days. succeeded by warmer
ones. but owing to press of other work the writer was unable to give
them and their insect enemies as much personal attention as they
deserved, and another reason was that the species involved, Disonycha
.,anth/rnmelansa Dalm.. has already been written up with considerable
care.
Nevertheless there is always something new to learn, as there will
be of all species, as long as we continue to observe them utinder dif-
ferent environments and atmospheric condition-. The table beets
grew so rapidly that in spite of the larva, and adults of the spinach
flea-beetle, which peppered them full of holes,"' they made consid-
erable progress.
The spinach began to die rapidly about the beginning of the third
week of June.and in four days nearly every plant appeared as if dying.
In addition to the spinach flea-beetle, the spinach aphis (Rhopalosi-
phumn dianthi or .lyzus perstier auct.) was also present, but, as
affirmed by Dr. Erwin F. Smith, who, with thle writer, examined
the plants June 25, there was no evidence of disease or of malnutri-
tion. If the plat of spinach had been a field, the plants would un-
doubtedly have perished, owing to the combined attack of the flea-
beetles and the aphides, and this in spite of the fact that the aphides
were being rapidly destroyed by ladybirds.
To determine thle extent or degree of injury, comparison was made
of a beet root taken from our experimental plat, which had been very
little affected by this flea-beetle, with another lot which had been
badly affected, with the result that it required nine of the affected
roots to equal the weight of one that was practically unaffected.
The !mall roots were picked out at random by the writer from the
place most badly affected, which was at the sunny end of the plat.
It should be mentioned in this connection that plants growing
where they were shaded by hliedge plants, were comparatively little
i affected by insects. This came observation has been made in connec-
tion with thile imported cabbage caterpillar (Pontia rape L.), which is
not disturbed by wasps when feeding in shady places.






BuL 127, Part I, Bureau of Entomology, U. S Dept. of Agriculture.


FIG. 1.-MOTHS OF THE SPOTTED BEET WEBWORM (HYMENIA
PERSPECTALIS), MALE ABOVE AND FEMALE BELOW. MUCH
ENLARGED. (ORIGINAL.)


FIG. 2.-MOTH OF THE HAWAIIAN BEET WEBWORM (HYMENIA
FASCIALIS). MUCH ENLARGED. (AFTER MARSH.)


UAl


PLATE IV.








THE SPOTTED BEET WEBWORM.


Evidently this and other specie, of flea-beetles, or at lea-t nimany of
them, are in the habit of feeding to some extent in sunshine as well
as in shade.
In regard to remedies for the spinach flea-beetle, while conducting
some experiments in July. 1912. F. H. O'Neill. student assistant.
spraying for cabbage butterflies and honey bees.' to see if sweetened
and poisoned substances would kill any of them, observed that a
mixture of arsenate of lead used at the rate of 6. 12, and 25 pounds,
and similar amounts of molasses, to 100 gallons of water, did not
destroy the butterflies or bees, but about 60 dead individuals of this
flea-beetle were counted beneath the radishes July 16. The flea-
beetles were not in particular evidence during these days; but they
had peppered "' the beets within the usual small hole, and must.
therefore, have been abundant about the roots of the plants and come
up to feed on the leaves, to their very swift undoing. It wa, not
expected that the poison would kill either the butterflies or the honey
bees which were present, and these were practically all unharmed.

TIE HAWAIIAN BEET WVEBWVORM.
(I! yt1 rilia fnfI 'iili" f'';.i:ll. I
In a single instance the Hawaiian beet webworm (Hy,?in',i fi''sc;,-
lis Cram.) was reared from Swiss chard with thle ,potted webworni
at Washington, D. C. Moths issued on October 7. The chard is, a
new food plant. The species is recorded by Marsh as attacking table
and sugar beets, stock beets or mangel-wurzels. and several species of
Amaranthus, Euxolus, purslane ( Port 0 ac( ole0area), cIICuLInbers, and
chenopodiaceous weeds. The moths of the two species are shown, for
comparison, in Plate IV.

NATURAL ENEMIES.

On several occasions during October the last two stages of the
nymph of the spined soldier-bug (Pod;.qius o,,ti.';iae;t,;s Say I were
observed attacking the lara' of the spotted beet webworm. This
was the only predaceous insect observed, although there are probably
several others.
The same is true of the parasitic enemies, a single one being noticed,
a small braconid, Hemiteles sp. (Chttn. No. 194-'). This latter
was reared October 7.
The very closely-related Hyinmenrtia fa eials has several parasites,
and the probabilities are that if the present species were studied more
carefully in other regions a number of other natural enemies would
SThese experiments were made at the request of torre




10 INSECTS AFFECTING VEGETABLE AND TRUCK CROPS.

be discovered. Undoubtedly also wasps of the genus Polistes, be-
sides Limneri'm hu utuniiensc Cram.. ('helomnus blackburni Cram., and
(' .ct,,'astti., /yincii', Vier.. enemies of 1. fascialis in Hawaii, will
attack this species in its larval condition.

CONTROL.
It is obvious from the notes on the occurrence of this insect that
injury was discovered too late for the application of insecticides. In
practically every case the larvae were in the last stage, the few younger
larvae merely indicating the exception to the rule. Such being the
case it was not p)Ossible to test any remedies whatever. It is inter-
esting to relate, however, in the case of Swiss chard, that many of the
plants. being able to withstand a considerable degree of cold, re-
covered and( put forth new leaves, practically a second crop of leaves
developing, and that the moths hatched from all larve and did not
deposit egg-. at least not in confinement. iWhat they would do under
natural conditions is not quite certain for this latitude.
In the case of the related Hawaiian beet webworm, Mr. H. 0. Marsh
has demonstrated that Paris green applied at the rate of 2 pounds
in 100 gallons of water (lid not burn beet foliage, and the same would
be true of chard and the ornamental l)lants which this species attacks.
Whale-oil soap at the rate of 8 pounds to 100 gallons of water is
iihlded, and serves as an effective adhesive agent or "' sticker," thus
enabling a more even distribution of the poison over the leaf surfaces.
In addition to Paris green. Mr. Marsh demonstrated that nicotine
sulphate, used at the rate of 1 fluid ounce to 4 ounces of whale-oil
.soap and 4 gallons of water, sprayed upon cabbage, resulted in the
destruction of other ,small and larger larva,. He expresses the belief
also, reasoning from analogy, that this formula, although not actually
tested on Hymenia larvT, would probably prove entirely effective.
Arsenate of lead and arsenite of zinc should both be tested for this
insect should it occur in numbers and an opportunity be afforded for
an early application of these poisons as sprays. The most important
item in the control of this insect is the detection of injury early in the
-:eason before actual damage i- accomplished. Among other remedies
fall plowing shouldd be practiced. It is unwise to grow susceptible
plants in the same locality in which this insect has been abundant
the previous season.
There is no proof as yet that as far north as the District of Colum-
bia this species will in the near future renew attack or become as bad
a pest as in 191"2. The possibility exists, however, and a close look-
out will be kept for its reappearance.






THE SPOTTED BEET WEBWORM.


BIBLIOGRAPHY.

1. HUBNER, JACOB.- SchMett. Eur.. Pyr., fig. 101, 1796. (Not seen.)
2. ZELLER. P. ('.-Leip. Micropterit in Caiffroruni holm, 1S54, pp. 55-57, 1S52.
Characteriziation of genus Zinckenia and description of pi imo,-diulh. n. sp.
3. GUENft, M. A.-Hist. Nat. inwcrtes. Deltoides et Pyralites. Paris, p. 2206, 1854.
Described as Spoladea Pi',sptetiflis from South America and North America.
Occurrence on Lilium aiiadcn.sc. Larva briefly described.
4. GUENftE, M. A.-Idem.
Described from Pernambuco, Brazil. as Spoladea animals n. sp. liDscri'tion as
Spoladefi cxporlalis n sp.. from New lHolland (Australia).
5. WALKER. FRANCIs.-Cat. Brit. Lepi). lHel., vol. 19, p. 932. ish.
Description as Drnsmiu rhiiianthali n. sp., from Sarawak, Borneo.
6. WALKERa. FRANCIS.-Cat. Brit. Lep. Het., vol. 19, p. 944. is..
Description as Hunicnifi phrasoiiisalis n. sp., from Rio de Janeiro. Brazil.
7. HAMPSON, SIR G. F.-Proc. Zool. Soc. Lond., p. 623, fig. 21 (fw.^ei'Ii.%), 1qi.!.
Description of genus: synonymy *ind references to species.
8. DAVIS. JOIIN JUNE.-In 27th Rept. State Eur. IlM., pp. li,3-lini. figs. 1i6-21.
1912.
General account, with notr- on habits and remedies.















ADDITIONAL COPIES of this publication
may be procured from the SLUPERrN rEND-
ENT OF DOCUMENTS, Government Printing
Office, Washington, D. C., at 5 cents per copy




UNIVERSITY OF FLORIDA
3 1262 08928 8236
,W..:ii kiEE
It

I
I

I
I




-A
,: -i i i i :i
%, !
I ".: ..