784 
Journal of Agricultural Research voi. xxx, no. 8 
Laboratory in the following plants: 
Egyptian lotus (Weiss, Riverton, N. 
J.); Nelumbo lutea (Wild.) Pers. (How¬ 
ell, South Bass Island, Ohio); Polyg¬ 
onum, lapathifolium L. (Craft, San¬ 
dusky, Ohio); Polygonum pennsyl- 
vanicum L. (Howell, Middle Bass 
Island, Ohio); rhubarb (G. A. Runner, 
Sandusky, Ohio). The rhubarb con¬ 
tained a great many larvae from the 
second to the fifth instars which were 
reared to adult moths. The rhubarb 
was badly damaged, entirely unfit for 
marketing. Just as the larvae of 
nubilalis in rhubarb eject gelatinous 
and gumlike castings from their bur¬ 
rows, so the larvae of penitalis feeding 
in the stems of the same plant push 
out of their tunnels similar exudations. 
The discovery of the larvae in rhubarb 
by Runner is apparently the first 
record for this species of economic 
note. F. W. Poos, Sandusky, Ohio, 
has since established beyond question 
the fact that the rhubarb in this case 
was not a host but a shelter plant. A 
large number of infested Nelumbo 
blooms were placed near the rhubarb 
plants. As these wilted the larvae 
deserted them for the rhubarb. Fur¬ 
thermore, Poos has been unable to 
rear the larvae on rhubarb and has 
likewise failed to find additional evi¬ 
dence that this species attacks rhubarb 
in the open. Vickery found the 
larvae of penitalis frequently in corn at 
Bay, Ohio, on September 13, 1921. 
These larvae were full grown and 
apparently were using the corn, as 
pointed out for ainsliei , as a place of 
shelter. 
The Nelumbo borer is known to 
occur from Maine south through New 
Jersey, Washington, D. C., Tennessee 
and Missouri to Texas, and north 
through Kansas, Illinois, and Ohio. 
Although Pyrausta penitalis has been 
collected in NewEngland, the writer was 
unable during 1920 and 1921 to locate 
an infestation of this insect and, con¬ 
sequently, it was not possible to observe 
it under field conditions. Larvae sent 
to the Arlington laboratory by various 
field men in Ohio emerged as moths in 
the insectary in 1921 over a period of 
18 days, from June 9 to June 27. An 
average of 14.7 days was spent in the 
pupal stage. Offspring from these 
moths brought through on Polygonum 
pennsylvanicum L. var. laevigatum Fer- 
nald were full grown larvae September 
10. Howell and Vickery in August, 
1921, found larvae commonly in all 
stages of development in Polygonum in 
northern Ohio. Apparently there is 
but one generation in Massachusetts. 
Poos finds three generations at San¬ 
dusky, Ohio. 
The larvae have much the same 
habits as P. nubilalis and P. ainsliei in 
that they mine out the pith columns 
and feed on the medulla of the plants 
they infest, extruding frass from their 
burrows. Usually they spend more 
time in the open after hatching from 
the eggs than either of the above men¬ 
tioned species, feeding on the leaf and 
flower buds, and the tender foliage. In 
confinement they have been observed 
to web together immature foliage and 
to feed therein for a considerable time 
prior to entering the stems of the plant. 
The larvae also appear to possess a 
greater silk-spinning ability than either 
nubilalis or ainsliei . When half grown, 
or before, they enter the plant and form 
definite burrows. While the larvae 
possess no particular body modifica¬ 
tion for aquatic life they are capable 
of remaining in water for days. In 
lotus stems they have been sub¬ 
merged for a month without apparent 
injury. Larvae on the surface film of 
water attain the sides of the vessel in 
which they are confined by convulsing 
the abdominal segments from side to 
side. Observers have noted that the 
larvae of this species are not to be 
found in lotus plants in the autumn, 
but in hollow reeds or other places of 
shelter on shore ( 2 ). To remain in the 
old lotus or Nelumbo plants as they 
collapse and fall into the water in the 
autumn, remaining submerged over the 
winter, apparently would not make for 
the welfare of the species. It was noted 
at Riverton, N. J., in 1918, that old 
lotus plants practically all disintegrate 
during the winter. 
Coquillett (J, p. 154) lists the follow¬ 
ing parasites of Pyrausta penitalis: 
Exorista vulgaris Fall.; Hypostena vari- 
abilis Coq.; Panzeria penitalis Coq.; 
Phorocera comstocki Will. 
Full-grown larvae of this species are 
larger and more robust than either 
Pyrausta nubilalis or P. ainsliei. The 
pupae are also larger but the adults are 
smaller than the former, almost equal¬ 
ing in size the moths of the latter. The 
larvae measure 22.5 mm. or 0.87 
inch in length, and are heavily pig¬ 
mented. They usually are brownish- 
black on the dorsum and white ven- 
trad. The head capsule is larger than 
in either of the above forms and has a 
mottled appearance, owing to the col¬ 
lection of the pigment in small regular 
areas, leaving the remainder of the 
chitin light colored. In ainsliei the 
pigmentation of the head is uniformly 
dark colored. However, in nubilalis 
specimens of the larvae can be found 
intermediate between ainsliei and peni¬ 
talis: in such cases the pigment collects 
into irregular blotches. Heinrich sepa- 
