4 
Eggs are shown a little larger than natural at ¢ of figure 1, and much 
magnified at a and 4 of figure 2, c showing the sculpture. 
The larva.—The larvais a soft, whitish, grub-like caterpillar of nearly 
cylindrical form, with a small, dark head and a few very sparse hairs 
on each segment. lLarve in the earlier stages of growth are illus- 
trated by d, e, and f of figure 2. A full-grown larva is shown in profile 
within an open stem at figure 1, d, and the head and first two thoracic 
segments appear in figure 2 at g. Mature larvee measure about an inch 
(25 ™™ in length). In the District of Columbia full-grown larve, as 
already observed, occur as early as July 16; in New Jersey, later in 
July, and are to be found upon the vines in different stages in October; 
at Washington, as late as the second week of November. 
After attaining maturity the larve desert the stems and enter the 
earth, burying themselves to the depth of 1 or 2 inches, and form 
their cocoons, in which 
they transform to pupe. 
The cocoon (fig. 1, f) iscon- 
structed of silk and coated 
externally with fine parti- 
cles of earth, which adhere 
onaccount of somegummy 
secretion of the larva. 
The pupa or chrysalis 
(shown in profile at e, fig. 
1) measures about 2 inch 
Fig. 2.—Squash-vine borer ( Melittia satyriniformis): a, gg in leneth (16 mm), it is 
as seen from above; 5, same from the side, showing sculp- oa he 
ture; c, sculpture of egg, greatly enlarged; d, newiy hatched shining mahogany brown 
larva; e, half-grown larva; f, head of same from side; g jneolorand its head isorna- 
head of mature larva from above; a, 6, and c, much en- : P 
larged; d, e, f, and g, less enlarged (author’s illustration) . mented in front just above 
and between the eyes with 
a horn-like process. By means of this the pupa cuts its way out of 
one end of its cocoon and by the aid of the abdominal hook-like spines 
forces itself to the surface of the earth before transforming to adult. 
Number of generations.—The question of the number of generations 
produced annually in localities of different temperatures which this 
insect inhabits has been solved by actual observation, the results serv- 
ing to indicate that it is practically single-brooded on Long Island and 
northward; that there is a tendency to two broods in New Jersey, the 
moths in exceptional cases completing their transformations late in 
August or September; that in the latitude of the District of Columbia 
the species is partially double-brooded, a larger portion of the moths, 
we may assume, developing as a second generation here than in New 
Jersey; and that in the Gulf States this series is undoubtedly fully 
two-brooded. 
[Cir. 38] 
