418 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
Table I.—Sizes of Nymphs in Different Instars 
Stage 
Length of 
antennae 
Beginning of instar 
End of instar 
Length 
Width 
Length 
Width 
(The greatest width 
is about the middle 
of the abdomen) 
1 
2 
2 \ mm. 
1J mm. 
4 mm. 
2 
3 
3 mm. 
lj mm. 
2 mm. 
3 
4 
5 mm. 
2 mm. 
4 
4.5 to 5 
8 mm. 
3| mm. 
9? mm. 
4§ mm. 
5 
4 to 7 
9.5-10 
4'ito 5 mm. 
13-14.5 
7 mm. 
shape. Viewed from either side or the bottom it has a round triangular 
outline, being compressed from these three directions. 
Development 
Adults. Those bugs which pass the winter live as adults for nine 
to twelve months, while others may die the same season they are 
hatched, after an adult life of a few weeks. The adults fly readily and 
strongly in the spring when finding food plants, and in the fall when 
seeking winter quarters. Through the active season they seldom fly, 
but remain close to the food plants, feeding, mating and ovipositing. 
They are inactive at night or in cool cloudy weather. 
The squash bug has a reproductive period of several weeks; one 
female having deposited eggs for slightly over two months. Repro¬ 
ductive activities are limited to warm weather with temperatures of 
60° F. or over. Reproduction begins under favorable conditions five 
or six days after the bugs become adult, and continue until death or cool 
weather. A number of females have deposited an average of ten eggs 
a day throughout the reproductive period. The eggs are placed in 
clusters of a few to forty-five, averaging fifteen, usually on the under 
side of squash or pumpkin leaves, and sometimes on the upper side or 
on nearby objects. Each egg is glued firmly to the leaf. In 1918, 92 
per cent of all eggs were deposited between 8 a. m. and 5 p. m. 
Egg. The egg stage at Wichita varies from seven to nine days in 
hot weather, while egg periods of from ten to seventeen days are re¬ 
corded for cooler weather early and late in the season. Chittenden 
records the egg stage at Washington, D. C., as from eight to thirteen 
days, and Weed and Conradi state that in New Hampshire it varies 
from six to fifteen days. 
Nymphs. Nymphs are very gregarious and are greedy feeders. 
The smaller nymphs are found in bands on the under side of the leaves, 
while the larger nymphs frequent the stems, as do the adults. The 
nymphs scatter when their food plants die, but can probably not go 
far before succumbing to hunger. Pot cages were relied on for data 
on length of instars in individuals, while large numbers of nymphs 
