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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
are also in part individual, since specimens hatching the same day from 
the same egg cluster and kept in the same cage have been known to 
become adult as much as fourteen days apart. 
A tabulation (Table 2) of the lengths of the various developmental 
stages shown by the cage records of three seasons at Amherst, compared 
with the findings of Chittenden (1), p. 24, Weed & Conradi (5), p. 17-18, 
and Wadley (4), p. 419, is of interest as showing regional variations in 
the lengths of the different developmental stages. 
Table 2. Developmental Stages of Squash Bug in Different Localities 
Stage Washington, D. C. New Hampshire _Kansas Massachusetts 
Egg 
9-10 days 
11 days 
7-17 days 
13.7 days 
1st instar 
3 
3 
2.1—5.2 
3.3 
2d instar 
8-9 
9 
6.2—9.2 
6.6 
3d instar 
7-8 
8 
8.1-13 
6.6 
4th instar 
6 
7 
10 
6.4 
5th instar 
8 
9 
12 
16.6 
Total 
41-44 days 
47 days 
45.4-66.4 days 
53.2 days 
Control Measures 
Since the chief injury by squash bugs in Massachusetts seems to be 
that caused by the overwintered adult bugs and because the vines 
largely cover the ground by midsummer when spraying for the nymphs 
must be carried on, an effort has been made to find a material which will 
kill adult bugs without injuring the vines. The investigation has so 
far proved fruitless, but it may be of value to report the materials tried, 
and the results obtained. In each test several bugs were treated, placed 
on a fresh leaf under a lamp chimney covered with cheese cloth, and 
kept under observation for three days. 
Standard Insecticide (Lemon Oil Co., Baltimore, Md.) 1-16, (3) p. 166. 
Against adults—no effect. 
Sodium sulfide (3), p. 165. 
Against adults—no effect. 
Sulco-V. B. (Cook & Swan Co., New York City) 1920 1 sample, 1-25. 
This material which is a miscible oil, was partially effective against 4th instar 
nymphs. Adults, however, were unaffected, and the foliage was killed. 
Emulsion of CS 2 and liquid soap, equal parts. 
Apparently killed all instars and adults very rapidly but all revived within a 
few hours of the application. 
Linseed Oil Emulsion, 1-9, (3), p. 168. 
Against adults—no effect. 
Linseed Oil Emulsion, 1-9, plus Black-leaf “40”, 1-500. 
Against adults—no effect. 
x The year is given because the material called Sulco-V. B. differed markedly in its 
composition in 1920, 1921 and 1922. 
