=o 
posts for hibernating pea weevils, says: "A staphylinid beetle was found 
in one post, accompanied by some pieces of dead pea weevils. It was 
taken to the laboratory, confined in a test tube, and given pea weevils 
to eat. It ate 29 weevils in 8 days. * * * As this beetle is fre— 
quently found in the hibernating quarters of the pea weevil it is highly 
probable that it accounts for the destruction of many weevils." 
nn ee ee en ee 
Ohoe, Fresno, Calif., "has obtained," accrding to Perez Simmons, "sig 
nificant results in the first few comparative tests of glass and of 
celluloid life-history vials. Three female raisin moths in glass vials 
averaged 155 eggs each, while three females kept in celluloid vials 
laid an average of 221 eggs. The percentage of eggs which hatched in 
Celluloid vials was 60.1, as compared with 41.6 in glass vials, and the 
average incubation pericd was 4 days in celluloid vials and 4.2 in 
glass vials. The average temperature of the parallel tests was 80° F." 
TOXICOLOGY AND PHYSIOLOGY OF INSECTS 
Tests of derivatives of rotenone.~-Following tests made by C. E. F. 
Gersdorff and J. Davidson, of the Bureau of Chemistry and Soils, of 
"Sunburned" rotenone against goldfish, the greenhouse whitefly, and 
aphids, in which the toxicity of this form of rotenone was found to be 
markedly reduced, F. L. Campbell and W. L. Sullivan redoubled their ef- 
forts "to find a light-stable, highly toxic derivative of rotenone." Mr. 
Campbell says, "during the month (March) we tested and retested 10 com— 
pounds, in addition to rotenone. * * * All solutions were made at a con- 
centration of 1-to-5,000 in absolute alcohol. The solution to be spray-— 
ed was placed in a 25 cms’ graduated cylinder which was filled to the 
go Cm3 mark. The solution was sprayed out till the meniscus fell to the 
5 cms mark. * * * In each test 50 flies in a large screen-covered Petri 
dish were sprayed directly and were then exposed for 3 minutes to the 
settling fog of the spray. * * * Counts of dead and moribund flies were 
made at the end of 46 hours, instead of 48 hours, so that the cages could 
be used again on the day on which they were released. * * * the follow— 
ing average results were obtained in terms of per cent effect: Rotenone 
86.4 per cent (10 tests); dihydrorotenone 65.5 per cent (10 tests); 
rotenone hydrochloride 30.0 per cent (10 tests); acetyl rotenone 25.0 
mer cont {7 tests),.*.* .* We have great. confidence in the accuracy oF 
our results on rotenone, dihydrorotenone, rotenone hydrochloride, and 
acetyl rotenone and, hence, in the order of value we have assigned to 
them, * * * we feel sure that rotenone is more toxic than any of its 
derivatives that have yet been tested, and that dihydrorotenone is the 
most toxic of these derivatives, being almost as good as rotenone. * * * 
With the assurance that dihydrorotenone is the most promising derivative 
of rotenone, the Insecticide Division proceeded to study the effect of 
light on dihydrorotenone in comparison with its effect on rotenone. * * * 
Goldfish tests indicated that the rotenone powder was only about half 
as toxic as it was before exposure (to the light of a powerful carbon 
