, 6 - 
Cor i z i.i s Hyal i n us ( F . ) 
McKinney (60) reported in 193b' that preliminary cage tests at the 
Phoenix, Ariz., laboratory of the Bureau indicated that a dcrris dust 
mixture containing 1 percent of rotenone "..1th clay as a diluent "was 
effective in controlling the adults of £. hya l inus , which had been causing 
considerable damage to lettuce grown for seed in the Salt liver Valley of 
Arizona and in the Yuma Valley. This dust mixture, however, was not so 
effective against the nymphs as against the adults. 
Corizus sp. 
McKinney (61_) in 1940 reported that derris-sulfur-talc and paris 
groen.-sulftir-tp.lo dusts controlled Cori zus sp. in small experimental 
plots of letttu e being grown for seed at Phoenix, Ariz. In one test 
3 applications of a derris dust containing 0.5 percent of rotenone in a 
mixture of 1 't of sulfur to 3 parts of talc gave 94-percent control 
of the ad (■'.Its and 91-percent control of nymphs where there was an average 
of S57 nymphs and 221 adults per plant on the undustcd plots. In the 
same test a mixture containing 1 part of paris green to 4 parts of sulfur 
and 5 of talc gave 93-percent control of the adults and 91-porccnt con- 
trol of the nymphs. The derris-sulfur mixture was applied at the rate 
of 60 pounds per acre per application, and the paris green-sulfur mixture 
at the rate of 49 pounds. During the period of these tests there were 
decided increases in the infestations o: r nymphs and adults of Corizus sp. 
on the unbrcat d plots in the series. Applications at intervals of 5 
days cr loss may he necessary to combat rcinf ©station of the lettuce 
brought about by the influx of this plant hug from outside sources and 
the rapid rate of its development. 
Dasynus piperis China 
Van der Vecht (90) in 1935- reported that an infestation of this 
species on black pepper on the island of Banka v/as reduced to about 3 
percent with a oust containing 1.5 percent of rotenone and to about 6 
percent by spraying with a suspension containing 0.04 percent of rotenone. 
Dusts and sprays diluted to half these strengths failed to give satisfac- 
tory results. 
Leptoco risa acuta (Thunbg.) 
This insect did not thrive in captivity and proved unsatisfactory 
as a tes~ insect for spraying and dusting experiments with derris. -- 
Federated Malay States Department of Agriculture (23) in 1934. 
Leptocor i sa sp. . 
In Is insect on rice may be killed by spraying v r ith derris. --Van 
der Vecht (90) in 1C36. 
