tests of calcium arsenate and derris sprays for the control of third and 
fourth instars of the alfalfa weevil in Utah. The sprays containing 0.015, 
0,0175, or 0,020 percent of rotencne vrere less effective than calcium arsen- 
ate at 2 pounds per acre. It va.^ concluded th?t a derris sprny containing 
0.020 percent of rotenone gives satisfactory control. 
Hynerq -punctata (FOj the clover leaf weeti'l 
Rockwood, in a tj'pewritteri report to the Division of Cereal and Forage 
Insect In^'estigations in 193^, stated tha.t a derris-infusorial-earth dust 
(1 percent of rotenone) killed v-eevils that had gathered on fence posts to 
escape flood waters, 
Listroderes oliliouus Klug, the vegetable weevil 
The Alabama Agricultural Experiment Station (7_)_ in IPIS reported on 
the toxicit;' tests vrith larvae of the vegetable vrp-evil. Sodium fluosilic-' te 
kil].ed 50 percent in I9 hours and 71 percent in 23 hours. Cube root killed 
57 percent in 23 hours and 71 percent in 36 hour^;. Other materials testod 
killed a much smaller percentage of the la.rvg-^ in the same period of time, 
except magnesium arsenate, which killed Jl percent in 36 hours. Toxicity 
tests with adult weevils resulted in the cube root and sulfur mixture (1:7), 
and sodium fluosilicatc , killing 100 percent within Ug hours. All the oth-r 
mat^ri'^ls test'^d wrre lesf; pff^-^ctivr, cryolite, and talc b^ing least toxic. 
Ka.-'rison ( igl ) in 1937 report-d on th--^ effici-'^ncy of rot-none compounds 
against larvae of the vegeta":'lr- weevil. In field ex-neri'^:rnts against the turnir 
aphid on turnips and mustard at th^- Bnton Rouge, La,, laboratory of th'~ Divis- 
ion of Truck Crop Insect Investigations of the Bureau it was incidrnt'-'lly 
shovrn th^t dust mixtures containing 1.0 pnrcent of rot^^nr^no, with enual parts 
of finely ground dusting sulfu?' and tobacco as th^ diluent, and derris sT^rnys 
containing aT^proxi-iately 0.0? percent of rotmon'-":, with or without alkylphonyl- 
br-nzrnesulfonic acid (lIlOOO) as a sr)roader and wetting agmt, w^ro effectiv.-^^ 
in protecting thr turnips and mustard from damage by larvae of Listroder'-^s 
obliouus . The check plots and also the plots tha*-. rec^iv-d applications of 
spra -s or dust mixtures, containing nicotine sulfat" vrwr'^ badly injured by th. 
larvF"-". Thr insecticide app] icp.tion'^ v^or'- begun when the -plants and thn i:a- 
frsting weevil Inrvee were sma.ll . They vrorn repeated at intrrvals of iH days, 
from ^ to 6 treat'Tients being applied. K. L. Cockerham and 0. I. Der>n, at th^ 
Biloxi, Miss., laboratory, foujid thn t sproys containing a->-^-nroximp,tely 0,02'^ 
percent of rotenone, with or without alkylph'-nylbenz.enesulf onic acid (l:6oo) 
as 0, snreader and wetting agent, vrcrr- not eff^ctivr against either quarter- 
grown or lo.rg'-r vegetable weevil larva'. Judging from thesf^ preliminn.ry ex- 
perimrnts, rot-^none compounds ma: br eff-'ctiv*^ against the v.-~gr tabl*- weevil 
when applird to plants infest<^d with nmaD.l larvrio, 
F. S. Cha^b-^rlin (75.) in 193^' report^-d that cubr— root povrder applied 
eitV'"r ns a du^t or in e i^w>^y gpve little control of vogotable vroevil lar"^''?V' 
in tobrcco plant b'ds. 
Cockerham and Deen (_^) in l''^3^ ronort^d in laboratory tests that a 
drrris-dust mixture containing 2 prrcint of rotenone vras effective against 
young larvae, causing g2,22 percent mortalit,)^. The l-p'^rcent-rotenone-du'^t 
mixtur*-' killed l.'-^J^,UU percent of the small larva.-.. The dust mixture contfiining 
