•70- 
A DDT aerosol produced excellent kills of the tarnished plant bug 
on potatoes •— Ditman (135) • 
A knapsack sprayer was used to apply a 20-? ere eat TOT spray five 
times on early potatoes and three times on late potatoes. Tarnished 
plant bugs were not serious*— -Gould (184 )* 
Lygus spp* 
Test 8 con duo ted in 1944 at Phoenix, Ari*», indicated that one appli- 
cation of a 4«5-peroent DDT dust produced results practioally as good as 
or better than two applications of pyrethrtm extract-sulfur dust previous- 
ly recommended for the oontrol of Lygus bugs on sugar beats grown for 
seed* DDT is very toxio to beneficial insects suoh as ladybeetles, lace- 
wings, and parasites which occur in beet fields and which are responsible 
for holding aphid infestations in cheok*— Hills (210) • 
Laboratory tests conduoted at Phoenix, Ariz*, indicated that 5 per- 
oent DDT and 1 peroent dinitro-o-creaol were equally as good as the py- 
rethrum- extraot sulfur dust recommended for Lygus control on seed beets, 
although somewhat slower in their action. Other tests showed that both 
sabadilla and DDT were effective against Lygus adults, primarily L. 
oblineatus (Say). The sabadilla killed much more rapidly, both a*t the 
20-percent and 5-percent strengths, than did the 3-percent DDT. DDT dusts 
containing sulfur gave somewhat better results than DDT in pyrophyllite* 
DDT produced the highest Lygus mortality of any of the materials tried in 
the field and produced no detrimental effect on the plants* Plots treat- 
ed with this material produced a better quality of seed than any plots 
treated with the pyrethrum extract-sulfur dust.— Hills and MoKinney (211) * 
In a field-plot test of three inseotioidal dusts on seed alfalfa 
in Utah, 10 percent of, DDT in pyrophyllite was found to be highly toxio 
to these bugs, effective for weeks after application, and definitely 
promising as a satisfactory control of Lygus bugs* DDT was outstandingly 
successful in accomplishing Ly^us contro 1 b ecau s e of its ability to re- 
main toxic throughout the period required for flowering and padding of 
the seed crop* One dusting of the alfalfa growth reduced and held the 
nymphs to negligible numbers* Sabadilla and pyrethrum dusts gave substan- 
tial population reductions, but with rapid hatching of eggs the popula- 
tion of nymphs was speedily rebuilt to menacing strength* The DDT resi- 
dues on samples of dusted alfalfa exceeded the DDT tolerance of 7 p.p.m., 
but in view of the high degree of Lygus control secured it seems likely 
that dosages can be reduced sufficiently to bring the DDT residues with- 
in the toleranoe and still maintain satisfactory Lygus control and eco- 
nomically profitable seed production.— Lleberman T^_45 ) ; also Packard (285 ). 
In preliminary tests with DDT favorable results were obtained in 
the oontrol of certain sucking bugs that oause distortion of peaches.— 
Baker and Porter (81). 
