-68- 
on May 11 and again on May 19; the DDT mixture -was applied on May 11. 
The results of the applications were recorded on June 1* The DDT dust 
gave 77 percent control and the pyrethrum dust 67 percent. Germination 
teste of seed produced on the experimental plots showed 65 percent of 
viable seed from the undusted plots, 89 percent from the pyrethrum plots, 
and 91 percent from the DDT plots*— White (573) * 
In tests on potato plants in western Nebraska, a S-peroent DDT dust 
and a spray of 4 pounds of 10-percent DDT in pyrophyllite per 100 gallons 
of water had no effect on the adults but greatly reduced the number of 
nymph b. —Hill (209) • 
Same as for Aceratagallla uhler i*- Tate et al* (342) * 
Same as for Lygus hesperue .— Ross (506 ) | Michelbacher et al. (257) • 
Lygus hesperus Blight, the western plant bug 
An experiment with BET in California was conducted in an alfalfa 
field whioh was heavily infested with Lygus hesperus aliiiough a few speci- 
mens of L* el i sua were present* On the basis of -the experiment, a 3- 
peroent "DD1? dust appears to be very effective in controlling Lygus bugs 
on alfalfa seed. The results are so promising that further and more ex- 
tensive work is strongly recommended* In this particular study a 2-aore 
plot in a 38-acre field was treated* For satisfactory control, two dust- 
ings appeared necessary* If, however, the entire field had been dusted, 
one treatment would probably have sufficed* This certainly would be true 
if the second dusting in the investigation was rendered necessary by 
large migrations of adult bugs from the undusted to the dusted area. The 
following points need further study* (l) Methods of application, (2) tim- 
ing of application, (3) rate of application, (4) concentration of material 
to use, (5) effect of the DDT dust on other insects, and (6) natural 
factors affecting the control of Lygus populations* Although DDT is ex- 
tremely promising for controlling Lygus bugs on alfalfa seed orops its 
use should not be recommended until further investigations substantiate 
the results of this season's study*— Michelbacher et al* (257) * 
Same as for L* elisus *— White (573) • 
See Chlorochroa sayi *-«ffelker (568 ) • 
Cotton plants lightly infested were dusted with 5-percent DDT dust 
(A-5) at the rate of 26 to 30 pounds per acre* After 24 hours no Lygus 
bugs were found on the plants*— Smith (324 ) * 
This bug on guayule succumbed readily to dusts containing 2 to 5 
percent of DDT and to emulsions containing from 0*15 to 0*3 percent of 
DDT*— Craighead and Brown (126) * 
