aR 
running as high as 7 to 8 per square foot in egg beds. Bee-fly and 
blister—beetle larvae were quite common, although not so abundant as in 
North Dakota. Given a relatively dry weather condition next June, . these 
heavily infested headlands of cornfield will prove a menace to the ad— 
joining crop and also to other fields in the immediate vicinity. The 
outbreak in 19335 will be much more localized, being confined. largely 
to these places, and generally speaking the grasshopper Situation sos 
been greatly mitigated." 
Sarcophagid flies aid control of grasshoppers in Sully County, 
S. Dak.--On the biological control of grasshoppers, Mr. Parker says: 
"Parasitism- by sarcophagid flies was quite prevalent, but of greater con— 
sequence in Sully County *** As high as 10 to 15 dead hoppers per square 
foot were found along the edges of cornfields, and in some fields from 5 
‘to 10 dead per linear foot of corn row were found. This greatly reduced 
Oviposition potential. When you consider causes other than weather, the 
greater part of the decimation of the grasshopper population, this year, 
in this part of the country was accomplished by the sarcophagid flies." 
COTTON INSECTS 
Sodium fluosilicate dust shows promise for control of cotton flea 
hopper.-—"A total of 109 cage toxicity tests were completed," by K. P. 
Ewing and assistants, Tallulah, La., "with adults of Psallus seriatus 
Reut. on croton and 72 with P. eerrauls nymphs on croton * * * Sodium 
fluosilicate stands at the top in percentage of mortality. of both adults 
and nymphs. Of the adults the mortality at the end of the fourth day 
was 90 per cent, and of the nymphs 77.3 per cent. Of the insecticides 
thus far experimented with that could be considered of practical value 
for field control, sodium fluosilicate is the aye) one that gives a els 
kill of both adults and nymphs." 
Rot *none found lethal to tarnished plant bug.—-G. L. Smith and as- 
sistants, Tallulah, report that "Derris root (rotenone) gave rather start— 
ling results (as an insecticide) in view of the previous experiments con- 
ducted with this material on other insects (than the boll weevil) here. 
The first series of four cage tests conducted with this material on ad- 
ults was in conjunction with four cages conducted with each of the four 
copper arsenites, potassium hexafluoaluminate, and sodium fluosilicate. 
It was found that 73.2 per cent of the insects in the cages dusted with 
derris root were killed at the time of the first reading, 5 hours after 
the dusting, while only 0.7 per cent were dead in the check cages. To 
eliminate the possibility of the host plant (Erigeron canadensis) , being 
a factor in producing the kill, two additional series of tests were con— 
ducted, using goldenrod and cotton as the host plants. In all the tests 
a@ comparatively high mortality resulted. The total mortality at the end 
of 4 days in the 17 cages on E. canadensis was 86.4 per cent; in the 9 

Sn Re ee ee ee 
cages on goldenrod it was 83.9 ner cent; and in the 5 cages on cotton, 
68.7 per cent." ‘ 

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