
-~ 19 . 
‘Mr. Ewing and assistants completed cage tests made during July and 
August with 5 hemipterous and 4 homopterous insects. Mr. Ewing says: 
"These tests were to determine whether or not each species of insect 
Studied caused damage to cotton plants and to note the type, intensity, 
etc., of the damage, if any. * * * Excellent results were secured, 
showing that Lygus pratensis L. and Adelphocoris rapidus Say caused se- 
vere injury to bolls and large squares. Psallus seriatus Reut. caused 
injury primarily to small squares, with an occasional large square show- 
ing slight damage." 
"Sweepings were made at weekly intervals" during August-"on 15 weed 
host plants and cotton to determine the populations of Psallus seriatus 
Reut., Lygus pratensis L., and Adelphocoris rapidus Say on their respec- 
tive host. plants," reports Mr. Ewing. "A total of 1,200 sweeps was made 
on croton with an average of 1,052.7 P. seriatus per 100 sweeps. * * * 
A total of 1,100 sweeps was made on Chamaecrista robusta with an average 
Of 126.9 A. rapidus per 100 sweeps. * * * This plant (C. robusta) is ‘by 
far the most important weed host plant of this insect at this season of 
the year. * * * Sweepings on cotton during August revealed a still fur- 
ther decrease of mirids on cotton since July. The predominating mirid in 
cotton during August in the vicinity of Tallulah was A. rapidus; however, 
in certain localities L. pratensis was still numerous enough to cause 
considerable damage." ai 
INSECTS AFFECTING MAN AND ANIMALS 
Encouraging results have been obtained by W. E. Dove and D. G. 
Hall, Charleston, S. C., with treatments designed to kill sand-fly larvae. 
A waste product known as "sumpage water," obtained during the process of 
creosoting pine timber, and consisting of water and pine sap impregnated 
with creosote oil, "gave a complete kill in dilutions of 1 to 1,500," re- 
ports Mr. Dove. "It gave approximately a 90 per cent kill in dilutions 
of 1 to 2,500, but required two hours or more. * * * We found that one 
part of crude carbolic acid to 20 parts of sumpage water gave a complete 
kill in ‘laboratory tests of 1 to 10,000. This product also gave us a 
kill on the larvae of Aedes aegypti L. in dilutions of 1 to 1,000,000. It 
was just as effective on larvae collected from the salt marshes and which 
we regarded as Aedes sollicitans Wlk. * * * In one instance the material 
was reached by a spring tide shortly after it was sprayed. This treatment 
gave us a kill which we estimate to be about 50 ver cent. On the second 
test with this larvicide, our experiment was not interfered with by the 
rise of the spring tide. Repeated collections from the latter area show 
that the larvicide is 95 to 96 per cent effective in destruction of the 
larvae." 
H. H. Stage, Portland, Oreg., reports that a "pyrethrum soap 
preparation was used to test its toxicity to mosquito larvae. A dilution 
of 1 to 10,000 killed (larvae) in 3 hours, 1 to 300,000 in 48 hours, and 
1 to 500,000 in 72 hours. It was claimed that a concentration of 1 
(part pyrethrum-soap) to 2,000,000 (parts) of water was toxic to mosquito 
larvae, but our tests showed that we could not get a 100 per cent kill 
at that dilution." 
