square feet of lawn area, fcr the control of the hairy chinch bug in 
Connecticut . It vras recommended that the first "brood be treated, 
preferably in the younger nymphal stages, about the first week of June. 
In very heavy infestations a second application should be made the 
following week. The second brood should bo treated about August 10, and 
a second application, if necessary, should be made about August 20, As 
the hairy chinch bug is difficult to control satisfactorily, examinations 
should be made to determine the growth stage of the insect, so that the 
insecticide may be applied at the best time. 
Hau.de (38) in 1939 recommended a cube or dcrris dust (0.75 to 1 
percent rotenone) at 6 to 10 pounds per 1,000 square feet of lawn. The 
dust should be applied during the hottest part of the duy, and best 
results have been obtained by not watering it in. 
Blissus leucopterus (Say), the chinch bug 
The Kansas Agricultural Experiment Station ( 50 ) in 1934 reported 
that young chinch bugs on wheat in an experimental planting -..-pre con- 
trolled by an application of Derrisol. 
Richardson, Deonier, and Simantor (75) in 1957 reported tests of 
certair insecticides against the chinch bug. In laboratory tests pyre- 
thrum extract in dilute acetone solution was highly toxic en the basis 
of total pyrethrin content and about equal to derris extract when the 
concentration of the latter was expressed as rotenone. On the above- 
mentioned bases both pyrethrum extract and derris extract were much more 
toxic than rotenone. The latter was almost nontoxic to adults and fifth 
instars. There was no difference in toxicity between acetone and carbon 
tetrachloride extracts of derris. YJhen tested as a spray, rotenone 
was less effective in the field than in the laboratory, as were also the 
derris extracts. In the field powdered derris (5.7 percent rotenone) 
used as a dust against third and fourth insto.rs gave the following results 
Dosage per acre Estimated mortality in -— 
Pounds 2 hours 4 hours 24 hours 
Percent Percent Percent 
7.2 5 15 25 
25.1 10 25 75 
The approximate order of toxicity in the laboratory of the various 
materials based on the median lethal concentrations for the adults was 
as follows: Pyre thr ins = derris extract (based on rotenene content) > 
nicotine "> sodium-base laundry soap ^> other potassium and sodium soaps y 
piperidine kerosene-naphthalene emu Is 5 on ^> kerosene emulsion. Rotenone 
is not included because the toxicity data are insufficient, 
Nysiu s ericae (Schill.), the false chinch bug 
Derris-fuller' s- earth dusts (rotenone 0.5 and 1.0 percent) gave 
practically nc kill of this insect on turnips in the lower Rio Grande 
Valley. —Fenton (26) in 1936. 
