Susceptibility of Some Florida Chironomids and Mosquitoes to Various Formulations ofBacillus thuringiensis serovar. israelensis123

Abstract

Three wettable powders (WP), IPS-78, R-153-78, and ABG-6108, and one flowable concentrate (FC), SAN-402-WDC, of Bacillus thuringiensis serovar. israelensis de Barjac were tested in the laboratory against Ist-and 3rd-instar Glyptotendipes paripes Edwards, and 3rd-instar Chironomus crassicaudatus Malloch, C. decorus Johannsen, and Tanyt~rsus sPI? The B. thuringie'!Sis serovar. israelensis formulations also were tested agamst 3rd-ms~ar A~des aegyptl (L.), ~nd Culex qlfinquefasciatus Say. The R-153-78 was mvanably the most actIve preparatIOn against midges (LC = 4.56-9.84 ppm) and mosquitoes (LC90 = 0.13 and 0.24 ppm) followed by IPS-78 The LC90 of th~ midge species ranged from 4.56 to 47.02 ppm, whereas the same rang~ for the mosq~ltoes was 0.13 to 0.99 ppm. The Ist-instar G. paripes was 10-to 14-fold m~re suscepttble to B. thuringiensis serovar. israelensis than its 3rd instar. The mos-9Utto la~ae were 1~-to 75-fold more susceptible to the various B. thuringiensis serovar. lSraelensl~ preparatIOns than ~ere the midge larvae even at half the exposure time. The provIsIon o~ fo.od ~o the mldg~ and the mosquito larvae impaired the effectiveness of each B. thurmglensls serovar. lsrae/ensis formulation.