Accession Number : ADA220951

Title :   Efficacy of Various Bacillus sphaericus Formulations against Psorophora columbiae Larvae as Assessed in Small Rice Plots.

Descriptive Note : Interim rept. Apr-Dec 89,

Corporate Author : SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TX

Personal Author(s) : Bowles, David E. ; Meisch, Max V. ; Weathersbee, Allan A. ; Jones, Jim W. ; Efrid, Paul

Report Date : JAN 1990

Pagination or Media Count : 13

Abstract : Bacillus sphaericus formulations were evaluated against Psorophora columbiae larvae in small rice plots. All formulations tested provided excellent control (> 84%) for all rates tested at 2 days posttreatment. At 10 days posttreatment, fair control (> 70%) was recorded for ABG-6232 (0.184 kg/ha), ABG-6262; 27-242-BA (0.766 and 2.298 liters/ha), and ABG-6262; 29-293-BA (2.298 liters/ha). Low, inconsistent mortalities (< 66%) recorded at 7 days posttreatment are possibly the result of partial settling of B. sphaericus spores between days 2 and 7; the spores subsequently reentered the larval feeding zone following a heavy rainstorm between days 7 and 10. Control did not exceed 27% at 15 days posttreatment for any formulation tested. Application rates for all formulations tested had, in general, little relationship with observed mortality, and control levels often were greater at the lower dosages tested. Bacillus sphaericus provides an effective means for controlling Ps. columbiae, but additional research is needed to determine the lower limit of effective treatment dosages and spore persistence in the rice field environment. Keywords: Biological pest control. (KT)

Descriptors :   *BIOLOGICAL PEST CONTROL, *CULICIDAE, *LARVAE, CEREALS, CONTROL, DOSAGE, FORMULATIONS, LIMITATIONS, PLOTTING, RAIN, RATES, SPORES, STORMS.

Subject Categories : Ecology
      Agronomy, Horticulture and Aquiculture

Distribution Statement : APPROVED FOR PUBLIC RELEASE