Life Table Analysis for Immatures and Female Adults of the Predatory Beetle, Delphastus catalinae, Feeding on Whiteflies Under Three Constant Temperatures

Immature development and reproductive life history of Delphastus catalinae (Horn) (Coleoptera: Coccinellidae) feeding on Bemisia tabaci biotype B (Gennadius) (Homoptera: Aleyrodidae) (= B. argentifolii Bellows and Perring) immatures was studied at three constant temperatures: 22, 26 and 30 degrees C. Lower developmental threshold temperatures (T0) were estimated at 9 and 9.9 degrees C, for males and females, respectively. Female adults weighed slightly more than males (0.587 and 0.505 mg, respectively). As temperature increased from 22 to 30 degrees C, developmental time from eggs to eclosion of the adult declined from 24 to 15 days. Thermal units required for immature development was approximately 300 degree-days. Percentage egg hatch declined at increasing temperatures, but no significant effect of time was found. The intrinsic rate of increase, r, increased from 0.048 to 0.082 and doubling time decreased from 14.44 to 8.45 days as temperature increased from 22 to 26 degrees C. Mean daily fecundity was modeled as a function of time and temperature to create a 3-dimensional surface. Overall, Delphastus catalinae was found to perform better at 22 and 26 degrees C while 30 degrees C was detrimental to immature development and adult reproduction.