Comparison of the life tables and predation rates of Harmonia dimidiata (F.) (Coleoptera: Coccinellidae) fed on Aphis gossypii Glover (Hemiptera: Aphididae) at different temperatures

The life histories and predation rates of the ladybird beetle Harmonia dimidiata (F.) were compared among beetles kept at 15, 20, and 25 degrees C. The beetles were fed on Aphis gossypii Glover and were maintained at 70 +/- 10% RH and a 14:10 (L:D) h photoperiod. According to the age-stage, two-sex life table, the net reproductive rates (R-0) were 147.4, 98.7, and 62.5 offspring for beetles kept at 15, 20, and 25 degrees C, respectively. Additionally, we employed both the jackknife and bootstrap techniques for estimating the means, variances, and standard errors of the population parameters. The sample means of R-0 and the other population parameters obtained using the bootstrap technique fit a normal distribution, but the jackknife technique generated biologically meaningless zero values for R-0. The net predation rates were 10963, 13050, and 7492 aphids for beetles kept at 15, 20, and 25 degrees C, respectively. For a comprehensive comparison of predation potential, we incorporated both the finite rate and the predation rate into the finite predation rate. When both the growth rate and the predation rate were considered, our results showed that H. dimidiata is a more efficient biological control agent for A. gossypii at 20 and 25 degrees C than at 15 degrees C. (C) 2012 Elsevier Inc. All rights reserved.