Comparative analysis of the demographic parameters of seven spotted ladybird beetle (Coleoptera: Coccinellidae) reared on various host aphid species

Abstract

The intrinsic rate of increase (<i>r</i>) was the highest in the <i>R. padi</i> predators (0.1946 per day), followed by the <i>S. graminum</i> (0.1435 per day), <i>S. avenae</i> (0.1400 per day), and <i>R. maidis</i> (0.1180 per day) predators. The differences in the net reproductive rate (<i>R</i> ₀) and the finite rate of increase (<i>λ</i>) when <i>C. septempunctata</i> was reared on the four aphid species were consistent with the <i>r</i> values. This trend was reversed for the mean generation time (<i>T</i>), which ranged from 29.02 days for the lady beetles reared on <i>R. padi</i> to 39.75 days for the lady beetles reared on <i>R. maidis</i>. Interestingly, <i>R. padi</i> was the most suitable host, while the congeneric <i>R. maidis</i> was the least suitable. The results of this study may be useful for future investigations regarding the ecological effects of predatory species and the mass-production of <i>C. septempunctata</i> in the laboratory for an augmentative release of an aphid predator.