Predatory Behavior and Life History of Tenuisvalvae notata (Coleoptera: Coccinellidae) Under Variable Prey Availability Conditions

Prey availability for predaceous insects can be uncertain in row crop ecosystems, requiring predators to employ flexible reproductive strategies to maintain their populations. In this study, we examined life history parameters and predatory behavior of the ladybeetle, Tenuisvalvae notata (Mulsant) (Coleoptera: Coccinellidae) under different conditions of prey availability. Females of T. notata exhibited a type III functional response when preying upon neonate striped mealybug [Ferrisia virgata Cockerell (Hemiptera: Pseudococcidae)] nymphs and a type II response when preying upon third instars and female adults. On average, T. notata females consumed 157.9 neonate nymphs, 3.6 third-instar nymphs and 2.2 adult females of F. virgata per day. When subjected to a one-day period of prey deprivation, T. notata females exhibited significant reductions in reproduction and survivorship. After 150 days of exposure 47, 13 and 20% of females were alive when fed daily or subjected to repeated one- or 2-day periods of prey deprivation, respectively. Prey consumption increased as a function of prey availability. Daily oviposition was observed for females fed daily, but a sharp reduction in egg production was observed under conditions of prey scarcity. These findings show that T. notata exhibits a positive response to prey availability preying upon the striped mealybug F. virgata.