Development and reproduction of a predatory stinkbug, Podisus nigrispinus in relation to two different prey types and environmental conditions

Abiotic factors, prey availability, prey type, and plant host actsimultaneously under field conditions. Their combined effects werepartially investigated for the predatory stinkbugPodisus nigrispinus(Dallas) (Heteroptera: Pentatomidae) preying on tomato leafminer (TLM)caterpillars Tuta absoluta (Meyrick)(Lepidoptera: Gelechiidae) (a preyfeeding on a plant host), and compared to yellow mealworm (YMW)Tenebrio molitor (Coleoptera: Tenebrionidae)pupae (a prey not feeding ona plant host). These experiments were carried out in the laboratory and inan open-sided greenhouse. In general, the environmental variationsbetween laboratory and open-sided greenhouse did not induce differencesin life history characteristics forP. nigrispinus feeding on the sameprey type. However, development and reproductionof P. nigrispinuswas greatly affected by prey type. Nymphal developmental times weresimilar between prey types under laboratory conditions; but were longer(and produced adults of lower body weight) when predators in theopen-sided greenhouse were fed on TLM compared with YMW. Mean mortalityduring the second instar was higher on both prey types in the open-sidedgreenhouse than in the laboratory. Adult emergencewas 38.5 and 50% inthe laboratory, and 32.5 and 48.6%in the open-sided greenhouse for bugsfed on TLM and YMW, respectively. Reproductive characteristics weresimilar for the different environmental conditions when the predator fed onthe same prey, but offspring production was greater for females fed on YMWcompared to females fed on TLM. These results suggest thatP. nigrispinus can adjust its performance accordingto the type of prey available, independently from environmentalvariations. It has the ability to survive on alternative prey,enabling it to maintain a presence in thetomato ecosystem until a primary pest species arrives.