Effects of Host Plants and Feeding Regimes on Selected Life History Characteristics of Podisus maculiventris (Say) (Heteroptera: Pentatomidae)

Effects of two different plants, potato, Solanum tuberosum L., and tomato, Lycopersicon esculentum Mill., and feeding regimes on selected life history characteristics of the predator Podisus maculiventris (Say) were investigated. Prey were third instar Colorado potato beetle, Leptinotarsa decemlineata (Say). Without access to prey, survivorship was initially higher for P. maculiventris provided either potato or tomato plants than for predators provided only water. However, no major difference in survivorship was detected after the 35th day of life. Predators provided only plants lived up to 50 days, and predators provided only water lived up to 60 days. Predators provided either plants or water lost weight initially but then maintained a low weight throughout the remainder of their lives. In contrast, P. maculiventris having no access to plants or water lost weight continually until death. When feeding on relatively few L. decemlineata, P. maculiventris maintained longevity but decreased reproduction. As the time between feedings of prey to predators increased, P. maculiventris laid fewer eggs, had lower body weights, and laid eggs later in life than those predators feeding on prey more frequently. These results support the concept of a trade-off between longevity and reproduction when P. maculiventris feeds on relatively few prey. This trade-off is not affected by the host plant upon which prey were reared. A tradeoff between longevity and reproduction is consistent with previous studies with P. maculiventris and may help to explain how this predator and others like it can maintain populations in fields where prey are not readily available.