Age-Dependent Fecundity of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) with Sublethal Doses of Gammacyhalothrin

摘要

Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) was exposed to gammacyhalothrin to study the stimulatory effect of low concentrations of this pyrethroid. The closes studied were 23.4375, 11.7188, 5.8594, 2.9297, 1.4648, 0.7324 mg.litre(-1) and water, as control. The third, fourth, and fifth instars P. nigrispinus were shorter with all the doses of this insecticide. The survival and longevity of this predator was highest with the lowest doses. The oviposition period of P. nigrispinus decreased as the doses increased. The lowest pre- and postoviposition periods were found with 11.7188 mg.litre(-1) of gammacyhalothrin. The dose 0.7324 mng.litre(-1) increased the clutch interval. The egg viability was similar between the treatments. The number of eggs per clutch, clutches per female, incubation period, and female body weight were not affected. The hormesis response could be used as a tool,for IPM programs, allowing the manipulating parameters of this predator in synergism with this insecticide.