Maternal age and egg weight affect offspring performance in the predatory stink bug Podisus nigrispinus

To investigate influences of maternal age and egg weight on developmental t ime and body weight of offspring in the Neotropical pentatomid Podisus nigr ispinus, a study was carried out using large (0.36 mg) and small (0.32 mg) eggs of young (two-week-old) females and large eggs of old (seven-week-old) females. Incubation period of eggs was influenced only by egg weight, i.e. small eggs took a relatively shorter time to hatch. Both maternal age and egg weight had significant effects on total nymphal and egg-to-adult develo pmental times. Overall, offspring of young parents had shorter developmenta l times. None of the developmental periods were significantly affected by s ex. No significant differences were found among various offspring groups fo r percentages of egg hatch, nymphal survival, and sex ratio. Variation of e gg weight in relation to the number of eggs per day observed within the fir st month of life suggests a trade-off between weight of individual eggs and oviposition rate. It is concluded that for mass production of the predator s in view of their use in augmentative biocontrol programmes, young parents (2-4 weeks old) should be preferred.