Abstract
The objective of this research was to evaluate the effect of the insect resistant soybean genotype IAC 17 on reproductive characteristics of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) females compared to the soybean insect susceptible genotype UFV 16. Treatments were: T1) females of P. nigrispinus fed on plants of the UFV 16 and Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) caterpillars reared on leaves of this variety; T2) females of P. nigrispinus fed on plants of the IAC 17 and A. gemmatalis caterpillars reared on leaves of this variety. Longevity of females, pre-oviposition, oviposition and pos-oviposition periods, number of eggs and egg masses/female, egg weight, interval between egg mass laying, number of eggs/egg mass, percentage of nymphs, number of nymphs/female and total number of prey killed/female of P. nigrispinus were evaluated. Most of the characteristics evaluated showed similar results between treatments, but the oviposition period was longer for females reared on the resistant genotype than on the susceptible one and the percentage of total females that laid eggs was lower on the IAC 17. Also, the resistant genotype caused higher mortality of P. nigrispinus females at the beginning of its adult stage and egg production by females of this predator was better spread along its adult stage with this resistant genotype. On the other hand, results suggest no effect of the resistant genotype on the offspring of this predator.
Highlights
Soybean culture in Brazil demands a considerable amount of chemical products for pest control, which can cause environmental impacts besides affecting non-target organisms (Zanuncio et al, 1998)
The objective of this work was to evaluate the effects of the resistant soybean IAC 17 on reproductive characteristics of P. nigrispinus fed on caterpillars of A. gemmatalis reared with leaves of this genotype compared to others reared with leaves of the susceptible soybean genotype Universidade Federal de Viçosa (UFV) 16
In spite of similar longevity (Table 1), P. nigrispinus female showed higher mortality at the beginning of the adult stage when associated with the resistant variety (Figure 1)
Summary
Soybean culture in Brazil demands a considerable amount of chemical products for pest control, which can cause environmental impacts besides affecting non-target organisms (Zanuncio et al, 1998). Biological control organisms are important for maintenance of populations of insect pests below economic levels in soybean fields. Among these organisms, Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) (Saavedra et al, 1997) is considered an important predator of Lepidoptera larvae associated to the soybean crop (Panizzi, 1990). Orr & Boethel (1986) showed that the soybean genotype PI 227687, resistant to insects, delays egg production of the predator Podisus maculiventris (Say) (Heteroptera: Pentatomidae) Adult longevity of this bug may be shorter and their fecundity and predation capacity could be lower on resistant plants. Kartohardjono & Heinrichs (1984) observed higher population reduction of Nilaparvata lugens (Stal) (Homoptera: Delphacidae) by the predators Cyrtorhinus lividipennis Reuter (Hemiptera: Miridae) and Microvelia douglasi atrolineata (Bergroth) (Hemiptera: Veleiidae) on susceptible rice plants compared to resistant ones. Orr & Boethel (1986) showed that the soybean genotype PI 227687, resistant to insects, delays egg production of the predator Podisus maculiventris (Say) (Heteroptera: Pentatomidae)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
