Reproductive characteristics of the predator Podisus nigrispinus fed with an insect resistant soybean variety

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.Index terms: Anticarsia gemmatalis, insects, reproduction, biological control, pest control. Características reprodutivas do predador Podisus nigrispinus alimentado com variedade de soja resistente a insetosResumo O objetivo desta pesquisa foi avaliar o efeito do genótipo IAC 17, resistente a insetos, nas características reprodutivas de fêmeas de Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae), utilizando o genótipo susceptível UFV 16 como controle. Os tratamentos foram: T1) fêmeas de P. nigrispinus alimentadas com plantas de UFV 16 e lagartas de Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae), criadas em folhas desta cultivar; T2) fêmeas de P. nigrispinus alimentadas com plantas de IAC 17, e lagartas de A. gemmatalis, criadas em folhas desta cultivar. Avaliou-se a longevidade das fêmeas, períodos de pré-oviposição, oviposição e pós-oviposição, número de ovos e de posturas/fêmea, peso dos ovos, intervalo entre posturas, número de ovos/postura, porcentagem de ovos eclodidos, número de ninfas/fêmea e número total de presas mortas/fêmea de P. nigrispinus. A maioria das características avaliadas mostrou resultados semelhantes entre tratamentos, exceto o período de oviposição, que foi mais longo para fêmeas criadas no genótipo resistente que no susceptí-vel, e a porcentagem de fêmeas que ovipositaram antes de morrer, que foi menor na IAC 17. Além disso, o genótipo IAC 17 causou maior mortalidade de fêmeas de P. nigrispinus no início de sua fase adulta e distribuição mais uniforme da produção de ovos ao longo do período adulto desse predado...

Podisus nigrispinus (Heteroptera: Pentatomidae) and IAC-24 Soybean Cultivar Are Compatible

“…The similar pre-oviposition period of P. nigrispinus is consistent with the one observed for this predator with caterpillars of A. gemmatalis in soybean cultivars IAC-17 and UFV-16 (Matos Neto et al, 2002) and for P. maculiventris with caterpillars of P. includens in PI 227687 and Davis soybean cultivars (Orr & Boethel, 1986). Moreover, the insect resistant IAC-17 soybean cultivar indirectly caused deleterious effects on the oviposition of P. nigrispinus with caterpillars of A. gemmatalis, indicating varying levels of resistance in soybean cultivars for this parameter (Matos Neto et al, 2002).…”

“…The similar number of eggs per female of P. nigrispinus shows the compatibility of the soybean cultivars IAC-24 (resistant to insects) and UFVS-2006 (susceptible to insects) for this predator that indirectly fed on these plants, as observed for the insect resistant IAC-17 soybean cultivar (357.79 ± 103.43 eggs) (Matos Neto et al, 2002) and for P. maculiventris that indirectly fed on insect resistant PI227687 soybean cultivar (Orr & Boethel, 1986). On the other hand, the number of eggs per female of the N. roseipennis predator was lower with caterpillars of P. includens in insect resistant PI229358 soybean cultivar (Pfannenstiel & Yeargan, 1998) (Zanuncio et al, 2000) and of P. nigrispinus (Lemos et al, 2001;Freitas et al, 2006), because predators of the stink bug feed on plants to increase their capacity of postures in habitats with lower prey availability (Coll & Guershon, 2002;Zanuncio et al, 2004;Lemos et al, 2009b).…”

“…Moreover, the insect resistant IAC-17 soybean cultivar indirectly caused deleterious effects on the oviposition of P. nigrispinus with caterpillars of A. gemmatalis, indicating varying levels of resistance in soybean cultivars for this parameter (Matos Neto et al, 2002). This was also reported for most small and large mines and mined leaves by Tuta absoluta Meyrick, 1917 (Lepidoptera: Gelechiidae) on 57 access and three commercial cultivars (Santa Clara, Moneymaker, and TOM-601) of Lycopersicon esculentum Mill.…”

“…The similar number of egg clutch and eggs per egg clutch by female of P. nigrispinus with caterpillars of A. gemmatalis in insect resistant IAC-24 soybean cultivar differs from the indirect deleterious effect of the IAC-17 soybean cultivar in the number of egg clutch and eggs per egg clutch by females of this predator (Matos Neto et al, 2002), but shows the compatibility of that cultivar in soybean farming systems. This finding corroborates the fact that the particularities of agricultural crops may affect the biological parameters of insects, as reported for the different impacts of Bemisia tabaci Gennadius, 1889 biotype B (Hemiptera: Aleyrodidae) on cultivars of Cucumis sativus L. (Cucurbitaceae).…”

“…(Solanaceae) in greenhouse, although those of HGB-674 and HGB-1497 were found to be promising for cultivars resistant to insects (Oliveira et al, 2009). The similar post-oviposition period of P. nigrispinus with caterpillars of A. gemmatalis in UFV-16 soybean cultivar is not consistent with the lowest value of the referred parameter for this predator with caterpillars of this prey in insect resistant IAC-17 soybean cultivar (Matos Neto et al, 2002). Nevertheless, this latter value would be interesting for the lower survival of females of P. nigripinus after its last egg clutch, which would reduce the number of infertile females in the field.…”