Effect of a Formulation of<i>Anticarsia gemmatalis</i>(Lepidoptera: Noctuidae) Nuclear Polyhedrosis Virus on the Predator<i>Podisus nigrispinus</i>(Heteroptera: Pentatomidae: Asopinae), Using the Fertility Life Table Parameters

Abstract

Two experiments were carried out in the laboratory to evaluate the effect of a formulation of the nuclear polyhedrosis virus (NPV) of the velvetbean caterpillar, Anticarsia gemmatalis Hu bner (AgNPV), on the predator Podisus nigrispinus Dallas. In the rst experiment, predators were exclusively fed A. gemmatalis reared on articial diet, treated with one formulation of the AgNPV (infected prey) or with water (healthy prey) as the control. In the second experiment, an additional treatment was incorporated in which the articial diet was treated with an inactive (autoclaved) AgNPV formulation. The predators were fed on these exclusive prey during their entire lifespans for three or four consecutive generations, during the rst and second experiment, respectively. Daily observation of oviposition and mortality were performed to provide data for the construction of fertility life tables and to determine daily oviposition patterns and survival distribution curves. For both experiments, no adverse effects were observed in the rst generation. However, signicant effects in the predator population were observed throughout the subsequent generations, when the predators were fed with prey that fed on infective or inactivated AgNPV diet compared with the healthy prey. The adverse effects observed might be due to some inert components present in the commercial formulation, because the AgNPV has been demonstrated to be highly specic to Lepidoptera and neither does it replicate nor has any adverse effect on P. nigrispinus. The fertility life tables proved to be a good tool to measure the potential impact of biopesticides on nontarget population under laboratory conditions. RESUMO Dois experimentos foram realizados em condic o es de laborato rio para avaliar o efeito de uma formulac a o comercial de V rus da Poliedrose Nuclear da lagarta da soja, Anticarsia gemmatalis Hu bner (AgNPV) na biologia de Podisus nigrispinus Dallas. No primeiro experimento, os predadores foram alimentados exclusivamente com A. gemmatalis criadas em dieta articial, tratada com uma formulac a o de AgNPV (presa infectada) ou com a gua (presa sadia), como controle. No segundo experimento, foi incorporado um tratamento adicional no qual a dieta articial foi tratada com uma formulac a o de AgNPV inativada (autoclavada). Os predadores foram alimentados com essas presas exclusivas durante toda a vida por tre s ou quatro gerac o es consecutivas, durante o primeiro e o segundo experimentos, respectivamente. Observac o es dia rias da oviposic a o e mortalidade foram feitas para se obter dados para a construc a o de tabelas de vida de fertilidade e para determinar os padro es de oviposic a o dia ria e distribuic a o das curvas de sobrevive ncia. Para ambos os experimentos, na o foram observados efeitos adversos na primeira gerac a o. Contudo, efeitos signicativos sobre a populac a o do predador foram observados nas gerac o es subsequentes nos tratamentos com AgNPV ativo e inativado, mas na o com o controle. Os efeitos adversos observados poderiam ser atribuidos a componentes inertes presentes na formulac a o comercial do biopesticida, uma vez que o AgNPV tem demonstrado ser altamente seguro a organismos na o alvos