Biology and morphometrics of the immature stages of Epinotia aporema on artificial diet

Abstract

-The objective of this work was to establish a life table for the immature stages of Epinotia aporema, as part of a wider investigation on its biological control. Insects were reared on an artificial diet at 25±1ºC and a 16:8 (light:dark) hour photoperiod. For the identification of larval instars for the study of pathogen-insect interactions under laboratory conditions, head capsule widths (HCWs) were also determined. The egg incubation period was 4.13±0.30 days, larval stage took 11.64±0.49 days, and the development time of the pupal phase was sex-dependent with 8.51±0.69 days for the females and 9.41±0.65 days for the males. Five larval instars were identified.Index terms: Glycine max, bean shoot borer, cephalic capsule, laboratory rearing, larvae. Biologia e morfometria dos estágios imaturos de Epinotia aporema em dieta artificialResumo -O objetivo deste trabalho foi estabelecer uma tabela de vida para os estágios imaturos de Epinotia aporema, como parte de um estudo mais amplo para seu controle biológico. Os insetos foram criados em dieta artificial a 25±1ºC e 16:8 (luz:escuridão) horas de fotoperíodo. Para a identificação dos estágios larvais para estudos de interação inseto-patógeno em condições de laboratório, as larguras de cápsula cefálica também foram determinadas. O período de incubação dos ovos foi de 4,13±0,30 dias, o estágio larval foi de 11,64±0,49 dias, e o tempo de desenvolvimento das pupas dependeu do sexo, com 8,51±0,69 dias para as fêmeas e 9,41±0,65 dias para os machos. Foram identificados cinco estágios larvais.Termos para indexação: Glycine max, broca-das-axilas, cápsula cefálica, cria em laboratório, larvas.The bean shoot borer Epinotia (syn. Crocidosema) aporema Wals. (Lepidoptera: Tortricidae) is a major soybean pest in Argentina and other South-American countries (Morey, 1972; Corrêa & Smith, 1975;Pereyra et al. 1991;Liljesthröm et al. 2001). The available information on E. aporema life cycle is limited and mostly restricted to its occurrence and development on soybean crops under variable conditions (Morey, 1972;Iede & Foerster, 1982). Nevertheless, some basic aspects of the insect biology and morphometrics are still poorly documented.Traditionally, various chemical insecticides have been used against this moth, but the interest in more environmentally friendly biopesticides such as Bacillus thuringiensis and baculoviruses has increased in the past few years (Ibarra et al. 1992;Sciocco-Cap et al. 2001;Sauka et al. 2007). A recently discovered granulovirus of E. aporema (EpapGV) (Sciocco-Cap et al. 2001;Goldberg et al. 2002) has been shown as a promising biological control agent when ingested by early larval instars. This led to the establishment of a laboratory-reared insect colony supplied with artificial diet, both to perform pathogen-host interaction studies and for virus multiplication. The infection process of EpapGV and other pathogens is age dependent.The aim of this work was to construct a life table of E. aporema larvae and to turn possible a reliable identification ...

Characterization of a new Helicoverpa armigera nucleopolyhedrovirus variant causing epizootic on a previously unreported host, Helicoverpa gelotopoeon (Lepidoptera: Noctuidae)

“…Purified OBs were quantified in a Neubauer chamber and used for subsequent electron microscopy analysis, genetic studies and bioassays. A virus-free colony of H. gelotopoeon needed to carry out the experiments originated from a laboratory rearing facility (AgIdea S. A., Pergamino, Argentina) and was further reared on artificial diet (Arneodo et al, 2010) at the Instituto de Microbiología y Zoología Agrícola (CICVyA-INTA, Hurlingham, Argentina). Third-instar H. gelotopoeon larvae were infected through diet (formaldehyde free)-surface contamination (Ignoffo et al, 1983) and conserved at -20 °C for future studies and applications.…”

Detection and kinetic analysis of Epinotia aporema granulovirus in its lepidopteran host by real-time PCR

“…A virus-free colony of E. aporema maintained on an artificial diet in a rearing facility at 25 ± 1°C and a 16:8 h (L:D) photoperiod [1] provided the insects for all of the experiments. The virus used in this study was propagated in and purified from initially healthy larvae infected by diet surface contamination with the characterized EpapGV isolate as reported previously [6,19].…”

“…Starved (18 h), newly molted last (fifth)-instar larvae, identified by head capsule width and color [1], were used. Fifth-instar larvae were used in order to compare the results with previous microscopic observations and also because advanced stages are used for mass production of virus.…”