Contribution to the biological knowledge of Euplectrus platyhypenae (Hymenoptera: Eulophidae), a parasitoid of Spodoptera frugiperda (Lepidoptera: Noctuidae) in Argentina

Abstract

This report is the first record of Euplectrus platyhypenae Howard, (Hym.: Eulophidae) as a parasitoid of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), in Argentina. Because of the importance of this pest, the need of establishing a rational control method to eliminate the excessive use of pesticides, and the lack of information about the behavior and bionomics of this parasitoid in Argentina, we carried out laboratory studies in order to establish some relevant parameters of its life cycle. S. frugiperda larvae were obtained from laboratory cultures maintained on artificial diet; rearing and testing of the insects were done at 25 ± 2 ºC, 70-75% RH and 14L:10D photoperiod in a climatic chamber. Duration of the different stages, pre-ovipositional period, longevity, fertility, fecundity, localization of the egg masses, and sex ratio, were assessed. This species parasitized all instars, except the first. Larvae of the fifth or sixth instar of FAW are capable of removing a great proportion of the eggs and/or newly emerged parasite larvae. The fecundity of the parasitoid is low and the sex ratio always favored females and only males were produced fromunmated females. The low fecundity and extended pupal stage duration of E. platyhypenae on FAW suggest that it may not be a typical or preferred host.

En este estudio se cita por primera vez a Euplectrus platyhypenae Howard, (Hym.: Eulophidae) como un parasitoide del cogollero del maíz Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae), en Argentina. Debido a la falta de información sobre el comportamiento y bionomía de este parasitoide en Argentina, se realizaron estudios de laboratorio con la finalidad de establecer alguno de los parámetros relevantes del ciclo de vida de este parasitoide.