Occurrence of Entomopathogenic Fungi and Parasitic Nematodes onSpodoptera frugiperda(Lepidoptera: Noctuidae) Larvae Collected in Central Chiapas, México

Abstract

Fall armyworm larvae (FAW), Spodoptera frugiperda (J. E. Smith) were collected from whorl-stage corn, Zea mays (L.), between the V 2 and V 4 stages, in 22 localities of Central, Chiapas, Mexico, called La Frailesca during late Jun 2009 to determine the occurrence of native entomopathogens and parasitic nematodes, and to determine the most parasitized instars. A total of 1,247 larvae were examined in search of native biological control agents. Overall total larval mortality was 16.36%. The percent larval mortality due to entomo- pathogens and parasitic nematodes was 12.99%. Hexamermis sp., probably albicans Siebold (Mermitha: Mermithidae) were isolated from 105 FAW larvae (8.42%) with highest incidence from the 4th, 5th, 6th and 3rd instars, respectively. A hyphomycete, Nomuraea rileyi Farlow (Samson), was recovered from 38 larvae (about 3.05% parasitism) with highest incidence in the 5th, 3rd, 4th, and 6th instars, respectively. Lowest percentage of FAW larval parasitism was caused by unidentified microsporidian or microsporidium (1.52%), infecting 19 larvae in the 6th, 5th and 3rd instars, respectively. First and 2nd instars did not show parasitism. This information is useful in designing future biological control programs.