Parasitoid complex of <i>Plutella xylostella</i> (L.) (Lepidoptera: Plutellidae) in cabbage (<i>Brassica oleracea</i> L.) ecosystem of Yamoussoukro, central Côte d'Ivoire

Abstract

This study investigates Plutella xylostella (L.) (Lepidoptera: Plutellidae), a major pest of cabbage (Brassica oleracea L.) cultivation in Côte d’Ivoire, and its associated parasitoid complex. Fieldwork was conducted in Yamoussoukro across two experimental sites, where P. xylostella larvae were collected and subsequently reared under laboratory conditions. Two primary parasitoids specific to P. xylostella were identified and described: Cotesia vestalis (Haliday) (Hymenoptera: Braconidae) and Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae). The field population dynamics of P. xylostella and its parasitoid cocoons were monitored. Field parasitism revealed that C. vestalis was the dominant species. Among 80 lepidopteran larvae collected, these two parasitoids accounted for 85% of total larval mortality, with C. vestalis and O. sokolowskii contributing 83% and 17% of the parasitism, respectively. The parasitism success of C. vestalis was significantly influenced by the host larval instar, whereas that of O. sokolowskii remained unaffected. These findings highlight the potential of these natural enemies, particularly C. vestalis, for integration into pest management (IPM) programs to reduce reliance on chemical pesticides.