Research conducted in the West Indies suggests that local wildflower strips can contribute to melonworm control thought the natural recruitment of parasitoid wasps [Practice Abstract]
The study conducted by researchers at INRAE Guadeloupe found that wildflower strips support the recruitment and maintenance of parasitoid wasps in the field. Moreover, wildflower strips provide a favorable environment for parasitoid communities, with a steady increase in the number of parasitoids sampled over time. Wildflower strip promote the recruitment of a high diversity of parasitoid wasps including many species associated with the regulation of the melonworm (Diaphania hyalinata), which is the main cucurbit pest in Guadeloupe due to the defoliation it causes.
One of the aims was to evaluate the occurrence of parasitoid wasp species regulating Diaphania hyalinata in Guadeloupe. The trials were carried out from November to December 2023 and July to August 2024 at the KaruSmart experimental micro-farm. Additional trials were conducted from August to September 2024 on partner farms. In total, approximately 1000 larvae and pupae and 500 eggs of Diaphania hyalinata were collected in the fields and reared in the laboratory. This work led to the identification of several species of parasitoids that were using the crop pest as host.
The parasitism rate of eggs was close to 50%, with Trichogramma pretiosum as the only egg parasitoid recorded. The parasitism rate on larvae was about 12%, with Schoenlandella montserratensis as the dominant parasitoid. Six additional species emerged from Diaphania hyalinata larvae (Eiphosoma dentator, Conura ferruginea, Brachymeria ovata, Apanteles impiger, Trichospilus diatraeae and Aphanogmus fijiensis).
This visible evidence of parasitoids directly on their farms presents a unique opportunity to raise farmers’ awareness on the importance of conserving local entomofauna and increase acceptance of biological conservation practices, especially the reduction of pesticides use and the introduction of service plants in agro-systems to encourage the presence of auxiliaries or beneficial organisms.
Keywords: Horticulture, Low input farming, Stripcropping, Transdisciplinary research
Country: France (Guadeloupe)
