Faunistic Survey and New Records of Pteromalidae (Hymenoptera) Parasitoids of Leafminer Flies on Vegetable Crops

Abstract

Extensive faunistic surveys were conducted in vegetable-growing regions to investigate the diversity and distribution of pteromalid parasitoids associated with leafminer fly infestations on economically important crops. Sampling was performed across multiple agroecological zones using direct collection of mined leaves, sweep netting, and laboratory rearing of parasitoids emerging from infested plant tissues. Several parasitoid species belonging to the family Pteromalidae were recovered from leafminer hosts attacking vegetable crops including tomato, cucumber, bean, eggplant, and leafy vegetables. Morphological identification based on antennal structure, wing venation, body sculpture, and metasomal characteristics revealed the presence of previously unrecorded species in the surveyed regions. Diagnostic taxonomic features were further supported through molecular characterization using mitochondrial cytochrome oxidase I (COI) gene sequencing, which confirmed phylogenetic placement within recognized pteromalid lineages. Parasitoid emergence varied according to host plant species, seasonal conditions, and leafminer population density. Higher parasitoid abundance was observed during moderate temperature periods coinciding with peak leafminer infestations, indicating strong synchronization between parasitoid activity and host availability. Certain parasitoid species exhibited broad host associations, while others demonstrated specificity toward particular leafminer taxa. Natural parasitism levels suggested an important ecological role of pteromalid parasitoids in suppressing leafminer populations under field conditions. Vegetable fields managed with reduced insecticide input supported greater parasitoid diversity and abundance compared with intensively treated production systems. The discovery of new regional records expands current knowledge of parasitoid biodiversity and highlights the significance of indigenous natural enemies in integrated pest management programs.