New Records of Hyperparasitoids (Hymenoptera: Ichneumonidae) Attacking Primary Parasitoids of Cereal Aphids

Abstract

New records of hyperparasitoids (Hymenoptera: Ichneumonidae) attacking primary parasitoids of cereal aphids were documented to enhance understanding of multitrophic interactions and parasitoid complex dynamics in cereal agroecosystems. Field surveys were conducted in major cereal-growing regions, and aphid mummies collected from infested plants were reared under laboratory conditions to obtain emerging primary parasitoids and associated hyperparasitoids. Specimens were identified based on morphological characters including wing venation, antennal segmentation, metasomal structure, and ovipositor morphology using standard taxonomic keys. Results revealed the occurrence of several ichneumonid hyperparasitoid species previously unreported from cereal aphid systems, indicating expanded host–parasitoid–hyperparasitoid associations. Hyperparasitism was observed primarily on aphid mummies parasitized by aphidiine braconids, with variation in attack rates across locations and seasons. Higher hyperparasitoid incidence was recorded in fields with dense aphid populations and well-established primary parasitoid activity, suggesting density-dependent interactions within the parasitoid community. Environmental conditions and crop stage also influenced hyperparasitoid abundance and emergence patterns. The study highlights the ecological complexity of cereal aphid biological control systems, where hyperparasitoids may modulate the effectiveness of primary parasitoids. These findings emphasize the need to consider higher trophic level interactions in integrated pest management programs and contribute to updated faunistic records of ichneumonid diversity in cereal ecosystems.