Taxonomy, Morphology, and New Records of Encyrtidae (Hymenoptera) Parasitoids of Mealybugs on Fruit Trees

Abstract

Encyrtid parasitoids (Hymenoptera: Encyrtidae) are among the most effective biological control agents regulating mealybug populations in fruit tree ecosystems, yet their taxonomic diversity and host associations remain insufficiently documented in several agro-climatic regions. The present study aimed to investigate the taxonomy, morphological characteristics, and new distributional records of encyrtid parasitoids associated with mealybugs infesting major fruit crops. Field surveys were conducted in orchards of citrus, mango, guava, and pomegranate, and mealybug-infested plant parts were collected for laboratory rearing of parasitoids. Emerged adults were preserved and examined using stereomicroscopy and compound microscopy for detailed morphological characterization, focusing on diagnostic traits such as antennal structure, wing venation, mesosoma sculpture, and ovipositor length. Identification based on standard taxonomic keys revealed several species belonging to key genera including Anagyrus, Leptomastix, and Gyranusoidea. Multiple species were recorded for the first time from the surveyed region, representing new faunal records associated with mealybug hosts. Host association analysis indicated that encyrtid parasitoids were primarily linked with Planococcus and Phenacoccus species on fruit trees. Parasitism levels varied across orchards and were influenced by seasonal temperature and humidity conditions, with higher activity observed during moderate climatic periods. The study highlights significant morphological diversity within Encyrtidae and underscores their ecological importance in regulating mealybug populations. These findings expand the known biodiversity and distribution of encyrtid parasitoids in fruit agroecosystems and provide baseline data for their conservation and utilization in biological control programs. Overall, the results support the integration of encyrtid parasitoids into sustainable pest management strategies aimed at reducing chemical pesticide dependence in fruit tree production systems.