New Records and Taxonomy of Mymaridae (Hymenoptera) Egg Parasitoids of Planthopper Pests in Rice Agroecosystems

Abstract

Members of the family Mymaridae (Hymenoptera), commonly known as fairyflies, are important egg parasitoids that contribute significantly to the natural biological control of planthopper pests in rice agroecosystems. Planthoppers are among the most destructive insect pests of rice, causing direct feeding damage and transmitting viral diseases that result in severe yield losses. Accurate taxonomic identification and documentation of parasitoid diversity are essential for understanding ecological interactions and improving biological control programs. The present study was conducted to investigate the diversity, taxonomy, and new distributional records of Mymaridae egg parasitoids associated with planthopper pests in rice-growing ecosystems. Field surveys were carried out in major rice cultivation areas, and parasitized planthopper eggs were collected from infested rice plants. Adult parasitoids emerging from host eggs were isolated and examined using morphological and taxonomic characteristics under stereomicroscopic observation. Selected specimens were further analyzed using molecular techniques to confirm species identity and phylogenetic relationships. The study resulted in the identification of several Mymaridae species associated with planthopper hosts, including new regional records that had not previously been documented in rice agroecosystems. Morphological and molecular analyses revealed considerable taxonomic diversity among the collected parasitoids, with some species exhibiting close similarity to previously described taxa while others showed distinct diagnostic characteristics. The identified parasitoids demonstrated a strong association with economically important planthopper species, indicating their potential role in suppressing pest populations under natural field conditions. The findings of this study contribute valuable information to the taxonomy, biodiversity, and distribution of Mymaridae parasitoids in rice ecosystems. The documentation of new records enhances current knowledge of parasitoid fauna and supports the development of sustainable biological control strategies for the management of planthopper pests in rice production systems.