Biology and Oviposition Behavior of Delia platura (Diptera: Anthomyiidae) on Seedlings of Different Leguminous Crops

Abstract

The seedcorn maggot, Delia platura, is an economically important pest causing serious damage to germinating seeds and young seedlings of leguminous crops in diverse agricultural systems. Laboratory and greenhouse experiments were conducted to investigate the biology, developmental characteristics, and oviposition behavior of D. platura on seedlings of different leguminous hosts. Adult flies were reared under controlled environmental conditions, and observations were made on developmental duration, survival, fecundity, and host preference for oviposition. Females deposited eggs predominantly near the base of seedlings and in moist organic substrates surrounding emerging plants. Oviposition preference varied significantly among leguminous crops, with certain hosts receiving higher egg deposition due to differences in seedling odor, moisture content, and tissue suitability. Larval feeding on germinating seeds and hypocotyl tissues caused severe injury, resulting in poor emergence, seedling wilting, and plant mortality. Development from egg to adult was successfully completed on all tested hosts, however, developmental duration, larval survival, and adult emergence rates differed according to crop species. Environmental conditions characterized by moderate temperature and high soil moisture favored egg hatchability and larval activity, enhancing infestation severity. Adult longevity and reproductive performance were also influenced by host quality and nutritional suitability of seedlings. Age-specific reproductive observations indicated that females exhibited peak oviposition during the early stages of adult life, followed by gradual decline in egg production. The biological traits and host selection behavior observed in the present study demonstrate the adaptive capacity of D. platura to exploit a range of leguminous crops under favorable environmental conditions.