Corn silk fly Euxesta chavannei

Systematic position: The insect belongs to the order Diptera, family Ulidiidae. Euxesta chavannei has become an increasingly significant agricultural pest, particularly in regions where maize production is intensive and monoculture practices are common.

Host crops: This pest primarily targets maize (corn). The fly is highly attracted to the corn ears during the silking and grain-filling stages, using the silk as a pathway to access the developing kernels beneath the husk leaves.

Biology and life cycle: The life cycle involves egg-laying on the silks or inside the husk. Upon hatching, the larvae feed on the developing kernels. The duration of the life cycle is highly dependent on ambient temperatures, allowing the species to rapidly multiply during the warm growing season of the host crop.

Damage and economic impact: The primary damage occurs when larvae feed on the milky-stage kernels, leading to significant yield reduction. Furthermore, the larvae introduce opportunistic pathogens and fungi, which can cause ear rot, leading to further quality degradation and potential loss of the entire harvest during storage and transport.

Control measures: Management requires an integrated pest management (IPM) approach to minimize chemical reliance:

• Adopting crop rotation to disrupt the insect's life cycle.
• Deep tillage after harvest to bury pupae and reduce winter survival.
• Selecting corn hybrids with "tight" husks that physically prevent the fly from entering the ear.
• Timed applications of insecticides to protect the silks during the peak flight of adult flies.