Bean seed fly
flies lay eggs near the base of bean plants, and upon hatching, the larvae burrow into the soil and feed on the seeds and roots of young plants. Larvae [...] typically has a shiny black or dark brown body with clear wings. The larvae, on the other hand, are small white maggots that can be found near the base of affected [...] discolored. Thirdly, search for the presence of larvae. Small, white maggots near the base of affected bean plants are a clear sign of bean seed fly infestation