Alfalfa seed chalcid

Systematic position: The Alfalfa seed chalcid (Bruchophagus platypterus) is a member of the order Hymenoptera, family Eurytomidae. This species is recognized globally as a significant pest specifically targeting legume seed production.

Host plants: The primary host for this pest is alfalfa (Medicago sativa). It focuses almost exclusively on alfalfa seeds as the mandatory resource for its larval development, making it a severe economic threat to seed producers.

Biology and life cycle: The adult is a tiny, black wasp. The female uses an ovipositor to insert eggs directly into the developing seed. The larvae feed inside the seed, consuming the endosperm and embryo, then pupate within the shell, eventually emerging as adults through a circular exit hole.

Damage and economic impact: Damage is internal and often goes unnoticed until the seeds are harvested and cleaned. Infested seeds are hollow and light, leading to significant yield losses. In cases of high infestation, the quality of the alfalfa seed lot can be severely degraded, causing rejection of the commercial crop.

Protection measures:

• Prompt harvesting of the seed crop to prevent the emergence and spread of the second generation.
• Deep plowing or soil cultivation to bury the infested debris where larvae overwinter.
• Sanitation of fields and surrounding areas to reduce alternative breeding sites.
• Use of chemical control targeted at adult wasps during the initial flowering stage.