Adult seed chalcid.
Alfalfa seed with chalcid emergence holes.
Seed chalcids are tiny wasps that develop as larvae inside individual seeds. Overwintered larvae pupate inside seeds around the end of April; adults fly from the middle of May until the end of June. Damage occurs during June, July and August. Alfalfa pods that are 8-9 days old are most attractive for oviposition. No satisfactory control exists for this tiny insect and insecticide applications are not recommended. Efforts at chemical control are usually ineffective because the oviposition period is of long duration compared to residual activity of products, which in turn have relatively short pre-harvest intervals.
Page last updated 10/29/2013 by J.P. Michaud.