Alfalfa Seed Chalcid
The adult female of the seed chalcid (length about one-eighth of an inch) has a needle-like structure used to insert eggs into immature alfalfa seeds. A single larva develops within each seed and destroys all contents, leaving only the seed coat.
If seed production is planned for the current season, alfalfa should be cut by May 15. Eliminate volunteer alfalfa along fence lines and roadsides by mowing or spraying with herbicides. Complete seed harvest by mid-August to avoid late season when the insect populations are highest. Do not store uncleaned seed through the winter as it may be infested with chalcids.
Additional information may be found in this newsletter article.
Please contact your local county extension office for current information.