Sitona cylindricollis
Pest description and crop damage Adults are gray or brownish gray and about 0.25 inch long. Weevils feed on and notch foliage. Most severe damage is to seedling plants. Sweet clover is the primary host, but weevils also attack alfalfa and have been found on ladino clover.
Management-chemical control
- bifenthrin (Batallion 2EC, Brigade 2EC, Discipline 2EC) at 0.06 to 0.1 lb ai/A. REI 12 hr. Do not apply to blooming crop or allow to drift while bees are actively visiting bloom. Do not make more than 3 applications per crop year. Allow at least 21 days between treatments. Do not graze clover after applying. Do not cut treated clover for hay or forage. Do not use harvested seed for sprouting. No part of the treated field, including seed, seed screenings, hay, forage, or stubble, may be used for human or animal feed. Processed seed must be labeled. 24c SLN: Brigade 2EC, OR-070013 (expires 12/31/2023), ID-070009 (expires 12/31/24); Discipline 2EC, ID-040009 (expires 12/31/24). Idaho only.