Unit 9: Alfalfa Insects

Alfalfa Weevil  Found throughout the U.S.  Damage done by larvae feeding on plant tips, new leaves, flowers  Can strip the entire plant  Damaged fields can appear whitish in color  Insecticides can control effectively Be cautious of withdrawal and cutting times

Unit 9: Alfalfa Insects  Ideal conditions Early first harvest  Weevil feed on new growth coming for 2 nd cutting  Crown buds  Can severely limit growth Late harvest  Feeds on regrowth  Can damage crop before going into dormancy  Can make crop more susceptible to winterkill

Unit 9: Alfalfa Insects Potato Leafhopper  Feeds by puncturing the leaves Causes yellowing of the plant  Usually not a problem w/ 1 st cut alfalfa due to life cycle  Can break cycle by cutting Leafhopper must have supply of succulent food to survive  Can be very damaging to new seedings  Very susceptible to insecticides, some resistant varieties

Unit 9: Alfalfa Insects Alfalfa Seed Chalcid  Can cause extensive damage to the seedling Adult deposits an egg on a developing seedling Hatched larvae can devour the entire seedling  Several generations/season  Late fall larvae overwinter in seeds and can reinfest the next crop  Mow/treat road ditches and perimeter for help w/ control

Unit 9: Alfalfa Insects  Heavy cleaning of seed alfalfa eliminates most problems Bug harbors inside seed Lighter weight seeds are removed