Bangasternus fausti
      Coleoptera: Curculionidae
      Biological Control Agent Links
      Photo from slide show: Biological Control of Noxious Weeds, by Reeves Petrof.
      Bangasternus faustiOrigin: Bangasternus fausti was first introduced into the United States 1990 (1).  The insect came from Europe.  It was introduced to help the fight against spotted and diffuse knapweed.  Bangasternus fausti has been released in the states of California, Colorado, Idaho, Minnesota, Montana, Nebraska, Oregon, South Dakota, Washington, and Wyoming (2)
      Life Cycle:
      Egg stage: Bangasternus fausti eggs are laid on the seed head, stem, or leaflets from May to mid August, and are covered with a black shell.  They hatch in 8 to 12 days under acceptable conditions (1).
      Larval Stage: The larva tunnel into the stem or bur. After this, it tunnels into the seed head where it feeds (1).
      Pupal Stage: Happens inside of the seed head. There, the larva severely damages the seed head.  This stage ends around May (1).
      Adult Stage: This stage occurs from May to late July.  Bangasternus fausti adults are grayish black.  The insect is .14 to .16 inches in length (1). It has a blunt snout that appears to have been cut off (2).
      Type of Damage to Host: The Bangasternus fausti does the most damage to the spotted and defuse knapweed at the larva stage.   During the larva stage, the insect destroys the seed heads, causing the knapweed to spread less quickly (1). It also does damage to the knapweed's roots in the larva stage when it tunnels into the root of the plant.  This may cause it to die (1).
      Host impact: It does the most damage as larva by consuming 95% of the seeds in the seed head.  This decreases the population density and slows the spreading of spotted and diffuse knapweed (1).
      Favorable Release Habitats:  Bangasternus fausti likes land with hot dry summers, light winters, and above freezing temperatures (1).  The site should have enough space for the weevils for ten years of growth.  It also shouldn't have livestock and shouldn't be sprayed (2).
      Redistribution: In order to redistribute the insects, you should collect the infested seed heads.  You should allow the adults to emerge in the spring, or you can collect the egg laying females with a sweep net.  You should release the insects quickly in a field of knapweed.  The adults will survive a week in shipment if kept cool and are provided with ample food (1).
      Bibliography:
      1)   Rees, Normanl, et. al., Ed., Biological Control of Weeds in the West, Western Society of Weeds Science, in Cooperation With USDA ARS, Mt Department of Ag, and MT State Univ., Color World Printers, Bozeman Mt, Feb., 1996.

      2).   R.F. Lang.  Bangasternus fausti.  Biological Control, A Guide to Natural Enemies in North America, Cornell Univ., [Online] Available:
      http://www.nysaes.cornell.edu/ent/biocontrol/weedfeeders/bangasternus_fausti.html  Last modified April 18, 1997.

      3).   Breitenfeldt, Todd, Personal Interview, Biology Teacher, Whitehall Schools, Box 1109, Whitehall, MT 59759.  (406) 287-3862.  9-1-99.
      By: Clay Deming      Published by: Jessica Bell
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