Dr. Bob Nowierski, and students Nick Wemen, and Kelly Hering.
For more info contact Bob at:
(406) 994-5080 or at nowierski@montana.edu
Or at the Department of Entomology at the University of Montana, Bozeman.


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Some of the biological control agents that these folks study and kindly talked about for us during the field trip are listed below:


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FLOWER-FEEDING BEETLE Brachypterolus pulicarius (Coleoptera: Nitidulidae) Flower-Feeding Beetles were accidentally introduced into the US in the early 1900's.  They are widely distributed across Northern United States and Canada.  They have one generation per year and over winter as an adult in plant litter.  Adults feed on flower buds, flowers, and young stems.  Larvae feed in flowers and young fruits.  Larval feeding may reduce seed production and dispersal but causes little impact in established stands, such as flowered yellow toadflax.

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Fruit-feeding weevils Gymnetron antirrhini and G. netum (Coleoptera: Curculionidae) The fruit-feeding weevils were accidentally introduced into the United States in the 1900's.  Scattered across the Northern United States and Canada, found more commonly on yellow toadflax than on Dalmatian toadflax, G. antirrhini are more common than G. netum.  Just like the flowering-feeding beetle, they have one generation per year and over winter as an adult in plant litter.  All the adults feed on flower buds and flowers.  Larvae feed within developing fruits, larval feeding may reduce seed production and dispersal but will have little impact in establishing toadflax stands.

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 Stem-boring weevil Mecinus janthinus (Coleoptera: Curculionidae) The stem-bording weevil was approved in 1995 in the United States to be released.  They were established in British Columbia, Alberta, and Montana.  Just like the other two above they have one generation per year.  It over winters as an adult within mined toadflax stems.  The larvae are usually killed in the toadflax stems.  In Canada they have shown the capability to kill Dalmatian toadflax plant and reduce infestation but, don't appear to be nearly as effective on yellow toadflax.  Adults feed on young shoot tips, and may reduce flowering when abundant.

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Dalmatian toadflax Linaria dalmatica (Scrophulariaceae) The Eurasian native plant Dalmatian toadflax was introduced into N. America in the early 1800's.  Now it is an exotic weed in at least 25 US states and 7 Canadian provinces.  It is primarily a pest in the Western North America.  Toadflax ranges in pastures, idle cropland, along highways or railroads, or on range land, and on the well-drained soils.  There is large infestations in Montana, Idaho, Washington, California, Oregon, Utah, Colorado, and Wyoming.   


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 Related subjects click here!!!!

Dalmatian Toadflax & Yellow Toadflax	Dalmatian Toadflax - A Toad on the Move	The Weed Hall of Shame	Dalmatian Toadflax Fact Sheet	Yellow toadflax
Brachypterolus pulicarius	Biological Control Agent Matrix: Dalmatian Toadflax Linaria dalmatica (L.) Miller	Ecology and Distribution of Linaria vulgaris	Biological Control of Weeds, Inc.	Principles of Biological Control

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The creators of this web page: Martina Iwen and Billy Kaufman.  1/30/01


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