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(insect photographs)
Canada Thistle Insects
Canada Thistle Stem Weevil and Larvae
Ceutorhynchus litura

Ceutorhynchus litura, the Canada Thistle Stem Weevil attacks the young Canada thistle plants as they sprout from the soil in the early spring. The developing "litura" larvae internally mine the stem of the thistle plant as the shoot elongates during the summer. Fully developed larvae will exit the Canada thistle plant at the root crown causing multiple exit holes. Larvae will pupate in the soil and emerge as adults later in the summer. Adults will over winter in the soil, ready to attack the emerging Canada thistle the following spring. The adults are cold hardy and can tolerate wet spring snow storms without difficulty. Releases of 105 adults are available during July and August for $200.00.

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Biological Control of Weeds, Inc.
1418 Maple Drive • Bozeman, MT 59715
Phone 406-586-5111

Email: bugs@bio-control.com