Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
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Upcoming Events

Discussion of 2018 gathering

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa

Photos from the 2010 Workshop in Grinnell, Iowa

Photos from the 2009 gathering in Washington


Species Rhinocyllus conicus - Thistle Head Weevil

Thistle weevil - Rhinocyllus conicus unknown weevil - Rhinocyllus conicus Rhinocyllus conicus (Frölich) - Rhinocyllus conicus Rhinocyllus conicus? - Rhinocyllus conicus weevil on thistle - Rhinocyllus conicus ID help please - Rhinocyllus conicus ID help please - Rhinocyllus conicus ID help please - Rhinocyllus conicus
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Polyphaga (Water, Rove, Scarab, Long-horned, Leaf and Snout Beetles)
No Taxon (Series Cucujiformia)
Superfamily Curculionoidea (Snout and Bark Beetles)
Family Curculionidae (Snout and Bark Beetles)
Subfamily Lixinae
Tribe Rhinocyllini
Genus Rhinocyllus
Species conicus (Thistle Head Weevil)
Explanation of Names
Rhinocyllus conicus (Frölich 1792)
conicus (G). 'a pine cone' (1)
4-6.5 mm(2)

Det. M.A. Quinn, 2015
widely dist., except se US; native to w. Palaearctic (Mediterranean basin to c. Europe & Turkmenistan), introduced in N. Amer. for weed control(3)
mostly: May-Aug (BG data)
on thistles (Carduus, Cirsium spp.)(3); released in N. Amer. to combat the noxious musk thistle (Carduus nutans)
Life Cycle
Univoltine; overwinters as adult. Female lays 100-200 eggs. Larva develops in flower heads; images of various stages
Controversial biocontrol agent used against noxious thistles in the genera Carduus, Cirsium, Onopordum, and Silybum. First introduced to the US in 1969 and now widely established, the weevil was found to be very effective in reducing the spread of invasive thistles, but also prone to attack native Cirsium spp. No longer recommended; releases prohibited in many areas.(4)
See Also
No scar on mandible so not Entiminae. (R.S. Anderson, pers. comm. to MAQ)
Print References
Louda S.M., Kendall D., Connor J., Simberloff D. (1997) Ecological effects of an insect introduced for the biological control of weeds. Science 277: 1088-1090.
Rose K.E., Louda S.M., Rees M. (2005) Demographic and evolutionary impacts of native and invasive insect herbivores: a case study with Platte thistle, Cirsium canescens. Ecology 86: 453-465.
Internet References
Cornell Fact sheet (Kok YYYY)(4) [use with caution]