Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar
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

TaxonomyBrowse
Info
ImagesLinksBooksData

Species Cassida rubiginosa - Thistle Tortoise Beetle

Thistle Tortoise Beetle - Cassida rubiginosa Unknown Bug - Cassida rubiginosa Coelidia olitoria, maybe, as a larval instar - Cassida rubiginosa Thistle Tortoise Beetle - Cassida rubiginosa Cassida rubiginosa Cassida rubiginosa? - Cassida rubiginosa Thistle Tortoise Beetle - Cassida rubiginosa Cassida rubiginosa ? - Cassida rubiginosa
Classification
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 Chrysomeloidea (Long-horned and Leaf Beetles)
Family Chrysomelidae (Leaf Beetles)
Subfamily Cassidinae (Tortoise Beetles and the Hispines)
Tribe Cassidini (Tortoise Beetles)
Genus Cassida
Species rubiginosa (Thistle Tortoise Beetle)
Other Common Names
Bloody-nosed Beetle, Thistle Defoliating Beetle
Explanation of Names
Cassida rubiginosa Müller 1776
Latin rubiginosus 'rusty/rust-colored'; supposedly refers to the beetle's ability to secrete a reddish liquid from its head, giving rise to its other common name of Bloody-nosed Beetle [source: anon.]
Size
6-7.5 mm
Identification
Adult: dorsum green in live individuals, fading to brown/yellowish in dead specimens; small double depression in surface of each elytron midway along anterior margin, usually marked by two dark spots, or sometimes with more extensive dark shading; anterior margin of both elytra collectively forms a very shallow concave arc when viewed from above - shaped more like a rounded bracket than a brace bracket; medial and inner areas of each elytron covered with small punctures but not deeply pitted; venter completely black; femora black; tibiae and tarsi brown or brownish-orange
Larva: oval, brownish or greenish, with dark branched spines around perimeter, and a forked tail spine on which it accumulates moult skins and excrement held as a protective parasol over the insect's back
Range
n. US & Canada, native to the Palaearctic Region(1); accidentally introduced in PQ in 1901, and spread since east to NB, west to AB, and south to n. US(2); intentionally introduced to VA to control thistles [map:(3)]
Habitat
weedy fields and waste places where food plants grow
Season
larvae and adults may be present from spring through fall
Food
various Asteraceae, incl. thistle (Carduus, Cirsium, Onopordum) and knapweed (Centaurea) spp.(1)
Life Cycle
described in great detail in(2)
one generation per year; overwinters as an adult in soil litter; beginning in spring, up to 1,000 eggs are laid on the underside of leaves in cycles of approximately 6 weeks, with 7-week rests; adult life span is about 80 weeks, with an egg to adult developmental period of 6 weeks
Remarks
used in biological control of thistles, but the impact is usually restricted by parasitoids; not approved for biological control because it feeds on several native and economically important thistle species(4)
Internet References
Fact sheet - D.W. Pierce, WSU Extension (4)