Chrysochus cobaltinus

Chrysochus cobaltinus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Chrysomelidae
Genus: Chrysochus
Species:
C. cobaltinus
Binomial name
Chrysochus cobaltinus
LeConte, 1857
Synonyms[2]

Chrysochus cobaltinus, the cobalt milkweed beetle or blue milkweed beetle, is a member of the diverse family of leaf beetles, Chrysomelidae. It is named after its cobalt-blue exoskeleton, which makes it easy to spot and distinguish, and its tendency to feed off milkweed plants. It occurs in the Western United States and British Columbia.[3]

These beetles use dogbane and milkweed plant species as their primary source of food. Both these plants contain toxic molecules known as cardenolides. C.cobaltinus beetles are resistant to cardenolide toxic effects and can further use them for their own protection against predators. By storing them in pronotal and elytra glands, they can utilize these toxins to their advantage and evolutionary benefit.[4]

These beetles participate in polygamous matings in which both female and male beetles mate with multiple partners. Females can particularly mate with three male beetles simultaneously. After the mating has occurred, males tend to stay mounted on the female's back for an average of 1.7 hours. This postcopulatory behavior has been attributed to increase the male's chance of producing his offspring with his paternal genes. It has been shown to prevent females from mating with other males (while the original male remains on her back) until the male removes himself.[5]

C.cobaltinus beetles have also been shown to partake in hybrid mating between its species and C.auratus (a sister species). In hybrid zones, both beetles live in close proximity which has led to introgression between these two species.[6]

  1. ^ a b c Marshall, T. A. (1864). "Corynodinorum Recensio". Zoological Journal of the Linnean Society. 8 (29): 24–50. doi:10.1111/j.1096-3642.1864.tb02004.x.
  2. ^ Horn, G. H. (1885). "Contributions to the Coleopterology of the United States (No 4)". Transactions of the American Entomological Society. 12: 128–162. doi:10.2307/25076454. JSTOR 25076454.
  3. ^ Cite error: The named reference :0 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference :2 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference :1 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference :3 was invoked but never defined (see the help page).