Saturday 24 November 2012

Two new species of Mosquito from the Eocene of Montana.

Mosquitoes are small Flies notorious for their habit of sucking blood. Only the females do this, the males tend to feed on pollen, nectar or plant sap. The larvae of Mosquitoes are aquatic carnivores, the adults emerging from the water to mate, lay eggs and die. This is clearly a successful lifestyle; Mosquitoes are found on every continent except Antarctica and have a fossil record dating back to the Middle Cretaceous, about 100 million years ago. 

In a paper published in the journal Zootaxa on 30 October 2012, Ralph Harbach of the Department of Life Sciences at the Natural History Museum in London and Dale Greenwalt of the Paleobiology Department at the National Museum of Natural History in Washington DC describe two new species of Mosquito from the early Eocene Kishenehn Formation of northern Montana.

Both new species are placed in the genus Culiseta, modern members of which tend to be restricted to cooler climates, but though modern Montana is rather cold, in the early Eocene it is thought to have been subtropical, with temperatures on average 15° higher than today. 

The first new species described is Culiseta kishenehn, which takes its name from the Kishenehn Formation, which in turn gets its name from the Kishenehn Creek. The name Kishenehn means 'no good' in the Kutenai language, but why it was applied to the creek is unclear. The species is named from eight adult specimens, of both sexes, the juveniles, eggs and pupae being unknown. Culiseta kishenehn was a 3 mm+ dark coloured Mosquito.

Culiseta kishenehn (top) male and (bottom) female. Harbach & Greenwalt (2012).

The second new species described is Culiseta lemniscatalemniscata meaning 'adorned with ribbons' in  Latin, the Insects having stripes on its abdomen which resemble ribbons. The species is named from two specimens, both adult females. 

Culiseta lemniscata, two female specimens. Arrows indicate position of lighter bands on the abdomen. Harbach & Greenwalt (2012).

Follow Sciency Thoughts on Facebook.