Response to day-length, or photoperiod, is a gene-based trait that affects the mosquitoes seasonal life cycle. Bradshaw and Holzapfel find that these northern mosquitoes are becoming more like their southern cousins suggesting that a genetic change has occurred.
Other populations also seem to be adapting to the longer growing season brought on by global warming. British birds began egg laying nearly nine days earlier in 1995 than in 1971. British frogs began spawning almost ten days earlier in 1994 than 1978.
The greatest consequence of altering the breeding seasons of insects such as W. smithii is a "discordance between predator and prey" says Bradshaw. Altering the breeding season affects all the creatures that rely on W. smithii as a source of food.
The great tit, for example, feeds on the mosquito larvae. However, if the mosquitoes have already hatched the chicks will go hungry.
Bradshaw anticipates that other species are also evolving and adapting to the extended growing season. Bradshaw and Holzapfel hope to identify the gene associated with response to daylight and the genetic changes responsible for delaying dormancy.
If there is some good news, it is that W. smithii doesn't bite.
Watch continued television coverage of this event on National Geographic Today, only on the National Geographic Channel, 7 p.m. ET/PT in the United States. Click here to request it.
SOURCES AND RELATED WEB SITES