Wyeomyia smithii

Description

Wyeomyia smithii, the pitcher plant mosquito, is an inquiline mosquito that completes its pre-adult life cycle in the phytotelma—that is, the water contained by the purple pitcher plant, Sarracenia purpurea. In this microcommunity of bacteria, rotifers, protozoa, and midges, W. smithii is the top-level predator; its presence determines the bacterial species diversity within the pitcher. It is not in any way a pest mosquito, neither biting nor approaching humans or livestock, although there are some populations in the southern US, such as that in the Apalachicola National Forest, that have been observed to take blood meals after laying an initial egg batch. In fact, it is the only known mosquito to have both obligatory biting and non-biting populations in the same species. Wyeomyia smithii is a model organism for the study of photoperiodism, the biotic process of controlling seasonal life history events by measuring day length as a reliable predictor of the seasons. W. smithii enters a state of developmental arrest, larval diapause, that is initiated and maintained by short day lengths and averted or terminated by long day lengths. Due to global warming and the shortening of winters, W. smithii has been observed to now require shorter days before going dormant, this led to the theory that this is an example of microevolutionary selection; mosquitoes that waited longer to go dormant and which had a greater fitness have been favoured.