Mosquito larvae often occur as temporary superabundant prey in nature. One study close to Dalälven shows that diving beetles are not dependent on the presens of mosquito larvae. They don't base their choice of habitat of presence of mosquito larvae. However some diving beetles may be dependent on them, for example the larva of Colymbetes paykulli. The cafeteria experiment in my study showed that R. exsoletus, R. frontalis, A. canaliculatus and N. glauca prefer to consume mosquito larvae when they are presented with isopods and daphnids at the same time. That means that they may act as natural controls when they are present among mosquito larvae. Unfortunately they didn't have a high consumption rate even in the beginning when they were extra hungry. So it is possible that they are not so effective. It has been shown that it is hard to increase the density of mosquito larvae since they seem to emmigrate when more are added. It is, however, possible to imagine that the predators still are of some importance. The mosquitoes might have been a larger problem without insect predators which occur naturally in small puddles where mosquitoes lay their eggs.
In the immigration experiment only Rhantus species immigrated to the puddles, especially to the larger ones. Since the predators seem to prefer the larger puddles the mosquitoes may benefit from breeding in the smaller ones.
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Last updated: 05/29/13