Study Compares Ecological Niches of the Asian Tiger Mosquito and the Yellow Fever Mosquito

The yellow fever mosquito, originally native to Africa, began to spread throughout the world 300 to 400 years ago - presumably with the expansion of sugar cane plantations and slave trade. The tiger mosquito, which today is considered one of the 100 worst invasive species, originally comes from South and Southeast Asia. Over the past several decades, it has been introduced and spread by trade and tourism, especially by the trade of automobile tires and lucky bamboo (Dracaena spp.). For example, tiger mosquito eggs, larva and pupae were transported great distances by sea, surviving in small water puddles inside used automobile tires, or in water containers for lucky bamboo. In their study, the scientists investigated the ecological niches of both species in their native and non-native range, i.e., the totality of environmental conditions in which a species can occur. In their new ranges of distribution, mosquitoes can encounter different environmental conditions than in their native ranges. Invasive mosquito species are said to be especially quick to adapt to new climatic conditions. The scientists, however, found no evidence to support this. Both species occupy a broad niche and occur in a large number of different environmental conditions in their native ranges. Since similar climatic conditions prevail in the new distribution ranges, worldwide expansion cannot be explained by a niche expansion through adaptation, although local adaptation and genetic changes in species' traits cannot be ruled out. The scientists were, however, able to identify a difference between the two species: that time plays an important role in the expansion or invasion of a species. With its longer time span of invasion, the yellow fever mosquito almost completely fills its niche in the new, non-native distribution ranges; i.e. it occurs under many climatic conditions that also exist in its native distribution range.

Advertisement

The Asian tiger mosquito is a different case. In the new distribution ranges, it does not (yet) occur in all habitats that offer suitable climatic conditions. The researchers therefore predict a further expansion potential for this species in the future. Klimpel sums up: "The Asian tiger mosquito can already be found in nearly all southern European countries, and due to its broad niche, it will inevitably spread and establish itself in northern Europe as well. Further exotic mosquito species such as Aedes japoniucs (East Asian bush mosquito), Aedes koreicus or Aedes atropalpus will follow - or have already arrived - in Central Europe."

Source: Eurekalert