Niche conservatism of Aedes albopictus and Aedes aegypti - two mosquito species with different invasion histories

Sarah Cunze,Sven Klimpel,Lisa K Koch,Judith Kochmann

doi:10.1038/s41598-018-26092-2

Abstract

Biological invasions have been associated with niche changes; however, their occurrence is still debated. We assess whether climatic niches between native and non-native ranges have changed during the invasion process using two globally spread mosquitoes as model species, Aedes albopictus and Aedes aegypti. Considering the different time spans since their invasions (>300 vs. 30–40 years), niche changes were expected to be more likely for Ae. aegypti than for Ae. albopictus. We used temperature and precipitation variables as descriptors for the realized climatic niches and different niche metrics to detect niche dynamics in the native and non-native ranges. High niche stability, therefore, no niche expansion but niche conservatism was revealed for both species. High niche unfilling for Ae. albopictus indicates a great potential for further expansion. Highest niche occupancies in non-native ranges occurred either under more temperate (North America, Europe) or tropical conditions (South America, Africa). Aedes aegypti has been able to fill its native climatic niche in the non-native ranges, with very low unfilling. Our results challenge the assumption of rapid evolutionary change of climatic niches as a requirement for global invasions but support the use of native range-based niche models to project future invasion risk on a large scale.

Highlights

Ongoing change in climatic conditions is expected to influence species’ distributions, which in turn will affect biodiversity patterns[1,2]
Climatic niche shifts contradict the assumption of a niche conservatism, which implies that species retain their niches in space and time[13]
Aedes albopictus and Aedes aegypti, two mosquito species that are listed among the world’s worst invasive alien species (Global Invasive Species Database, IUCN) and that are competent vectors for several diseases[16], were used as model species to assess whether climatic niches between native and non-native ranges have changed

Summary

Introduction

Ongoing change in climatic conditions is expected to influence species’ distributions, which in turn will affect biodiversity patterns[1,2]. Biological invasions are promoted by climate change[3] and are further enhanced by increasing global trade and tourism They have been associated with changes in the species’ realized climatic niches, with reports of niche changes between native and non-native populations[4,5]. Comparisons between species’ native and non-native range climatic niches may identify species that have undergone adaptive evolutionary changes during the invasion process (e.g. change of the fundamental climatic niche), but might generally benefit a better understanding of different niche dynamics[6]. Aedes albopictus and Aedes aegypti, two mosquito species that are listed among the world’s worst invasive alien species (Global Invasive Species Database, IUCN) and that are competent vectors for several diseases[16], were used as model species to assess whether climatic niches between native and non-native ranges have changed. Records from moderate climate zones are still missing or rare and may be the result of the species’ domesticity (feeding, mating, oviposition indoors) (e.g. Gloria-Soria et al.[23])

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