The Asian Tiger Mosquito (Aedes albopictus) is an invasive species that has spread globally from its native Southeast Asia. It is known for its black bodies with prominent white stripes, including a single white stripe down its back. Characterized by aggressive, daytime biting habits, this behavior sets it apart from many other mosquito species active at dawn and dusk. Its rapid global expansion is a significant environmental concern.
Displacement of Native Mosquito Species
The Asian Tiger Mosquito possesses competitive advantages that enable it to displace native mosquito populations. It is an aggressive biter with a broad host range, feeding on humans, domestic animals, and wild animals. This species adapts well to diverse breeding sites, utilizing natural habitats like tree holes and artificial containers such as discarded tires or flowerpots. This adaptability allows it to thrive in both urban and natural environments.
The mosquito has a rapid reproductive cycle, completing its aquatic stage from egg to adult in as little as 7 to 9 days. Females lay drought-resistant eggs just above the water line in containers, which survive dry periods and hatch when water levels rise. These traits facilitate its spread through global trade in items like used tires and “lucky bamboo,” contributing to its ability to outcompete and displace indigenous mosquito species, reducing local mosquito biodiversity. Studies show Aedes albopictus is a superior larval competitor over several North American native species, including Aedes triseriatus and Aedes sierrensis.
Transmission of Pathogens to Wildlife
The Asian Tiger Mosquito serves as a vector for pathogens affecting non-human animal populations. It transmits diseases such as heartworm to canids, including dogs, wolves, and coyotes. This mosquito has also been found infected with West Nile Virus, a pathogen that circulates between mosquitoes and wild birds, occasionally impacting wild animals and horses. Its opportunistic feeding behavior, which includes biting multiple hosts during a single egg development cycle, makes it an efficient bridge vector for cross-species pathogens.
While it can transmit pathogens, Aedes albopictus’s role in avian malaria (Plasmodium parasites) transmission to wild birds appears minor. Research suggests this is due to its feeding preference for mammals over birds. The introduction or amplification of diseases by Aedes albopictus can lead to morbidity, mortality, or reduced fitness in wildlife populations.
Alterations to Ecosystem Structure and Function
The displacement of native mosquito species by Aedes albopictus can alter local food webs. Native mosquito larvae and adults serve as food sources for aquatic and terrestrial predators, including fish, amphibians, birds, and bats. A reduction in native mosquito populations could impact the availability of these food sources. The invasive mosquito might introduce a new food source for some organisms, though this can disrupt the overall ecological balance.
Increased wildlife diseases from the Asian Tiger Mosquito’s vectoring capabilities can further weaken wildlife populations. This weakening alters predator-prey dynamics, impacting ecosystem stability. For example, if an Aedes albopictus-transmitted disease reduces a prey population, predators might face food scarcity. Conversely, a decline in a predator population could lead to an increase in its prey. These ripple effects extend beyond direct competition and disease transmission, influencing biodiversity and ecosystem resilience.