Tiger mosquito
(Aedes albopictus)
—Thanks for this Guest Post to entomologist Katie Westby of Tyson Research Center, the environmental field station of Washington University.
Chances are good that you have met the tiger mosquito while enjoying the outdoors in the Saint Louis region. Named the tiger because of its beautiful black and silver stripes, this incredibly adaptable species is a common nuisance especially in urban and suburban neighborhoods. Native to Southeast Asia, the tiger has spread around the globe, colonizing every continent except Antarctica. This mosquito is one of 100 of the most invasive species on the planet.
Like many invasive species, the tiger mosquito has many traits that contribute to its global success. It develops quickly as larvae in small aquatic habitats, will take its blood meals from a wide variety of hosts, is aggressive towards other mosquito species that occupy the same ecological niche and is even capable of mating interference rendering other species infertile. Despite its origins breeding in natural water holding containers in forested areas, such as tree rot holes and bamboo stumps, the tiger has adapted to breed in human-made containers and is now closely associated with human habitation. You can find their wriggling larvae developing in the saucers under your planters, in your watering cans and gutters, or pretty much any water holding container that is not in the direct sun.
As ectothermic organisms, they are incredibly sensitive to temperature and often spend the hottest parts of the day resting in humid and shady vegetation, trying to avoid desiccation, a severe drying that will cause death. When the weather cools and the days get shorter, the adult females begin to lay eggs which are dormant and wait to hatch until conditions improve in late spring. Interestingly, this mosquito’s reproduction trait, called diapause, is correlated with latitude; populations from southern latitudes with mild winters have reduced incidence of diapause compared to more northern populations. In St. Louis, female tiger mosquitoes are laying only diapause eggs by mid-October, but they may continue biting into November on warm days.
For all species of mosquitoes, it is only the females that take blood meals, using the protein to make her eggs. Both male and female mosquitoes take sugar meals and use the carbohydrates for energy for flight and other somatic (bodily) functions. Sources of sugar meals can be honeydew, rotting fruit, but most commonly nectar from flowering plants. Mosquitoes are pollinators!
So, before you squash the next mosquito that visits you, take a minute to appreciate her for her silver stripes and for being the interesting ecological creature that she is. Then, please do swat.