I keep reading that we have one of the mosquitoes here in Massachusetts that can transmit Zika virus. What does it look like so I’ll know if I have it here in my yard? C. F., Blackstone, MA

You’re talking about the Asian tiger mosquito, Aedes albopictus. Although this mosquito is not the primary vector of Zika virus, it has transmitted Zika in other countries and it is presumed that it is capable of doing the same here in the U.S. You’re probably already aware of this mosquito’s presence in your yard but just haven’t made the connection.

The yellowfever mosquito, Aedes aegypti, is the main mosquito responsible for transmitting Zika virus nearby in Latin America, Mexico, and now Puerto Rico. This mosquito occurs in the U.S., but primarily in southern coastal states. It is sometimes found incidentally farther north but it is not established in the Northeast. Its close relative, the Asian tiger mosquito ranges farther north in the U.S and does occur here in New England (see Advance Warning! – Zika Virus Can Occur in New England).

It’s Actually a Pretty Little Mosquito!

Fortunately, the Asian tiger mosquito is quite distinctive in coloration and fairly easy to identify. It is 1/8 inch long, dark brown or black with noticeable silvery-white bands marking the joints on its legs and white spots on the sides of its abdomen and on its mouthparts. The yellowfever mosquito has similar black and white markings, but what distinguishes the Asian tiger mosquito is a white line down the center of its back (although sometimes the white scales are worn off). Both mosquitoes have a pointed abdomen compared to many of our other common mosquitoes (including Culex) that have an abdomen with a blunt tip.

Besides its unique markings, the Asian tiger mosquito has unique habits as well. It is primarily a daytime biter, something that most people are not expecting. Both of the Aedes mosquitoes tend to be smaller, faster, and more aggressive than other mosquitoes.

The Asian Tiger Mosquito Stays Close to Home

The female Asian tiger mosquito will lay a few eggs in many different small sites that either contain standing water or are due to be filled or flooded when it rains. This mosquito can develop in natural containers such as tree holes or in manmade containers that hold water, ranging from plant saucers to buckets to old tires (see Worried About Mosquitoes). It generally doesn’t travel more than 300 feet from its breeding site, so if you have a lot of Asian tiger mosquitoes in your yard, it’s a good bet that you are providing the containers they are breeding in. They also readily come indoors so you can sometimes even have indoor breeding sites (see Mosquitoes Breeding Indoors!).

While it’s a good thing that folks are now getting just a little worried about Zika virus, don’t forget that in our region Zika is just one disease transmitted by just one mosquito. This same Asian tiger mosquito also transmits other diseases that already occur here, including West Nile virus. West Nile can also be transmitted by Culex mosquitoes which are common here. So don’t forget about mosquito protection if your biting mosquitoes don’t seem to be Asian tigers. There are plenty of other mosquitoes and mosquito diseases to be worried about.

P.S. For more photos of the Asian tiger mosquito, just Google it. It’s all over the Internet.