During the summer of 2017, an entomologist with the Bristol County Mosquito Control Project, Todd Duval, received a phone call from a New Bedford homeowner about unusually aggressive mosquito pests that had attacked her two children during the daytime. The two children were taken to the doctor due to the high number of bites that they had sustained in the mosquito attack. In 2017, no mosquito species inhabiting Massachusetts fit the mother’s description, as mosquito pests in the state become active biters at dusk, with the only exception being the day-biting Asian bush mosquito, a Japanese native. However, neither the Asian bush mosquito, nor any other mosquito species that had existed in Massachusetts during 2017 were known for biting humans as aggressively as the mosquitoes described by the mother. Duval visited the residence where the attack occurred in an effort to better understand what happened.

Upon arriving at the home, Duval found numerous plastic containers strewn throughout the yard, all of which contained stagnant rainwater. These containers included plastic toys, corrugated downspout extensions, and even multiple buckets that had been deliberately left outside to collect rain for garden watering. Containers on residential properties that are filled with stagnant water make for ideal breeding sites for the Asian tiger mosquitoes (Aedes albopictus), and these mosquitoes are the most aggressive biters in the US along with its close relative the yellow fever mosquito (Aedes aegypti). Duval naturally suspected that Asian tiger mosquitoes had perpetrated the attack on the two children, as this invasive species had made occasional appearances in southern Massachusetts before 2017.

Scientists claim that Asian tiger mosquitoes are rapidly expanding their invasive US habitat northward through New England because the warming climate is making temperate regions more hospitable to the tropical pests. Asian tiger mosquitoes transmit numerous diseases in tropical regions, and during 2014 they likely transmitted chikungunya locally in Florida and North Carolina. These two cases marked the first incidents in which chikungunya had been locally transmitted in the US, and experts believe that the virus will likely become more common in the country. Also in 2014, four Boston residents contracted chikungunya while visiting the Carribean region, and such cases are problematic because infected individuals provide mosquitoes with a disease-reservoir upon returning to the US. Despite being introduced into the US as recently as 1985, Asian tiger mosquitoes have become the most commonly controlled mosquito pests on residential and commercial properties nationwide.

Have you ever struggled to control mosquitoes on your property?