With summer heat comes pool parties, beach days, backyard cookouts – and of course, swarms of bloodthirsty mosquitoes. But the species doing the biting are changing in historically temperate regions like New England. As climate change makes these areas warmer and wetter, their ranges are expanding – along with any diseases they carry.

In Connecticut, for example, a statewide mosquito monitoring program has detected 54 different species, including invasives like the Asian tiger mosquito, which can transmit potentially serious diseases such as dengue and Zika. The mosquito’s historical territory is in hot and humid climates farther south, but it has been moving north.

‘There are a number of new species that are creeping into our area,’ said Philip Armstrong, chief scientist at the Connecticut Agricultural Experiment Station, which coordinates the state’s mosquito trapping and testing program. Programs like these are key for preventing mosquito-borne diseases, especially as climate change alters the risks. ‘You really do have to test the mosquitoes to know where the hot spots are for these viruses,’ he said. ‘By the time we learn about human cases, it’s usually too late to do anything.’

There aren’t statewide monitoring programs in much of the country. Instead, a patchwork quilt of more than 1,000 mosquito control agencies tries to keep ahead of an evolving problem. Most are run at the local level, with a wide range of organizational structures and monitoring practices.

The US ought to have a national surveillance database collecting and sharing information from all monitoring programs, said Dan Markowski of the American Mosquito Control Association, a nonprofit that works to reduce mosquitoes and vector-transmitted diseases. But, he added, ‘it all obviously comes back to money.’