A new type of mosquito species found in Florida could increase the chances of more people getting affected by viruses such as West Nile and others, scientists said.

Traces of the pests, known by the scientific moniker Culex lactatator, have been found in Miami-Dade, Collier and Lee counties so far. This is their second appearance since 2018, and this time they have come to the Sunshine State to stay forever, according to a study published in the Journal of Medical Entomology. Apart from these three regions, Culex lactatator mosquito is feared to gain a strong foothold in more counties in the future.

The newest members of Florida’s growing list of non-invasive mosquito species have come from Central and South America, Lawrence Reeves, the study lead author and a mosquito biologist at the UF/IFAS research center in Vero Beach, said in a statement.

Reeves said despite researchers constantly monitoring the counties for new non-native mosquito species, they remain unsure regarding how far they can harm humans.

“That’s particularly true for species from the tropical forests, where mosquitoes are diverse and understudied,” Reeves pointed out in the statement. “Introductions of new mosquito species like this are concerning because many of our greatest mosquito-related challenges are the result of nonnative mosquitoes, and in a case like this, it’s difficult to anticipate what to expect when we know so little about a mosquito species.”

C. lactator belongs to the genus Culex, other members of which are known to transmit dangerous pathogens like West Nile and St. Louis encephalitis viruses, Live Science reported. However, it’s not clear if the new species found in Florida are able to transmit the viruses.

“It’s too early to know whether Culex lactator will exacerbate these challenges, but the implications are often difficult to predict because not all mosquito species are equally capable of transmitting a particular virus or other pathogens,” Reeves added in the statement.

In its statement, the UF/IFAS noted that Florida has become warmer as a result of climate change, thus growing more habitable for mosquitos coming from the tropics. Reeves said they found a few specimens of the newly-arrived C. lactator carrying the blood of warbler birds, which may be a major cause of concern as infected birds are majorly the sources of mosquitoes picking up the harmful pathogens before transmitting them to humans.