Gooosh! I have no idea what it is, but here's a precautionary note just in case.
While mosquitos may appear to be worthless and simply bother people, they play a crucial role in the ecology. Mosquitoes are an important source of biomass in the food chain, acting as larvae for fish and adult flies for birds, bats, and amphibians, and some species are important pollinators.
Many mosquitos, both harmless and harmful, serve an important biological function. They can help pollinate plants by feeding on nectar (their regular food supply outside of the essential blood meal phase), and they can also provide a significant source of food for larger animals.
Avoiding mosquito bites has long been a concern in locations where mosquito-borne diseases such as dengue fever, malaria, and yellow fever are endemic. More information is available here.
The spray frequently kills the mosquitos with which it comes into contact and then dries, leaving a repellent residue on the leaves and trees. To keep mosquitos away from exposed skin, wear long-sleeved shirts, long pants, and socks. Tuck your shirts into your jeans and your pants into your socks to conceal any gaps in your clothing through which mosquitoes could enter your skin. Stay indoors whenever possible, especially if a mosquito-borne disease alert is in force.