Mosquitos and PFAs

By Carol Allen

There has been significant press on the presence of “forever chemicals” in the environment. Per- and polyfluorinated alkyl substances (PFAS) are a large chemical family of more than 4,700 highly persistent chemicals that do not occur in nature. They are in paper packaging, nonstick cookware, cosmetics, electronics, and other products.

Research has shown PFAs to be present in blood and breastmilk of both people and wildlife around the world. This rising concern might be what prompted two researchers at the University of British Columbia to look at how the presence of microplastics might affect the health of mosquito larvae. Mosquito larvae may not be our favorite insects, but in the ecosystem and far away from our backyard barbeques, they are an important part of the food chain.

Markus Thormeyer and Michelle Tseng, Ph.D. reported their findings in the February 2023 edition of the Journal of Medical Entomology (https://academic.oup.com/jme/ advance-article/doi/10.1093/jme/ tjad014/7043721). They carried out their studies on Culex pipiens, the common house mosquito, and Culex tarsalis, the Western Encephalitis Mosquito. Both are natives of the United Sates. Their goal was to look at the possible impact microplastics would have on developing mosquito larvae. Their study found no impact, but another group found conflicting evidence in a 2020 Brazilian study (https://ecotoxbrasil. org.br/).

We should be concerned about the continued proliferation of microplastics in the environment. That is especially important since this study from

Chemosphere (https://www.sciencedirect.com/science/article/abs/pii/S00 45653522011596?via%3Dihub) found that female mosquitoes can potentially transmit microplastics in their bites.

Check your water features for active larvae and distribute Mosquito Dunks/ Bits (https://amzn.to/3JQTqZI) now!

Seriously: I am currently finding live mosquito larvae in standing water here in central Maryland. The unusually warm late-winter weather has allowed mosquitoes to breed as well as flowers to bloom early. o

Carol Allen describes herself as a committable plant-a-holic. She has more than 25 years’ experience in the horticulture industry, with a special interest in plant pests and diseases; is a Licensed Pesticide Applicator in the state of Maryland; and is an ISACertified Arborist. She can be contacted at carolallen@erols.com.