Frequent rains creating a buzz

All the rain has provided many neighborhoods some relief from watering lawns and landscape plants, but not from the onslaught of pest problems. Frequent rains are creating a buzz as we see an increase in the number of mosquitoes.

Mosquitoes have always been a part of our summer environment. This is not surprising since Florida has 80 species, more than any other state. Of those, 33 can create problems for humans and/or domestic animals in Florida. For example, adult female mosquitoes can transmit West Nile virus, eastern equine encephalitis, dengue fever, Zika virus, St. Louis encephalitis and other diseases.

If you are a horse or chicken owner, there are two mosquito-borne viruses of concern: West Nile virus and eastern equine encephalitis. In both cases, mosquitoes transfer the virus from infected birds to mammals (horses, humans). According to Alicia Halbritter, Duval Extension forage/livestock agent, eastern equine encephalitis, is prevalent during the summer months, and a high number of cases have already been reported in 2018. According to the Florida Arbovirus Surveillance, positive samples from one human, 35 horses, one mule, one donkey, one owl, one emu, four emu flocks, two mosquito pools and 77 sentinel chickens have been reported from 27 counties, including Duval. It is very important to make sure horses are vaccinated and humans limit their exposure to mosquitoes during the summer months. For updates on mosquito-borne disease surveillance in Florida, go to http://www.floridahealth.gov/diseases-and-conditions/mosquito-borne-diseases/surveillance.html.

Not all mosquitoes are the same. Different mosquitoes spread different viruses and are active at different times of the day. As I was weeding in the landscape last weekend in the afternoon, the mosquitoes were active, which goes against what many of us were taught. In fact, the Aedes aegypti and Aedes albopictus can feed at night but are primarily daytime feeders and spread Chikungunya, Dengue and Zika viruses. Compare that to the Culex species, which is an evening to morning feeder and spreads West Nile virus.

Mosquito control is something that should be taken seriously and we can all do our part to help. Mosquitoes need just a small amount of water to lay eggs and develop, so it’s critical to get rid of standing water around your home. For starters, get rid of any unnecessary container that holds water. Old tires, pots, pool covers, boats and cans are known breeding areas for mosquitoes. Clean roof gutters so water can drain properly.

Flush out birdbaths, bromeliads, tree holes and other containers once a week to get rid of mosquito larvae. Scrub the sides of the birdbath to eliminate eggs. If birdbaths and pet dishes are not in use, turn them over so they don’t collect rainwater.

Swimming pools should be cleaned and chlorinated when not being used. Empty any plastic kiddie pools when not in use.

If you have a rain barrel, this is a perfect habitat as well. Place a fine screen over rain barrels to keep mosquitoes out and/or treat water with a larvicide. Bacillus thuringiensis israelensis (Bti) is a great larvicide available in granules, bits or dunks. The same product can be used to treat standing water in a swale or rain garden.

Next, keep mosquitoes outside. They can live indoors and will bite at any time, day or night. Keep doors and windows shut and use air conditioning to stay cool. If doors and windows are left open, make sure the screens are in good condition and snugly installed.

Mosquitoes travel 2 to 3 miles for a meal, so just because breeding areas are eliminated on your property doesn’t mean your yard will be mosquito-free. To reduce exposure to mosquitoes, avoid their peak times by staying inside at dawn, dusk and early evening. If you must go outside at these times, wear light colored clothing with long sleeves and long pants.

Use fluorescent lights outside because they neither attract nor repel mosquitoes. Avoid using incandescent lights because mosquitoes are attracted to them.

More importantly, use effective mosquito repellents on your skin. Before purchasing a mosquito repellent, look at the label to check for the active ingredient and read the application methods. Make sure you avoid getting repellents in your eyes. Mosquito repellents which have proved to be effective along with protection time based on lab experiments include OFF! Deep Woods (23.8 percent DEET for 5 hours), Sawyer Controlled Released (20 percent DEET for 4 hours), OFF! Skintastic (6.65 percent DEET for 2 hours), Bite Blocker for Kids (2 percent Soybean Oil for 1.5 hours), OFF! Skintastic for Kids (4.75 percent DEET for 1.5 hours), Skin-So-Soft Bug Guard Plus (7.5 percent IR3535 for 23 minutes), Natrapel (10 percent Citronella for 20 minutes) and Herbal Armor (Citronella and various oils for 19 minutes). Keep in mind that these were tested under laboratory conditions, and the effectiveness may be reduced if you are outside sweating in the Florida heat. To find the repellent that is right for you, go to https://www.epa.gov/insect-repellents/find-repellent-right-you.

If mosquitoes are a problem in your neighborhood, contact the Mosquito Control division in your county. Marah Clark, the Mosquito Control Entomologist with the City of Jacksonville, suggests that Duval County residents call 630-CITY (2489) or make the request online at http://630city.coj.net by clicking on “create issue” and then select “mosquitoes, inspect or spray.”

Stay safe this summer by helping prevent mosquito breeding and avoiding exposure to mosquitoes. Stay tuned to The Florida Department of Health (http://www.floridahealth.gov/) for health advisories and alerts on their website. For more information about mosquitoes and mosquito-borne diseases, go to http://mosquito.ifas.ufl.edu.

Terry Brite DelValle is a horticulture extension agent with the Duval County Extension Service and the University of Florida/IFAS.