The Connection

Kasha Helget, Arlington Regional Master Naturalist, busted a few myths about mosquitoes and ticks when she gave a talk for Encore Learning in April. Think Citronella will keep mosquitoes away? It doesn’t really help. Bug Zappers? Nope. Think there are one or two types of mosquitoes lurking in the dusk? There are three species in Arlington and it’s a growing number.

Helget’s aim was to help residents deal with ticks and mosquitoes in the summer of 2020 and included input from the Virginia Cooperative Extension and Master Gardeners of Northern Virginia. Her main point: there are safe and effective ways to control ticks and mosquitoes, and there are ineffective and dangerous ways.

Mosquitoes are important, according to Helget, and the goal should not be to kill them all but to keep them away from your garden. They provide food for other animals like birds and bats, although that's another myth: the Purple Martin’s favorite meal is not mosquitoes, after all.

Helget urged residents to avoid the false sense of security you get when you use pesticides. It is a particularly false sense of security when the mosquito evolves to defeat the pesticide, or when spraying does not in fact hit its target.

The local mosquito spraying companies are making money selling their services to residents who don’t like mosquitoes, but there are more effective ways to keep them away.

To spray or not to spray is the question. That is why Helget went to the trouble of explaining what the “enemy” looks like biologically, and then, how to combat it In simple, clean, behavioral ways.

There are over 3,000 species of mosquitoes worldwide and at least 40 in Virginia, Helget said. The three mosquito species we have to deal with locally are two Aedes and one kind of Culex.

Culex – the small brown mosquitoes, are not very aggressive, can spread Chikungunya, and may also spread Yellow Fever, Dengue Fever, West Nile, and Zika viruses. They have a range of up to two miles. All mosquitoes lay eggs in still water, so anytime you have storm drains, flower pots, or those black plastic pipes people use to exfiltrate water from their yard, but often contain still water, you are inviting mosquitoes. They bite at dawn and dusk. Mosquitoes need blood to ingest in order to lay eggs. Only females need that blood; males don’t bite.

The second major type found in Arlington, Aedes Albopictus, can travel 600 yards. They are daytime biters, the black aggressive mosquitoes. They like clean water to breed in. They may transmit Dengue, Chikungunya, and may also spread Yellow Fever, West Nile, and Zika viruses.

The third type, Aedes aegypti mosquito, is slightly larger than A. albopictus. It is the primary transmitter of Dengue, Yellow Fever, Chikungunya, and Zika viruses. It may also transmit West Nile virus.

Good natural predators for eradicating mosquitoes in the yard are dragonflies, frogs and toads, water striders, Mosquitofish, and mosquito catchers, a large insect many people mistakenly kill because it looks like a large mosquito. Bats and birds also keep the population down.

David Landeck of Arlington says: “Eliminate standing water, get a bird feeder so lots of birds are around. Get a bat box. We haven't had a mosquito problem for years. Been eating outside every night lately.”

In the spring time mosquitoes emerge as either eggs frozen over the winter or new females lay eggs in still water. They are very effective breeders and can lay up to 300 eggs at a time. It only takes the egg seven days to become a fully functioning ankle biting adult.

But if you really want to get rid of mosquitoes, according to Helget, the Virginia Cooperative Extension, and Master Gardeners, just get rid of any standing water around the house: leaky hoses, ponds, outdoor toys, little red wagons, neglected pools, corrugated drain pipes, upturned lids, pet water bowls, uncovered boats, uncovered trash cans, clogged rain gutters, saucers under your outdoor pots, even bottle caps — 300 mosquito eggs can fit in a bottle cap quite easily.

Helget says use biological larvicides where you can’t just dump the water, as in fountains or ponds. BTi (Bacillus thuringiensis israelensis, the active ingredient in Mosquito Dunks and Bits), kills mosquito larvae without harming birds, toads, bees, butterflies, beneficial insects, or other wildlife.

For keeping mosquitoes off individuals in the garden, use a lotion which is 25-30 percent DEET, or Picaridin or oil of eucalyptus. Bracelets don’t work, nor do citronella candles. Many people recommend just putting a fan where you are sitting: mosquitoes like still air. They aren’t strong flyers.

Mosquitos are drawn to type O blood; type A is least attractive to them. A very effective way to keep them away is to wear long sleeves and trousers, and, if you are living in an area where disease is prevalent, like Zika or Dengue, then Permethrin treated clothes work well. This is a very toxic substance to animals and should be used with caution. Permethrin kills bees, moths, and arthropods; most people only use it when they have no other choice.

Once you have let mosquitoes breed in your garden, getting rid of adults is harder. But Helget continued to warn that spraying should be a last resort. Pyrethroids – the chemicals most sprayers use – have low toxicity to mammals and birds, but are toxic to fish, aquatic arthropods, and non-target insects like bees and beetles. Organophosphates have low toxicity to mammals, birds, and fish but are very highly toxic to honeybees. These broad spectrum pesticides should be avoided at all cost, said Helget.

Joan McIntyre, a Master Gardener in Arlington said, “As mosquitoes don’t generally rest on leaves, this residual effect (of spraying) is much more harmful to pollinators and other insects which can pick up or ingest the toxin. Culex mosquitoes, one of our more common species, spend most of their time in the tree tops and are least likely to be killed from these sprays.”

Helget was not in favor of hiring a mosquito eradication company, but she offered that if one absolutely did have to hire one, only VDACS (Virginia Department of Agriculture and Consumer Services) licensed pest control companies should be on your list. When calling, ask if they practice any IPM — integrated pest management — getting rid of water in the yard, using biological defenses like mosquito dunks, larvicides, etc. You should compare proposals, just like you would for any service, and carefully check the company’s reputation. Use low volume sprays if hiring a spray company; the applications should never be during the day, when pollinators are active, on windy days, the hottest part of the day, over water, or before rain. They should not be used on flowering plants that pollinators visit.

Helget urged her audience to work with neighbors; ask them to try these techniques since mosquitoes travel extensively. Conversely, if they are spraying, it is reasonable to ask them not to spray in the direction of your property. Most neighbors will understand that if you keep bees or have pollinator plants, you want to keep them safe.

Arlington residents have spoken out about spraying: Trudi Harlow said: “Friends, I don't care what the companies doing this are telling you, but the spray they use kills pretty much all insects. I suspect it's not particularly safe for humans, either, looking at all the safety gear these guys wear. My immediate concern is that they are spraying when the wind is blowing, effectively moving the insecticide to areas where other residents may not want it. I walked out of my house this morning and could hardly breathe from all the spray that was being carried up to our house from a house down the street. My windows are open and my house now stinks. I ask you to think twice before contracting with one of these services.”

Spraying Listerine, wearing dryer sheets, VapoRub, Vanilla, Citronella, wristbands, ultrasonic devices and clip-on replelants do not work. Eating garlic doesn’t work. Most “all natural” treatments don’t work, especially if the lawn has mosquito-friendly English ivy or other dense groundcover in it (a favorite place for mosquitoes to hide) or neighbors with habitats friendly to mosquitoes. The bottom line for Helget: just don’t let mosquitoes breed and since they need water to do that, keep the garden water moving, even installing a bubbling machine for a fountain.

Ticks

Helget’s presentation moved on to the more frightening of the “biters” that plague area gardens: ticks. Most Arlington residents have never had Dengue Fever, Zika, or Yellow Fever, but many have had or know someone who has had Lyme disease or Anaplasmosis.

The Longhorn tick bite infects people with a pathogen that causes an allergic reaction to meat.

Helget’s lecture concentrated on three basic rules: know your ticks, know the diseases, and manage the exposure. Without going into the details of how to identify each tick, which requires knowing about the scutum, the anal groove, and the festoons, there are four common ticks of Virginia: the American Dog Tick, the Deer Tick, the Lone Star Tick, the Brown Tick. Two newcomers, the Gulf Coast Tick and the Asian Longhorned Tick, are starting to make an appearance here. Most ticks are active from April to September but the deer ticks are also active in winter.

The bad news, said Helget, is that even the larvae and nymphs can bite, and they are tiny - the size of black pepper or poppyseeds. And if mosquitoes are efficient breeders, ticks are even better at it. They can lay from 3,000 to 7,000 eggs at a time. They can be active all year. The female can produce one to two batches of eggs before she dies, and they can live for up to three years.

Ticks are quick movers, but they don’t jump or fly, as many think. They just hang out on the grass until you walk by: they are looking for a warm moist spot, like the groin, or the belly button, or armpit. They have a natural tendency to climb upwards, and like to get into hair or ears. The good news is that it takes minutes or hours to attach themselves. Helget joked, “You know how to socially distance, so … socially distance from overhanging shrubs or tall grasses. If you do think you have gone too near to tick habitat, check right away. A moving piece of pepper is tick larva.”

Helget warmed to her theme of repelling ticks: “wear light coloured clothing so you can spot ticks more easily. If you aren’t sure about the clothes you wore, put them in a hot dryer. Wear DEET or permethrin treated clothes if you are in a tick area for a long time. Shoes should also be treated.

Helget recommended keeping grass low, keeping brush in the garden to a minimum, cleaning up leaves, and installing either a mulch or gravel barrier between woods and lawn. Gravel is best because ticks hate to cross things that are dry and love moisture. Ticks spread disease from other animals like deer and squirrels. Keep wildlife out of the yard if you can.

As in the case of mosquitoes, Helget said commercial sprays have limited effectiveness. While it is tempting to use sprays, these insecticides kill pollinators and many other beneficial insects. With insect populations dropping worldwide, and bird populations diminished in the billions over the past 50 years, better “long view” strategies are needed to deal with garden pests.

If you do find a tick on you or your pet, it is good to have a tick kit with you for safe removal. That tick kit should contain: narrow tweezers, not wide ones, a baggie to put the tick in for identifying later, and an alcohol swab. Grab the tick by the mouth, pull slowly up and out, not sideways. Don’t use fire, a lighted cigarette, or alcohol to get the tick off. Hot water showers won’t kill ticks, but might get them off if they haven’t attached yet. Swab the area with alcohol. The Virginia Cooperative Extension can help identify a tick, and the Virginia Department of Health is interested in information on new ticks in the area.

Resources

Arlington Regional Master Naturalists is a group of volunteers who engage in citizen science projects and stewardship in the environment like removing invasive plants. For more about them, see: https://armn.org/

Northern Virginia Master Gardeners are a group of volunteers who maintain gardens and teach gardening in Arlington and Alexandria. For more, see: https://mgnv.org/

To learn more about bugs and human health, see: https://www.vdh.virginia.gov/environmental-epidemiology/bugs-human-health/

For more information about controlling mosquitoes, see:

https://www.fairfaxcounty.gov/news2/your-field-guide-to-battle-mosquitoes/

To watch Helget’s presentation, Encore Learning presents: Safely Enjoy the Outdoors Despite Mosquitoes and Ticks, see: https://www.youtube.com/watch?v=GN8un6lremA&feature=youtu.be

To learn more about mosquitoes and how to control them, check out these articles written by the Extension Master Gardeners of Arlington and Alexandria:

Protecting Yourself From Mosquitoes ... Without Harming Pollinators: https://mgnv.org/2020/04/16/protecting-yourself-from-mosquitos/#more-22921

Mosquito Control Begins with a Home Walk-Around: https://mgnv.org/2019/04/24/mosquito-control-begins-with-a-home-walk-around/

For more information about mosquitoes and ticks, contact the Virginia Cooperative Extension Office at 3308 S. Stafford Street, Arlington, VA, call the Extension Master Gardener Help Desk at 703-228-6414, or email mgarlalex@gmail.com. Check out the resources at https://mgnv.org/reading-room/mosquito-and-tick-control/ and https://armn.org/mosquitos-and-ticks/

And: https://newsroom.arlingtonva.us/release/ticks-virginia-lyme-disease-prevention/