News

Ocracoke public enemies: Mosquitoes, ticks and green heads

Editor’s note: The Ocracoke Mosquito Control Board will meet at 6 p.m. today (Aug. 25) in the Ocracoke Volunteer Fire Dept. meeting room. Open to the public and press.

By Peter Vankevich

Considering that Ocracoke is a barrier island consisting primarily of natural habitats, one can expect lots of flora and fauna, much of which is wonderful to behold.

An exception to this are biting arthropods, the worst offenders of which are mosquitoes, ticks and green head flies.

Besides the short-term aggravation from bites, there can also be long-term health consequences.  The number of these pests at any given time varies depending on environmental factors such as rain amounts and temperatures.

Mosquitoes

In the world, there are about 27,000 species with about 150 in the United States, 61 in North Carolina and about 25 in Eastern Carolina.

Three species are common on Ocracoke.

Asian tiger mosquito. Photo from the Centers for Disease Control and Prevention.

The Asian tiger mosquito (Aedes albopictus), is the worst biter in the state. First documented in Texas in 1985, they were found in used truck tires from Japan. When the tires were distributed, the Asian tiger mosquito spread rapidly throughout the Southeast. They are diurnal only.

As sunset approaches, another species is ready for to take over.

The eastern salt marsh mosquito forces (Aedes sollicitans) come out at dusk all over the island, though they can also be active during the day. Without arming yourself with spray, they can take the joy out of a sunset walk.

At night, the Culex mosquito, the common house mosquito, is active.

Mosquitoes can transmit a variety of diseases making them a serious concern. The most recent is the Zika virus. The Aedes aegypti mosquito is most likely to transmit the Zika virus but is not common in North Carolina, and, even if present, would not necessarily carry this virus.

On July 12, N.C. Health and Human Services reported no locally acquired Zika virus cases in the past two years.

Mosquito spraying using Permethrin on Ocracoke is done only within the confines of the village under the administration of the Mosquito Control Board. Beaver Tillett, who does the spraying, has strong advice for minimizing their numbers:

“Tip and toss”

Get rid of standing water, he says, since it doesn’t take much for mosquitoes to successfully breed.

That means, tip out water in buckets, tires, gutters, on tarps—anywhere water will stand.

Bird baths should be refreshed regularly. Doing these inspections is particularly important after heavy rains because during warm weather, it may take only a week for the tiger mosquito to grow from egg to adult.

Removing standing water is helpful for controlling Asian tiger mosquitoes since they are weak flyers and do not travel far from where they hatch.

Bats are a natural control measure since mosquitos are part of their insect diet.

The Ocracoke Mosquito Control Board (MCB) worked with the school’s shop class to build and distribute about 30 boxes to islanders earlier this year. To date, there have been no reports of bats on island and the MCB is looking for advice from bat experts on how to attract them to the island. Being nocturnal, bats have no noticeable impact on tiger mosquitoes.

Ticks

Lone star tick. Photo from US Center
for Disease Control

 

Like mosquitoes, tick numbers can vary depending on environmental conditions and may be present well into the fall and early winter. Ticks can cause serious diseases. The blacklegged tick, aka the deer tick, transmits Lyme disease, which can cause fever, headache, fatigue and a characteristic skin rash called Erythema migrans. If left untreated, infection can spread to joints, the heart, and the nervous system and can be very difficult to treat.

An increasing tick-related illness, “southern tick associated rash illness” or STARI, has been affecting northeastern North Carolina and is transmitted by the lone star tick, named for a white spot on its back. This disease can cause a strong allergy to red meat.

Greenhead flies

The most aggressive and most difficult to control is the greenhead fly (Tabanus nigrovittatus), which can be in big numbers in marshy areas and on the beach.  Females swoop in, cut through the skin for blood, causing bleeding and fly off before one has time to make a swat. When biting, they inject an antiseptic-saliva that stimulates blood flow. It burns and causes nerves to respond with pain.

A greenhead fly. Photo courtesy of Commons Wikimedia

These flies are not deterred by most bug sprays. One product that claims to work is Dak’s Greenhead Repellent, which contains DEET. All sprays come off in the water and have to be reapplied. Some claim that green heads are attracted to saltwater on skin causing them to attack even more aggressively.

How to best to limit exposure to these arthropods? In addition to removing standing water and sprays, clothing with long legs and sleeves are a must when venturing into mosquito- and tick-infested areas. Afterwards, check for ticks on the body and also on pets.

For more information, visit the North Carolina Mosquito & Vector Control Association website here.