Purdue Extension Service

Vanderburgh County, Indiana

More Summer Insects

By Larry Caplan, Extension Horticulture Educator, Vanderburgh County, IN

For the Evansville Courier and Press, June 7, 2009

Last week, I talked about some common summer landscape pests, such as bagworms, Japanese beetles, and grubs. Based on my phone calls and e-mails over the last few days, we need to talk about insects that attack humans.

The largest number of calls are asking about tiny biting insects. These are biting midges, but may also be known as no-see-ums, punkies, Buffalo gnats, and several other more colorful names. Basically, these are small flies, ranging in size from 1-3 mm in length. They typically are grayish, but more reddish when filled with blood.

The mouthparts of biting midges consist of are four, minute cutting blades that lacerate the skin, inflicting sharp, burning pain. These bites can cause different reactions in humans, ranging from a small reddish welt at the bite site to local allergic reactions that cause significant itching.

Biting midge larvae develop in a variety of semi-aquatic or aquatic habitats, depending on the species. For example, larvae of some species of the genus Culicoides are truly aquatic, developing both in streams and ponds, but those of most other species are found in organically rich, semi-aquatic sites such as marshes, bogs, tree holes, and saturated rotting wood. Anything that catches rain water, such as tires, children's toys, or clogged house gutters, can hold enough water for both midge and mosquito larvae.

Control of biting midge larvae and adults is very difficult. Flying insect sprays and fogs have not proven to be effective. While emptying anything that holds water will reduce mosquito populations, midges can breed in a wider range of sites, making this option less useful. Window and door screens with a mesh size smaller than normal prevent female biting midges from entering homes and porches.

Repellents containing DEET and clothing impregnated with DEET or permethrin provide only limited protection against biting midges. Scheduling outdoor activities to avoid daily peaks of biting midges is the most effective way people can avoid being bitten. However, this is hard to predict: certain species prefer to feed during the day, while others come out at dusk and feed throughout the night.

Ticks have been very bad this year. Even with the use of repellents, my wife and I still wind up removing ticks in the process of embedding themselves in our skin. Besides the gross-out factor of having something attached to you and sucking out your blood, ticks can spread several very serious diseases, including Lyme Disease and Rocky Mountain Spotted Fever. These diseases can be difficult to diagnose, but with early treatment, are usually kept from being life-threatening.

Protect yourself from ticks by avoiding tick-infested areas, and wear protective clothing. Stay on established trails, and avoid brushing against vegetation (especially tall grass). Wear light-colored clothing, long pants, and long-sleeved shirts so that ticks can be more easily seen. Tuck in your shirt, and pull your socks over the pant cuffs.

Apply an insect repellent to your shoes, socks, and pants. Effective tick repellents are those containing diethyl toluamide (DEET) or permethrin. Occasionally check yourself and your children for ticks, especially on the head, groin, and underarm area. Showering after coming indoors may help remove ticks that have not yet attached to the skin. Inspect pets after they have been outdoors, and remove ticks found.

For more information on insects that attack humans, please call the Purdue Extension Service at (812) 435-5287.