Insecticide For Yellow Jackets

Dolichovespula spp. and their sister species Vespula spp. are collectively known as yellowjackets. These black wasps with jagged yellow markings are considered beneficial because they feed on large numbers of pest insects, nectar and tree sap. Despite this, many people view yellow jackets as pests themselves, because they can deliver wicked stings when agitated.

Although yellow jackets typically prefer nesting in quiet, out-of-the-way locations, some colonies develop in areas that experience a lot of human activity. Those nests need to be eradicated to prevent painful and potentially harmful stings. The best chemical for the job depends on whether you’re dealing with an exposed aerial nest or one hidden beneath the ground.

Some yellow jacket queens build exposed nests that hang out in the open from tree limbs, shrub branches or roof eaves. Treat aerial nests with a pyrethroid-based insecticide. Pyrethroids quickly kill yellow jackets but only have low toxicity for people, pets and birds. According to Texas A&M AgriLife Extension, the common names of pyrethroids always end in “-ate” or “-thrin,” such as “cypermethrin” or “lambda cyhalothrin,” both commonly used to kill the stinging pests.

To treat the nest from a safe distance, choose a pyrethroid product that comes in a ready-to-use aerosol format with a jet propelled trigger that sprays a stream of insecticide at least 20 feet away. Shoot the pesticide directly into the entrance, usually located at the bottom of the nest, and thoroughly soak the exterior of the nest as well. Wait at least 24 hours before returning to the treatment site to check for yellow jacket activity. Repeat the spray treatment every three days until you no longer spot live yellow jackets in the nest area.

Ground-dwelling yellow jackets are more difficult to control than those living in aerial nests because they’re often located in hard-to-find abandoned rodent burrows and other protected cavities. Carbaryl-based dust pesticides effectively control subterranean yellow jacket populations, but you must get the dust inside of the nest for it to work. Once you locate the nest entrance, wait until dusk, and until you no longer see yellow jacket activity, to sprinkle carbaryl dust around the entrance hole.

Then use a hand duster or a dry liquid detergent bottle half full of the insecticide product to get several puffs of the dust inside of the opening. Immediately leave the treatment area, and don’t return for at least 24 hours. Repeat the dusting process about every three days for as long as you see yellow jacket activity in the nest area. Once you successfully eliminate the stinging insects, seal the entry hole with soil treated with carbaryl dust or a pyrethroid-based aerosol insecticide. This should keep any surviving yellow jackets from reestablishing a colony.

Mid- to late spring is the best time to chemically treat a yellow jacket nest because the queen has started establishing her colony but its numbers are still quite small. If you find an exposed aerial nest earlier in the season, simply knock it down with a strong blast of water from a garden hose. Apply chemical treatments at dusk or after dark when cool evening temperatures arrive and most of the foragers are calmly resting in the nest. Yellow jackets are sluggish and have trouble flying when the temperature dips below 50 degrees Fahrenheit.

Yellow jackets attack as soon as they sense their nest being threatened by poison. Protect yourself from both stings and chemical exposure by wearing heavy clothing, goggles, thick work gloves, socks and shoes, a hat, and a face mask or bee veil. Wear a long-sleeved shirt and pants, taping the fabric around your ankles and wrists to keep the agitated insects from getting beneath your clothes.

Light can startle yellow jackets into aggressiveness, so avoid shining a light source directly at a nest opening. If you need to use a flashlight, cover it with red cellophane because the insects can’t see red light, reveals the University of Nebraska-Lincoln. Never, ever try to treat a nest if you’re allergic to yellow jacket venom. Enlist the help of a non-allergic person or a professional exterminator instead. Always use the insecticide responsibly by not spraying on windy days and by following all of the manufacturer’s instructions