Any chemical control should be a last option as worker populations will die following a hard freeze or a number of frosts. You can find literally many insecticide products in many different formulations labeled for hornet and wasp control. Control of these social wasps, though usually not tough, does have it’s element of danger in being stung.
It is ideal to conduct control operations on nests at dusk or even after sunset in order to avoid being stung, because almost all of the hornets and wasps will have returned to their nest.
When applications must be made during daylight hours, the use of protective equipment, like gloves, hat, bee veil, coveralls, etc., will help prevent stings from any airborne wasps and hornets.
For control of hornets and wasps that build aerial nests near windows, eaves, in trees, etc., insecticides are formulated in pressurized containers that emit a long, narrow stream of spray 15 to 20 feet. Wasp freeze or wasp stopper compounds, containing highly volatile solvents mixed with resmethrin, pyrethrins, carbamates or some of the newer pyrethroids, produce almost instant knockdown for wasps hit.
While getting close to a wasp or hornet nest, spraying in a sweeping motion, the area may be cleared of guards at the nest, followed by directing the spray stream into the entrance hole at the nest bottom to kill those inside. During the day, this technique does not alarm other hornets returning from the field.
No other insecticide needs to be introduced into the nest since all adults present are killed and the immature stages (eggs and larvae) die from lack of care. Ordinarily after one to two days, the nest can be removed carefully. Northern or paper wasp nests are easier to treat.
There are many other insecticides labeled for control including chlorpyrifos (Dursban), diazinon, allethrin, fenthion (Baytex), acephate (Orthene), cyfluthrin (Tempo), cypermethrin (Demon, Cynoff), fenvalerate (Conquer), deltamethrin (Suspend SC), lambda-cyhalothrin (Command CS, Command Pestab) and permethrin (Prelude).
Persons who are specifically sensitive to stings ought to get a few competitive cost estimates from reputable, licensed, specialist pest management providers who have the ability, equipment and most effective insecticides to get the best job done.
