Wasps are commonly encountered social insects that vary in size, appearance and behavior. These insects may cause people concern due to their stinging habits. Yellowjackets and bald faced hornets tend to be the most feared of the family Vespidae, and easily differentiated by body coloration. Yellowjackets have alternating black and yellow bands on the abdomen, while bald faced hornets have white markings on the head, thorax and abdomen.
There is a difference between wasps and bees. Wasps have a shiny appearance, with a slender body, thin 'waist' and wings that are held lengthwise at rest. Bees are covered with more hair, have broad mid sections and specialized hind leg and abdominal hairs for collecting pollen. Unlike some bees, wasps have smooth stingers that enable them to sting repeatedly. This can be especially dangerous and possibly fatal for individuals who have allergic reactions to the venom that is injected with a sting.
Wasp Prevention
- Keep screens for doors and windows in good repair. Seal any potential entry points such as window cracks, doorframes and vents.
- Place garbage into a bin or can with a lid that is well fitting.
- Destroy abandoned animal burrows (e.g. gopher holes) before wasps inhabit them. It is common for ground nesting wasps to use such structures as a nest location.
- Cover and/or remove food wastes to reduce wasp encounters. Food sources left outdoors in the form of compost piles, animal food, and leftovers from picnics and barbecues are attractive to wasps in spring and early summer when they seek protein-based foods
- Keep food containers closed and pop/juice drinks covered. In late summer and early fall when food supplies are dwindling, male and worker wasps scavenge for food and may act aggressively while in pursuit of sweet tasting food.
- If you have fruit trees in your yard, remove all over-ripened or rotting fruit lying on the ground or attached to a branch.
Wasp Trap
Using materials around the home such as pop or plastic milk bottles, you can construct a homemade wasp trap. Pour fruit juice into the trap container to a depth of 2 inches and add a small piece of raw meat (hamburger or fish). An odor that attracts wasps will be given off as the juice ferments and the meat spoils. When wasps enter the bottle, they will fall into the juice and drown. In order to get the best results you may have to experiment with the amount of each ingredient and type of container used. A trap will be most effective if drown wasps are removed regularly and ingredients are replaced.
Removing Wasp Nests
Nests for both species consist of layers of comb that are made out of chewed up wood fiber. Wasp nests that are found in an around areas of human activity may require control measures if they raise concern about stings.
To ensure personal safety, wear layers of protective clothing that cover the entire body. Even a small exposed area could become a target for wasps. In addition, it is recommended to wait until dusk or dark since wasps are more docile and slower to react at cooler temperatures.
Do not attempt to destroy a wasp nest by burning or flooding, as wasps will respond with aggression. Also, do not use gasoline to control ground-nesting yellowjackets due to potential fire hazards and environmental damage.
Ground Nests
First locate the nest entrance by observing where wasps are flying in a straight line. This is likely the path to or from a nest. Cover the entrance with a large, clear bowl. To ensure that wasps cannot escape, push the bowl into the ground and leave it in place for a few weeks. This strategy will confuse wasps and is effective if there are no other entrances. The wasps are unlikely to dig a new entrance.
A second alternative is to pour soap and water solution into the nest entrance. If this does not effectively control the wasps, use a registered lawn or soil insecticide.
As a last resort, cover the nest entrance with soil and pack the surface soil down so that the wasps become entombed.
Concealed Nests
These are often located in walls, along foundations or in attics of houses, which can often be difficult, so contacting a pest control company is recommended. An insufficient control strategy may inadvertently force wasps to move further into a home and become a greater nuisance.
Exposed Nests
There are various remedies to eliminate nests that are visible (e.g. in tree branches or under eaves). The easiest is a wasp and hornet aerosol that can be sprayed into the nest entrance. Follow the label directions for optimal results. If wasps still persist, repeat the aerosol application in subsequent day.
Mechanical control is an option for nests that are accessible and not too large, although there is a greater risk of being stung. At night, quietly approach the nest and place a bag over the nest, quickly tie it off and remove it from its point of attachment. Either a cloth (such as a pillow case) or plastic bag will work. Once tied, place the bag into a pail of water and place a rock on top of it to submerge the nest and drown the wasps. Placing the bag in a freezer or leaving it in direct sun will also destroy the wasps.
Various wasp control products are available at most home and garden centres. Some of these products include hornet and wasp killer foam, pest strips and yellow jacket/wasp traps.
Old Nests
Wasps never re-use a nest, so if a nest is found in winter or spring, you will not encounter live wasps and the nest can be safely removed.
