by Joe D. Shorthouse
MANITOULIN – Wasps and bees are well-known garden insects that are valued for pollinating our flowers, vegetables and fruit trees. However, come fall, wasps known as yellow jackets can become a serious threat to our comfort and health.
Yellow jackets are one of several species of large wasps found on Manitoulin Island. Adult wasps are yellow with numerous black markings. They have smooth bodies with few hairs compared to bees.
They are social insects that make paper nests from wood fibres. Each colony has a queen who lays all the eggs, and many non-reproductive worker females who feed the young and protect the nest. Worker females become aggressive when their nests are disturbed.
The yearly cycle of yellow jackets begins with an overwintering queen foraging in the spring for nectar and insects she captures for food. She starts a new nest by herself then her eggs turn into workers that take over foraging and enlarge the nest.
New queens and males are produced late in the season and leave the colony to mate. Workers, males and the old queen die with the first hard frost; nests are not reused.
During the spring and summer, yellow jacket workers are out in force feeding on flowers in order to nourish themselves and their colonies. They can be commonly seen searching plants for caterpillars and beetle larvae which are chewed and fed to the colony larvae.
However, in the fall after the queen stops laying eggs and there are no young to feed, and food sources become sparse, the workers begin to starve. Starvation makes them aggressive as they seek food, and this is when the chances of being stung increase.
When a yellow jacket stings, it pierces the skin with its stinger and injects a poisonous venom. Stingers of wasps are not left in the skin as is the case with honeybees. Yellow jackets can sting many times and frequently will do so if trapped between clothing and skin.
What to do if you are stung
Being stung by a yellow jacket is extremely painful and the affected area will usually begin to swell and turn red within a few minutes. A burning sensation at the site lasts for one to two hours. Itching and warmth around the injection site are also common.
Quickly applying ice in a bag or towel, or bags of frozen produce, to the site helps reduce pain and swelling. Elevating the area if it’s on an arm or leg helps reduce swelling. Take an antihistamine for severe swelling and an acetaminophen product such as Tylenol, or an ibuprofen product such as Advil to help alleviate the pain.
Applying a solution of baking soda and water with a cotton ball also helps neutralize the venom. Likewise, applying a little vinegar with a cotton ball on the affected area will act as an astringent and to keep from scratching.
For most people, a wasp sting is a temporary, treatable discomfort. However, for others, a sting can cause anaphylaxis which is a severe life-threatening allergic reaction throughout the body. People with allergies and asthma are at high risk.
If you or someone you are with has been stung, and there are signs of anaphylaxis such as hives, chest tightness, difficulty swallowing and breathing, vomiting, or fainting, call 911 or rush the person to a hospital.
Try and keep the person calm. Lie them on their back, raise their feet and cover them with a blanket. Do not give them anything to drink and avoid lifting their head, especially if they are having trouble breathing.
The danger for such individuals became evident about three weeks ago when a resident of a summer home near Sheguiandah was stung on the elbow by a yellow jacket. He was sitting on a lawn chair outside when he accidently pressed his elbow on a wasp that had landed on the arm rest.
He immediately felt the sting, and within five minutes the area became red and swollen. More worrisome was that his face began to swell within 15 minutes and he had trouble swallowing and breathing.
Fortunately, a neighbour had an epinephrine (adrenaline) autoinjector EpiPen®. He was injected and rushed to the Little Current hospital. Attending physicians in the emergency ward immediately saw that he was in a life threatening situation and gave him further medication intravenously for about two hours.
This individual quickly recovered and was told that his body would likely react more severely with future stings and that he should carry an EpiPen with him at all times. It was also recommended that he have one in his home, vehicle and fishing boat.
Some kinds of traps are on the market for yellow jackets, but they are most effective in the spring when the colonies are small. By fall, colonies can contain hundreds of individuals so traps have little impact on overall numbers. Insect repellents do not work against stinging wasps.
Stinging insects are part of Manitoulin ecosystems so we cannot eliminate them. But we can take steps to make sure we don’t attract them to us.
How to avoid being stung by wasps
The top culprit that brings yellow jackets to our yard, picnic table, or deck is food. Worker wasps are hungry and are attracted to meat, vegetables and fruit on our dinner plates.
When wasps are common in your area, never leave open cans and bottles of pop or beer unattended as wasps will try crawling inside. Check beverage cans, bottles. and glasses for wasps before taking a drink. Wasp stings on the lips, tongue or mouth are especially serious.
Cover food that is sitting outside. Set up buffets inside if you are hosting a patio party. Remove food on picnic and deck tables as soon as you finish eating and take dirty dishes inside.
Be careful where you place your hands and elbows when sitting outside. Never go barefoot in your yard or on your deck. Wasps will defend themselves by stinging if you press against them with your hands, arms, legs or feet.
Wear long sleeves, long pants, and closed-toed shoes to keep wasps from landing on your skin. Wear light-coloured clothing.
Keep lids tightly in place on garbage cans. Dispose of your bags of waste quickly at open garbage containers frequented by wasps and do not linger in the area.
Don’t swat at yellow jackets since this makes them more likely to attack. If one lands on you, remain calm and don’t make sudden movements. Slowly brush it away or wait for it to fly off.
Avoid using flowery or fruity smelling lotions, perfumes, and hair care products, all of which will attract wasps.
Avoid driving down roads with your elbow out the window. Wasps can bounce off arms and land in your lap. If a yellow jacket is in your car, stop and roll down the windows so it can get out. Stinging wasps and bees can cause car accidents.
Joe Shorthouse is a retired entomologist with Laurentian University and a summer resident of Manitoulin Island. He is on the Steering Committee of the Great Lakes Islands Alliance and helps coordinate studies of natural history on the 15 inhabited islands.