Will this be a “wasp” summer? We wonder with some trepidation whether we will be retreating from the picnic table or the barbecue area and rushing to put up wasp traps. As the season approaches when these insects are prevalent, it seems like an opportune time to increase our understanding of what role wasps play in nature and what our best options are for comfortably co-existing.
Wasps are found everywhere in the world with the exception of the polar regions.
Solitary or Social
Wasps can be divided into two groups: solitary and social wasps. The vast majority of wasps are solitary. It is estimated that there are over 100,000 species of wasps; of this number only 1000 species are social.
Solitary wasps are a very diverse group but, generally, an individual female solitary wasp will choose a nest site in a variety of cavities above or below ground and operate independently to build the nest and provision it.
The most commonly known wasps, such as yellowjacket wasps and bald-faced hornets, are in the family Vespidae and are eusocial. This term indicates that they live together in a nest with an egg-laying queen and non-reproducing workers.
Common Types of Wasps on the Sunshine Coast
Although there are approximately 18 species of wasps in BC, the 3 most common types of wasps on the Sunshine Coast - yellowjacket wasps, paper wasps, and the bald-faced hornets - are all social wasps.
Yellowjacket wasps are the smallest of these three, and much brighter with distinct black and yellow stripes.
Paper wasps are larger, not as bright and dangle their legs in flight.
The bald-faced hornet is black and white with most of the white on their heads. It is commonly referred to as a hornet because of its large size and aggressive nature, but the bald-faced hornet is actually a relative of the Yellow Jacket.
Characteristics and Anatomy
Like all insects, wasps have a hard exoskeleton and a three-part body (head, thorax and abdomen).
The head has one pair of sensory antennae. At the sides of the head are two kidney-shaped clusters of compound eyes and on the top of the head are three simple eyes known as ocelli. These provide the wasp with low-resolution vision. Current research suggests that some wasps have developed the ability to recognize the faces of other wasps and can learn to recognize human faces. There is growing opinion that wasps are smarter than we originally thought. Adult social wasp mouthparts include mandibles (for tearing up prey, harvesting wood and building the nest) and a short tongue (for taking up sugary fluids and water).
The thorax features six spindly, jointed legs and two pairs of membranous wings. Hooks appear in a row on the smaller hindwing and catch on to a ridge on the lower margin of the larger forewing. These hooks, called hamuli, allow both wings to operate as one and ensure well controlled flight.
The wasp, like many other insects, stays aloft and hovers by using a wing maneuver known as “clap and fling”. This involves clapping its wings together and flinging them open some 400 times a second.
The abdomen contains the majority of the wasps' organ systems. In the female, the abdomen ends with the stinger. These stingers are highly modified ovipositors (egg-laying tubes) that are connected to venom glands. The stinger is not barbed (unlike a bee’s) and can be used many times in defence of the nest or when threatened. Male wasps are considered harmless.
All wasps make nests. The nesting sites of social wasps are chosen by the queen wasps who look for locations that offers shade, warmth, shelter and protection from predators. Consequently, you will find wasp nests in the ground, in trees, in compost heaps, and in hollow logs etc. They also choose a large variety of urban and suburban locations and use man-made structures to build nests under decks, eaves, porches and in garages and attics etc.
The diet of a social wasp changes significantly when it leaves the larva stage and becomes an adult. Larvae are carnivorous and are fed spiders, flies, caterpillars, beetles, crickets, and aphids, etc. that have been caught and chopped up by the adult workers. Adult wasps feed on sugary fluids: a sugary liquid regurgitated by the larvae, nectar from flowers and honeydew from aphids. Late in the season with the decline of larvae, adult wasps are pressed to find sugary substances in rotting fruit, garbage cans and outdoor eating venues
Large nests with hundreds or thousands of wasps are amazing architectural structures. They consist of a honeycomb-like series of six-sided cells that are the work mainly of female worker wasps. These wasps chew very thin strips of dead wood that they scrape from logs, fencing, garden furniture, etc.
The mixing of these thin wood fibres with the wasp’s saliva results in a pulp that is used in constructing the cells. As the pulp dries, it forms a sturdy paper nest where young wasps will be born and develop.
Much can be said about these nests, but to gain a visual appreciation and a detailed understanding please watch the following video: "What’s Inside a Wasp’s Nest".
Yellowjacket wasps prefer to build nests completely or partially below ground in cavities such as abandoned rodent burrows.
Stylised cross section of a social wasp nest. landcareresearch.co.nz
Bald-faced hornets often build large football-shaped nests above ground at a height of 3 feet or more in trees or man-made structures.
Bald faced hornet nest, source: University of Maryland
Paper wasps tend to build small umbrella-shaped nests; the cells open to view because there is no external envelope. These nests are often secured under eaves and porches. Nests are occupied from spring until late fall and then abandoned. The following year will see a new queen, a new site and a new nest.
Paper wasp nest
Life Cycle of a Wasp
The four stages of wasp development (egg, larva, pupa and adult) all take place in the cell. From the time the queen lays an egg in a cell until the new adult emerges takes approximately 28-48 days depending on environmental conditions.
The eggs hatch into larvae in 5‒8 days. The workers and the larvae now embark on a symbiotic feeding exchange where the workers feed insect prey to the larvae and the larvae produce a sugary substance that sustains the workers. Because the worker wasps have very few enzymes in their guts, they cannot digest much of the food they gather and so feeding the larvae becomes part of an essential cycle for both adult worker wasp and developing young.
After five moults over about 15 days each larva spins a silken cap over the cell and enters the pupa stage. An adult wasp will emerge 8-18 days later.
Life Cycle of the Wasp Colony
Each year the life cycle of a wasp colony begins in early spring with a new queen wasp, and ends in winter with the death of the colony’s queen.
The new queen wasp awakes from hibernation in the spring and after a short period of feeding and exploring, she flies off on a journey, sometimes as long as 70 km, in search of the perfect dark, dry nesting site. She builds the first few cells of this new nest and then lays eggs that develop into the first worker wasps. Once the workers take over the duties of enlarging and guarding the nest, rearing the young, and foraging for food, the queen settles into her primary task of egg-laying, producing 200-300 eggs each day.
This is a time of rapid growth for the colony. Aerial wasps with nests in trees are estimated to have between 100 and 1000 wasps and underground colonies often grow to have 2000-4000. Workers continue to add cells to the nest and many nests that started out the size of a golf ball approach the size of a football.
Towards the end of summer, the growth of the colony has reached its maximum and the queen lays the last of her eggs. These eggs will produce the new queens and fertile male drones.
With the end of summer and the advent of cooler weather, the existing queen reaches the end of her life and the organization and purpose of the nest fade away. The remaining wasps have no commitment to the nest, no larvae to provide them with food and dwindling sources of nectar in the environment. It is at this point that wasps are found searching for sugary foods, such as a rotten fruit and being particularly annoying around any food you may place on your picnic table.
The new queens have emerged, been fertilized by the male drones and flown off to find a safe crevice to hibernate in for the winter. Once all food sources have disappeared the worker wasps and the male drones die and the life of the colony is at an end.
Keep Wasps Away
The following information is summarized from the BC Government site www.2.gov.bc.ca (Yellow Jackets)
When eating outdoors, keep food and drinks covered and clear away scraps or dirty plates as soon as the meal is over.
Set up baited yellow jacket traps around the edge of picnic areas or on the table – drown wasps caught by sinking the traps in a bucket of soapy water.
Remove nests early in the season while they are still small and leave larger nests until the end of the season when the wasps die.
Use chemical wasp sprays with caution and wear gloves to remove and dispose of an exposed nest that has been sprayed as soon as the wasps are dead.
Don’t use poison baits and never pour gas or kerosene into an underground wasp nest where it poisons the soil.
Consider using a professional pest control service for nests that are very large or in locations that are difficult to access.
Avoid Getting Stung.
Minimize Your Chances of Getting Stung
Remove all outdoor food sources attractive to wasps – feed pets indoors, keep garbage cans tightly covered, wash cans regularly, bury fallen fruit and table scraps deep in compost piles and don't compost meat scraps or bones.
Watch where you sit or step – don't go barefoot!
Be especially careful to look before reaching into berry bushes or picking fruit and pick in the early morning or evening when wasps are less active.
Be cautious when sitting on or handling wet beach towels.
Never swat at a yellow jacket hovering around you – instead, quietly move away or let the wasp leave.
If you accidentally disturb a nest and hear buzzing, protect your face with your hands and run!
Ecological Role of Wasps
While there is still much to be learned about wasps, it is clear that they are greatly under-appreciated. The good that they do goes largely unnoticed. The wasp is a predator and a rather non-fussy one at that; happy to prey on the pest that is available and/or abundant. As a result, farmers and gardeners are getting a superb pest control service without the use of toxic pesticides. It is not an exaggeration to say that predatory wasps are one of nature's most effective regulators of pest populations. It is evident that without wasps we would have a much greater problem with crop damage caused by insects, such as caterpillars and aphids.
Because wasps seek nectar, they also contribute to pollination, although not as efficiently as bees since their bodies are not hairy. Again, because wasps are generalists they are thought to fill a gap by pollinating a broader range of plants. Researchers have found evidence of wasps visiting 960 plant species. Among these plants were 164 species that are completely dependent on wasps for pollination, including some species of orchids. Being less fussy means that wasps may be useful back-up pollinators in habitats such as cities and farmland, where there are not enough of the right kinds of flowers for bees to thrive. Wasps may become more important pollinators in the future, as more of the natural world becomes disturbed and urbanized.
The last word from an article in earth.com: “…many wasp species are declining from factors such as climate change and habitat loss. As such, there is urgent need to address their conservation and ensure that habitats continue to benefit from the far-reaching ecosystem services that wasps provide."
Food for Thought
What We Have Learned From the Way Wasps Build Their Nests
There is an interesting connection between wasps and the making of paper. Early paper was made from things like rags, bamboo and mulberry plants. Thanks to a nature walk by a French scientist named René-Antoine Ferchault de Réaumur, scientists began to observe that wasps had the ability to make a durable paper-like substance. The idea from paper wasps finally took hold in the mid 1800’s and after much trial and error, wood-based paper has become the norm.
The following paragraph, found on line, is food for thought. “Wasps had it down since the beginning and we took almost 2000 years to figure it out. With the mass expansion and new ease of making quality paper at a fraction of the cost this also lead to the new boom and greater forms of mass communication for humanity as a whole. It’s interesting that watching a few bugs building their home could have such an impact on such an important resource humans have used over the centuries. So the next time you swing a newspaper or book at a wasp, pause to contemplate the irony of the situation!”
Buzz Off by CBC, facts about wasps: https://www.cbc.ca/news/canada/prince-edward-island/pei-wasps-1.3754751
Hiking website with excellent information: https://gohiking.ca/animals/insects/wasps/
Government of British Columbia: https://www2.gov.bc.ca/gov/content/environment/pesticides-pest-management/managing-pests/insects/yellow-jackets?keyword=wasp
Britannica website page on Wasps:https://www.britannica.com/animal/wasp
Amanda, a bee conservationist and enthusiast has created an impressive website that includes wasps: https://www.buzzaboutbees.net/about-wasps.html
Article: Much-Maligned Wasps do us a World of Good by Daniel T Cross: https://www.sustainability-times.com/environmental-protection/much-maligned-wasps-do-a-world-of-good-for-us-and-the-environment/
BeesWiki website, includes Wasp Identification: https://beeswiki.com/wasp-identification/
Wikipedia - Wasp: https://en.wikipedia.org/wiki/Wasp
Wasps are Valuable for Ecosystems, Economy and Human Health (just like bees), article about a review paper by researchers at UCL and University of East Anglia. Source, University College London: https://www.sciencedaily.com/releases/2021/04/210430093209.htm