Noticeable rise in New England’s swarming wasps this spring, explained
There’s something to be said for that first warm sunny day of early spring in New England.
Those of us who hail as die-hard New England’ahs know all too well the sigh of relief spring procures from winter’s snowy grip; and this spring was no exception.
We had a few teaser warm spells this year, with 60 degrees or more cresting randomly in February and March, but April tends to present itself as a true bringer of seasonal change.
April 10th saw reports of 70 degrees+ at the peak of the day, and I took full advantage with the first forest hike of the year.
By noon, my Sunday hike had turned into a full fledged work day affair, as urgent calls and emails came rolling in from prospective clients seeking reprieve from a common spring invader - the paper wasp.
With the temperatures maintaining 70 degrees for most of the day, and the sun shining bright, swarms of wasps also took full advantage of the New Hampshire spring gift - emerging from their winter hiatuses in droves to scout for new places to establish this year’s nests.
Know your foes
The Brown Paper Wasp. (Photo | Ken Thomas)
New Hampshire is home to two primary species of paper wasp - the brown (or northern) paper wasp (Polistes fuscatus) and the European paper wasp (Polistes dominula).
When not raiding personal space around the home, these wasps are considered valuable insects, particularly to gardeners - preying on a variety of caterpillars and agricultural pests.
Paper wasps differ from their stinging insect cousins - bees, hornets, and yellow jackets, mainly by their appearance.
While some subspecies have the iconic black and yellow striping (synonymous with other bee and yellow-jacket species), their dangled legs, thin body structure, and long skinny wings are noticeable paper wasp characteristics.
They also differ from other stinging insect species by their nest construction - building open celled “umbrella-like” paper nests in small clusters (ranging from the size of a cherry tomato, to the size of a large fist).
Ranging slightly in size from 15 to 21 millimeters, they prefer areas of wooded habitat. As the name implies, paper wasps require wood which they mix into a pulp with their oral fluid to construct their nests.
Each spring, the first generation of larvae develops into infertile females, which will become the workers of the newly established colony. The second stage of larvae will mature into males and fertile females - which will become the next generation of queens. Dominant queens on each nest whom have established the first spring colony will produce the next generations of queens, and die.
The average life span of an individual paper wasp is about one year.
This spring “swarm” of wasps that undoubtedly have so many homeowners on edge actually gets its start the year before - in the fall.
All The Single Ladies…
The seemingly overwhelming swarms observed this spring are likely to be all ladies - as females tend to withstand winter’s bite and emerge energized in the spring’s warmth.
Male wasps will become incredibly active during the fall to mate with females - in another “solarization” event taking place prior to winter’s onset. Unbeknownst to them, most male wasps won’t survive the winter; and tend to expire prior to snowfall.
Those fertilized females, fresh off of a mating event, will ride out the winter in the nooks and crannies of our homes, barns, garages, sheds, and natural shelters in the forest. A cache of fat stores in their bodies will assist with the task of “riding-out” the winter; and ensure the cycle of wasp rebirth commences in the next year.
Its these clusters of fertilized females (holed up in the attics and crevices of homes to survive the winter) who emerge in the spring to establish new nesting sites.
All it takes is a few warm spring days (around 70°) to awaken lethargic wasps from their winter hiatus. Whether they’ve harbored in wall voids, chimney/vent stacks, or within tree voids, these wasps emerge (sometimes on the wrong side of the walls) in their bid to start spring anew.
While mostly slow moving when trapped inside, crawling around floors or windows indoors, these wasps become incredibly active in the spring sunlight - particularly on the sunniest sides of homes around peaks of gable roofs and trim areas.
These swarming paper wasps are not particularly defensive and are not as likely to attack as they would be when defending a full nest or during the fall mating time. This sunny swarming behavior tends to subside at the end of the day once temperatures cool down.
Establishment is key
Once the average spring temperatures become consistent, female paper wasps will build a new nest and start to lay eggs for the upcoming seasonal brood. Occasionally, two dominant females will remain on the nest, jockeying for the title of queen of the new colony.
A traditional New Hampshire paper wasp nest. Note the umbrella-like shape. (Photo | Jeff Traynor, A.C.E.)
While the overwhelming presence of hundreds of swarming wasps on a warm spring day is short lived, the activity is a good indicator of where you can expect the paper wasp’s telltale “umbrella-shaped” nests to be found later in the season.
These nests tend to be found most commonly on the sunny sides of homes, where your structure’s soffit and gable points mimic that of the wasp’s natural nesting sites on the sides of rocky mountains and trees.
Nests are constructed using wood pulp and saliva, forming exposed oval combs with visible hexagonal cells used for laying eggs. Once a cell is filled with a fertilized egg, it is sealed with an orb-like white cap of silk. Upon emergence, larvae are fed caterpillars.
Outside of chemical control, some preventive measures to reduce paper wasp entry include caulking or screening around window sills, pest-proofing exhaust vents, and screening gable or attic vents to reduce the number of entry points for wasps to access the structure indoors.
Monadnock Pest & Wildlife Services offers a catalog of wasp control services to address immediate stinging insect issues around your home. Our years of experience and dedication to understanding this insect’s biology allows us to selectively address wasp harborage and nesting sites, as well as active wasp/hornet nests that pose a threat to your property and safety.
We also offer a fall treatment which aims to reduce the entry of overwintering female wasps into your home’s attics and walls - to lessen their emergence throughout the winter into your home’s living spaces. Our treatments are performed with consciousness placed upon the surrounding environment and other beneficial insects.
Read more about our Wasp Treatment Programs (here) and Fall Invader Programs (here).
Having trouble with wasps? Not keen on sharing your home with stinging insects? If you live in southern New Hampshire, I’m willing to help - contact Monadnock Pest & Wildlife today to assist with minimizing paper wasp presence around your home this summer!
