Wasps are social insects that live in colonies and build nests to house their larvae and store food. Many species of wasps, like yellowjackets and hornets, build intricate nests out of paper made from chewed wood fibers mixed with saliva. These nests can often be spotted hanging in trees, under the eaves of houses, or in holes in the ground. But what happens to these nests at the end of summer when the colonies die off? Do wasps reuse the same nests year after year or do they build new ones from scratch each spring?
The Annual Life Cycle of Wasps
All species of social wasps have an annual lifecycle that revolves around the founding of new colonies in spring. In temperate parts of the world, wasp colonies completely die off at the end of summer and autumn with the exception of young, mated queens. These fertilized queen wasps go into hiding over winter, emerging in the spring to start building small starter nests.
Founding the Nest
Once spring warmth awakens her, the queen begins gathering fibers from old wood, plant stems, and cardboard to build a small nest about the size of a walnut. She builds it up into a papery comb with hexagonal cells. Inside the cells, she lays her first tiny eggs and feeds the larvae that hatch from them. These first offspring will grow up to be sterile female worker wasps.
Expanding the Colony
Once the first worker wasps have matured, they take over nest expansion duties from the queen. They collect more fibers and enlarge the nest, building up more combs and hexagonal cells. The queen then dedicates herself solely to egg-laying while the workers maintain and provide for the colony. Nests can grow to house several thousand wasps by late summer.
Decline of the Colony
Wasps have completed their life cycle by late summer. No more larvae are raised and the current adult wasps begin dying off. The queen stops laying fertilized eggs and instead lays unfertilized eggs that hatch into males. These males mate with new queens to fertilize them before themselves dying off. By autumn, the original queen, workers, and males have all perished, leaving mated new queens to overwinter and restart the cycle in spring. The abandoned nest eventually weathers away.
Do Wasps Reuse Nests?
With very rare exceptions, wasps do not reuse nests year after year. There are a few reasons for this:
Nests Deteriorate Over Winter
Even though wasp nests are sturdily built from wood fibers and saliva, they cannot stand up to months of exposure to rain, snow, and wind. The paper envelopes that encase the nests are particularly vulnerable to deterioration. By spring, most abandoned wasp nests have become too weather-beaten to offer much structural integrity for a new colony.
Disease Risk
Old nests contain pathogens, shed exoskeletons, and food waste that can harbor diseases dangerous to developing wasp larvae. Reusing an old nest would expose the colony to excessive risk of infection. Starting with a new clean nest helps control disease.
Lack of Space
Wasps need room to expand their colonies over the course of a summer. An old nest from the previous year would be too small to accommodate the growth of a new colony. Queens need to start fresh with small starter nests that can be built up over the seasons.
Difficulty Finding Old Nests
Even if they wanted to reuse a nest, new queens would face great difficulty locating the previous year’s nest in the spring landscape. Nests are often well-hidden or in high, inaccessible places. And with vegetation dying back, landmarks for finding old nest locations disappear over winter. Starting a nest from scratch in a new site is easier for foundresses than finding old ones.
Exceptions
There are a handful of wasp species that do reuse nests for more than one year:
Tropical Social Wasps
In tropical climates where colonies do not die back entirely, some social wasp species like umbrella wasps occupy the same nest for multiple years. The nests may require annual repairs and expansion, but the framework remains usable from one year to the next.
Polistes Cristatus
This paper wasp native to parts of Europe will occasionally reoccupy and repair old nests in the spring if they are still intact and usable. However, starting a new nest from scratch is still more common practice.
Vespula vulgaris
The common wasp of Europe has been known to reuse parts of abandoned nests to expand their new colonies in spring. Again, full nest reuse is uncommon but partial reuse of materials does occur.
Do Related Species Reuse Nests?
While social wasps themselves rarely reuse entire nests, old wasp nests are often recycled by other animal species:
Birds
Birds like house wrens, chickadees, and bluebirds will readily move into old wasp nests. The paper provides insulation, warmth, and a solid base for building a new bird’s nest inside. Woodpeckers may also excavate holes in old nests for roosting and nesting.
Insects
Honeybees, bumblebees, and solitary wasps like mason wasps will occupy old social wasp nests. Bees fill cells with nectar and pollen or lay new eggs inside. The sturdy paper walls provide excellent protection.
Mammals
Mice, rats, squirrels, and bats may take up residence in an old wasp nest for its warmth and shelter. The complex structure of combs and cells makes an ideal habitat.
Reptiles & Amphibians
Snakes and lizards will bury inside a abandoned wasp nest to safely hibernate through winter or escape summer heat. The insulation keeps their body temperature stable. Frogs and toads may also burrow into ground nests.
Conclusion
While wasp nest reuse from year to year is uncommon, the nests do not go to waste. Their intricate and sturdy construction makes them valuable real estate for many other animal species seeking food, shelter, insulation, and nesting sites. The wasps’ labor goes on to benefit birds, mammals, reptiles, amphibians, and even other insects. So even after the wasp colony is gone, their nest continues to provide key ecological services in nature.