Wasps are common insects, and a frequent question concerns their nesting habits, particularly whether they build nests in trees. While some species do construct their homes in trees, their appearance and location vary significantly. Understanding which wasps utilize trees for nesting, how to identify their distinct nests, and what steps to take if you encounter one can help you navigate these situations safely.
Wasps That Build Nests in Trees
Several wasp species commonly build nests in trees, including bald-faced hornets, European hornets, and certain paper wasps. These insects create their nests from a paper-like material, produced by chewing wood fibers and mixing them with saliva. The specific wasp type often dictates the preferred nesting location within a tree, whether suspended from branches or hidden within cavities.
Bald-faced hornets, a type of yellowjacket, frequently construct large, enclosed nests in exposed locations on tree branches or in shrubs. These nests are typically elevated, sometimes up to 60 feet high. European hornets, the only true hornet species in the United States, prefer sheltered nesting sites. They often build large, papery nests within hollow trees, tree cavities, or other enclosed spaces like wall voids. Paper wasps build smaller, open-celled nests that resemble an upside-down umbrella. These nests are commonly found hanging from tree branches, dense vegetation, or under eaves or porch ceilings.
Identifying Wasp Nests in Trees
The appearance of a wasp nest can provide clues about the species residing within. Bald-faced hornet nests are distinctive, appearing as large, spherical or football-shaped structures that are grayish to brownish. They are made from a papery material and typically have a single entrance hole, often near the bottom. These nests can grow to considerable sizes, sometimes reaching two feet in length and 30 inches in diameter.
European hornet nests have a papery texture and are often brownish-tan, distinguishing them from the grayer bald-faced hornet nests. These nests are usually irregular in shape and concealed within hollow trees, with only a portion sometimes visible. Unlike bald-faced hornets, European hornets rarely build freely suspended nests. Paper wasp nests are smaller and characterized by their open, hexagonal cells visible on the underside, giving them an umbrella-like appearance. These nests are attached to a surface by a single stalk or petiole and are made from a paper-like material that can vary in color from gray to brown.
Encountering a Tree Nest
Discovering a wasp nest in a tree requires careful consideration, as disturbing an active nest can provoke aggressive defensive behavior. It is advisable to observe the nest from a safe distance, as wasps will not sting unless they feel their nest is threatened. If the nest is located high in a tree, far from human activity, and poses no immediate risk, it can be left undisturbed. Wasp colonies are annual, meaning the nest is not reused the following year.
If a nest is in an area with high human traffic, such as near a pathway, play area, or close to your home, removal may be necessary. Attempting to remove a large or high nest yourself can be dangerous due to the risk of multiple stings. Professional pest control services have the equipment and expertise to safely assess and remove the nest. To help prevent future nesting, clear food sources like fallen fruit, prune overgrown trees to reduce sheltered spots, and seal hollows or cavities in trees. Homeowners can also use decoy nests or plant wasp-repelling plants like mint or eucalyptus, as wasps are territorial and may avoid areas they perceive as already occupied.