Yellow jackets are common insects known for their distinctive black and yellow markings. While often seen outdoors, they do not consume wood for nutritional purposes.
Yellow Jacket Diet
Yellow jackets have a diverse diet that changes throughout the season. In spring and early summer, adults primarily seek protein to feed their developing larvae and support egg-laying queens. They hunt live insects like flies, caterpillars, and spiders, chewing them to bring back to the nest. They also scavenge for meat from sources such as animal carcasses, pet food, and discarded human food.
As the season progresses into late summer and fall, their diet shifts. Adults develop a strong preference for sugary substances, needing carbohydrates for energy. Common sugar sources include ripe fruits, flower nectar, tree sap, and honeydew from aphids. They are also attracted to human foods like soft drinks, fruit juices, and other sweets, often appearing at picnics. This dietary flexibility brings them into regular contact with humans.
How Yellow Jackets Use Wood
Yellow jackets use wood for nest construction. They create their characteristic paper nests by scraping fibers from weathered wood sources like fences, logs, or cardboard. Wasps then chew these fibers, mixing them with saliva to create a paper-like pulp. This process transforms the raw wood into a malleable material, similar to papier-mâché.
This pulp is used to build their nests, found in various locations. Some species, like the German yellow jacket, build nests in enclosed cavities such as wall voids, attics, or crawlspaces. Other species, including the Eastern yellow jacket, construct nests underground, often in abandoned mammal burrows. The resulting paper material forms the nest’s structure, including hexagonal cells for larvae and an outer protective envelope.
Distinguishing Wood Damage
When observing wood damage, differentiate between yellow jackets and other insects that structurally damage wood. Yellow jackets do not create tunnels or holes for feeding or nesting within wood itself; they only use surface fibers for nest material. Therefore, if you find holes or tunnels in your wooden structures, the damage is likely caused by other pests. Termites, for instance, consume wood and often leave behind mud tubes on foundations or hollow-sounding wood.
Carpenter ants excavate wood to create galleries for their nests but do not consume it. Their tunnels are smooth and clean, and you might find piles of wood shavings or sawdust (frass) near their activity. Powderpost beetles create small, round exit holes, often pinhead-sized, leaving behind fine, flour-like dust. Carpenter bees bore circular holes into wood for nesting, with sawdust-like material visible beneath. Understanding these distinctions helps identify the true cause of wood damage.