Yellowjackets: what to look for and how to prevent
By Ralph H Maestre BCE
Yellowjackets are predatory wasps that occur throughout North America. The German yellowjacket is now the dominant species in the area. A typical yellowjacket worker is about 1/2-inch long with alternating black and yellow bands on the abdomen. Queens are visibly larger, approximately 3/4-inch long. The larvae within the nests are white and grub-like. Mouthparts of yellowjackets are well-developed for capturing and chewing insects with a tongue for sucking nectar, fruit, and other juices. Yellowjackets do not produce honey, so none will be found within the nest. The nest are usually found in the ground or within a wall void made of a paper-like material and may get quite large.
Yellowjackets found in the Queens, Bronx, Brooklyn, Manhattan and Nassau county areas are social, living in annual colonies containing workers, queens, and males (drones). Fertilized queens overwinter in cavities and other protected places. These queens emerge during the warm days of April and early May. After feeding on nectar and insects, she selects a nest site within a secluded cavity. She initially builds a small paper nest in which she deposits her eggs, individually, in brood chambers. The queen feeds the young larvae for about three weeks, which then pupate and emerge as worker-daughters that assume the tasks of the nest. These workers expand the nest, foraging for food, caring for the queen and developing larvae, and colony defense. The sole duty of the queen is to lay eggs and expand the colony.
Nests are constructed entirely of wood fiber mixed with wasp saliva and are completely enclosed, except for a small opening at the bottom. The nest will quickly grow by August and late September. Adults feed primarily on items high in sugars and carbohydrates while the larvae need proteins. Adult workers chew and condition the captured insects or meat to feed to the larvae. Larvae in return secrete a sugary substance fed upon by the adults. The last generation produces new queens and males called drones that mate upon leaving the nest.
The workers, drones, and old queen die at the onset of cold temperatures, while fertilized, new queens seek protected places to overwinter. Abandoned nests typically decompose and disintegrate during the winter.
In the late summer (August-October), their food preferences change from proteins to sweets. At this time, yellowjackets are known to be persistent, unwelcome guests at picnics and other outdoor events. They fly about scavenging for food, especially sugary foods and drinks. Large numbers of the wasps may be attracted to garbage cans, sweet beverages, fruit, and perfume. Yellowjackets rarely cause structural damage to buildings, but they may build their nests in attic and wall voids. Their stings are painful and even dangerous if an allergic reaction occurs.
Yellowjackets primarily sting to protect the nest, but they will also sting away from the nest, if they are threatened or restrained.
Many insecticides are labeled for control. "Restricted Use Pesticides" can only be applied by a licensed pesticide applicator or trained service person. Control of social wasps (yellowjackets), although usually not difficult, has its element of risk of being stung. It is highly recommended to hire a professional such as Magic Pest Management Technicians to kill and remove wasp nests! Contact us today for a free on-site estimate.