The Eastern Yellow jacket ranges in size from 1.25-1.8 cm long, depending on its caste (queen, worker, male). Perhaps the most distinguishing features on the Eastern Yellow jacket are the black and yellow stripes that accent the abdomen. The patterns on the abdomen are also determined by caste. Vespula malculifrons workers are typically 1.25 cm in length and have abdominal markings that consist of thick black bands with a sliver of yellow between each band. The male yellow jacket is the same size, but he has a slightly different pattern of black and yellow than the worker. Males have one thick black band at the region closest to the thorax and as the band progresses towards the anus, the black bands decrease in thickness while the yellow bands increase in thickness. The queen Eastern Yellow jacket is slightly larger than the male and worker at 1.8 cm. The queen's markings consist of a large flared black band at the anterior region of the abdomen followed by thinner bands of black that progresses to the posterior end of the abdomen. In between the black bands are two dots that, if the point of the flare were extended towards the anus, would be located on either side of the imaginary line.
Female Eastern Yellow jackets have a stinger located on the posterior end of the abdomen (gaster). The yellow jacket is able to sting its victims repeatedly, however the stinger is slightly barbed and has a tendency to become stuck in the victim.
The yellow jacket also has well-developed mouthparts that are specially designed to capture and chew prey (such as many kinds of caterpillars). Along with strong jaws the yellow jacket has a highly developed tongue for sucking nectar and fruit juices from the plants.
Range length: 1.25 to 1.8 cm.
Other Physical Features: ectothermic ; bilateral symmetry ; venomous
Sexual Dimorphism: female larger; sexes colored or patterned differently