The term “ground hornet” commonly refers to certain species of yellow jackets that build nests underground. Understanding their distinct visual and behavioral cues is important for accurate identification and differentiation from other insects.
Defining Physical Characteristics
Yellow jackets, often called ground hornets, possess specific physical traits. Worker yellow jackets typically measure 0.47 to 0.6 inches (12 to 16 mm) in length, while queens are noticeably larger, ranging from 0.75 to 1 inch (19 to 25 mm). Their bodies are sleek and shiny, lacking the dense hair found on many bees, and feature a segmented structure with a distinct, thin waist.
Their most recognizable feature is black and yellow coloration. They display alternating black and yellow bands across their abdomen, with specific patterns varying slightly among species. Their faces are often yellow with dark eyes, and the thorax may exhibit a prominent yellow stripe. Some species may have black dots forming rings on their abdomen, or even black and white markings, such as the bald-faced hornet, which is a type of yellow jacket.
Yellow jackets have six thin, typically yellow legs, which are not designed for carrying pollen. Their antennae are conspicuous and long, usually black. They have two pairs of elongated, transparent wings that appear dark. When at rest, yellow jackets characteristically fold their front wings lengthwise against their bodies.
Behavioral Cues for Identification
Yellow jackets are primarily identified by their nesting habits. They construct nests underground, often utilizing abandoned rodent burrows or other existing soil cavities. Nests are built from a paper-like material, created by chewing wood fibers and mixing them with saliva.
An active ground nest entrance is often a small, inconspicuous hole. This opening will have consistent insect activity, with yellow jackets flying in and out. Sometimes, a horseshoe-shaped mound of excavated dirt is visible at the tunnel’s opening, indicating recent digging activity.
Their flight patterns near the nest are distinctive. Yellow jackets exhibit a rapid, side-to-side flight before landing directly at the nest entrance. These insects are highly protective of their colonies and can become aggressive if their nest is disturbed or approached too closely. They are capable of stinging multiple times and will release alarm pheromones to alert other colony members if they feel threatened.
Distinguishing from Similar Insects
Distinguishing yellow jackets from other insects is important for accurate identification. Honey bees, for instance, are often confused with yellow jackets but have key differences. Honey bees are covered in dense, fuzzy hair and possess flattened, hairy hind legs adapted for carrying pollen, while yellow jackets have sleek, mostly hairless, glossy bodies. Honey bees are generally less aggressive and typically sting only once, losing their stinger in the process, unlike yellow jackets that can sting repeatedly.
Paper wasps also differ from yellow jackets in appearance and nesting behavior. Paper wasps usually have a more slender body and a narrower waist, and their coloration often includes more brown with yellow or red markings, rather than the bright yellow and black of yellow jackets. They build exposed, umbrella-shaped paper nests, often hanging from structures, whereas yellow jackets typically nest in enclosed cavities, especially underground. Paper wasps are generally less aggressive but will defend their nests if provoked.
Cicada killer wasps are another insect sometimes referred to as a “ground hornet.” These are significantly larger than yellow jackets, with females reaching up to two inches in length. Cicada killers have black bodies with yellow markings on their thorax and reddish-orange or brownish wings. Unlike social yellow jackets, cicada killers are solitary wasps that dig individual burrows in the ground, and they are generally less aggressive unless directly threatened.