Cicada killers are large, solitary wasps that can cause alarm due to their imposing size and striking appearance. Measuring 1.5 to 5.0 centimeters (0.6 to 2.0 inches) in length, they feature hairy, reddish, and black areas on their thorax and black to reddish-brown abdomens marked with light yellow stripes. Their wings are typically brownish or amber, and their legs can appear reddish or orange. While their coloration resembles some yellowjacket or hornet species, cicada killers are distinct and among the largest wasps in North America.
Nighttime Activity
Cicada killers are exclusively diurnal, meaning they are active only during daylight hours. They rely heavily on sunlight for primary activities like hunting, navigation, and mating. At dusk, cicada killers return to their burrows and remain inactive until morning.
Their reliance on light for visual cues makes nocturnal activity impractical for survival and reproduction. The absence of light prevents them from effectively locating prey or navigating their environment.
Daytime Behavior and Habitat
During the day, cicada killers focus on reproduction and sustenance. Adult wasps emerge in summer, from late June or early July, and remain active until September or October. Females fly low over lawns, searching for suitable sites to dig underground burrows. These burrows, 25–50 centimeters (10–20 inches) deep and about 1.5 centimeters (0.59 inches) wide, are often constructed in well-drained, sandy, or loose soil, especially in full sunlight.
Their most notable daytime activity is hunting cicadas, the sole food source for their developing larvae. A female cicada killer locates a cicada, paralyzes it with a sting, and transports it back to her burrow. This often involves carrying a cicada heavier than the wasp, sometimes requiring the wasp to lug its prey up a tree to gain altitude for the flight back to the nest. Males patrol nesting areas, challenging other males for territory and investigating anything that moves nearby.
Dispelling Common Concerns
Despite their intimidating size, cicada killers are generally not aggressive towards humans or pets. They are solitary wasps, meaning they do not live in colonies like social wasps such as hornets or yellowjackets, and thus have no communal nest to defend. Female cicada killers possess a stinger, primarily used to paralyze cicadas, but rarely sting humans unless directly provoked or mishandled, such as being stepped on or caught in clothing.
Male cicada killers, while exhibiting territorial behavior and sometimes appearing to “dive-bomb” people, do not have a stinger and cannot sting. Their aggressive displays are typically directed at rival males or are investigative. Encounters with these wasps are rarely dangerous, as their focus remains on reproduction and hunting cicadas.