Cicada Killer
As their name suggests, cicada killers attack cicadas, sometimes in mid-flight. Adults of the species, scientifically named Sphecius speciosus, also feed on the nectar of flowers, but they don't generally sting humans. Cicada killers are most commonly seen in the summertime, when their underground nests can be an annoyance to gardeners. A combination of black, yellow, brown and orange, they average between 1 and 2 inches in length.
Common Thread Waisted Wasp
The Ammophila procera, as they're referred to by scientists, are only parasitic as larvae. Adult females sting and paralyze other insects and bring them to the young in their underground nests. Adults, which are black, yellow, orange and red in color, drink flower nectar and can grow to be nearly 2 1/4 inches long.
Ichneumon Wasp
Scientifically identified as the Megarhyssa macrurus, these wasps have disproportionately long abdomens. Females also have a long ovipositor that looks like a stinger but is actually used to deposit eggs deep into wood, where the larvae can feed on other insect larvae. Neither males nor females have actual stingers. Adults are brown with yellow and orange markings, and females can be more than 5 inches long including the ovipositor. These wasps are found in wooded areas of North America.
Pigeon Tremex
The pigeon tremex, or horntail wasp, is another non-stinging, wood-boring wasp. Adult females have a long ovipositor attached to their hind ends, which can be just as long as their 1 1/2-inch bodies. As with ichneumons, the ovipositors are used to inject larvae into trees. They are generally brown in color, with yellow markings.