There is little doubt among scholars that the Hebrew and Greek words refer to both hornets and wasps.

Hornets and wasps are closely related species, with the hornets being larger than the wasps. Like bees they both belong to the zoological order Hymenoptera, which means that they have stiff, transparent, membrane-like wings. The hornets are usually black or brown; some species have yellow bands. Wasps are often greenish and may also have yellow or light green bands. The larger hornets can be 30-40 millimeters (1-1.5 inches) long.
Both hornets and wasps are characterized by having a long narrow waist between the thorax (chest) and the abdomen (stomach). All have a sting that, because of their large size, can be very painful, even dangerous. Unlike bees, hornets and wasps do not have a detachable sting and can sting repeatedly. They feed on insects, caterpillars, and spiders, and many types sting their prey and then deposit the paralyzed but still living insect or spider near the hornet’s eggs, as a readily available source of food for the larvae when they hatch from the eggs. Some species actually lay their eggs on the paralyzed victim.

One of the most dangerous varieties is the Oriental Black Ground Hornet Vespa orientalis, which establishes large underground nests. They are large shiny black hornets, and when their nest is disturbed they emerge in numbers and attack any animal or person nearby. They are very sensitive to vibration, and a single animal or person walking nearby is enough to arouse them. Once they begin to sting, the smell of the sting arouses them even further, and they may remain in this angry state for hours, with each fresh sting stimulating their ferocity afresh. Some of their victims may end up paralyzed or may even die.

Black ground hornets are found across tropical Africa, through the Middle East, and across Asia to eastern China. In many of these countries known black ground hornet nest sites are marked in some way, such as with a sharpened stick pointing to the nest, as a warning to passersby.

It is little wonder that hornets are a symbol in the Bible for a dangerous enemy or an attacking army.

Although hornets or wasps are found in most warm countries, some large dangerous-looking hornets are relatively harmless. For instance, the black house hornet found all over Africa does not live in swarms but on its own. It makes mud nests on walls or under a roof. It is large and has a sting, but it is not aggressive and very seldom stings any person or animal. Thus care should be taken by translators to choose the name of a hornet that both lives in swarms and is dangerous. In cases where all local hornets or wasps are relatively harmless, a descriptive phrase meaning “warrior hornet”, “war hornet”, “army hornet”, “death hornet” or something similar can be used.

Source: All Creatures Great and Small: Living things in the Bible (UBS Helps for Translators)