hawk moth

elephant hawk mothElephant hawk moth (Deilephila elpenor).

hawk moth, (family Sphingidae), any of a group of sleek-looking moths (order Lepidoptera) that are named for their hovering, swift flight patterns. These moths have stout bullet-shaped bodies with long, narrow forewings and shorter hindwings. Wingspans range from 5 to 20 cm (2 to 8 inches). Many species pollinate flowers such as orchids and petunias while sucking nectar. The proboscis (feeding organ) of some species measures up to 32.5 cm (13 inches). Some hawk moths migrate.

The common name for Acherontia atropos, death’s head moth, derives from the fancied facsimile of a human skull on the upper surface of the body. Common in Europe and Africa, these moths have a short proboscis and often feed on honey from beehives. They produce loud chirping or squeaking sounds by forcing air out through the proboscis. In the larval stage they make distinct cracking noises.

The species Xanthopan morganii praedicta, named in honour of its predicted existence by Charles Darwin and Alfred Russel Wallace, exclusively pollinates the Madagascar orchid, Angraecum sesquipedale. The proboscis of this hawk moth is long enough to reach the nectar receptacle of the orchid, which is between 20 and 35 cm (8 and 14 inches) in length.

The leaf-feeding larva generally has a smooth body with a characteristic dorsal caudal horn, hence the common name hornworm. Two economically destructive North American species, the tobacco, or southern, hornworm (Manduca sexta) and the tomato, or northern, hornworm (M. quinquemaculata), attack tomato, tobacco, and potato crops. These leaf-feeding pests are green and can be 10 cm (4 inches) long. Control includes the use of a natural enemy, the braconid wasp (Apanteles congregatus), which parasitizes the larvae. Pupation occurs in an earthen cell or loose cocoon at the soil surface.

Certain species of hawk moths have been widely used in scientific research aimed at better understanding insect physiology and animal flight. The tobacco hornworm, for example, has played a key role in advancing knowledge about neurohormones known as allatotropins and their ability to regulate the biosynthesis of juvenile hormone. In addition, the discovery of the tobacco hornworm’s ability to finely tune flight control through abdominal articulation has shed light on how insects stay airborne while hovering, which is of special interest for the development of small flying robots.

The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Meg Matthias.