Ammophila sabulosa


Ammophila sabulosa, the red-banded sand wasp, is a species of the subfamily Ammophilinae of the hunting wasp family Sphecidae. Found in northern Europe, the wasp is notable for the mass provisioning behaviour of the females, hunting caterpillars mainly on sunny days, paralysing them with a sting, and burying them in a burrow with a single egg. The species is also remarkable for the extent to which females parasitise their own species, either stealing prey from nests of other females to provision their own nests, or in brood parasitism, removing the other female's egg and laying one of her own instead.

Description

Ammophila sabulosa is a large and striking solitary wasp with a very long narrow "waist" of two segments. The species can be told from A. pubescens as the waist widens out very gradually into the "tail" of the abdomen. The pattern of the forewings also differs: the third submarginal cell makes broad contact with the cell to its front and the rear end of the abdomen has a faint metallic blue sheen. The whole body is black except for the front half of the "tail", which is orange.

Behaviour

The adults fly in summer on heathland and sandy places, hunting for caterpillars. The wasp grabs the upper side of each caterpillar, and angles her long abdomen around under the caterpillar to sting it on its lower side, paralyzing it. The female digs burrows in sandy ground, provisions each burrow with a food supply of paralyzed caterpillars, and lays one egg, always on the first caterpillar. A female may make up to ten nests, one at a time; about half the nests are provided with one large caterpillar, and half with two to five smaller caterpillars. The burrow is sealed with stones, twigs or pieces of earth and then covered with sand. The female camouflages the nest with debris such as pine needles and pebbles unless the surface in the area is bare sand. Females are normally active only in direct sunlight. Nests are nearly always mass provisioned, which means fully stocked with enough food to take the wasp larva through to pupation, and then permanently closed.

Brood parasitism

Females often parasitize their own species, either stealing prey from nests of other females to provision their own nests, or in brood parasitism, removing the other female's egg and laying one of her own instead. Brood parasitism "appears to be a cheap and easy route to producing offspring", as it takes only about 30 minutes to switch eggs in an existing nest, but about 10 hours to build and provision a new nest; however, more than 80% of brood-parasitized nests were themselves parasitized by another female.

Distribution

Ammophila sabulosa is widely distributed across Eurasia with records from France, the Netherlands, Germany, Austria, Hungary, Poland, Norway, Sweden and Finland, then ranging eastwards as far as the Russian Far East, with a very few records in India and Japan. It is also found in the southern half of Britain.

Former Subspecies

Several subspecies have been described, but none of these are presently considered as conspecific with sabulosa;