Pompilus cinereus

Distribution

It is widespread throughout the Old World, including Mediterranean islands, Canary Islands, Madagascar, Sri Lanka, Japan, the Philippines, Borneo, Java, and Australia. In Britain, it is mainly found in the south, but extends north to the central belt of Scotland.

Behavior

In northwestern Europe, spiders of the family Lycosidae are the most frequent prey for "P. cinereus", spiders of the families Gnaphosidae, Miturgidae, Clubionidae, Pisauridae, and Thomisidae have also been recorded as prey, albeit with much less frequency than Lycosidae. "P. cinereus" locates in the sand or encounters on the surface a prey individual which is stung into immobility. The prey is then transported by the wasp, which holds the prey in its mandibles and walks forwards. Most frequently, the prey is temporarily interred whilst a suitable nest site is sought and a burrow excavated. Significant time and effort may be spent on trial burrows before a site is finally selected. When the nest is complete, the prey may be taken to the entrance and carried in. The prey spider is carried into a terminal cell big enough to accommodate both wasp and prey. The egg is laid on the upper forward part the prey's abdomen. The wasp then closes the burrow, pulling in the walls and roof with its mandibles and then tamping the soil with the tip of the abdomen. The spider in the cell recovers from paralysis some time between 3 and 6 hours after being stung and begins to walk aimlessly about the cell, spinning silk continuously resulting in a silk-lined cell of considerable structural integrity. After three days, the small larva emerges from the egg and begins to consume the trapped spider, killing it by consuming its abdomen.

"P. cinereus" is ecologically versatile and takes a wide variety of prey and is the dominant pompilid spider wasp in many parts of its range. The smaller males hatch from unfertilised eggs and are provisioned with smaller spider prey than female eggs.

Habitat

It is found in coastal dunes and sandy river beds and banks. "P. cinereus" shows a distinct preference for loose sand and may be abundant in sheltered, sunny areas in dune systems.