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Suffolk Natural History, Vol. 32
REPORT ON THE BREEDING POPULATION OF BEE WOLF WASPS (.PHILANTHUS TRIANGULUM)
AT WEST STOW COUNTY PARK
C. GREGORY The species was first identified at the site in 1983, and at the time it was believed to be the first breeding record of this species on mainland Britain this Century. Apart from a colony on the Isle of Wight, it was considered to be extinct in the U.K.; in fact the Bee-wolf has been extending its ränge quite spectacularly in recent years and many colonies have now been located in southern England.
Philanthus triangulum Q (x4) The Bee-wolf (or Bee-killer) is a solitary wasp and is common and widespread on the Continent where it is often regarded as a pest because it preys predominantly on Honeybees (Apis mellifera). In Great Britain it is still considered rare enough to be classed as a Red Data Book 2 species. Despite its name it often nests in loose colonies or aggregations in this country, usually in sandy banks and cliffs where the female wasp excavates tunnels up to a metre in length. Each tunnel has several Chambers leading from it and a Single egg is laid in each. Each nest cell is stocked with several bees which eventually provide sustenance for the newly emerged grub. Prey is caught and paralysed then slung under the wasp's body before being carried to the nest-hole. As well as eating Honeybees the adult wasps feed on nectar from plants such as thistles, heather, ragwort, toadflax and hemp agrimony. They hunt over these and other pollen-producing flowers that are likely to attract Honeybees. The Bee-wolf superficially resembles the Common Wasp (Vespula vulgaris), its abdomen is striped yellow and black, but it has a flauer head and larger mandibles. It may be possible to make an approximate identification in the field from the triangular black shapes on the abdomen and the general behaviour of the insect. However, positive identification requires close scrutiny of the pattern of the veins on the forewing. The wasp has excellent eyesight so is often difficult to approach. In flight it is faster and more manouverable than the Common Wasp. It often hovers near the nest-site. The colony at West Stow Country Park is located in the car park (TL796715) where the eroded sandy banks provide an ideal nesting habitat. Observations
Trans. Suffolk Nat. Soc. 32 (1996)
BREEDING POPULATION OF BEE WOLF WASPS
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during the summer of 1995 indicated that there are two main aggregations comprising of up to 100 nest-holes. Several females were seen entering the nestholes with prey, but at present it is not clear where the wasps hunt. Potential sites in the immediate vicinity include two of the islands in the car park, where numerous Rosa rugosa bushes grow. All the other plant species mentioned grow in the park and the wasps may also hunt in the nearby King's Forest where the open clearfells and rides support a wide ränge of flowering plants. The long, hot summer of 1995 was an exceptionally good year for this species at the park. However, it is well known in Europe for its dramatic fluctuations in distribution in response to climatic change so it will be interesting to see whether the population continues to increase in the years to come. References Falk, S. (1991). A review ofthe scarce and threatened bees, wasps and ants of Great Britain. N.C.C. Yeo, P. F. & Corbet, S. A. (1983). Solitary Wasps. Naturalists' Handbook 3, The Richmond Publishing Co. Wildlife Reports - The British Wildlife Mag., 1993, 55; 1954, 259; 1995, 123. Chris Gregory, Park Ranger, West Stow Country Park, Icklingham Road, West Stow, Bury St. Edmunds, Suffolk IP28 6HG
Trans. Suffolk Nat. Soc. 32 (1996)