Crossocerus cetratus

Another small, predominantly black wasp - the swollen front leg is distinctive in this species. There are several similar species and care is needed with identification. Most solitary bees and wasps are difficult to identify, and can rarely be identified from photos taken in the field. All red-rated records should include a photo or set of photos of the specimen, illustrating the key characters taken from a standard key, which should also be referenced (e.g. ‘Falk, 2015’). The full set of key characters are generally not visible in field photos and photos are rarely sharp enough. To aid in the verification of your records, please include face shot, side, top and wings. The notes should state whether male or female, and explain how the specimen met the key characters. Although NS may not be able to identify the species even if these reference photos are provided, the photos will be stored with the record and may allow it be identified in future. Alternatively, NS will accept records identified by a recognised local or national expert, or that have been identified via BWARS Facebook Group . If you have obtained this advice, please note the name of the person/organisation identifying the record in the ‘determiner’ field (e.g. ‘Stuart Roberts, BWARS Facebook’) rather than just a comment of ‘BWARS Facebook’. Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used and describe the size and identifying characters. Occurring in sunny spots where suitable nest sites are available, such as margins of woods, hedgerows, scrubby heaths, parks and gardens. Mainly May to August and more sparingly into September. Small diptera are widely held to be the main, if not sole prey items. This small wasp nests mainly in dead wood but also in hollow plant stems. It appears to utilise a wide variety of trees and shrubs. Quite widely recorded across England and Wales, just reaching southern Scotland. No additional images available for this species.