Early stages - Pachygastrinae

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Recognising the genus

1. cf Pachygaster atra (Dark-winged Black) - larva only

Photos by Daniel Blyton. Probably Pachygaster atra larva, based on dark stripes on body. Found 21 December 2020, in a North Essex garden. It was about 6mm long (not extended).

2. Pachygaster leachii (Yellow-legged Black) - confirmed by rearing

Jane Thomas found a larva in a compost bin on 26 March 2020 (Mid-west Yorkshire) and reared it through, with an adult female emerging on 16 June 2020.

Identification features for Pachygaster leachii:

3. Eupachygaster tarsalis (Scarce Black) - larva only

Photos by Martin Harvey. Found 18 September 2021, from a small rot-hole at the base of a dead branch stump at about head height on the main trunk of an oak (Quercus robur) tree. From a woodland SSSI in Buckinghamshire (an adult E. tarsalis was recorded earlier in the year at the same site). Length 6mm long. This is a rare species associated with ancient woodland, but has been found more widely in recent years. It uses a range of broadleaved trees, including beech and ash as well as oak, and may be under-recorded due to its use of small rot-holes high in the trees.