Oak Apple Gall Wasp - Biorhiza pallida

Size 2 to 3.5 mm, the sexual generation male and females wasps are a golden chestnut colour. The agamic wasps are larger, and wingless. 

The oak-apple galls are large and spongy, pale green becoming cream/pink or red, and later brown; they persist as old galls over winter.  Inside are multiple larval chambers.  They are formed by the sexual generation; the agamic galls are on the roots, and thus rarely recorded

Sexual oak-apple gall Asexual (root) gall Adult

Around varieties of oak.

Adults emerge from the Oak Apple Galls in June and July.

The spongy galls contain many insects, but each gall contains only one sex. Like many Cynipidae species, Biorhiza pallida has two generations in its life cycle. One being sexual and the other agamic (females who can reproduce without mating). With Biorhiza pallida both stages of take place on Pedunculate Oak, the more commonly seen "Oak Apple Gall" is the sexual generation on the buds and the agamic generation root gall is found on the roots of the tree.

Quite common and widespread throughout Britain.

Fairly common in Leicestershire and Rutland.