Oak apple gall wasp

Biorhiza pallida

1.7 to 2.8 mm. Small, brown wasp. Galls are spherical, reaching more than 30 mm in diameter

What habitats does it normally live in?

Oak trees.

What does it feed upon?

Oak apples appear on oaks in April or May. Males and females emerge from the galls in June or July. Males appear a day to two in advance of the females and the galls often contain only one sex. Females deposit eggs in the root of the oak. Each gall is only about 10 mm in diameter and contains a single larva. The adults, which emerge in December or January, are all wingless females. These crawl up the tree to lay eggs in buds in the canopy. These result in oak apple galls and the sexual generation of gall wasps.

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