Cola-Nut Gall

<em>Andricus lignicolus</em> is a gall wasp in the family Cynipidae. The name "Cola-Nut Gall" refers to the gall structure this species induces on oak trees, rather than a conventional common name for the organism itself. <em>Andricus lignicolus</em> has been recorded across parts of western and northern Europe, including Belgium, Denmark, France, Ireland, and the Netherlands. The species occupies a broad range of terrestrial and freshwater habitats within its range, reflecting the wide distribution of its host oak trees. Gall wasps in the genus <em>Andricus</em> have complex life cycles often involving alternating sexual and asexual generations, with different generations producing distinct gall morphologies on the same or different oak species. The species has not been assessed under the IUCN Red List. Diet data and specific biological measurements for <em>Andricus lignicolus</em> are not documented in available sources. Biological traits of this species remain poorly documented in the scientific literature. Its ecological role is tied to its host plants, and like other cynipid gall wasps, it likely hosts a variety of inquiline and parasitoid insects within its galls.