Blotched Barkfly

Graphopsucus cruciatus

This species is about 3 mm long. This is one of many species of Barklouse in Britain which usually go unnoticed. These small, harmless insects feed on microscopic mould, fungi, and starch. Despite their name, they are not true lice, do not bite humans, and do not transmit diseases. They are usually found outdoors on tree trunks, branches, and foliage, where they consume micro-organisms such as algae, lichen, and fungi. When disturbed, they primarily walk, crawl, or fly away. Barkflies play a beneficial role in the environment as scavengers, grazing on micro-flora and epiphytes on bark and leaves. They are often found in woodlands and gardens, favouring trees like oak, beech, yew, and pine, and are particularly abundant in areas with significant lichen or algae growth. Barklice belong to the same scientific order as booklice, but the term "barkfly" is now often used to distinguish the outdoor species from household pests.