Deadwood invertebrates

This very rare micro moth’s caterpillars feed under bark of dead trees, and the adult moths fly from May to June. They need a humid environment within woodland. This beautiful species is now very rare and was believed to only survive in Somerset and Devon until recently. It is recorded to be in the Teign Valley at present.  

Relies on dead wood and possibly fungi, in Ancient Woodlands with records from Hembury Woods and southern Dartmoor.  Rare micromoth restricted to a few woodlands in the midlands, south Wales and Southern England.   

Decaying wood is perhaps the richest of all micro-habitats for true flies and supports many specialist species.   

Although exceptional communities are associated with ancient treesA tree that has reached a great age compared to others of the same species and has cultural, landscape or biodiversity value. Ancient trees are veteran trees, but not all veteran trees are old enough to be ancient. More, deadwood flies can also be found on twigs or small rot holes. Beech, aspen, elm and horse chestnut are particularly good for deadwood flies. Many of these flies are reliant, as larvae, on decomposing fungi, notably on the fruiting bodies of macro-fungi like bracket fungi, and are associated with moist white rot. 

This focus group contains a rich diversity of true flies, all of which are Nationally Scarce, unless stated otherwise. Notable species included in the group are the Orange-sided comb-horn (Ctenophora pectinicornis), a near threatenedA species likely to qualify for threatened category in the future, perhaps very quickly. More cranefly (Rhipidia ctenophora), the hoverfly also known as a flower fly (Brachyopa bicolor), and  Madiza britannica (provisionally Vulnerable). A list of all the species within this group can be found within the full deadwood flies expert profile, linked in Find out more.  

This rare beetle is an excellent example of how important it is to have a diverse range of deadwood available within the landscape. For two to three years, the larvae will feed exclusively on the heartwood of native broadleaves (e.g., oak, beech, and hornbeam) that are being decayed by oak curtain crust fungus (Hymenochaete rubiginosa). The larvae will then pupate within dry sapwood in early spring before flying as adults during warmer weather.  

 They are strongly attracted to a range of white flowers growing in sunny glades and wood edges, particularly umbel, and likely require the nectar before being able to breed. The beetle is thought to breed in old, barkless oak branches and trunks in semi-shade at wood edges, glades or rides, but has also been found in the open and on living trees where some dead heartwood is exposed.  

Of the six known British locations, the only definite colony in the southwest is located at Watersmeet SSSISite of Special Scientific Interest More, Exmoor. Key threats include the loss of suitable trees to sycamore (a densely shading invasive). Invasive non-native species such as rhododendron and Japanese knotweed are also present at Watersmeet and threaten much of the wildlife onsite through over-shading decaying wood and outcompeting native flora. However, the National Trust, who own the site, leave as much deadwood in-situ as possible and have begun a pollarding programme alongside the creation of new glades and wood pasture, as well as reduce grazing on the woodland edges.