Invertebrates living in dead wood on the Northmoor Trust Estate
'one of the two or three greatest resources for animal species in natural forest' (Charles Elton 1966)
There is more to 'dead wood' than the humble rotting log. 'Dead wood' is a broad term used to cover a wide variety of features mainly associated with mature and dead trees.
There have been no detailed surveys of the dead wood species occurring at Little Wittenham NR, but a number of characteristic species have been collected by chance during the course of general invertebrate surveys.
Hoverflies, in particular, have been well recorded both by hand-netting and Malaise trapping of the reserve's wetlands. A good number of hoverflies with larvae occupying dead wood habitats have been discovered. Examples are the Criorhina berberina (associated with hollow trees), Brachypalpoides lenta (wet rot holes) and Volucella inflata (sap runs). Another dead wood fly of note is the Cranefly Tanyptera atrata, a large and spectacular ichneumon-wasp mimic.
The majority of these flies are typically associated with ancient deciduous woodland and the list compares favourably with other ancient woodlands in Oxfordshire. This suggests a long term continuity of dead wood habitat on or adjacent to the reserve.
Dead wood beetles are notoriously elusive, but the few collected 'by accident' include three species of Jewel Beetle Agrillus spp. All are associated with dead limbs on over-mature oak trees. Many more species undoubtedly await discovery. These and other species of note are listed in the table below.
Some of the less common Invertebrates utilising Dead Wood recorded from LWNR since 1990.
| Species | GB Status | Preferred Habitat | Larval micro-site |
| Craneflies | |||
| Dendrotipula flavolineata | Local | Ancient woodlands | Rotting wood |
| Dictenidia bimaculata | Nb | Fens or ancient woodland | Rotting wood |
| Tanyptera atrata | Nb | Damp or heathy woods | Rotting wood |
| Soldier flies | |||
| Eupachygaster tarsalis | Nb | Parks and woods | Under bark of decaying trees |
| Neopachygaster meromelaena | Nb | Parks and woods | Under bark of decaying trees |
| Praomyia leachii | Local | Woodland and hedges | Decaying wood |
| Xylomyiidae | |||
| Solva marginata | Nb | Ancient woodlands | Rotting wood |
| Assassin flies | |||
| Laphria marginata | Nb | Ancient woodlands | Decaying wood |
| Hoverflies | |||
| Brachypalpoides lenta | Local | Ancient woodlands | Decaying wood in hollow tress |
| Brachyopa scutellaris | Local | Ancient woodlands | Sap runs on damaged trees |
| Chalcosyrphus nemorum | Local | Ancient woodlands | Decaying wood or Rot holes |
| Criorhina asilica | Nb | Ancient woodlands | Decaying wood in hollow tress |
| Criorhina berberina | Local | Ancient woodlands | Decaying wood in hollow tress |
| Criorhina ranunculi | Nb | Ancient woodlands | Decaying wood in hollow tress |
| Ferdinandea cuprea | Local | Ancient woodlands | Sap runs on damaged trees |
| Sphegina clunipes | Local | Ancient woodlands | Rotting wood |
| Volucella inflata | Nb | Ancient woodlands | Sap runs on damaged trees |
| Xylota sylvarum | Local | Ancient woodlands | Decaying wood or Rot holes |
| Xylota tarda | Nb | Ancient woodlands | Decaying wood or Rot holes |
| Jewel beetles | |||
| Agrillus angustulus | Nb | Woodland | Dead wood on Oaks |
| Agrillus laticornis | Nb | Woodland | Dead wood on Oaks |
| Agrillus pannonicus | Na | Ancient woodlands | Dead wood on Oaks |
| Furniture beetles | |||
| Dorcatoma dresdensis | Na | Ancient woodlands/wood pasture | Bracket fungi on trees |
Key to GB Status:
RDB - Red Data Book species - occurring 15 or less 10km grid squares in Britain
Na - Nationally Notable A - occurring in 16-30 10km grid squares in Britain
Nb - Nationally Notable B - occurring in 31-100 10km grid squares in Britain
Local - Local species - occurring in 101-500 10km grid squares in Britain
