All the photos in the post were taken by me on one day (10.06.25). apart from the Great Spotted Woodpeckers, all the species photographed in this blog were living on, in or under a single Pendunculate oak at SU 96936 22927
I approached this Oak from a distance, walking through the pasture woodland of Petworth Park. Wood pasture is classified as a mosaic habitat valued for individual park-like trees particularly veteran and ancient, and the fauna, flora and fungi it supports, including a number of species that only occur in wood pasture and parkland. Grazing animals are fundamental to the habitats existence and many sites are also important historic landscapes. Woodland Trust Wood Pasture
SU 96936 22927 is the blue pin. What Three Words
As I got near, I realised that there was a bright green shape on the trunk, highlighted by the grey of the oak’s trunk. As I got closer I realised it was a beautiful moth.
I used the Obsidenity App to make a preliminary identification in the field as I hadn’t seen this species of moth before. I then checked this identification in my field guide later. I used Obsidentify for all the invertebrates I saw around this Oak, and checked the observations with field guides at home. It is a Scarce Silver-lines Moth, Bena bicolorana. The caterpillars feed on the leaves of oak (Quercus).
When I reached the Oak I could see that part of it was dead; this part appeared to have been killed, probably by heart-rot fungi. This is the way most Quercus robur die, but the process of dying is long. The decorticated decomposing heart wood had many holes.
Most of the known species dependent on oak trees are invertebrates, and a majority of these interact with the fungi in the tree in some way. Many make their homes and find their food where heart-rot decay fungi have been in action, leaving partially decayed material that is physically broken down by insects, creating mounds of composting wood mulch that creates further habitat for other invertebrates. Oaks and fungi in the UK. R. Wright, J. Finch & N. Brown. 31/05/2022
An insect landed on my hand. A believe it is a Lymexylon navale. A beetle belonging to the family Lymexylidae. The size of this beetle can vary a lot, between 8-15mm. Its yellow with black head and orange pronotum. The larval development take place in fresh oak wood in parts lost the bark. Saproxylic beetles
Saprolyxic organisms, especially insects, that are directly or indirectly dependent on dead or decaying wood for at least part of their lifecycle. Buglife: Saprolyxic Invertebrates
Lymexylon navale, commonly known as the ship-timber beetle, is a type of wood-boring beetle that is associated with wood structures, including ships, houses, and trees. Specifically, its larvae are wood-boring and can damage both sapwood and heartwood in living and decaying trees, as well as timber structures like ships.
An uncommon beetle in Britain it is which is currently designated as Red Data Book 2 (vulnerable). Nature Spot Lymexylon navale
The larvae of Lymexylon navale bore into wood, which can weaken and damage ship and other wooden structures. Lymexylidae, including Lymexylon navale, have a symbiotic relationship with certain fungi. The larvae create tunnels in the wood, and the fungi grow within these tunnels, providing a food source for the larvae. Ship-timber beetles have been found in ancient shipwrecks, indicating their long-standing association with human-made wooden structures. Lymexylidae also play a role in the ecosystem by helping to break down wood and are an important food source for other animals. Sources: Sônia A. CasariLarva of Atractocerus Brasiliensis (Lepeletier & Audinet-Serville, 1825) (Lymexylidae, Atractocerinae) Universidade de São Paulo, Museu de Zoologia , São Paulo, São Paulo, Brazil; Cletus P. Kurtzman, Christie J. Robnett (2013) Alloascoidea hylecoeti gen. nov., comb. nov., Alloascoidea africana comb. nov., Ascoidea tarda sp. nov., and Nadsonia starkeyi-henricii comb. nov., new members of the Saccharomycotina (Ascomycota). FEMS Yeast Research 13: 423–432. doi: 10.1111/1567-1364.12044 (published in Spanish and English) and Piper, Ross 2007 Extraordinary animals : an encyclopaedia of curious and unusual animals.
This Lymexylon navale (and its many mates) may have made the holes into which I saw, what I believe to be Trypoxylon attenuatum.
A widely distributed species recorded from much of Britain, including the Scilly Isles and the Channel Islands. … Has been recorded from a variety of habitats including woodland, parkland, gravel pits, sandy sites, chalk grassland and heathland. … On the wing between mid-May and mid-September… Nest burrows are stocked with small spiders such as Tetragnatha (Tetragnathidae) (Lomholdt, 1984).Nests are constructed in pre-existing cavities. Richards (1980). … Richards (1980) gives a generalised overview of Trypoxylon nesting sites such as “Anobium burrows, cut stems, hollow roots, rarely in small holes in vertical earth-faces”, but T. attenuatum seems to nest “exclusively in hollow plant stems” (Lomholdt, 1984). Nests are constructed in cavities 2-4 mm in diameter (Tormos et al., 2005). Bees Wasps and Ants Recording Society Trypoxylon attenuatum..
So it sounds as if Oaks may not be a typical nesting sites for this solitary wasp.
I then moved on to looking at lichens – the primary purpose of my trip to Petworth Park.
First I saw Gold Dust Lichen, Chrysothrix candelaris
I initially got very excited because I thought it may be the rare pin lichen Chaenotheca chrysocephala; which had been recorded on a specific Quercus robur nearby, but it wasn’t!
When I was looking at lichens on the bark I saw two more invertebrates. One on the bark next to a lichen I was examining, and one which fell on my jumper.
The one on the bark was Oak Leafhopper nymph, Iassus lanio. Leafhoppers are [sap sucking] insects belonging to the family Cicadellidae in the order Hemiptera. They are recognized by their piercing-sucking mouthparts and by the presence of rows of spine-like setae (hairs) in their hind tibiae. Dietich Leaferhopper Lab
The relatively short and broad form of this genus is characteristic; the head is wide (equal to the width of the pronotum) and the sides of the pronotum are shorter than the eye.In I. lanio the forewings vary in colour from green to pale brown and the vertex, pronotum and scutellum are heavily dark-mottled. The vertex is rounded and uniformly narrow from above. …common on oak across the UK. Adult: June to OctoberLength 6.5-8 mm British Bugs: Iassus lanio
The insect that fell on my jumper:
was a Striped Oak Bug, Rhabdomiris striatellus
A very striking bug which is frequently found on or near oak across Britain, but particularly in the south. Females are usually paler then males. The only possible confusion risk is the larger and more elongate Miris striatus, which has a completely yellow/orange cuneus and an entirely dark head. Overwintered eggs hatch in April, the larvae feeding on unripe catkins and becoming adult from mid-May onwards. Adult: May-July British Bugs: Rhabdomiris striatellus
There were many lichens on the Oak; here are few of them:
Physconia grisea Grey Frost Lichen
Dendrographa decolorans.
Thin whitish, lilac-grey or pinkish-grey thallus. When the surface (fungal hyphae) of the thallus is scratched, its photobiont (an alga of the orange Trentepohlia) is revealed.
Evernia prunastri. The vernacular name of this lichen is Oak Moss; even though it is not a moss! It is very common on Oaks, but it is common on other trees too.
Most of the lichens on this oak were of the Mature Mesic Bark Community (Pertusarietum amarae); shade tolerant communities on rougher bark, with Pertusaria species dominant. They are particularly characteristic of Beech and Ash, but also on less damp Oak bark. The basic community is composed of widespread species particularly Pertusaria s. lat. species British Lichen Society Lichen Communities
Pertusaria pertusa Sometimes called Pepper Pot lichen, for obvious reasons.
Pertusaria flavida; the orange part of this photo, which can only be identified (by turning orange) with UV light and/or a chemical spot reagent test, which reacts to lichen substances (mostly secondary metabolites). I did both the UV and the reagebts tests in the filed
Lepra amara The vernacular name of this lichen is Bitter Wart Lichen, because it tastes very butter if licked. I do not lick it to confirm its identification!
As I was identifying these lichens I head a Crow, Corvus corone, directly above my head. When I looked up a parent crow was feeding a juvenile. Here is the juvenile
Crows can nest almost anywhere, but they prefers well-covered trees with broad branches and solid tree forks, like Oaks
Crows are not the only birds to use Oaks. Earlier in the day I saw two Great Spotted Woodpeckers, Dendrocopos major, drumming on the trunk of another Pendunculate Oak. Great spotted woodpeckers can be found across mainland Britain, but are limited to the west of Ireland. Mature broadleaved woodland is prime habitat Woodland Trust Great Spotted Woodpeckers
At this point I walked into Petworth to get a coffee. When I came back I could see Fallow Deer under the tree. A social, elegant species with a signature speckled coat and mighty palmate antlers. First introduced by the Romans, fallow deer became extinct in Britain until they were reintroduced before the Norman Conquest around the year 1,000. Woodland Trust Fallow Deer
The herd of Fallow Deer have been at Petworth Park, according to the National Trust, for 500 years. The magnificent herd of fallow deer have called Petworth Park home for over 500 years; they were reportedly hunted by Henry VIII on his visit to Petworth in the 1520s. National Trust Petworth Park. There were probably Fallow Deer in the park since the land was gifted by Henry I (the fourth son of William the Conqueror) to Joscelin de Louvain, a Norman feudal baron. The pasture oaks of the deer park have provided shade for Fallow Deer for nearly 1000 years; this ancient oak has been shading deer for probably 400 years. The Fallow Deer I saw today are johnny-come-latelys!
Sim's Nature Notes 