Invertebrate visitors to an artificial tree-hole of wild service wood

 

by Patrick Roper

 

In a storm in late September 1999, a small live branch about 3 metres long of a wild service tree, Sorbus torminalis L., growing in the lane outside our house blew down.  These trees, which I have studied for nearly 30 years, are inclined to have water-filled holes at the point where the main branches diverge from the trunk, and they often suffer with heart-rot which is accessible from outside.  Growing, as they do, to a large size, often in ancient woodland, wild services, as well as their other virtues, often provide a habitat for saproxylic, rot-hole invertebrates.

 

In view of this, and in view of the fact that European rot-hole studies often seem to have involved beech and other more abundant tree species (Rohnert, 1950; Kitching, 1971), I decided to make a ground-level artificial tree-hole with the branch and suspend a trap for insects above it.  Accordingly I cut the wood, with bark intact, into roughly half metre lengths, with some tears and broken ends and placed these vertically in a plastic, 4-litre bucket with the still green leaves.  The bucket was then filled with fresh rain water and the whole placed in deep shade on bare soil close to the trunk of a 20-year old wild service at the end of our garden in Sedlescombe, East Sussex (TQ783188).  On 3 October a cylindrical black net breeding cage sleeve was suspended over the bucket with its lower hem coming to the level of the bucket rim.  The longer pieces  of wood served to keep the sleeve in place, but it was quite easy for flying insects to get underneath and then, hopefully, rise into the roof of the trap.  This meant that several categories of invertebrate were captured: those investigating a potential breeding or feeding site, those that emerged from early stages spent in the rot hole itself or the wood above, and those that arrived casually and were caught on the same principle as that of insects entering a malaise trap – because they happened to be passing by.  Retrieval of specimens was quite easy by removing the sleeve, holding it up to the light and putting both head and pooter into the trap from below.

 

During the course of the first year the bucket did not have to be replenished with water and the level fell no lower than 2/3rds of the bucket height at any time.  This was rather unexpected as the volume of water was quite small since much of the interior of the trap was taken up with wood and dead leaves and, although the summer of 2000 was generally regarded as wet, the rainfall for England and Wales as a whole was only 79% of average.  This indicates that tree holes in shaded situations may often be more permanent bodies of water than pools, ponds and streams in woodland and elsewhere, though many lose water from leakage as well as evaporation.

 

During the course of the project, I have named as many of the species found in the trap as I could.  There were, however, many Sciaridae, Cecidomyiidae (Lestremiinae) and Psychoda spp. that were not determined to species level as well as arachnids, myriapods, isopods and other invertebrates that I was unable to name.  There were also several Hymenoptera Parastica – Ichneumons, Braconids, Chalcids and others – some of which may use rot-hole-breeding species as hosts.  Additions to the overall list will be published whenever a suitable opportunity presents itself.

 

During the first few weeks of the project a surprising number of insects, mainly diptera, appeared in the trap.  This phenomenon was not repeated during the same period one year later or subsequently and I have little doubt that this early performance was due to the attractiveness of  fermenting sap.  During this period virtually all captures were female: the first male insect was a specimen of Phaonia signata on 26 October by which time nearly 300 females of 36 different species had been recorded. Not surprisingly, numbers fell to a low level during the colder weeks of the winter and did not pick up again until the arrival of warmer weather and longer days in April.

 

The species profile changed regularly throughout the warmer months and there were weeks as late as November which had the same number of species as weeks in July, but fewer individuals.  At the beginning of the second December numbers again fell sharply to virtually nil, although the weather was often mild and quite a number of insect species were still on the wing in the garden.

 

After these two years work was halted until 17 December 2008 when a new sleeve was put in place over the bucket.  At this point it was full of water with many dead leaves and the pieces of wood installed in September 1999 still in situ, though much reduced in size. (For diary of events from 17 December 2009 see end of this paper)

 

As already mentioned, the manner and the period over which invertebrates appeared in the trap varied from species to species and some notes have been given in the list below.  The behaviour of two species of diptera - Eudasyphora cyanella (Meigen) (Muscidae) and  Sciapus platypterus (Fabricius) (Dolichopodidae) -  was, however, sufficiently interesting to merit a more detailed account.

 

Eudasyphora cyanella

 

On 18^th April 2000, a cold, grey day with heavy showers there were, unexpectedly, seventeen Eudasyphora cyanella (Meigen), all female, in the trap.  Several females of this species had appeared during the autumn, but none had been recorded since then.  E. cyanella breeds in fresh cow dung (Skidmore, 1991) and larvae have also been recorded from sheep dung (Smith, 1989)  .  Both cattle and sheep graze regularly in pastures about 100 metres from the trap, but the insects would have had to fly through woodland and scrub to reach the rot-hole.  The species hibernates as an adult 

 

During the next few weeks numbers of E. cyanella rose steadily, though there were several days when none, or few appeared.  Females were quite quickly joined by males and, on the 25^th April there were at least 200 examples of this species in the trap showing a marked clustering behaviour as they gathered on the ‘roof’.  Though they were extremely active, no mating was observed.  During this period several other species of Diptera were, as usual, found in the trap but in nowhere near the quantity of E. cyanella.

 

On 24^th April, a reasonably sunny but quite cool day, I spent some time watching the trap area in the early afternoon.  E. cyanella were sunning themselves on leaves at ground level near the trap and a some would rest on the side of the bucket.  On one occasion one was observed on the rim of the bucket apparently drinking from the moisture there and on one of the projecting pieces of wood (these had by now absorbed much water).  On leaving they tended to fly up into the hanging sleeve.  The flies seemed to make little distinction between warm, sunny days and cool, cloudy ones, but numbers were much lower during or after rain, the inference being that there was plenty of free moisture available to drink from vegetation.

 

By 18^th May the numbers of E. cyanella had fallen virtually to nil, but the species was frequently observed in the wider countryside and singletons turned up in the trap until mid-August.

 

One of the characteristics of Eudasyphora is that, unlike nearly all other Muscids, the adults hibernate in winter (Skidmore, 1991).  One of the possible explanations of the observed behaviour was that, after their winter rest, they needed to drink, though why they should be particularly attracted to a rot-hole at a period when plenty of alternative sources of water were available is not clear.  Whatever the reason for their behaviour, it had some further ecological consequences.  They produced, for example, a substantial amount of excrement much of which must have finished up in the rot-hole, thus significantly increasing the nutrient-level of a habitat which is normally nutrient-poor.  At this time the trap also attracted a considerable swarm of the biting midge Culicoides obsoletus (Meigen). They would settle in some numbers on the black netting and in rather smaller quantities on my arms and face.  They bit occasionally, but their main interest seemed to be the trap and once this was set aside they no longer settled on my arms or head.  On looking carefully at these midges, they seemed to be more attracted to the droppings of the Muscids (which adhered to the netting) than the flies themselves, though I did see them settle on some of the larger species as though to bite.  C. obsoletus breeds in a wide range of moist decaying matter and it has been reported from both rot-holes (Smith, 1989) and sheep dung (Edwards, 1926).  It was not, however, biting me in other parts of the neighbourhood and would therefore appear to have been attracted by E. cyanella and the other flies, rather than by Homo sapiens.

 

Sciapus platypterus (Fabricius)

 

Two males of this common Dolichopodid fly appeared in the trap on 6^th June.  Subsequently this insect was a regular visitor and numbers rapidly increased during the course of the month up to a maximum of just over 30 a day.  The species was present on most days until the end of July and continued to be found intermittently until 24 August.  The remarkable thing was that over 90% were male with the first female not putting in an appearance until 19 June in company with 24 males.

 

Larvae of this species have been found in soil under leaves in a beech forest (Smith, 1989), Alexander (1999) reports its early stages under bark, and it appeared in some quantity (with both sexes in roughly equal numbers) in an emergence trap over a pile of decaying wood in our garden between 9 June and 10 July 1999.  Marc Pollet from Belgium explains this phenomenon by pointing out that S. platypterus is a true tree-trunk dweller as an adult and is often found in Malaise traps as well as on the tree trunks themselves.  Females are thought to remain among vegetation and other materials at ground level.  Thus it seems that the males, making their way along the ground, must have though the bucket was a tree trunk and climbed up it.  I feel there may also be other factors involved.

 

Species list

 

COLLEMBOLA

 

Collembola were found in the trap fairly regularly during the warmer months and many of these have been set on one side for later determination.  Those mentioned here were identified with the help of the new AIDGAP Test Key (Hopkin, 2000) due to be revised and published in 2001.

 

Entomobryidae

 

Entomobrya nivalis (L.)

An extremely abundant tree-dwelling species.  Found in the trap from early in the year until the end of November 2000.

 

Willowsia platani (Nicolet)

Apparently a rare species possibly synonymous with W. nigromaculata.  It has previously been recorded out of doors only once in Britain - from under bark in the Isle of Wight (Brown, 1929).  There are also several examples in the Natural History Museum collected from houses.  One was found in the trap on 10 October 2000.

 

Sminthuridae

 

Dicyrtomina ornata (Nicolet)

A common and widespread species.  Not seen in the trap until 2 December 2000 when two examples appeared.

 

Sminthurus viridis (L.)

One of the commonest species of the order.  One example in early October 1999.

 

ORTHOPTERA

 

Tettigoniidae

Meconema thalassinum (De Geer)    Oak Bush-cricket

A largely carnivorous, arboreal cricket found on many trees as well as oak.  The female lays her eggs in crevices in bark.  Widespread in southern England and Wales.  One specimen was found in the trap on 16 August 2000.

 

DERMAPTERA

 

Forficulidae

Forficula auricularia L.  Common Earwig

This common insect occurred regularly from mid-April to late-November 2000 both as adults and nymphs, no doubt using the netting of the trap purely as a place to shelter.

 

PSOCOPTERA

 

I have found most of the species listed here on the branches and leaves of the wild service tree beneath which the trap was situated.  Most of the insects trapped would probably have been returning to the trunk or foliage have earlier been dislodged from above.  All the species recorded are common.  Most occurred intermittently from June until late autumn.

 

Caecilidae

Caecilius flavidus (Stephens)

Stenopsocidae

Graphopsocus cruciatus (L.)

Stenopsocus immaculatus (Stephens)

Lachesillidae

Lachesilla ?pedicularia (L.)

Ectopsocidae

Ectopsocus briggsi McLachlan

Trichopsocidae

Trichopsocus dalii (McLachlan)

Psocidae

Trichadenotecnum sexpunctatum (L.)

 

HEMIPTERA/HOMOPTERA

 

A wide range of bugs and plant hoppers was taken in the trap during the period of the project.  Most of them are common in deciduous woodland, scrub and gardens and, the predatory ones in particular, spend much time exploring their environment.  Some will have been dislodged from foliage above and several hibernate as adults and probably entered the trap while looking for suitable sites.

 

Acanthosomidae

Acanthosoma haemorrhoidale (L.)

Pentatomidae

Palomena prasina (L.)

Cimicidae

Anthocoris nemorum (L.).  Also in May 2009

Anthocoris confusus  Reuter

Miridae

Campyloneura virgula (Herrich-Schaeffer)

Orthops cervinus (Herrich-Schaeffer)

Cercopidae

Philaenus spumarius (L.)

Cicadellidae

Empoasca vitis (Göthe)

Eupteryx urticae (Fab.)

Ribautiana debilis (Douglas)

Ribautiana tenerrima (Herrich-Schaeffer)

Typhlocyba quercus (Fab.)

Alnetoidea alneti (Dahlbohm)

Zygina angusta Lethierry

Zygina flammigera (Geoffroy in Fourcroy)

Issidae

Issus coleoptratus (Fab.)

This was found on seven separate weeks from August to November 2000 and again in 2009, sometimes as adults, more often nymphs.  I have also taken this species from time to time in emergence traps over decaying wood.  Although a plant-feeder and particularly associated with ivy, holly and other woody plants a well as moss (Le Quesne, 1960), it probably often seeks shelter in dead wood close to food sources.

Aleyrodidae

Aleroydes ?proletella

 

COLEOPTERA

 

While many of the beetles found in the trap were undoubtedly casuals, some seemed to have a more specific association with the habitat and a few were probably living as larvae or pupae in the branch wood before it was blown down.

 

Staphylinidae

Anotylus sculpturatus/mutator

The commonest beetle in the trap, this occurred at two specific periods: mid-June and late September/early October, often several at a time.

Quedius sp.

Tachyporus hypnorum

Tachyporus obtusus

Tachinus marginellus (F.)

Tachinus pallipes (Gravenhorst)

Elateridae

Athous campyloides Newman

A distinctive, ‘Notable b’ click beetle recorded mainly from grasslands.  The adults fly in the evening and are gregarious and the larvae live in the soil at the roots of plants.  One example was found in the trap on 8^th July.  I have not seen it before in the Sedlescombe neighbourhood.

Agriotes pallidulus (Illiger)

A common click beetle also associated with grasslands.  The larvae are the well-known wireworms that live on roots.

Cantharidae

Cantharis decipiens Baudi

A common carnivorous soldier beetle with larvae that develop among grass and low herbage.

Anobiidae

Anobium punctatum (Degeer)  Furniture Beetle

The larvae bore in the sapwood and heartwood of living or dead trees and were probably present in the wood before the trap was constructed.  Recorded on several occasions in summer 2000.

Cryptophagidae

Cryptophagus dentatus (Herbst)

Alexander (1999) says this species is found in fungi and in buildings.  The larvae will feed on dead and dying insect larvae.

Lathridiidae

Aridius bifasciatus (Reitter)

An introduced species that has become one of the commonest beetles in Britain in litter, compost, moss and grass tussocks.

Tenebrionidae

Cylindrinotus laevioctostriatus (Goeze)

One of the commonest under-bark beetles in our area.  Develops in decaying timber and in peaty, heathland soils with the larvae feeding on algae and other organic material (Alexander, 1999).  Found once in the trap in early November 2000. 

Salpingidae

Vincenzellus ruficollis (Panzer)

A local species predatory on small invertebrates under the bark of various broadleaf trees (Alexander, 1999).  In the trap over three weeks at the end of April and the beginning of May 2000.

Cermabycidae

Grammoptera ruficornis (Fab.)

A common species that develops in dead twigs and branches of deciduous trees.  One or two in the trap in June 2000.

Chrysomelidae

Phyllotreta ?nigripes (F.)  Turnip Flea Beetle

Phyllotreta undulata Kutschera    Small Turnip Flea Beetle Aphthona atrocaerulea (Stephens)

A species found almost everywhere in our area during much of the year.  It has increased substantially since linseed started to be grown commercially.

Anthibiidae

Platystomos albinus (L.)

A “Notable b” species in dead wood on dead and dying trees, fungus-infected stumps and Daldinia fungus.  One example in the trap in the last week of May.

Attelabidae

Rhynchites caeruleus (Degeer)    Apple Twig Cutter

A common species on wild service and other trees in our area.  The adult females sever young shoots and lay their eggs in the detached portion where the larvae develop.  One example was found in the trap in the last week of October 2000 indicating that at least some hatch from their pupae in autumn and hibernate during the winter.

Curculionidae

Pentarthrum huttoni Wollaston    Wood-boring Weevil

One example in the last week of June.

Brentidae

Ceratapion carduorum (Kirby) (sensu Hodge & Jones, 1995)

A local weevil associated with thistles.

 

MECOPTERA

Panorpidae

Panorpa germanica L.

A common scorpion fly with soil-dwelling larvae.

 

LEPIDOPTERA

Psychidae

Psyche casta Pallas

Tineidae

Monopsis laevigella Bradley & Fletcher    Skin Moth

Gracillariidae

Phyllonorycter trifasciella Haworth

Geometridae

Operophtera brumata (L.)    Winter Moth

One of the wingless females that had, presumably, emerged from a pupa in the ground and crawled up into the trap rather than up the tree trunk.  A male was also taken on 1 January 2009.

 

DIPTERA

Tipulidae

Tipula variicornis Schummel

A cranefly of wet woodland.

Tipula pabulina Meigen

A woodland cranefly whose larvae live in soil.  Also several in mid-May 2009.

Tipula varipennis Meigen

Pediciidae

Limoniidae

Limonia nubeculosa Meigen

An extremely common species whose larvae live in leaf litter, though it has also been reared from a sycamore rot hole (Alexander, 1999).  Found in 2000 and 2009.

Neolimonia dumetorum  Only on 24 May 2009

Austrolimnophila ochracea (Meigen)

A common species that breeds in dead wood, even small pieces.

Erioptera lutea Meigen

Common in damp places.  Larvae live in wet mud.

Ormosia albitibia Edwards

A local species thought to breed in moist soil.

Ormosia nodulosa (Macquart)

A much commoner species than the above, also thought to breed in moist soil.

Rhypholophus varius (Meigen)

Psychodidae

Several British moth flies are known only from rot-holes, e.g. Telmatoscopus rothschildi Eaton, T. tristis (Meigen) T. laurencei Freeman and T. advenus (Eaton) (Withers, 1989) but none were recorded from the trap in 1999.  Psychoda spp. occurred almost every day during the warmer months, but only a few that could only be identified with dissection were determined to species level.  No Psychoda is truly aquatic, but some might have been breeding at the air/water interface.

Boreoclytocerus ocellaris (Meigen)

A common species that develops in stagnant shaded pools, usually in woodland.  One example only on 3 March 2000.

Psychoda ?cinerea Banks

P. cinerea is a common species that breeds in sewage beds, drains and, occasionally, decaying fungi (Withers, 1988)

Psychoda erminea Eaton

This apparently rare species has been bred from an otter spraint (Withers, 1988 and 1989), but I have found it regularly in our garden, usually in the colder months and it must therefore breed in other dung and/or decaying material.  Withers, 1988, points out that nearly all examples he knew of had been collected in autumn or winter and this is consistent with my experience.  The first example appeared in the trap in early November 1999 but none were seen again until the end of September 2000, and several more arrived in November 2000.

Psychoda grisescens Tonnoir

One of the commonest moth flies.  It has been bred from dung and fungus (Withers, 1988)

Psychoda lobata Tonnoir

A species that is thought to breed solely in higher fungi (Withers, 1988).

Psychoda surcoufi Tonnoir

A widespread species frequently recorded from gardens (Withers, 1988).  It has been reported as a pest in potato stores and bred from cow dung and milk bottles (Smith, 1989).  I once found many examples emerging from wet, rotten sacking (Roper, 1996) and Laurence (1999) has speculated that its apparent increase in the last 50 years might be due to the more widespread use of compost accelerators.

Culicidae

Anopheles plumbeus Stephens

The first adults of this water-filled rot-hole breeding species appeared on 3 June 2000 and continued until the end of September, often in some numbers.  According to Snow (1990) the adult season runs from April to late autumn and the winter is normally passed in the larval stage.  Also from mid-May 2009.

Aedes geniculatus (Olivier)

Another water-filled rot-hole breeder that was present from mid-June until the end of September 2000, but in rather smaller numbers than Anopheles plumbeus.  Overwintering is in the egg or larval stages (Snow, 1990).  A. geniculatus is widespread in England, mainly in the south and east (Rees & Snow, 1995), but has not been recorded as far as I know from elsewhere in the British Isles.  Also from mid-May 2009.

Culex pipiens L.

A common species that breeds in many different kinds of small bodies of water such as water butts and stagnant pools.  The species was noted in the trap from early July to late September 2000 but in smaller quantities than either of the two preceding species.

Ceratopogonidae

Forcipomyia ?radicicola Edwards

One example, possibly of this species, in early November 2000.  The early stages have been found in old tap roots of Arctium, Angelica etc. (Edwards, 1926)

Atrichopogon lucorum (Meigen)

Recorded in the trap twice in June 2000.  Larvae have been found in a hollow tree occupied by ants (Edwards, 1926)

Dasyhelea versicolor (Winnertz)

This species has been recorded as breeding in water-filled tree holes and from sap exudations as well as from other aquatic or semi-aquatic habitats including an aquarium (Smith, 1989) and a font (Kieffer, 1925).    Noted only in mid-September.

Culicoides obsoletus (Meigen)

Has been recorded as breeding in tree holes and damp debris (Smith, 1989).  It was attracted to the trap in large quantities during the period when the Muscid Eudasyphora cyanella was also present in large numbers (see above) during the first three weeks of May, but no further examples were noted, though it is generally common in the neighbourhood.  According to Laurence (1996) this is one of the most abundant and widespread of British Diptera.

Chironomidae

Apart from Metriocnemus martinii which is a rot-hole breeder, all the Chironomidae found in the trap are those with adults that fly mainly in the colder months.  The explanation is possibly that these species seek out the most sheltered places in bad weather or at night time, though it is difficult to see why this does not also apply to the Chironomidae of the warmer months many of which are abundant in the garden.

    Metriocnmeus cavicola Thienemann  

    A well-known rot-hole breeder, most frequently recorded from beech (Kitching, 1971; Cranston, 1982; Langton, 1991).  Bryce & Hobart (1972) say it also has been bred from wet birch leaves, but this needs confirmation.  First occurred in the trap 

    in late June 2000 and thereafter common (both sexes) until mid-September.  Still present in quantity in 2009 when emergence bagan in mid-April.

Gymnometriocnemus brumalis (Edwards)

A very common species of winter woodlands, at least in much of southern England and Wales.  It is believed to breed in wet leaves or woodland soil and I have taken both sexes in a trap on the woodland floor.  Found frequently in the rot-hole trap from late September to February, often after frosty nights.  On 25 December 2000 there were three males and two females present, the most ever, after a bitterly cold day, with temperatures not much above freezing and a keen north east wind.  The males were clearly very freshly emerged and it may therefore well be that they were breeding in the rot-hole trap or the projecting wood.

Limnophyes habilis (Walker)

This is the true L. habilis as defined by Saether (1990).  It is common in our garden in late winter, often sheltering in evergreens and dense vegetation generally.  Occurred in the trap twice in February and March.  It probably breeds in drowned grass and other terrestrial/aquatic interfaces.

Smittia aterrima (Meigen)

A cow-dung breeding species that is widespread and abundant.  Reaches its peak adult emergence in the colder months.  Found once in the trap in November 1999.

Micropsectra notescens (Walker)

This and the next species are common in our garden in the colder months of the year.  Langton (1991) says both species breed in streams, rivers and lakes but they are often observed swarming close to small garden ponds here, where I suspect they breed as the nearest permanently flowing water is at least one kilometre distant.  One on 2 December 1999.

Micropsectra atrofasciata (Kieffer)

One on 2 February 2000.

Trichoceridae

Trichocera rufescens Edwards

Several Trichocera species occur in the garden and this is one of the less common.   They breed in soil, wet leaves an other decaying organic matter, carrion and fungi and, occasionally, in old cow pats (Skidmore, 1991).  I have also seen female T. annulata laying eggs in fresh badger dung.

Trichocera regelationis.  On 23 April 2009 only.

Anisopodidae

Sylvicola cinctus (Fab.)

Sylvicola fenestralis (Scopoli)

The early stages of this species are on of the most important members of the cow-dung community (Skidmore, 1991).  Recorded only in the second week of October 1999, shortly after the trap was set up. According to Laurence (1996) this is one of the most abundant and widespread of British Diptera.

Mycetobiidae

    Mycetobia pallipes Meigen

A nationally scarce ‘Notable b’ insect that has been bred from exuded sap and slime on or beneath the bark of several tree species (Hancock, Robertson & MacGowan, 1996; Smith, 1989) as well as from a rot-hole (Alexander, 1999).  It occurred regularly in the trap in small numbers in mid-June and early August 2000.

Bibionidae

Dilophus febrilis (L.)

Larvae usually live in soil or dung, often in woodlands, where they feed on plant roots or decaying material (Freeman & Lane, 1985; Smith 1989).  This is one of several Bibionids that have also been bred from rotten wood (Alexander, 1999).  Only once in the trap in mid-May.  Also on 2 May 2009

Keroplatidae

Macrocera fasciata Meigen

One example in early July 2000.  Has been bred from Trametes versicolor (L.) (Chandler, 1993).

Mycetophilidae

Mycomya cinerascens (Macquart)

A widespread species that was recorded once, in early November 2000.  Members of the genus have been bred from Stereum and other fungi associated with dead wood (Edwards, 1924; Smith, 1989)

Acnemia nitidicollis (Meigen)

A widespread species that is common in our garden in association with decaying timber.  One example in the trap in early November 1999, after which it occurred not uncommonly between late May and early September 2000.  It has been reared from a pupa found under rotting wood (Edwards, 1925)

Anatella ?ciliata Winnertz

One female, probably of this species, in late October 2000.  The early stages of Anatella are little known, but it is thought that most may be associated with various wood-decay fungi (Alexander, 1999).

Tarnania ?tarnanii (Dziedzicki)

One example in the first week of October 2000.  One member of this genus has been reared from rotten wood (Alexander, 1999)

Cordyla crassicornis Meigen

Has been bred from various Russula spp. (Edwards, 1925; Chandler, 1993).  One example in the trap in late August 2000.

Trichonta sp. incert.

One member of this genus in the trap in mid-May.  Most species have early stages that feed on bark-growing fungi (Edwards, 1924).

Phronia (tarsata group female)

One captured in the trap in late September 2000.  Has been bred from a wide range of arboreal and terrestrial fungi (Chandler, 1993).

Sciaridae

Trichosia splendens Winnertz

Several Trichosia spp. have been bred from rotten wood or have early stages found beneath bark.  One only in the trap at the end of June.  A widespread species but not recorded from East Sussex by Freeman (1983), though I have taken it in our garden on previous occasions.

Trichosia pilosa

One record in mid-August 1999.

Epidapus atomarius(De Geer)

One example in mid-October 1999. Has been reared from rotten wood (Alexander, 1999).  Not recorded from East Sussex by Freeman (1983).

Epidapus gracilis  (Walker)

One example in early August.  Associated with dead beech wood (Alexander, 1999).  Not recorded from East Sussex by Freeman (1983), though I have found it previously in the garden.

Bradysia placida (Winnertz)

This is the B. fimbricauda Tuomikoski of Freeman (1983) who did not note in from East Sussex though it is one of the commonest species here and elsewhere.  One of the most widespread British Diptera species according to Laurence (1996) but it only occurred once in the trap in early May 2000.

Bradysia aprica (Winnertz)

One example in late June.  Not recorded from East Sussex by Freeman (1983)

Scatopsciara pusilla (Meigen)

Not recorded from East Sussex by Freeman (1983)

Zygoneura sciarina Meigen

A widely distributed species but not recorded from East Sussex by Freeman (1983)

Cecidomyiidae

Xylopriona atra (Meigen)

A common species around decaying logs and branches.  Found in the trap once in late October 2000.

Hybotidae

Ocydromia glabricula (Fallén)

The early stages of this species are known only from dung (Skidmore, 1991), but Collin (1961) points out that he mainly found adults hovering or swarming is damp, shady places.  Occurred once in the trap, in mid-July 2000.

Drapetis parilis Collin

Occurred once in the trap in late June.  Drapetis sp. have been bred from cow dung (Skidmore, 1991), from early stages found under bark (Smith, 1989) and others are associated with woody debris and tree trunks (Collin, 1961).  D. simulans has been bred from rot-holes (Alexander, 1999)

Platypalpus pallidiventris (Meigen)

According to Collin (1961) and Laurence (1996) this is one of the most widespread of British Diptera and it is one of the most frequently met in our area.  It was found in the trap once in June and once in July 2000.

Oedalia holmgreni Zetterstedt

A common species associated, like other members of the genus, with decaying wood.  Found once in the trap in mid-June 2000.

Empididae

Rhamphomyia longipes (Meigen)

Larvae of Rhamphomyia have been found in soil, under moss and in decaying wood (Smith 1989; Alexander, 1999).  This species was in the trap once in mid-June 2000.

Empis caudatula Loew

A common early summer species in the area.  In the trap once in late May 2000.

Hilara manicata  Meigen

One of the most abundant species of a genus that has early stages in soil, under leaves and in decaying wood (Smith, 1989).  In the trap once in mid-August 2000.

Dolichopodidae

Dolichopus arbustorum Stannius

I have found this abundantly over several weeks in summer in an emergence trap over a pile of decaying logs.  It occurred  only once, however, in the tree hole trap (in early August 2000)

Medetera abstrusa Thuneberg

Has been reared from fungus growing on dead wood (Alexander, 1999).  In the trap in June and July 2000.

Medetera ?diadema (L.)

Once in the trap in mid-July 2000.

Medetera impigra Collin

Typical of many species of Medetera with early stages under bark and in the galleries of the Elm Bark beetle Scolytus scolytus and other Coleoptera. Has also been reared from the fruiting body of the wood-decay fungus Daldinia.

Rhaphium ?appendiculatum Zetterstedt

Other members of this genus have been found in woodland soil, but the early stages are generally little known.  One example in the trap on 10 August 2000.

Sciapus platypterus (Fabricius)

See account in introductory section above.

Lonchopteridae

Lonchoptera lutea Panzer

Larvae live in decaying vegetable matter generally.  According to Laurence (1996) this is one of the most widespread of British Diptera and examples often appear here in traps of various kinds, sometimes in mid-winter.  It occurred in the tree hole trap briefly at the end of April, then almost continuously in October and November 2000.

Lonchoptera tristis Meigen

This species, though far less common than the former, is not infrequent in our area beside stagnant bodies of water in heavily shaded situations.  It appeared once, in early October 2000.

Phoridae

Megaselia sp. aff. densior Schmitz

One specimen found in September was run down to M. densior in Disney, 1989.  The densior of Disney is, however, an undescribed sibling species (Chandler, 1998).  The species seems to be widespread but rather uncommon.

Megaselia ruficornis (Meigen)

A widespread species that I have found on other occasions associated with decaying wood.  It occurred in the trap throughout the summer and autumn 2000.

Megaselia rufipes (Meigen)

One of the commonest British Phorids.  In the trap once in October 1999.

Syrphidae

Baccha elongata (Fabricius)

Found in the trap a few times in August and September 2000.  The adults are usually found among low vegetation in shady places (Stubbs, 1983).  The larvae feed on aphids (Smith, 1989).  Also on 24 April 2009.

Melanostoma scalare (Fabricius)

A widespread and common fly in grassland and in scrub and woodland margins (Stubbs, 1989).  Found in the trap once, in late August 2000.  Melanostoma larvae are aphid feeders, but have been recorded from other materials, both animal and vegetable (Smith, 1989)

Brachyopa scutellaris Robineau-Desvoidy

A widespread, but uncommon, species that has been taken mostly at sap runs.  Larvae have been found in these runs and under bark (Smith, 1989)  Found in the trap once in early June 2000.

Dryomyzidae

Neuroctena anilis (Fallén)

Breeds mainly in carrion or rotting fungi (Smith, 1989).  According to Laurence (1996) this is one of the most widespread of British Diptera.  Found in the trap in May and June, and September and October 2000.

Chamaemyidae

Chamaemyia juncorum (Fallén)

A widespread species whose larvae feed on Coccids (scale insects) on grasses (Smith, 1989).  Found in the trap once on 26 July 2000.

Lauxaniidae

Minettia longipennis (Fabricius)

Most Lauxaniidae breed in decaying vegetable matter (Collin, 1947) but, so far as I know, the early stages of this fairly common species have not been described.  Found once, at the end of June 2000.

Minettia inusta (Meigen)

Another widespread species that has been reared from a mole’s nest (Smith, 1989), but can perhaps develop in a wide range of decaying vegetable matter.  Occurred once at the end of August 2000.

Sapromyza sordida Haliday

A common species that has been reared from a wren’s nest (Smith, 1989) but, as with the above, probably breeds in a wide range of decaying vegetable material.  Found once in mid-June 2000.

Lyciella pallidiventris (Fallén)

A common species whose larvae have been found under rotten bark, in garden earth and in flood refuse (Smith, 1989), thus it is a species that might well have a breeding interest in a rot-hole.  Found twice, in late May and early September 2000.

Lyciella rorida (Fallén)

Another very common species among rank vegetation.  Larvae have been found in several situations: beneath bark on a decaying tree and in rotting leaves, for example (Smith, 1989).  Occasional in the trap in August, September and October 2000.

Heleomyzidae

Suillia bicolor (Zetterstedt)

One of the commonest members of the genus which has been bred from many different fungi, including some wood decay species (Withers, 1987; Alexander, 1999).  Found once in early September 2000.

Suillia fuscicornis (Zetterstedt)

A common and widespread species that has been bred from a wide range of fungi (Smith, 1989).  Found once in mid-November 2000.

Suillia notata (Meigen)

Has been bred from roots of aster and from fungi (Withers, 1987; Smith, 1989; Bland & Rotheray, 1996). According to Laurence (1996) this is one of the most abundant and widespread of British Diptera.  Occurred only in October 1999 and October 2000. 

Tephrochlamys rufiventris (Meigen)

A common species, often on the wing in the colder months.  Has been bred from a wide range of decaying animal and vegetable matter (Smith, 1989) including rot-holes (Alexander, 1999).  Occurred once, in mid-November 1999.

Sepsidae

Nemopoda nitidula (Fallén)

A cow and other animal dung breeder (Smith, 1989) that hibernates as an adult.  According to Laurence (1996) this is one of the most abundant and widespread of British Diptera.  Found once, in late November 2000.

Sphaeroceridae

Although primarily associated with dung, these lesser dung flies also breed in a wide range of decaying animal and vegetable matter and are commonly found among leaves, deep in grass and in animal runs.

Crumomyia fimetaria (Meigen)

Adults have been recorded from many kinds of decaying materials in woodlands (Pitkin, 1988).  Not, as far as I know, previously reported from East Sussex.  Found once, in late October 1999.

Crumomyia nigra (Meigen)

According to Laurence (1996) this is one of the most abundant and widespread of British Diptera. It has been reared from cow-dung (Smith, 1989) and adults are found on a wide range of other decaying material (Pitkin, 1988).

Sphaerocera curvipes Latreille

Adults are found on carrion, dung and decaying vegetable material (Pitkin, 1988).  Has been reared from cow dung and human excrement (Smith, 1989)

Chaetopodella scutellaris (Haliday)

A common species as an adult on decaying animal and vegetable matter (Pitkin, 1988).  Has been reared from cow dung (Smith, 1989). 

Pullimosina moesta (Villeneuve)

Adults have been found on a wide range of dung and decaying vegetable materials (Pitkin, 1988).  According to Laurence (1996) this is one of the most abundant and widespread of British Diptera.

Spelobia parapusio (Dahl)

A woodland species mainly associated with fungi and carrion (Pitkin, 1988).  Not previously reported from East Sussex as far as I know, though I have found it from time to time locally.

Opomyzidae

Opomyza germinationis

According to Laurence (1996) this is one of the most abundant and widespread of British Diptera.

Clusiidae

Clusiodes verticalis

Odiniidae

Odinia boletina

Drosophilidae

Drosophila histrio

Drosophila phalerata

Drosophila ambigua

Drosophila obscura

Drosophila subobscura

Chloropidae

Oscinella sp.

Meromyza femorata

Calliphoridae

Calliphora vicina

According to Laurence (1996) this is one of the most abundant and widespread of British Diptera.

Calliphora vomitoria

Lucilia silvarum

Pollenia griseotomentosa

Scathophagidae

Scathophaga lutaria

Scathophaga stercoraria

According to Laurence (1996) this is one of the most abundant and widespread of British Diptera.

Anthomyidae

?Botanophila hucketti

Anthomyia procellaris

Delia sp. female

Hylemya nigrimana  Also in May2009

Fanniidae

Fannia sp. aff. novalis

Fannia aequilineata

Fannia ?mutica

Fannia pallitibia

Fannia speciosa

Muscidae

Polietes lardarius

Eudasyphora cyanella

     Neomyia cornicina

Azelia cilipes

Azelia nebulosa

?Azelia trigonica

Denrophaonia querceti

Hydrotaea cyrtoneurina

     Phaonia errans

Phaonia pallida

Phaonia turguriorum

Phaonia subventa  Also in spring 2009

Phaonia valida

Phaonia mystica

Phaonia rufiventris  Only in spring 2009

Helina pertusa

Hebecnema affinis

Hebecnema vespertina

Hebecnema nigricolor

Hebecnema umbratica

Mydaea anicula

Mydaea orthonevra

Mydaea corni

Mydaea urbana

 

HYMENOPTERA

 

Many Hymenoptera Parasitica were taken throughout the first year.  These included Ichneumonids, Braconids, Proctotrupoids and Chalcids.  I have made few attempts to identify these, but have kept voucher specimens.

 

Vespidae

Vespula sp.

Apidae

Bombus pascuorum

 

Discussion

 

The project has shown that, when a tree is damaged, the fermenting sap and similar substances initially attract a wide range of invertebrates.  Species that appeared in the trap during its first three months (October-December 1999) included:

 

This is very different to the species profile in the same period a year later:

 

The following were present in the first three months of the project but have not been recorded since:

 

Many species that are known to breed in rot-holes arrive during its first year of establishment and, in some cases, are able to produce one or more generations during this first season.  Known rot-hole breeders included:

 

Other species, such as Eudasyphora cyanella and Sciapus platypterus (both discussed above) clearly have an affinity with rot-holes, or at least with small bodies of standing water, but  it is not clear what this is.  Species that occurred on xx or more weeks since the trap was installed, but are not known rot-hole breeders, include:

 

A surprising number of species from the trap are associated with animal dung:

 

 

The area beneath the wild service tree where the trap was sited would, from a field entomologist’s perspective, look extremely unpromising.  Undoubtedly some insects found themselves in the trap when they were passing through and this accounts, no doubt, for many of the singleton records.  Many species are also associated with the higher parts of the tree up to the canopy layer and would have arrived in the trap as they attempted to re-ascend following dislodgement from above; others would simply have been seeking shelter, food (especially as predators) or places to hibernate.  A few may have pupated in the soil below or close to the trap and others, particularly the coleoptera, may have been developing in the wild service branch before it blew from the parent tree.

 

The unexpectedly high level of invertebrate activity also had a very long seasonal spread, with some late autumn weeks having a higher species count than others in high summer.  The weather seemed to have less effect than one would imagine on the number of species recorded, though numbers were markedly lower when the weather was very windy or cold.