HEMIPTERA

K.N.A. Alexander

The Hemiptera are divided into three distinct groups of bugs: the Heteroptera (shield bugs, seed bugs, etc.); the Auchenorhyncha (leafhoppers); and the Sternorrhyncha (aphids, whitefly, scales, etc.). The first group, the Heteroptera, are moderately well-studied in Cornwall, but the others are very poorly known in the region. The Heteroptera include many species which in Britain are confined to the south-west, and this has been an important factor in attracting specialist entomologists from all over the country. These southwestern species are largely coastal and this has had the unfortunate result that the fauna of inland districts has been relatively neglected. The acknowledged hot-spots in Cornwall are the Lizard Peninsula and the West Penwith coastline, especially from Sennen Cove northwards.

The key management issues relate to the conservation of semi-natural habitats and natural processes. The concentration of Cornwall’s known rarities onto the narrow coastal fringe means that the main problems lie with the maintenance or restoration of cliff grazing and the management of visitor pressure. Most, if not all, of the seacliff and sand-dune specialities have a special requirement for warmth, and shelter can be important in maintaining this.

Open swards are essential, where the vegetation is broken, leaving patches of bare ground where the sun warms the surface very quickly and temperatures can become much higher than in the adjacent sward. These conditions are best maintained by controlled grazing by ponies or cattle; sheep are not the best option as they tend to graze the turf to a uniform close sward with little flowering and seed-setting of the herbs which are the foodplants of the bugs. Rabbits can also be very important in maintaining the right conditions - scrapes and burrows make excellent bare ground habitat - and need to be taken into account in any grazing regime. Visitors are a mixed blessing. Low levels of trampling can be very beneficial in creating and maintaining short swards, with bare ground and good flowering, and can be important in sites no longer grazed. At higher levels, however, trampling begins to cause serious erosion and loss of habitat. Additionally, many visitors bring dogs with them, which may cause two further problems: i) stock-worrying, often leading to the abandonment of grazing, and ii) local nutrient enrichment from dung and urine.

There are four other main categories of habitats in Cornwall important for threatened bugs:

i) heaths, moors and bogs.

ii) mesotrophic wetlands.

iii) saltmarshes.

iv) disturbed ground communities, such as unsprayed arable fields.

Drainage or the abandonment of grazing have led to severe losses of open wetland habitats throughout Cornwall, and the value of early successional vegetation (“weeds”) has also not been fully recognised.

The one BAP Priority Species known in Cornwall draws attention to another Cinderella habitat; traditional orchards. Modern records for the Apple-tree Lace Bug Physatocheila smreczynskii appear to be mainly from Cornwall and Devon. Protection and restoration of Cornwall’s old orchards will now be on the conservation agenda.

A new review of knowledge of the entire Cornish Hemiptera (Alexander, 2008) has enabled this section of the RDB to be both fully updated and completed. Emphasis still remains on Heteroptera however due to the limited recording effort on the other two sections of the group and the lack of a national status review on the Sternorhyncha. There are 12 RDB Hemiptera in Cornwall and the Isles of Scilly, one candidate RDB, and 39 Nationally Scarce species, all with relatively recent records. Three Locally Scarce species are included which are rare in Cornwall. Several species are included despite not having been recorded in the region for many years; the Hemiptera are such an under-recorded group that in many cases these species could still be present here. The number of post-1980 one kilometre squares are given for each species. The following species accounts draw heavily on A review of the scarce and threatened Hemiptera of Great Britain (Kirby, 1992). I am grateful to Pete Kirby (the author of the above-named reference), who provided much useful information for the first edition; to Steve Judd (Liverpool City Museum), who provided a print-out of his Lygaeidae Database; to Paul Gainey for his efforts to build up knowledge of the Cornish Heteroptera; and to Bernard Nau for a continuing national overview. A new feature of this RDB is a listing of species which have been known in Cornwall in the distant past but which have not been seen for more than 75 years.

1. RDB Hemiptera

Lasiacantha capucina Thyme Lace Bug

Halticus macrocephalus A plant bug

Nabis brevis A damsel bug

Piesma quadratum spergulariae A piesmatid bug

Emblethis griseus A seed bug

Pterometus staphyliniformis A seed bug

Trapezonotus ullrichi A seed bug

Peritrechus gracilicornis A seed bug

Geotomus punctulatus A shield bug

Odontoscelis fuliginosa A shield bug

Eysarcoris aeneus A shield bug

Balclutha saltuella A leafhopper

2. Nationally Notable Hemiptera

Hebrus pusillus A Sphagnum bug

Aepophilus bonnairei A shore bug

Catoplatus fabricii A lace bug

Physatocheila smreczynskii Apple-tree Lace Bug

Myrmedobia coleoptrata A microphysid bug

Myrmedobia inconspicua A microphysid bug

Capsodes flavomarginatus A plant bug

Capsodes sulcatus A plant bug

Strongylocoris luridus A plant bug

Globiceps flavomaculatus A plant bug

Globiceps fulvicollis cruciatus A plant bug

Tytthus pubescens A plant bug

Nabis pseudoferus A damsel bug

Berytinus hirticornis A stilt bug

Heterogaster artemisiae A seed bug

Drymus pilicornis A seed bug

Scolopostethus pictus A seed bug

Taphropeltus hamulatus A seed bug

Tropistethus holosericeus A seed bug

Aphanus rolandri A seed bug

Megalonotus antennatus A seed bug

Megalonotus dilatatus A seed bug

Megalonotus praetextatus A seed bug

Megalonotus sabulicola A seed bug

Graptopeltus lynceus A seed bug

Rhyparochromus pini A seed bug

Dicranocephalus agilis A spurge bug

Legnotus picipes A shield bug

Odontoscelis lineola A shield bug

Sciocoris cursitans A shield bug

Sehirus biguttatus A shield bug

Aphrodes albifrons A leafhopper

Ulopa trivia A leafhopper

Agallia brachyptera A leafhopper

Oliarus leporinus A lace-hopper

Cixius remotus A cixiid bug

Delphacodes capnodes A planthopper

Paradelphacodes paludosus A planthopper

Xanthodelphax flaveolus A planthopper

3. Locally Scarce Hemiptera

Xylocoris cursitans A bark bug

Issus coleoptratus Ivy Hopper

Ledra aurita Giant Leafhopper

4. Hemiptera which may have become extinct in Cornwall (no records in past 60 years)

Heteroptera

Family CERATOCOMBIDAE

Ceratocombus coleoptratus (Zetterstedt)

Family CORIXIDAE

Cymatia coleoptrata (Fabricius)

Sigara selecta (Fieber)

Sigara limitata (Fieber)

Sigara semistriata (Fieber)

Family SALDIDAE Shorebugs

Halosalda lateralis (Fallén)

Family TINGIDAE Lacebugs

Acalypta carinata (Panzer)

Family MICROPHYSIDAE Minute bugs

Myrmedobia distinguenda Reuter

Family MIRIDAE Capsid bugs

Deraeocoris scutellaris (Fabricius)

Megacoelum infusum (Herrich-Schäffer)

Megaloceraea recticornis (Geoffroy)

Halticus apterus (L.)

Blepharidopterus diaphanus (Kirschbaum)

Malacocoris chlorizans (Panzer)

Orthotylus nassatus (Fabricius)

Pseudoloxops coccineus (Meyer-Dűr)

Chlamydatus saltitans (Fallén)

Hoplomachus thunbergii (Fallén)

Megalocoleus tanaceti (Fallén)

Orthonotus rufifrons (Fallén)

Psallus betuleti (Fallén)

Psallus variabilis (Fallén)

Family NABIDAE Damsel bugs

Himacerus boops (Schiødte)

Family ANTHOCORIDAE Flower bugs

Anthocoris gallarum-ulmi (DeGeer)

Orius majusculus (Reuter)

Orius vicinus (Ribaut)

Family CIMICIDAE Bedbugs

Cimex columbarius Jenyns

Cimex lectularius Linnaeus

Family LYGAEIDAE – Seed-bugs or groundbugs

Henestaris halophilus (Burmeister)

Acompus rufipes (Wolff)

Eremocoris podagricus (Fabricius)

Raglius alboacuminatus Goeze

Auchenorrhyncha

Family CERCOPIDAE Froghoppers

Aphrophora costalis Matsumura

Family CICADELLIDAE Leafhoppers

Austrogallia sinuata (Mulsant & Rey)

Euscelidius variegatus (Kirschbauen)

Platymetopius undatus (DeGeer)

Family DELPHACIDAE Planthoppers

Laodelphax striatellus (Fallén)

Stenocranus fuscovittatus (Stål)

Sternorrhyncha

Family APHIDIDAE

Mizosiphon ribesinum (van der Goot)