Orthoptera of Cornwall & the Isles of Scilly: Native
Species
E. C. M. Haes & M. Lee January 2004
Bush-Crickets
| Ground-Hoppers | Grasshoppers
| Cockroaches | Earwigs
(A) BUSH-CRICKETS:
There are eight native Cornish bush-crickets, given below
in the order of frequency of occurrence here (by number of
tetrads).
1) Speckled Bush-cricket Leptophyes punctatissima
Our most commonly recorded bush-cricket, from over 300 tetrads
throughout the county. However, it is surprisingly well camouflaged,
and not easy to spot. Most records have come from the use
of bat detectors to pick up its distinctive ‘tick’
call, which is virtually inaudible by ear. Found in a wide
variety of habitats, including gardens, particularly in bramble
thickets. Recently established on St Mary's in the Isles of
Scilly.
Speckled Bush-cricket
(body length† c15mm)
Leptophyes punctatissima
photograph taken by Malcolm Lee
2) Dark Bush-cricket Pholidoptera griseoaptera
Recorded from over 250 tetrads, in scrub, herbage, and lightly
managed Cornish hedges. It has an easily heard call, typically
a brief ‘chip’, but there is a longer aggression
call when males meet. Much easier to pick up on a bat detector.
Not resident in the Isles of Scilly.
Dark Bush-cricket
(body length† c17mm)
Pholidoptera griseoaptera
photograph taken by E. C.
M. Haes
3) Great Green Bush-cricket Tettigonia viridissima
Found in over 150 tetrads, mainly in scrub and tall herbage,
this is our largest bush-cricket. It has a preference for
the coast, although less so in the far south west of the county.
Its very loud call may be heard from many tens of metres away,
although older recorders may be unable to pick up its high
pitched call, when a bat detector can be a useful aid. Only
resident on Tresco and St Mary's in the Isles of Scilly.
Great Green Bush-cricket
(body length† c40mm)
Tettigonia viridissima
photograph taken by E. C. M. Haes
4) Grey Bush-cricket Platycleis albopunctata
Recorded from some 70 tetrads. Strictly coastal, and found
in the warmest micro-climates. It is much more common on the
south coast. On the north coast there is a large population
at Penhale dune complex, but just small scattered populations
elsewhere. Its stridulation is almost inaudible, but easily
picked up on a bat detector. Final instar nymphs may be partly
green, and can be confused with our rarest bush-cricket, the
Bog B-c. Only known from Bryher in the Isles of Scilly.
Grey Bush-cricket
(body length† c22mm)
Platycleis albopunctata
photograph taken by E. C. M. Haes
5) Oak Bush-cricket Meconema thalassinum
Found in just over 40 tetrads, in trees and shrubs, particularly
in sheltered valleys. No stridulation, but males drum on leaves
to produce a faint sound which is not easy to hear, and inaudible
at more than a few metres. It comes freely to light, and moth
recorders may be the first to detect its presence. A check
around outside lights in August may be fruitful. Not resident
in the Isles of Scilly.
Oak Bush-cricket
(body length† c15mm)
Meconema thalassinum
photograph taken by Malcolm Lee
6) Long-winged Cone-head Conocephalus discolor
A very recent arrival to south Cornwall, probably from France.
It was first recorded in 1990 by S. P. Jones near Devoran.
It is now found in more than 30 tetrads, all still around
the south of the county. A northward spread may be expected
over the coming years. It could be found in any area of coarse
herbage. The continuous stridulation is best heard with a
bat detector. Resident on several islands in the Isles of
Scilly, since 1990.
Long-winged Cone-head
(body length† c17mm)
Conocephalus discolor
photograph taken by E. C. M. Haes
7) Short-winged Cone-head Conocephalus dorsalis
Only found in 15 tetrads, but populations can be extensive
where it occurs. It has a specific habitat requirement in
Cornwall, being found in salt marshes and grassy margins of
some of our tidal rivers (Gannel and Fowey, as well as the
Tamar river complex). A similar call to the Long-winged, also
best heard on a bat detector. There is a rare fully winged
form of this species, which has yet to be recorded in Cornwall.
Female fully winged forms can be readily separated from the
Long-winged Cone-head by the shape of the ovipositor –
almost straight in the Long-winged Cone-head, whereas that
of the Short-winged Cone-head is distinctly up-curved (as
in pictures below). A fully winged male would not be easy
to separate. Resident on several islands in the Isles of Scilly,
since 1989.
Short-winged Cone-head
(body length† c17mm)
Conocephalus dorsalis
photograph taken by E. C. M. Haes
8) Bog Bush-cricket Metrioptera brachyptera
Our rarest bush-cricket, with just five known extant colonies
within the county, all in wet heathland. It has a ‘chuffing’
call, akin to the sound of a steam train, and best heard with
a bat detector. As a distinctive, partly green, apterous bush-cricket,
it is unlikely to be confused with any other species, apart
from a final instar nymph of the Grey Bush-cricket. However,
the habitat alone should be a sufficient guide to avoid confusion
here. Not recorded in the Isles of Scilly.
Bog Bush-cricket
(body length† c17m)
Metrioptera brachyptera
photograph taken by E. C. M. Haes
Crickets & Mole-crickets:
See 2004 Cornwall Orthoptera Atlas. House Crickets are sporadic
pet trade escapees, and the RDB1 Mole-cricket has not been
seen for 40 years, being almost certainly extinct in Cornwall.
(B) GROUND-HOPPERS:
All three UK species occur in Cornwall, with Cornish populations
of Cepero’s Ground-hopper being of national importance.
These are the species, in order of frequency of occurrence
here (by number of tetrads).
1) Common Ground-hopper Tetrix undulata
The commonest species, found in over 150 tetrads. A wide
range of habitats, both damp and dry, in woodland rides, grassy
fields, heath and moorland, and mine sites. Identified by
the shorter pronotum, which does not reach the end of the
abdomen, and ‘chunky’ appearance. This is the
only resident ground-hopper in the Isles of Scilly, but on
Tresco only - probably introduced.
Common Ground-hopper
(body length† c10mm)
Tetrix undulata
photograph taken by Bryan Thomas
2) Slender Ground-hopper Tetrix subulata
Not quite as frequent as the Common G-h, found in just under
a hundred tetrads. This species is normally found in wetter
habitats than the Common, alongside streams, ponds and marshes.
In late summer it appears to move uphill onto drier ground.
In this, and the next, species the pronotum extends well beyond
the end of the abdomen. Not recorded in the Isles of Scilly.
Slender Ground-hopper
(body length† c10mm)
Tetrix subulata
photograph taken by E. C. M. Haes
2) Cepero’s Ground-hopper Tetrix ceperoi
Just 16 tetrads for this ground-hopper, but it is not readily
separated from the above in the field, and may be under-recorded.
Generally a more colourful species than the Slender G-h. Outside
of the Lizard, where there are strong populations, most records
are right on the coast. Not recorded in the Isles of Scilly.
Cepero’s Ground-hopper
(body length† c10mm)
Tetrix ceperoi
photograph taken by E. C. M. Haes
(C) GRASSHOPPERS:
There are only five confirmed resident Cornish grasshoppers,
plus two other former residents, at least one of which might
still persist. The species are given below in order of frequency
of occurrence here (by number of tetrads).
1) Meadow Grasshopper: Chorthippus parallelus
The most common grasshopper, and our most common orthopteran,
being recorded from over 350 tetrads. Readily identified as
our only flightless grasshopper (in hot summers, overcrowded
colonies may give rise to fully winged individuals). There
are a variety of colour forms. It can be found in just about
any grassy area, including moorland, road verges and set aside.
Its stridulation is a series of short ‘chuckles’,
easily heard by ear, although a bat detector will increase
the range. Not resident in the Isles of Scilly.
Meadow Grasshopper
(body length† c20mm)
Chorthippus parallelus
photograph taken by E. C. M. Haes
2) Field Grasshopper: Chorthippus brunneus
Not quite as common as the Meadow, being recorded in just
over 300 tetrads. It is usually brown, but can be variable
in colour. A distinguishing feature is its ‘hairy chest’
on the underside of the thorax. It requires a warmer habitat
than the Meadow, found on short, sparse, grassy areas and
sunny slopes, including footpaths and roadside verges. Its
call is a brief ‘zip’, repeated each second. It
is barely heard on a bat detector. Several surveys have confirmed
that this is the only resident grasshopper in the Isles of
Scilly.
Field Grasshopper
(body length† c20mm)
Chorthippus brunneus
photograph taken by E. C. M. Haes
3) Mottled Grasshopper: Myrmeleotettix maculatus
Considerably less common than the two species above, being
recorded from about 120 tetrads. It is smaller than the above
two species, and a key feature is the clubbed antennae, bent
at the tip. There are a variety of colour forms and mottled
markings. This species will be found in sunny, short turf
habitats, being recorded on many derelict mine sites. Its
stridulation is a series of buzzes, rising in volume, and
then stopping abruptly. It is heard on a bat detector. Not
resident in the Isles of Scilly.
Mottled Grasshopper
(body length† c15mm)
Myrmeleotettix maculatus
photograph taken by E. C. M. Haes
4) Common Green Grasshopper: Omocestus viridulus
Almost as frequent as the Mottled, being found in around
110 tetrads. Its habitat is almost exclusively unimproved
grassland, where it tolerates cooler conditions than our other
species. This is our loudest grasshopper, having a persistent
call lasting 20 seconds or more, which can be heard on a bat
detector. Not resident in the Isles of Scilly.
Common Green Grasshopper
(body length† c20mm)
Omocestus viridulus
photograph taken by E. C. M. Haes
5) Woodland Grasshopper: Omocestus rufipes
An uncommon species, with just over 20 tetrads, virtually
confined to coastal heathland on the Lizard and Penwith. A
small population in North Cornwall at Tidna Valley, Morwenstow,
has not been seen in recent years. It is a small grasshopper,
with a very colourful underside, and white palps, as in the
picture below. Its stridulation is similar to the Common Green,
but quieter and of shorter length, typically 10 seconds or
less. Not recorded in the Isles of Scilly.
Woodland Grasshopper
(body length† c17mm)
Omocestus rufipes
photograph taken by E. C. M. Haes
Note: Any record of this species must include unambiguous
confirmation of sight of the white palps.
Woodland Grasshopper (underside)
Omocestus rufipes
photograph taken by Malcolm Lee
The following species may no longer be resident here.
Stripe-winged Grasshopper: Stenobothrus lineatus
A colony persisted on Penhale dunes from the 19th century,
but has not been seen or heard since 1996. It may still be
present on the restricted MoD areas. The key identification
feature is the wing (see inset), with its bright white stigma,
the white stripe on the wing, and an enlarged medial area
with many veins running across it.
Stripe-winged Grasshopper
(body length† c20mm)
Stenobothrus lineatus
photograph taken by E. C. M. Haes
Rufous Grasshopper: Gomphocerippus rufus
The last Cornish record of this species was in 1973 on Brae
Hill, Daymer Bay, but several recent searches have failed
to detect it there. There are a handful of very old records
for coastal areas. The key identification feature is the white
tipped, and clubbed, antennae.
Rufous Grasshopper
(body length† c20mm)
Gomphocerippus rufus
photograph taken by E. C. M. Haes
(D) COCKROACHES:
Only two species of native cockroaches have been recorded
in recent years.
Lesser Cockroach: Ectobius panzeri
This is the only common species, being recorded from around
70 tetrads, including the Isles of Scilly. Mostly coastal.
The adults are not easy to find, and nymphs are more visible
on yellow flowers in June, as below.
Lesser Cockroach with egg case
(body length† c7mm)
Ectobius panzeri
photograph taken by E. C. M. Haes
Lesser Cockroach (Nymph)
Ectobius panzeri
photograph taken by E. C. M. Haes
Tawny Cockroach: Ectobius pallidus
Recent records are from Pencarrow Head (SX1550) in 1979
and Nare Head (SW9137), last seen in 1995.
Tawny Cockroach
Ectobius pallidus
photograph taken by E. C. M. Haes
(E) EARWIGS:
Only three native earwigs.
Apart from the ubiquitous Common Earwig Forficula auricularia,
now found in every Cornish 10km square, these other two resident
earwigs may be under-recorded.
Lesne’s Earwig: Forficula lesnei
Although long known on Scilly, there are just a handful
of mainland sightings since the first modern record in 1993,
and all are coastal. Only specific searching is likely to
come across this insect. The best method is to split open
dry umbellifer stems, particularly Hogweed, in autumn or winter,
where earwigs will be hibernating.
Common (left) and Lesne’s (right)
photograph taken by Malcolm Lee
Key differences
in males
Size: Lesne’s
about two thirds length of Common
(Common c12mm, Lesne’s c8mm)
A: Common – wings protrude from elytra.
Lesne’s – no wings to protrude
B: Common – Basal plate less than a
third of pincers
Lesne’s –Basal plate about half
of pincers
Lesser Earwig: Labia minor
A minuscule species, little bigger than an ant. Formerly
common in dung heaps, but, with the demise of horse transport,
rarely recorded now. Recently found in numbers in an enclosed
garden compost bin, a habitat worth searching on a hot day,
when the free flying tiny earwigs may be seen.
Lesser Earwig
(body length† c4mm)
Labia minor
photograph taken by Malcolm Lee
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