''Gryllus campestris'', the European field cricket or simply the field cricket in the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

, is the type species of

crickets Crickets are orthopteran insects which are related to bush crickets and more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 886 ...

in its genus and tribe

Gryllini GrylliniLaicharting (1781) ''Verzeichnis und Beschreibung der Tyroler Insecten'' 1. is a tribe of crickets (Orthoptera: Ensifera) and typical of the family Gryllidae. Species are terrestrial, carnivorous or omnivorous and can be found in all con ...

. These flightless dark colored

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s are comparatively large; the males range from 19 to 23 mm and the females from 17 to 22 mm.

Habitat

''Gryllus campestris'' used to be common over most of

Western Europe Western Europe is the western region of Europe. The region's extent varies depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the Western half of the ancient Mediterranean ...

. It prefers dry, sunny locations with short vegetation, like dry grasslands. At the northern edge of its range, it is restricted to

heath A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and is characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a coole ...

lands and

oligotrophic An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates o ...

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

s. The species is flightless and unable to migrate long distances, and it therefore does not commonly recover on its own from local extinction.

Reproduction

The reproductive season of the

univoltine Voltinism is a term used in biology to indicate the number of broods or generations of an organism in a year. The term is most often applied to insects, and is particularly in use in sericulture, where silkworm varieties vary in their voltinism. ...

species lasts from May to July. The males make a burrow with a platform at the entrance from which they attract females with their

courtship Courtship is the period wherein some couples get to know each other prior to a possible marriage or committed romantic, ''de facto'' relationship. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marri ...

stridulation. They chirp during daytime as well as the first part of the night, only when the temperature is well above 13 °C. Nymphs hatch in June till mid July and hibernate during their tenth or eleventh

instar An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...

. The final moult takes place at the end of April or at the beginning of May. Males are territorial and defend their burrows fiercely, while females are vagrant and are attracted by singing males. They lay their eggs in bare ground either close to a burrow or inside the burrow. Populations of ''G. campestris'' are known to undergo extreme fluctuations and are strongly affected by weather conditions.

Threats

''Gryllus campestris'' has long been considered the most endangered cricket species in the British Isles, occurring only in southern England. It is declining and red-listed in large parts of Central and Northern Europe, such as the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

, the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

Luxembourg Luxembourg, officially the Grand Duchy of Luxembourg, is a landlocked country in Western Europe. It is bordered by Belgium to the west and north, Germany to the east, and France on the south. Its capital and most populous city, Luxembour ...

, and

Lithuania Lithuania, officially the Republic of Lithuania, is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea, bordered by Latvia to the north, Belarus to the east and south, P ...

. It has declined severely in part of its northern range due to the disappearance of its heathland habitat; by the early 1990s, the species was reduced in the UK to a single surviving colony of just 100 individuals in

Coates, West Sussex Coates is a downland village in the Chichester district of West Sussex, England. Coates lies one mile (1.7 km) southwest from Fittleworth and four miles (6.8 km) south-east-by-south from Petworth. It is within the ancient divisions o ...

, and it is considered

extirpated Local extinction, also extirpation, is the termination of a species (or other taxon) in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a chan ...

from

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

Conservation efforts

Fragmentation of habitats and loss of (sub)populations have been recognized as main threats for many species, including the

Field cricket Field cricket may refer to: * Insect species ** In the British Isles a "field cricket" is the insect species ''Gryllus campestris''; ** in North America it may refer to various species in the genus ''Gryllus''; ** elsewhere, the term may be used for ...

. The artificial establishment of new populations is, therefore, a consistent method for enhancing the survival probability of a species. The aim of translocation projects is usually to reduce the risk of extinction for an endangered species by creating additional self-sustaining populations. Studies of translocation and natural populations of ''G. campestris'' in Germany have shown that translocation does not result in a significant loss of genetic diversity. Translocation of nymphs from different subpopulations may in fact be a suitable method to decrease the loss of genetic diversity and reduce the risk of inbreeding, and large numbers of nymphs may be translocated without negative effect on the source population. Field crickets are one of the species in the Back from the Brink project, which in 2018 translocated crickets to RSPB Pulborough Brooks to form a new population. In April 2022, 70 crickets from Spain were introduced to an organic field near the

Helford River The Helford River () is a ria (flooded river valley) in Cornwall, England, fed by small streams into its many creeks. There are seven creeks on the Helford; from west to east these are Ponsontuel Creek, Mawgan Creek, Polpenwith Creek, Polwheve ...

Cornwall Cornwall (; or ) is a Ceremonial counties of England, ceremonial county in South West England. It is also one of the Celtic nations and the homeland of the Cornish people. The county is bordered by the Atlantic Ocean to the north and west, ...

. It was last recorded in Cornwall in 1906. A follow-up survey in July 2023 estimated a population of 1000.

References

Sources

* Pearce-Kelly P, Jones R, Clarke D, Walker C, Atkin P, Cunningham AA (1998) The captive rearing of threatened Orthoptera: a comparison of the conservation potential and practical considerations of two species’ breeding programmes at the Zoological Society of London. J Insect Conserv 2:201–210 * C. Venne, F. Ahnfeldt (2003) Neuansiedlung der Feldgrille (''Gryllus campestris'') in Bielefeld? Ber. Naturwiss. Verein für Bielefeld u. Umgegend, 43, 407–417 * S. Fischer (1994) Die Bedeutung der Wanderschäferei für den Artenaustausch zwischen isolierten Schaftriften. Diplomarbeit Univ. Marburg. FB Biologie, Naturschutz * A. Hochkirch, K. Witzenberger, A. Teerling, F. Niemeyer (2007) Translocation of an endangered insect species, the field cricket (''Gryllus campestris'' Linnaeus, 1758) in northern Germany. Biodivers Conserv. 16:3597–3607

External links

*
Large photo of cricket

* ttps://ww2.rspb.org.uk/our-work/conservation/projects/field-cricket-reintroduction Field cricket reintroduction (RSPB) {{Authority control campestris Orthoptera of Europe Insects described in 1758 Taxa named by Carl Linnaeus