Guidelines for the Selection of Biological Heritage Sites
7. Section 2: Species Guidelines
7.8 INVERTEBRATES: GRASSHOPPERS AND CRICKETS (ORTHOPTERA)
Application (all invertebrate guidelines)
Identification of sites on the basis of their invertebrate animal species should take account of the needs of many invertebrates for habitat and structural diversity, both at the 'macro' and 'micro' scales. Small-scale habitats of particular importance to some invertebrates, such as dead wood or small patches of bare ground, occur and indeed may shift their position over time within large scale habitats e.g. woodland or grassland, on which the invertebrates also depend. Moreover the larval and adult phases of the same species often need quite different habitats. Invertebrates generally have annual life cycles, and their survival on a site depends on the continued availability of the right mixture of habitats at the right time of year - every year. Such factors should be taken into account when determining site boundaries.
Species lists, especially for less well-recorded groups of invertebrates, should be regarded as tentative. They include species recorded in Lancashire since 1950, those not recorded since 1978 being shown with an asterisk, or other notation.
It should be noted that the category 'nationally scarce', referring to species believed to occur between 16 and 100 10km squares of the National Grid, is sometimes subdivided in relation to invertebrate groups into 'Notable A' and 'Notable B'. This subdivision has not been recognised in the following guidelines.
Justification
In Lancashire, as elsewhere, there are more species of invertebrate animals than of all plants and other animals combined. Many invertebrate groups and species have declined dramatically in recent decades, and their conservation is a matter of widespread concern in Europe. Until recently, it was thought that if sites were selected (and managed) on the basis of their botanical interest, then the invertebrates would automatically be catered for too. This is not so: it is important that due regard is paid to the contribution that invertebrates make to biodiversity, and of their habitat needs, in their own right, insofar as available information allows.
With such a large number of invertebrate groups, and the relative lack of knowledge about many of these, it is impossible to develop individual sets of guidelines for every species-group at the present time. Where there is an adequate database for a particular species-group relating to Lancashire, specific guidelines have been devised and appear below. For the remainder, there is a single, 'catch all', section which follows the standard approach adopted throughout the species section.
iii) GRASSHOPPERS AND CRICKETS (ORTHOPTERA)
Application (all grasshopper and cricket guidelines)
Much less mobile generally than Lepidoptera or Odonata, acceptable evidence of grasshopper or cricket populations includes sightings of the animals, or hearing of their songs if recorded by a competent surveyor.
Justification (all grasshopper and cricket guidelines)
A popular group whose species are readily identified in the hand in most cases. Most species are found in unimproved dry or damp grassland, marshes or bogs, but the specific requirements of particular species - like the height of the vegetation, for example - may be quite precise.
Or1 Any site which regularly supports a population of a species of grasshopper or cricket included in British Red Data Books: 2 Insects.(1)
Application
There are no known Lancashire records for the species to which the guideline applies.
Justification
The species in the above category are either threatened or rare in Britain and there is a national responsibility for their conservation.
Or2 Any site which regularly supports a population of a 'nationally scarce' species of grasshopper or cricket.
Application
The species to which this guideline applies include:
| Metrioptera brachyptera | Bog Bush-cricket |
| Metrioptera roeselii | Roesel's Bush-cricket |
Justification
Nationally scarce species are recorded only from 16-100 10km squares (inclusive) in Britain; their conservation is a matter of national concern.
Or3 Any site which regularly supports a population of a species of grasshopper or cricket which occurs at 3 or fewer localities in Lancashire.
Application
Any site for species in this category which are not covered by Guidelines Or1 or Or2 may be considered. The species to which this guideline may apply include:
| Meconema thalassinum | Oak Bush-cricket |
| Pholidoptera griseoaptera | Dark Bush-cricket |
| Tetrix subulat | Slender Ground-hopper |
Justification
These are species which, although frequent in some parts of England, are rare in Lancashire. Subject to further localities being colonised or discovered, they may provisionally be regarded as 'endangered' in a County context.
Or4 Any site which regularly supports a population of a species of grasshopper or cricket which is recorded from more than 3 localities in Lancashire, but which could be at risk because of small populations, recent rapid decline, habitat loss or change, or is at the edge of its British range, where such populations contribute significantly to the distribution pattern or the total population size of that species in the County.
Application
Sites for species in the above categories (not included under Guidelines Or1 or Or2) may be considered for inclusion where they significantly extend the known geographical range of the species in Lancashire, or support a significant proportion of the estimated total County population of that species. Further survey may show that this guideline may apply to one or more species listed under Guideline Or3.
Justification
Such species, whilst not qualifying under Guideline Or3, are nevertheless either of very restricted distribution, or exist only as small scattered populations, in Lancashire.
Or5 Any site which regularly supports populations of 3 or more grasshopper or cricket species.
Application
Any site which satisfies this guideline should be included. The following species are relevant for the purposes of this guideline:
| Chorthippus brunneus | Field Grasshopper |
| Chorthippus parallelus | Meadow Grasshopper |
| Myrmeleotettix maculatus | Mottled Grasshopper |
| Omocestus viridulus | Common Green Grasshopper |
| Tetrix undulata | Common Ground-hopper |
Justification
The purpose of this guideline is to identify sites which have structural and habitat diversity suitable for a range of grasshoppers.
(1) Shirt (1987)