Wildlife Review 2022 - Grasshoppers, allies & other invertebrates

Grasshoppers & allies

A disappointing year for this group with some expected species not recorded. Only 14 species were recorded compared with a record 19 in 2021. The normally numerous Common Groundhopper, a species of damp areas, wasn't recorded: the dry winter and spring may have affected its life-cycle. Seemingly less affected by the conditions, Common Earwig were first recorded on 19 Mar with the locally distributed Lesne's Earwig the next day, both found in leaf litter.

Lesne's Earwig - Kevin Rylands

The first true grasshopper of the year was Meadow Grasshopper on 12 May, quickly followed by Lesser Cockroach on 13th, Grey Bush-cricket on 14th, Great Green Bush-cricket and Long-winged Conehead on 21st. All of these were first recorded in various instar or nymph stages, as was the first Speckled Bush-cricket found on 11 Jun.

Speckled Bush-cricket - Kevin Rylands

By July adult grasshoppers and bush-crickets were at their most numerous with the first Mottled Grasshopper and Oak Bush-cricket on 1st. Encouragingly at least three Roesel's Bush-cricket were recorded from 5 July; heard rather than seen, they were located in Greenland Lake and the Back Meadow. The first site record was only in 2018, with the second only last year. Field Grasshopper appeared from 9th, Tawny Cockroach was found on 10th and Common Green Grasshopper, a recent arrival, were active from 21st.

Field Grasshopper - Alan Keatley

Field Grasshopper could still be seen and heard on warm days into mid October and a late Dark Bush-cricket was seen on 23rd.

Molluscs

Fifteen species of slugs and snails were recorded, although dry conditions during the early part of year seem to have restricted numbers, especially slugs. Three new species were found all under wood, Draparnaud's Glass Snail Oxychilus draparnaudi on 2 Apr, Winter Semi-slug Vitrina pellucida on 13 Nov and Tawny Soil Slug Arion owenii on 20 Dec.

Winter Semi-slug Vitrina pellucida - Alan Keatley

Annelid Worms

Three widespread earthworms were recorded during the year, Roundhead Worm Lumbricus rubellus, Brandling Worm Eisenia fetida and Compost Worm Eisenia veneta. The highlight was a freshwater leech Erpobdella testacea, discovered new for the Recording Area on 10 Dec.

Erpobdella testacea - Alan Keatley

Isopoda

The ubiquitous Common Rough Woodlouse Porcellio scaber and Common Shiny Woodlouse Oniscus asellus were often found alongside the striped woodlice Philoscia muscorum and less frequently Porcellio spinicornis. The second record of the small, blind, white Ant Woodlouse Platyarthrus hoffmannseggii was found in ant nest nest on 5 Jun and several Rosy Woodlouse Androniscus dentiger, new to the Recording Area, were found on 22 Oct.

Rosy Woodlouse - Alan Keatley

Myriapods

Millipedes (and centipedes) are a very under-recorded group on the Warren and were also difficult to find this year, with just four species; Common Flat-backed Millipede Polydesmus angustus on 27 Feb, the millipedes Cylindroiulatus latestriatus and C. punctatus on 2 Apr and Striped Millipede Ommatoilus sabulosus from 5 May, the latter species is usually abundant across the site, but very few were seen this year.

Common Flat-backed Millipede Polydesmus angustus - Alan Keatley

Psocotera

Barkflies have a simple wing structure with most species under 6mm. Eight species were identified this year including Mesopsocus immunis, new for site on 24 Apr and both Ectopocus petersi and Trichopsocus clarus on 3 Jan. 

Pteroxanium kelloggi (nymph) - Alan Keatley

Other insects

These included a gorse thrip Odontothrips ulicis on 27 Feb, Scorpion-fly Panorpa communis from 3 May, Pond Olive Mayfly Cloeon dipterum on 15 May, a brown lacewing Micromus variegatus on 22 May, and two new caddisflies for the Recording Area; Limnephilus marmoratus on 19 May and Limnephilus lunatus on 1 Jul, both to light. Two new ant species were also found, both on the railway wall near Langstone Rock, the closely related, Formica fusca on 16 Jul and Formica cunicularia on 29 Jul.

Formica fusca - Alan Keatley

Archaeognatha

Two bristletails were found near Langstone Rock with Sea Bristletail Petrobius maritmus on 7 Apr and Heathland Bristletail Dilta littoralis on 18 Jun.

Dilta littoralis - Alan Keatley

Collembola

Springtails are very numerous and found in leaf litter and soil, but their small size can make them difficult to identify to species level. 12 species were recorded, including two new globular springtails; Dicyrtomina minuta on 13 Nov and Sminthurides aquaticus on 19 Nov.

Dicyrtomina minuta (above) & D. fuscus - Kevin Rylands

Arachnids (Spiders, Harvestmen and mites)

In the absence of any specialist visits just 36 spider species were recorded (cf. 75 in 2021). Despite this three new widespread species were noted for the first time, Invisible Spider Drapetisca socialis, Theridion varians, a comb-footed spider and Buzzing Spider Anyphaena accentua.

Buzzing Spider Anyphaena accentua - Kevin Rylands

Unfortunately there were no reports of Wasp Spider this year but better news from Warren Point, where the Dune Jumper Marpissa nivoyi was refound on the shore of the Bight, having been seemingly lost from the outer beach due to erosion. 

Dune Jumper Marpissa nivoyi - Kevin Rylands

Six species of Harvestman were recorded with the second site record of the non-native Opilio canestrinii in the same location as the previous 2020 record.

Opilio canestrinii - Kevin Rylands

Acari are small microscopic mites, many of which cause visible galls on their host plants, 21 species were noted including three new for the Recording Area. There were Acalitus rudis which causes a felt gall on birch, Aculops fuchsiae which forms a distorted leaf gall on Fuchsia and Aculus rubiae, which does the same on Wild Madder.

Aculops fuchsiae galls - Kevin Rylands