Berkshire Moth Group Terminology Side view – typical resting posture The Common Grass Moths Apical Outer Two-thirds Half One-third Inner Towards or in region of apex. of Berkshire (VC22) Basal Tornus Palps Dorsum Towards or in region of base. Dorsal edge Base A guide to identification Costal l streak Termen Longitudina Towards or in region of costa; Costal edge Fringe costal edge: edge facing costa; Costa Introduction The Grass Moths (Crambinae) are represented by 39 species costal half: half of wing adjacent Apex to costa. Subterminal Cross-lines in the British Isles. Most are associated with grasses or rushes, cross-line Dorsal and can often be disturbed during the day, sometimes in Length measured from tip of wing to palps significant numbers. Towards or in region of dorsum; dorsal edge: edge facing dorsum; dorsal half: half of wing adjacent This guide covers the eleven species most commonly found Top view – wings spread in Berkshire (VC22). It should be possible to make a positive to dorsum. Fringe identification of all these species based on visual characteristics. Apex Subterminal Where there are similar species which are either uncommon or Long thin scales projecting beyond cross-line termen; also known as cilia. Cross-lines absent in the region the differences are described. Costa Inner Palps Towards head/base of wing. It will not be possible to identify all specimens unequivocally Termen Costal edge Longitudinal streak as there will always be oddities and worn individuals where Longitudinal Fringe there is room for doubt. Along length of wing, e.g. Dorsal edge longitudinal streak: streak running Base The species are grouped according to similar appearance, along length of wing Tornus Dorsum rather than in taxonomic order. Inset pictures are actual size. Oblique At an angle to costa or dorsum, i.e. Understanding Flight season (phenology) graphs Key to distribution maps neither parallel nor perpendicular to Hind wing Flight season wing edges. the data J FMAMJJASOND Tetrads (2 kilometre squares) in VC22 where the moth has been One half/one-third/two-thirds etc recorded. Approximate position along wing taken from base. Tetrads where any recording These show the number of records activity has occurred (i.e. at Outer from each month, as a percentage of least one record of any moth). Away from head/base of wing. the total (range 0-100%). Total number of records is also shown. Subterminal Key to text: Data is taken from the VC22 County Immediately before termen. Moth Records database and includes Status indicates national status. Terminal all records up to December 2008. Length is measured from palps to At end of wing; towards termen. Vernacular names wingtip, with wings closed. Tornal Taken from A Label and Checklist Classification numbers used are Towards or in region of tornus. of the British Micro-lepidoptera with Bradley & Fletcher. Vernacular Names by Jim Porter2. Not as yet widely used. Copyright © Berkshire Moth Group 2009 1 Berkshire Moth Group Pyralidae: Crambinae Species comparisons Agriphila tristella Common Grass-veneer 1305 Flight season Flight season Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Length (mm) 0 10 20 J FMAMJJASOND Crambus lathoniellus Agriphila straminella 3 2 1 Length: 15-18.5mm Chrysoteuchia culmella Crambus lathoniellus VC22 distribution Crambus pascuella Chrysoteuchia culmella 594 records Crambus perlella Catoptria falsella Agriphila straminella Catoptria pinella Catoptria pinella Agriphila geniculea Status: Common. Habitat: Tall grasses. Often disturbed Catoptria falsella Crambus perlella by day. Comes to light. Distinctive features: Variation Agriphila selasella Crambus pascuella Strong longitudinal streak 1, Generally very variable both in ground often narrowing at one third 2, Agriphila inquinatella Agriphila inquinatella colour and strength of markings. splitting into four ‘fingers’ 3. Agriphila tristella Agriphila selasella Similar species Agriphila geniculea Agriphila tristella 1 Graphs show percentage of records for each Bars indicate minimum and maximum month, on a scale of 0 to 100. lengths, although this is a guide only. If food sources are restricted (e.g. in © Ian Kimber drought conditions) smaller specimens A. selasella: Fingers less prominent. may well be found. Streak splits into two fingers 1 rather than four. Termen rounded and roughly perpendicular to costa. Streak pure white, of uniform width. Generally smoother appearance. © Malcolm Storey 2 3 Berkshire Moth Group Pyralidae: Crambinae Agriphila selasella Pale-streak Grass-veneer 1303 Crambus perlella Satin Grass-veneer 1302 Flight season Flight season J FMAMJJASOND J FMAMJJASOND 1 Length: 12.5-17.5mm VC22 distribution VC22 distribution 71 records 179 records 3 2 © Ian Kimber Length: 14-19mm Similar species Variation Status: Local. Status: Common/abundant. Ground colour quite variable. Habitat: Grass. Can be disturbed by Habitat: Tall grass. Very easily 1 f.warringtonellus day. Nocturnal. Comes to light. disturbed by day. Nocturnal. Distinctive features: Comes to light. Pure white longitudinal streak of Distinctive features: roughly even width 1 with dark Shiny white colour, lack of markings. costal edge 2 dividing into two © Jeff Higgott Variant f.warringtonellus ( ) has faint ‘fingers’ 3. Termen rounded, strong white longitudinal streak 1 A. tristella: ‘Fingers’ more prominent, perpendicular to costa. Smooth plus another streak along costa 2. four rather than two 1. Narrowing of appearance. 1 streak at one third. Termen straight, not perpendicular to costa. Rough 2 appearance. © Malcolm Storey Similar species Variation Little variation in typical form. Some variation in strength of markings in f.warringtonellus. © Richard Eagling A.straminella: Smaller size. More tapered overall shape. 4 5 Berkshire Moth Group Pyralidae: Crambinae Chrysoteuchia culmella Garden Grass-veneer 1293 Agriphila straminella Straw Grass-veneer 1304 Flight season Flight season 1 J FMAMJJASOND 2 J FMAMJJASOND 2 Length: 11-15mm VC22 distribution VC22 distribution 962 records 611 records 1 © Malcolm Storey 4 Similar species Variation © Richard Eagling Status: Very common/abundant Ground colour and strength of Status: Common/abundant. markings very variable. ‘C’ shaped Habitat: Tall grasses. Frequently Habitat: Grasses, esp. Sheep’s cross-line can be rather faint but is disturbed by day. Comes to light. Fescue (Festuca ovina). Often 1 5 always visible. 3 Length: 9.5-12.5mm Distinctive features: disturbed by day. Flies by day and night. Comes to light, often in ‘C’ shaped outer cross-line numbers. (C for culmella) 1. Brassy metallic sheen. A.straminella: Smaller size. No Distinctive features: Fringe uniform colour 2. cross-lines. Small size. Lack of cross-lines. 1 © M.Parsons/Butterfly Conservation Fringe metallic, outer half lighter . Faint longitudinal streak 2. Often speckled with brown 3. Strongly tapered overall shape. 2 Male: Two-tone appearance – dorsal half of wing light, costal half dark 4. Similar species Variation Female: © Charly Streets Degree of brown speckling and Platytes cerussella (no records): More uniform in tone. overall colour quite variable . Much smaller (Length 6-8mm). Streak splitting into faint fingers 5 © Malcolm Storey C.culmella: Larger size. Angled outer cross-line. Metallic sheen. © Mathias Biere C.perlella: Shiny appearance. Larger © Jeff Higgott size. More uniform breadth. 6 7 Berkshire Moth Group Pyralidae: Crambinae Crambus pascuella Inlaid Grass-veneer 1294 Crambus lathoniellus Hook-streak Grass-veneer 1301 Flight season Flight season J FMAMJJASOND J FMAMJJASOND 4 6 2 Length: 13-16mm Length: 11-14mm 2 VC22 distribution VC22 distribution 334 records 189 records 1 3 4 5 5 1 3 © Jan Haseler Status: Common/very common Status: Common. © Mike Wall Habitat: Grasses and bushes. Easily Variation Habitat: Tall grasses. Easily disturbed 7 disturbed by day. Comes to light by day. Nocturnal. Comes to light. Distinctive features: Distinctive features: Thick, white longitudinal streak 1, Longitudinal streak 1, notched dorsal edge more or less straight 2, halfway along 2, costal edge fairly costal edge angled at two-thirds 3, straight 3. Strong, sharply bent broken by thin oblique brown line 4. subterminal line with dark inner edge Triangularly shaped and marked apex Ground colour, and hence apparent strength of markings, fairly variable. 4. Triangularly shaped and marked 5. Hind wing pale. apex 5. Hind wing dark. Male: Streaks between veins greyish Similar species 6. Wing speckled with blackish scales. Variation Female: Streaks between veins white 1 7, fewer dark scales on wings, Overall colour quite variable. In male, blackish speckling varies in intensity. hence much paler overall appearance than male. 1 1 2 © Jan Haseler © Paul Harris © Jens Christian Schou Similar species C.lathoniellus: Narrow, notched Crambus silvella (1 unconfirmed Crambus uliginosellus (5 records in 1 longitudinal streak, costal edge record): Streak rounded not angular, Baker): Smaller size. Longitudinal See previous page for photographs. fairly straight 2. Less pronounced extending beyond subterminal line 1. streak touches costa to half way 1. C.pascuella: Longitudinal streak triangular apex. Hind wing dark. broad, not notched. Hind wing pale. Crambus hamella (4 records): Longitudinal streak unbroken. Crambus silvella (1 unconfirmed record): Longitudinal streak broad, © Richard Eagling © Mathias Biere 1 © Rob Petley-Jones without notch. Crambus hamella (4 records): Crambus pratella (no records): Crambus pratella (no records): Costal Longitudinal