Species Account
Distribution
Summary Data
Season (Adult / Immature):
|
National Status: Common Local Status: Scarce and thinly distributed resident. Local Record: Grade 3 See here for explanation Flight time: Two generations, Apr-Jun, Jul-Aug. Forewing: 12-13mm. Foodplant: Herbaceous plants. |
Record breakdown:
VC9 | VC11 | Region | |
---|---|---|---|
Year first recorded | 1929 | 1970 | 1929 |
Year last recorded | 2011 | 2011 | 2011 |
Number of records | 438 | 110 | 1096 |
Number of individuals | 664 | 133 | 1594 |
Unique positions | 48 | 8 | 112 |
Unique locations | 45 | 8 | 106 |
Adult records | 429 | 108 | 1074 |
Immature records | 0 | 0 | 0 |
For the region, we have a total of 1096 records from 106 sites. Earliest record on file is in 1929.
Photos
Species Account
Similar species: 1724 Xanthorhoe spadicearia (Red Twin-spot Carpet).
For further information refer UK Moths.
Davey, P., 2009: A widespread species in Britain, the larval foodplant is unknown. In Dorset, the moth is very local, being recorded from marshes, river banks, wet margins and ditch habitat where common marsh-bedstraw (Galium palustre), fen bedstraw (Galium uliginosum) or water dock (Rumex hydrolapathum) are potential foodplants. This species is likely to have a similar distribution to that of the Oblique Carpet1719.
Hill, L., 2013:
Underside: uniform grey; little contrast. Red Twin-spot Carpet has strongly contrasting pattern; deep ‘ginger’ colouration towards the apex of the forewing.
Some of the upperside diagnostics are subjective so whenever possible, refer to the underside.
Differences in wing markings between Xanthorhoe ferrugata (Cl.) and X. spadicearia [(D. & S.)] (Geometridae) are discussed. Examination of a long series of male genitalia confirm that presence of a notch in the inner edge of the central forewing fascia near the costa, is an unreliable determining feature. Approximately one third of X. spadicearia and two-thirds of X. ferrugata are notched. The degree of contrast between the pale post-median fascia and the terminal and sub-terminal areas, and other features of banding are useful indicators, and can in combination be used to safely identify many specimens. The red-banded and dark-banded forms in X. spadicearia form a continuum and are not clearly distinct as in the black-banded and red-banded forms of X. ferrugata. Examples with bold underside markings are likely to be X. spadicearia. Recording bias created by use of the notch is likely to favour X. ferrugata and would therefore have partly masked any decline in X. ferrugata. The 92% decline in X. ferrugata, as recorded in long term light trap data, is unlikely to have been affected by any bias. The apparent scarcity of the typical form of X. ferrugata (with red median forewing fascia) would appear to be genuine (Townsend, 2010).In accordance with (Townsend, 2010), all records of X. ferrugata Dark-barred Twin-spot Carpet must be considered unsafe if determined by the notch character alone. This is likely to be the majority of Dorset records.
Reference
Townsend, M. 2010. Observations on the use of wing-markings and genitalia to distinguish Dark-barred
Twin-spot Carpet Xanthorhoe ferrugata (Cl.) and Red Twin-spot Carpet X. spadicearia ([D. & S.])
(Lep.: Geometridae) and on the implications for recording these species. Entomologist's Rec. J. Var.
122(3):120-127.
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