49.267 Eucosma fulvana (Tawny Knapweed Tortrix)
ws: 19-25mm; Jun-Aug; greater knapweed (Centaurea scabiosa); status uncertain but possibly widespread in GB*
* The distribution map in MBGBI5.2 shows this species occurring throughout most of England but not in Cornwall and north Devon and parts of north England; south Wales, but not central and north Wales; and patchily in south and central eastern Scotland, on the Outer Hebrides and Shetland - but, as §1 was the first record for Norfolk and it has not yet been recorded in Essex, this distribution map should be regarded as a work of fiction. The foodplant has its main area of distribution in central south England, extending east along the south coast and north-east into Norfolk and Lincolnshire and more scarcely distributed in south-west England, south Wales and north England and is almost entirely absent from Scotland.
* The distribution map in MBGBI5.2 shows this species occurring throughout most of England but not in Cornwall and north Devon and parts of north England; south Wales, but not central and north Wales; and patchily in south and central eastern Scotland, on the Outer Hebrides and Shetland - but, as §1 was the first record for Norfolk and it has not yet been recorded in Essex, this distribution map should be regarded as a work of fiction. The foodplant has its main area of distribution in central south England, extending east along the south coast and north-east into Norfolk and Lincolnshire and more scarcely distributed in south-west England, south Wales and north England and is almost entirely absent from Scotland.
Eucosma fulvana §1 female
ID: Very similar to E.hohenwartiana and E.parvulana - see E.hohenwartiana group for more detailed information on distinguishing these species.
§1 was obtained at a site where Greater Knapweed is known to occur; it's size is sufficient to exclude E.parvulana and it's female genitalia show a full suite of characters supporting identification as E.fulvana. Identification of §2 is somewhat less clear-cut - see below.
§1 was obtained at a site where Greater Knapweed is known to occur; it's size is sufficient to exclude E.parvulana and it's female genitalia show a full suite of characters supporting identification as E.fulvana. Identification of §2 is somewhat less clear-cut - see below.
DIssection
Female genitalia
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E.fulvana: b:a <2.4; b >1mm; e ~0.49mm; b:c <2; e:d <1
E.parvulana: b:a <2.4; b <1mm; e ~0.39mm; b:c <2; e:d 1 E.hohenwartiana: b:a >2.4; e ~0.57mm; b:c 2; e:d 2 Measurements for §1 are spot-on for E.fulvana a=0.52mm; b=1.02mm(left),1.12mm(right); c=0.65mm(left), 0.66mm(right); d=0.53mm; e=0.49mm; b:a= 1.96(left), 2.16(right); b:c=1.57(left), 1.70(right); e:d=0.92 |
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Measurements for §2 are more equivocal, but none support ID as E.hohenwartiana; the length of the 8th sternite (e) would probably exclude E.parvulana; the measurement of b and especially d, both of which favour E.parvulana over E.fulvana, are more subject to variations in compression of the preparation.
a=0.62mm b=0.87mm c=0.74mm d=0.44mm e=0.52mm b:a=1.4mm b:c=1.18mm e:d=1.18mm |
§1 Cranwich Camp, Norfolk; 29/06/2017; female; fw 8.9mm; by sweeping late afternoon - FIRST FOR NORFOLK
§2 Cranwich Heath, Norfolk; 05/07/2018; female; fw 9.1mm; to light
All images © Chris Lewis
§2 Cranwich Heath, Norfolk; 05/07/2018; female; fw 9.1mm; to light
All images © Chris Lewis
Page published 28/11/2017 (§1) | §2 added 11/01/2019
