Photo © Mike Wall

Fern

Horisme tersata

Checklist Number
70.127 [B&F: 1782]

Verification
Record will be accepted (subject to date and location checks)

Classification

Family:Geometridae
Subfamily:Larentiinae
Genus:Horisme
Species:tersata
Authority:([Denis & Schiffermüller], 1775)

Common in open woodland and hedgerows, and on downland and calcareous grassland throughout much of southern England and Wales. In Hampshire and on the Isle of Wight like Small Waved Umber H. vitalbata, depends upon Clematis, but unlike this species, has declined considerably in recent years, and is seen most frequently on the downs. Wingspan 31-36 mm. Characterised by streak on dorsum at one third, and streak on abdomen, which together form a single streak when the moth is in its natural resting posture, but see the recently discovered close relative Cryptic Fern H. radicaria which occurs in our area. Larva feeds on Traveller's-joy and Cultivated Clematis.

The abundance in each month is indicated as follows:

No records
Very occasional
Irregular
Uncommon
Off-peak, but not unusual
Off-peak, but not unusual
Main flight time
J F M A M J J A S O N D
Adult
Larval

Records by week (adult)

Records by week (larval)