Species Account

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Summary Data

Season (Adult / Immature):

National Status: Local

Local Status: Rare and local resident.

Local Record: Grade 3   See here for explanation

Flight time: One generation, May-Jul.

Forewing: 16-20mm.

Foodplant: Woody plants. Bog-myrtle, Heather, Bilberry etc.

Regional breakdown:

Year first recorded18831883188318831880
Year last recorded20042014201420132014
Number of records83843336
Number of individuals13820283
Unique positions62832256
Unique locations72132246
Adult records42729293
Immature records08011

For the county, we have a total of 128 records from 90 sites. First recorded in 1880.


73.042 Light Knot Grass 05
© Tony Moverley, 23 May 2017
73.042 Light Knot Grass 04
© Derek Parkinson, 28 May 2004
73.042 Light Knot Grass 03 larva
© Andy Nunn
73.042 Light Knot Grass 02 larva
© Derek Parkinson
73.042 Light Knot Grass 01
© Damian Money

Species Account

Sutton & Beaumont, 1989: Apparently very local, mostly on high moors and less widely recorded than in previous years. Also recorded from sites just to the north of the County in Upper Teesdale (Dunn & Parrack, 1986).

Argus 58, 2009: It is surprising that this moth of heathland and moorland has not been found previously in VC65. A record of this distinctive larva, just on the VC65 side of the 64/65 boundary was a good find.
VC65. Mossy Bottom, larva 28.8.2009 (DP). NEW VICE-COUNTY RECORD.

2012 (CHF): In Porritt's time this species was commoner and he described it as "generally common on heaths and moors" in 1883 and in 1907. It certainly seems to be a lot more local now but we still receive small numbers of records from many upland areas of the county. It also occurs on our lowland heaths with many records from Strensall but very few from Skipwith. It has not been recorded from Thorne Moors since 1967. Occasionally wandering specimens are recorded from lowland areas eg one at Spofforth on 5.6.2008.

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