35.066 Monochroa tenebrella (Hübner, 1817)

Status and Distribution

Local over all of the British Isles and the Channel Islands; can occasionally be locally common.

National Status: Local
Bradley & Fletcher no: 735
Photographer: © P Clement

Provisional map



Set Specimens

Monochroa tenebrella male bred Rumex acetosella, Trowlesworthy Warren, Devon 1999 (Photo: © R J Heckford)  Monochroa tenebrella female bred Rumex acetosella, Trowlesworthy Warren, Devon 1999 (Photo: © R J Heckford)

Wingspan 10 - 12mm. Two specimens found at The Old Head of Kinsale, Ireland in 1964 had a wingspan of 14mm (E. C. Pelham-Clinton).

Foodplant and Larval Feeding Signs

Rumex acetosella (sheep’s sorrel), see plant distribution map, and Rumex acetosa (common sorrel) (South Devon in 2013 - R. J. Heckord and S. Beavan pers. comm.).

There are no external signs of feeding damage.


Monochroa tenebrella habitat South Uist (Photo: © S Palmer)  Monochroa tenebrella habitat Eriskay (Photo: © S Palmer)

Open grassland and banks on acidic, impoverished, stony or sandy soils, dry heaths, drier raised banks in marshes, scrubland and amongst clear-felled conifer plantations.

Finding the Moth

Larva: feeds in the rootstock from September onwards and pupates in the larval feeding place in May.

Adult: can be readily swept from amongst the foodplant where it flies in sunshine and occasionally comes to light.

Similar Species

Oxypteryx unicolorella females have wholly dark antennae as opposed to the white apical third of female M. tenebrella - male antennae are the same colour. The third segment of the labial palpus is shorter than segment two in M. tenebrella and of equal length in O. unicolorella. Examination of these feature can be tricky in live moths, particularly in poor or artificial light.

Where moths are attracted to light (i.e. potentially away from an obvious habitat or foodplant association) and it has not been possible to examine the palps or antennae carefully in good light (or if the moth has dark antennae) retention of a voucher specimen and, if necessary, dissection is recommended for any new sites for either species.

January, February, March, April, September, October, November, December
June, July

Single brooded in June and July.

Earliest : 26th May 1990 (VC15)

Latest: 14th August 2001 (VC9)