036 Monopis laevigella

12.036 Monopis laevigella (Skin Moth)

ws:13-20mm; May-Sep; common throughout UK

Monopis laevigella §1

ID: M.weaverella is said to be most easily distinguished from M.laevigella by having a large pale tornal spot (MBGBI2)
However, M.laevigella sometimes has a pale tornal spot. Further features given for separation of these two species are:
1) Position of the pale hyaline spot at .4 from base to apex of forewing in M.laevigella and .45 in M.weaverella.
2) Irroration with transparrent whitish scales more marked in M.laevigella.
3) More striking contrast between darker wing and pale cilia in M.weaverella.
Male genitalia
Male genitalia 4) Gnathos has a blunter tip in M.weaverella. 5) Valvae more elongate in M.weaverella. 6) Saccus longer in M.laevigella.
Saccus:valva ratio 1.4-1.7 for M.laevigella, 1.0-1.2 for M.weaverella. 4) Tip of gnathos blunter in M.weaverella.
See Monopis for more detail

Female genitalia: In comparing of the images of female genitalia of M.weaverella/laevigella at Moth Dissection, both show a ring of signa at around halfway along the corpus bursae. In M.weaverella ~8 angular relatively coarse signa are shown; in M.laevigella ~16 relatively fine signa are shown. However, this distinction does not seem to fit with specimens I have examined. §4 for example has no pale tornal spot, the hyaline spot is at .36 from the base, but it has at least 14 fairly course angular signa. Possibly the short sclerotised section of DB from the ostium is present in M.laevigella and not in M.weaverella - more work needed.

Variation
Dissection
Male genitalia
Female genitalia

§1 Westcliff-on-sea, Essex, 23/04/2007
§2 Dungeness, Kent, 25/09/2010; female
§3 Removed (misidentification)
§4 Silverdale, Lancashire; 18/06/2014; female; fw 8.0mm
§5 St Marys, Isles of Scilly; 30/09/2014; male; fw 7.4mm
§6 Christon Bank, Northumberland; 16/09/2014; male
§7 Foulness, Essex; 20/05/2018; male; fw 6.7mm
All images © Chris Lewis