Coleophora impalella Toll, 1961

Takacs, Attila, Szaboky, Csaba, Boldog, Gusztav, Jordan, Sandor, Bozso, Miklos, Fueloep, David & Toth, Balazs, 2022, Biology and DNA barcode analysis of Coleophora lessinica Baldizzone, 1980 and Coleophora impalella Toll, 1961 (Lepidoptera, Coleophoridae) with description of their larval cases, Nota Lepidopterologica 45, pp. 191-205 : 191

Coleophora impalella Toll, 1961

Case and behaviour.

Construction of the case begins in late August or early September from the leaves of the host plant, Galatella sedifolia . This finding does not support Richter (2021), who has found cases on G. linosyris (L.).

The case is made of 2-6 mm long and 2-4 mm wide strips spun to each other with overlap, resulting in a sheath case (Figs 24 , 25 ). Feeding lasts until drying of host plant in autumn. The overwintering case is 12 mm long and is attached to a broader section of the dried plant. The larva continues feeding on fresh leaves in spring. Early case is greyish black, changing to dark brown after overwintering. Mouth directed in 40 ° angle to longitudinal axis of case, case slightly tapering towards anal end, caudal 2/3 part slightly curved, anal end flattened, bivalved.

Adults emerge 10-12 days after the permanent attachment of the case. They fly in daytime and remain close to the host plant. Mating was observed between 11 h and 13 h.

L5 larva

(Figs 18-23 ). Length 5.5 mm. Head brown, adfrontal suture black. Body light brown, with inconspicuous pinacula around prolegs on segments A3-A5. Thoracic shields shiny black, rounded; prothoracic shield ovoid, more than 1.5 times as broad as long, very finely divided along median axis except anterior margin; mesothoracic shield D-shaped, divided to two halves by gap medially, gap being narrowest at middle, shield gradually broadening towards anterior and posterior margins, anterior margin straight, lighter than rest of the shield; metathoracic shield made of two separated ovoid plates with dentate inner edges, plates separated by gap slightly broader than the plates (Fig. 18 ). Spiracular sclerites oval, of equal length, sclerite on prothorax half as broad as those on meso- and metathorax, latter two sclerites with uniform shape and size (Fig. 19 ). Thoracic legs brown; proximal parts of segments darker than distal parts (Fig. 20 ). Prolegs on segments A3-A5 with 6-6 crochets in two uniordinal rows; on segment A5 two crochets in anterior, four crochets in posterior row, three crochets in each of remaining row (Fig. 21 ). Anal plate matt black, heavily irrorated with tiny hollows (Fig. 23 ). Anal proleg half-moon-shaped, each with 17-19 crochets (Fig. 22 ).

Conditions of collecting.

Ten cases of C. impalella were collected in Bélmegyer, Fáspuszta (Figs 24 , 25 ), on 24.ix.2020. Dates and numbers of emerged specimens: 1 ♂, 29.iii.2021, 1 ♀, 31.iii.2021, 1 ♀, 13.iv.2021, 1 ♂, 03.v.2021.

In addition to the Hungarian locality already known, the species was also found in Szabadkígyós, Kígyósi puszta on 12.v.2021 (Fig. 26 ). One case was collected in Elek on 06.x.2021 and one case in Grăniceri, Romania on 06.x.2021. This latter record is the first one outside Russia and Hungary. New to Romania.

Habitat.

Coleophora impalella feeds on Asteretum sedifolii Soó 1947 corr. Borhidi 1996 (Pannonic salt steppes and salt marshes), a species that is highly influenced by dry continental climate with extreme temperatures and uneven distribution of precipitation. This habitat type was formed by secondary salinisation (Fig. 27 ). It is characteristic for the Continental climate zone and can also be found in the Ukrainian and Russian steppe belt ( Borhidi 2003).

Parasitoids.

No cases of C. impalella and C. lessinica specimens have given parasitoid specimens in our rearings to date.

Figures

Figures 24 - 27. Some stages and habitat of C. impalella. 24. L 5 case of C. impalella before overwintering, Belmegyer, 13. x. 2020; 25. L 4 case of C. impalella before overwintering, Belmegyer 24. ix. 2020; 26. Imago of C. impalella from Szabadkigyos, Kigyosi puszta, 12. v. 2021; 27. Habitat of C. impalella in Szabadkigyos, Kigyosi puszta, 20. v. 2021. Scale bar: 3 mm (24); 2 mm (25); 2.1 mm (26). Figs 24, 26: photo by A. Takacs, Figs 25, 27: photo by G. Boldog.

Figures 18 - 23. Larval morphology of Coleophora impalella. 18. Head and thorax, dorsal view; 19. Head and thorax, lateral view; 20. Head and thorax, ventral view; 21. Prolegs on segments A 3 - A 6, ventral view; 22. Anal prolegs, ventral view; 23. Anal plate, dorsal view. Scale bar: 1 mm, cranial direction top, caudal direction bottom, photos by A. Takacs.