Stigmella lediella

Diagnostic description: 

Diagnosis.  Somewhat similar to S. auromarginella but easily separable  by the copper-brown proximal half of forewing and broad bluish silvery  fasciae in lediella.  The male genitalia differ from all European Stigmella  in having the narrow valvae with very long, inwardly curved distal process  and aedeagus with relatively few and short cornuti.  The female genitalia  of lediella are similar to those of S. splendidissimella but differ in  having longer and narrower vestibulum and dense cover of pectinations on  corpus bursae.  The illustrations of the male genitalia of two Rhododendron-  feeding species from South-eastern USSR: S. magica Puplesis, 1985c and S.  rhododendri Puplesis, 1985c show only minor differences from lediella.  External features and female genitalia of the Japanese species S. sesplicata  Kemperman & Wilkinson, 1985 (on Rhododendron) show only very slight differences  from lediella.

Morphology: 

Male. Wingspan: 5.0-5.7 mm.  Head: frontal tuft ochreous, vertex  orange; collar dark brown; scape pale golden; antenna three-fifths length  of forewing.  Thorax shining copper brown.  Forewing: area proximal to  fascia shining copper-brown, slightly darker before medial fascia; with two  fasciae, one medial, broad and oblique, and one short and narrow along distal  margin, both shining brightly bluish to greenish silver; distal to medial  fascia dark brown to almost black; terminal cilia dark grey-brown, slightly  paler at tips.  Hindwing: yellowish grey with bronze reflections; cilia  pale grey-brown.  Abdomen dark grey-brown, more or less suffused with copper  and purple. Female.  Wingspan: 5.2-6.0 mm.  Antenna approximately half length of  forewing.  Fascia usually broader.  Otherwise similar to male. 
Male genitalia. Vinculum short and broad with distinct  medial emargination.  Uncus relatively small, subtriangular with broad,  square medial emargination and small or indistinct paramedial notches.  Gnathos with lateral arms and anterior processes forming rectangular plate;  horns strong, forming a V.  Valva with narrow inner lobe and very long,  inwardly curved distal process.  Transtilla with long transverse bar and  long sublateral processes.  Juxta present.  Aedeagus as long as genital  capsule, with 20-25 cornuti: 12-15 in proximal half, 4-5 cornuti distally,  and a cluster of 6-8 needlelike spines. Female genitalia.  Vestibulum long and narrow.  Corpus  bursae large, entirely covered with longitudinal rows of very minute folds  and transverse rows of pectinations.  Accessory sac approximately half  length of corpus, without spines and pectinations.  Ductus spermathecae as long as corpus, posterior half with dense cover of spines. Apophyses  posteriores distinctly longer than anteriores.

Associations: 

Host plants:  Ledum palustre.  Egg:  on upper surface of  leaf.  Larva: yellow.  Mine : a conspicuous, gradually  widening gallery, usually following the margin of the leaf.  Frass deposited  as a black, frequently interrupted central line.  Cocoon: yellowish brown.

Distribution: 

Not in Denmark and Norway.  In Sweden from Sk. to Nb.  Widely distributed in Finland up to Ks. - Eastern C. Europe: Estland, Poland,  Czechoslovakia and Austria.

Life cycle: 

Voltinism:  in Scandinavia univoltine.  Mines from mid-September to early  October.  In Poland supposed to be bivoltine (Schleich, 1867) but this has not  been confirmed by breeding.  Wet localities; bogs and damp woods. 


Citation: 

Description based on Johansson and Nielsen (1990)

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith