Nepticula sanguisorbae, Stigmella, Stigmella sanguisorbae, Nepticula
Diagnosis. Externally very similar to S. thuringiaca, but slightly larger and forewings darker and more suffused with purple. Also very similar to S. viscerella but there are wide differences in the genitalia, see that species. The male genitalia of sanguisorbae and thuringiaca closely resemble each other and show much variation, particularly in the shape of vinculum and gnathos. Although there is some variability, also in the shape of uncus; sanguisorbae and thuringiaca can usually be separated by the angle between the uncus lobes (acute in sanguisorbae, right to obtuse in thuringiaca) and the presence of pectinations on the vesica of thuringiaca (absent in sanguisorbae). The female genitalia of these two species differ in sanguisorbae having a larger and more distinct accessory sac, broader and less pointed abdominal tip and stronger apophyses of equal length. Mine very similar to that of poterii but larva greenish, not bright yellow as in poterii.
Male. Wingspan: 4.4-5.0 mm. Head: frontal tuft pale ochreous to yellow brown; scape and collar yellowish white to pale ochreous; antenna slightly longer than half length of forewing. Thorax concolorous with base of forewing. Forewing: olive brown to dark grey-brown, with faint purple tinge on entire wing or only distally; terminal cilia concolorous or slightly paler. Hindwing: greyish brown. Abdomen: dark greyish to olive brown; with small fuscous anal tufts. Female. Wingspan: 4.5-4.8 mm. Similar to male, but without anal tufts. Antenna slightly less than or equal to half forwing-length.
Male genitalia. Vinculum with moderately to deeply emarginate anterior margin, lateral corners rounded. Uncus with pair of triangular lobes, usually at an acute angle to each other. Gnathos with transverse bar of varying length, long horns and heavy anterior processes. Valva tapering from midlength into curved distal process; inner lobe narrow. Transtilla with long transverse bar and small sublateral processes. Aedeagus slightly shorter than genital capsule; vesica with many slender cornuti in two groups of unequal size. Female genitalia. Bursa copulatrix half as long as abdomen. Anterior half of corpus bursae oval and completely covered with pectinations; signum consisting of slightly heavier pectinations on a slightly sunken medial band over anterior half, from ventral to dorsal side. Accessory sac globular with distinct reticulate field at base. Apophyses of equal length.
Host plant: Sanguisorba officinalis. Egg: usually on underside of leaf, on or near leaf margin. Larva: yellowish green. Mine : starts as a relatively wide gallery, usually following the serrations of the leaf for 1.5 to 2 cm then it doubles back, widens and forms a false blotch by fusion. Frass throughout the mine as a broad, loose central line. Cocoon: dark brown. Voltinism: univoltine, mines found in August and first half of September.
Not in Fennoscandia and Denmark. - Known from eastern Europe (Germany, Poland, Austria, Hungary). It is now extremely rare and possibly endangered because of destruction of habitat in the northern part of its range.
Description based on Johansson and Nielsen (1990)