Stigmella kao

Diagnostic description: 

Diagnosis. Externally resembling the other fasciate species with edged scape (vandrieli, kurokoi, clisiotophora, castanopsiella), but male with short androconiae only and frontal tuft pale orange; possibly not to be distinguished externally from S. clisiotophora. Male genitalia rather aberrant within the oak miners: aedeagus short, with many short and similar cornuti only; female genitalia without accessory sac and lacking all sclerotizations.

Morphology: 

Description. Male. Forewing length 2.8-3.0 mm (n=3), wingspan 6.0-6.7 mm. Head: frontal tuft pale orange; collar lead-grey; scape silvery white, posteriorly and distally narrowly edged grey; flagellum grey-brown. Antennae with 30 segments (n=1).
Thorax shining lead-grey. Forewings basal half with purple gloss, followed by dark brown band, a shining silvery fascia at 2/3, constricted in middle or usually broken; wingtip dark brown, with distinct cilia-line, terminal cilia silvery; underside brown. Hindwing on upperside with pale brown indistinct small androconial scales. Underside grey-brown, with patch of slightly darker scales. Abdomen not examined.
Female. Forewing length 2.8-2.9 mm (n=3), wingspan 6.1-6.3 mm. Antennae all broken. Similar to male, hindwing grey.
Male genitalia. Capsule length 210-245 µm (n=3). Tegumen band-shaped, narrow. Vinculum with narrow anterior excavation. Uncus wide, with 2 pointed lobes wide apart. Gnathos with posterior processes widely separated, pointed; no anterior processes. Valva length 160-165 µm (n=2), about triangular, with prominent squarish inner lobe, slightly protruding posteriorly and a pointed distal process; transtilla with short sublateral processes. Aedeagus 325-355 µm long (n=3), 140-150 µm wide, comparatively short, cylindrical; vesica in distal half covered with relatively small triangular cornuti and in basal half with very small truncate, partly pectinate cornuti. Manica spinose, covering basal half of aedeagus.
Female genitalia. T 8 rounded, with about 7 setae on either side, no furrows or rims; apophyses narrow, equal in length. Bursa total length 465-470 µm (n=2), narrow and elongate, with longitudinal folds, anteriorly wrinkled; completely without spines or pectinations. Accessory sac absent, ductus spermathecae with narrow convolutions, ca. 13-15.

Associations: 

Hostplant. Castanopsis orthocantha. an evergreen cupuliferous tree with slightly serrate, coriaceous leaves. Mines collected on leaves of 45-95 mm long.
Leafmines. Egg on leaf upperside, always along midrib, 5-35 mm away from petiole. Mine starting as a linear mine along midrib towards tip for 21-38 mm, occasionally in last part following a lateral vein; then suddenly turning back and becoming an elongated blotch of 11-24 mm long, 4-7 mm wide. Frass almost filling gallery, in blotch in two lateral lines. Total length of mine 37-59 mm (n=14). Mine resembling that of some Ectoedemia species, such as E. intimella (Zeller) in Europe.
Larva. Greenish white, with black trapezoid tergites on metathorax and abdominal segments 1-8. Head pale brown. Feeds dorsum upwards.

Distribution: 

Yunnan.

Life cycle: 

Life history. Larvae found in October, adults reared in November.

Citation: 

This taxonomic description is based on Van Nieukerken (2000).

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