Blastesthia Obraztsov
Type species: turionella Linnaeus
DIAGNOSIS
External characters:
Venation:
venation B. turionella
Forewing: Chorda extending from mid-distance R 1-R 2 to base of R 5 or anteriorly to it; median stem vestigial, terminating at M 2-M 3 or at CuA 1; M 2-M 3 approximate or connate.
Hindwing: M 2 and CuA 1 stalked; M 2 - M 3 separate or connate.
Forewing shape and markings:
examples of Blastesthia spp.
Forewing without costal fold, rather slender. Pale forewing ground colour partly mixed with orange- or tawny-brown.
Genitalia:
Male:
male genitalia B. turionella
Uncus vestigial; socius drooping, elongate, hairy. Basal opening of valva short, valva with large notch in ventral margin; clasper well developed, close to posterior edge of basal opening; costal hook well developed; aedeagus simple, vesica with bunch of deciduous cornuti.
Female:
female genitalia B. posticana
Sterigma cylindrical; cingulum developed, large; corpus bursae with one signum.
Early stages:
Swatschek, 1958, provides the following diagnosis for the larvae based on chaetotaxy.
L1, L2 and L3 do not share one pinaculum on the ninth abdominal segment; SV group bisetose on seventh, eighth, and ninth abdominal segments; prothoracic plate with small thorns; no small fourth L seta present on abdominal segments; SD1 situated equally high as spiracle on eighth abdominal segment; second stemma equidistant from first and third.
Biology:
There is one generation yearly; hibernation takes place in the larval stage; larvae feed on conifers; turionella is an important pest.
Distribution:
Palaearctic Region.