Adult
This is a small, rather primitive moth, with wing venation that is heteroneurous and a female reproductive system with a single opening used both for mating and for oviposition. [4] [5] [6] [7]
A tergosternal connection can be observed, posterior to the first abdominal spiracle, formed by a ventrocaudal process of the first tergite that connects to the anterolateral extension of the second sternite. [5] [8]
The forewing is lanceolate with a rounded apex; it is dull brownish-grey with greenish iridescence and strongly marked veins; the termen tends to be slightly darker. [1] Microtrichia are present and uniformly distributed. [4]
Its hindwing is stouter and more rounded, a uniform off-white with silvery reflections; [1] as in all Adelidae, there is a reduction of the system associated with the radial sector (Rs) of the hindwing, with anastomosis of Sc and R from the fourth basal to the termen, and an unbranched Rs; wing coupling is frenate, with a single composite bristle frenulum in the male and multiple bristles in the female. [4] [9] A coupling apparatus between the forewing and metathorax is present; a precoxal bridge [10] and loss of the first abdominal sternite can also be observed, while the second is divided into a smaller anterior sclerite (S2a) and a larger posterior one (S2b). [4] [5] [11] [12]
Its head is yellowish. The antennae are filiform and, especially in the male, exceed the body length by a considerable margin. An intercalary sclerite is present, as well as lateral spinules (probably derived from sensilla [13] ) on some proximal segments of the male flagellum. [4] [14] The basal antennomeres appear alternately white and black, then become more or less uniformly white in the distal portion of the antenna. [1]
Ocelli are absent, as are chaetosemata. The male's eyes are fairly developed. The proboscis is fully functional, covered in scales, and longer than the head capsule, extending beyond the maxillary palps; the latter are elongated. The labial palps have three segments, short, with lateral setae on the second; the apical segment shows a vom Rath organ. [4] [15] [16]
On the legs, the tibial spur formula is 0-2-4. [4] [5]
The male genitalia show, on each valva, a comb-like structure called a pectinifer. The uncus is absent, while the vinculum has an elongated saccus. The juxta is arrow-shaped and the aedeagus is slender. [4] [5] [16] [17]
In the female genitalia, the ovipositor is well developed and piercing, with laterally flattened apices that allow eggs to be inserted into the leaf tissues of the host plant; this feature is considered a secondary specialization of the Adelidae. The cloaca is narrow and tube-like. The apophysis is strongly sclerotized; the corpus bursae is developed and membranous, without signa. [4] [5] [13] [16] [17] [18]
Its wingspan is 15–20 mm. [1] [19]
Larva
The caterpillar, almost cylindrical, has a rounded head that is not flattened and is prognathous, with a pronounced epicranial groove and six stemmata per side. [4] [16] [20]
Two genal setae, G1 and G2, are present, while the absence of seta AF2 is considered a secondary evolution. [13] [16] [17]
A well-sclerotized shield is visible on the prothorax. [16]
The thoracic legs are well developed, while the prolegs, on abdominal segments III–VI and X, are strongly reduced; the proleg crochets, absent on segment X, are arranged in multiple rows. [4] [16] [20]
