Sapromyzosoma quadricincta (Becker 1895)

The mature larvae relatively large, soft and dorsoventrally flattened, the welts and crevices well developed. The Malpighian tubules slightly and irregularly inflated.

Egg (Figs 30–32). Length 0.81–0.95 mm. Robust, dorsal and ventral side poorly differentiated; ridges well developed, seldom fusing; micropylar pole with star-like collar; posterior pole with tubercle with several aeropyles.

First instar (Figs 146, 147). Length 1.25–1.98 mm. The first row of scraping cirri very dense, long (number of cirri exceeds 60) and directed oblique to the longitudinal body axis; below the first row are visible several small and sparse cirri. The ventral organ with two digitiform process; the central sensilla with outer horn as long as the outer digitiform process.

Cephaloskeleton (Fig. 176). Length 0.27–0.32 mm. Mouth hooks broad, spatulate, with 10–12 teeth, basal part hyaline and slender. Epistomal sclerite longer than broad, with prominent beak-like outgrowth from apical part of labrum. Parastomal bars slender. Subhypostomal sclerites opposite. Posterior sclerite voluminous. Very similar to P. vittata .

Second instar (Figs 148, 149). Length 2.11–2.98 mm. The facial mask broad and flat, number of scraping cirri per row exceeds 30. The peristomal cirri triangular to filamentous, with long marginal hairs.

Cephaloskeleton (Fig. 191). Length 0.59–0.60 mm. Mouth hooks almost parallel, slender, with 4–5 apical teeth. Intermediate sclerite slender; ventral bridge very broad, descending posteriad. Epistomal sclerite rounded. Subhypostomal sclerites peculiar, resembling sunglasses. Parastomal bars and rami very slender. Dorsal bridge trapezoid. Dorsal cornua slender, shorter than ventral ones. Ventral cornua very broad, finely striolated at connection with the vertical plates, dorsal margin convex and sclerotised. Cibarium hyaline.

Third instar (Figs 150–155). Length 3.89–6.17 mm. The facial mask as in the second instar, but the number of scraping cirri per row reaches 40. The first thoracic segment smooth; the second thoracic segment with smooth anterior third and two large dorso-lateral areas covered by hairs; the third thoracic segment anteriorly with comb spines, posteriorly covered by hairs. The abdominal segments densely covered by spines and hairs, except of small area behind dorsal pair of medial tubercles; ventrally, the spines and hairs are more gentle and sparse. Anal division relatively small and strongly tapering; completely covered by spines; the posterior spiracles on short sprouts. Anterior spiracles with 7 papillae.

Cephaloskeleton (Fig. 206). Length 0.98–1.01 mm. Basic organization as in the second instar, but tips of mouth hooks simple.