Adicella syriaca Ulmer, 1907

Waringer, Johann, Malicky, Hans, Graf, Wolfram & Vitecek, Simon, 2017, The larva of AdicellasyriacaUlmer 1907, including a key to the European larvae of Adicella McLachlan, 1877 (Trichoptera, Leptoceridae), ZooKeys 711, pp. 131-140 : 132-133

Adicella syriaca Ulmer, 1907

Diagnosis.

Head with pattern composed of dark bands and dark muscle attachment spots; case with spiral pattern, constructed of plant material; metanotal sa3 reduced to a single seta per side; pronotum with 56-65 setae of varying length per pronotal half; total number of setae per mesonotal sclerite 11-13; outermost seta of abdominal dorsum IX setal group approximately as long as width of this segment.

Biometry.

Body length ranging from 6.8 to 7.7 mm, head width from 0.58 to 0.60 mm (n = 2).

Head.

Head capsule surface smooth, with very shallow wrinkles, elongated and hypognathous. Base coloration pale yellow, with dark, reddish brown, oval muscle attachment spots on lateral and postero-ventral sections of parietalia. Frontoclypeus and parietal bands along frontoclypeal and coronal sutures dark reddish brown (Figs 1-3). White ring present around eyes (Fig. 3). Complete set of primary setae present (Figs 1-3). Frontoclypeus elongated, narrow, without central constriction (Fig. 1). Subocular ecdysial line running from foramen occipitale to ventro-lateral section of parietalia. Anteriorly of the eyes the subocular ecdysial line bends dorsally, eventually meeting frontoclypeal suture in a straight line (Fig. 3, arrow). Antennae slender, approximately six times longer than their basal width, situated at extreme anterior end of parietalia and originating from a socket-like ridge; antennal apex with single seta (Fig. 1a). Labrum light brown, quadrangular, with anterior median notch, ventral brush and six pairs of primary setae (Fig. 1). Ventral apotome medium brown, with darker brown anterior border, elongated quadrangular, with irregular lateral and posterior sides (Fig. 2). Mandibles black, each with ventral and dorsal cutting edge and terminal teeth along edge (Fig. 2).

Thorax.

Pronotum yellowish brown, with dark brown roundish muscle attachment spots (Fig. 3); with continuous row of widely-spaced, straight, black setae along anterior border; pronotal surface densely covered by 56-65 black setae of varying length per pronotal half (Fig. 3). Pleural sclerites irregular, elongated, pale, with black ventral margins; anteriorly, with brownish, finger-like protrochantin with blunt tip bearing one dark terminal seta (Fig. 3). Prosternal horn absent.

Mesonotum covered by two sclerites, each posterior half with large, semicircular central constriction; sclerites pale yellow, with distinct markings and muscle attachment spots along anterior margin and at center (Fig. 4). Total number of setae of varying lengths per mesonotal sclerite is 11-13 (sa1 without setae, each sa2 with 3 setae, each sa3 with 8-10 setae; Fig. 4). Mesopleurites pale, with narrow, blackish central bar (Fig. 3). Mesoventer without setae.

Metanotum without sclerotization except pleural sclerites; metanotal sa1 without setae, each sa2 with 1 seta each, sa3 reduced to a single seta per side (Fig. 5, arrows). Metaventer with a row of 4-5 setae per side (Fig. 11). Pleural sclerite arrangement as on mesonotum.

Legs orange-yellow, with very numerous setae, especially on coxae, trochanters, and femora (Figs 6-8); tibiae and tarsi undivided and without central constrictions. Femur of foreleg much wider than those of mid- and hind legs. Claw of mid leg curved and not hook-shaped as in genus Leptocerus (Fig. 7, arrow). Long fringes of swimming setae absent on hind legs.

Abdomen.

Abdomen white, cylindrical. First abdominal segment with one dorsal and two lateral protuberances (Fig. 9); dorsal sa1 and sa3 not developed, dorsal sa2 with single seta on each side (Fig. 5); oval and light orange lateral sclerite with strongly sclerotized, dark, curved and sickle-shaped posterior process; lateral sclerite with 1 ventral seta (Figs 9, 10). Abdominal tergum IX with pale, weakly sclerotized tergite, bearing 6 long and 4 short terminal setae; abdominal segment IX with 1 posterodorsal seta on either side (Fig. 12). Outermost seta on abdominal dorsum IX approximately as long as width of segment IX (Fig. 12, arrows). Anal prolegs pale and weakly sclerotized, each with large lateral sclerite and more strongly sclerotized anal claw with two tiny accessory hooks (Fig. 13). Each lateral sclerite bearing several long, black setae (Figs 13, 14). Each anal proleg medially with small group of pale, soft ventral setae (Fig. 13vs); tooth-edged plates around anal slit absent (Fig. 14). Gills and lateral line not visible; however, a lateral row of forked lamellae is present on abdominal segment VIII (Fig. 13fl).

Case.

In the final instar larvae, straight, cylindrical, tapering, constructed of equally sized pieces of thin plant stems and roots arranged in a typical single spiral (Fig. 15). Case length 12.2-13.9 mm, anterior width 1.9-2.2 mm, posterior width 1.0-1.2 mm (n= 2).