Oecetis mizrain Malicky & Graf, 2012

Terefe, Yonas, Vitecek, Simon & Graf, Wolfram, 2018, Description of the larva of Oecetismizrain Malicky & Graf, 2012 (Trichoptera, Leptoceridae) and Lepidostomascotti (Ulmer, 1930) (Trichoptera, Lepidostomatidae) from Chilimo Forest, Central Ethiopia, ZooKeys 766, pp. 63-77 : 63

Oecetis mizrain Malicky & Graf, 2012 Figs 1-6, 7-11, 12

Material.

8 larvae: Ethiopia, Oromia Region, Chilimo forest N of Ginchi, 2451m a.s.l., 9.059719°N, 38.14332°E; 20.ii.2016; leg. & det. W. Graf; specimens deposited in the research collection of W. Graf at the University of Natural Resources and Applied Life Sciences Vienna [contact: [e-mail]] and the Senckenberg Research Institute and Natural History Museum Trichoptera collection [collection number SMFTRI00018576; contact: Steffen U. Pauls - [e-mail]].

Description of the 5th instar larva.

Biometry. Larva eruciform, body length 4.5-5.0 mm, head width 0.69-0.78 mm (n=4).

Head. Head capsule hypognathous, elongated, with smooth surface; head capsule distally slightly narrower. As in all final instar larvae of Leptoceridae , subocular ecdysial line present on parietalia, running from foramen occipitale to lateral section of parietalia, ventrally to eyes, at anterior region of eyes bending dorsally, meeting frontoclypeal suture (Fig. 2, black arrow). General color of head capsule pale to golden brown (Figs 2, 3); posterodorsal margin whitish, ventral occipital margin whitish with pale-brown line; ventral apotome brown with white corners; lateroventral sclerites defined by subocular ecdysial suture dorsally brown; parietalia and frontoclypeus around dorsal ecdysial line with distinct, pale muscle attachment spots; white ring around eyes, slightly wider than eye diameter. Head capsule with complete set of primary setae, and additional linear groups of setae around setae #16 and 17. Frontoclypeus scutiform, without distinct medial constriction. Labrum light brown, with setal brush and all primary setae. Mandible slender, elongate, with single cutting edge and 3 teeth. Ventral apotome isosceles trapezoidal, rounded corners. Antennae near distal parietal border (Fig. 2), long (more than 6 × longer than wide) and with single terminal seta (Fig. 2).

Thorax. Prothorax fully covered by 2 large sclerites, light brown to brown; small fragments of sclerites present posterior to each pronotal half (Fig. 4). Including anterior setal rows, 25-28 setae of varying lengths distributed over each pronotal half (Figs 4, 5). Mesonotum with 2 large sclerites covering about 50% of its area while not reaching lateral margins, each with small anterior sclerite. Including anterior setal rows, 3-4 setae distributed over each mesonotal half; setae of setal area 3 (sa3) on the unsclerotized part of each mesonotal half (Fig. 4; dashed oval). Metanotum completely unsclerotized; metanotal setal areas sa2 and sa3 each with single seta only; setal area sa1 not developed (Fig. 4). Metasternum with transverse band of setae on either side, each comprising 2-3 setae (Fig. 5). Legs yellowish beige, with numerous setae (Figs 6-8); foreleg with numerous stout setae on anterior face of femur and with row of stout yellow setae along ventral edge of femur (Fig. 6); foretrochantin with single seta (Fig. 6); tarsal claw of mid leg curved (Fig. 7); hind leg much longer than mid leg, as typical for this genus (Fig. 8).

Abdomen. Abdomen white, cylindrical (Fig. 9). Abdominal segment I with 3 protuberances (Figs 4, 5; arrows); dorsal setal areas sa1 and sa3 not developed, dorsal setal area sa2 with single seta on either side (Fig. 4, dashed square); lateral sclerite weakly sclerotized, mostly translucent, oval, with 1 seta (Fig. 5, dashed outline). Abdominal tergum IX with weakly sclerotized, mostly translucent sclerite, bearing 6 long setae in 2 groups concentrated laterally (Fig. 10, dashed oval). Anal proleg weakly sclerotized, each with large lateral sclerite and more strongly sclerotized anal claw and little accessory hook; each bearing several long setae; spines or tines on anal prolegs absent (Fig. 11, arrow). Lateral line not visible, a group of setae (2-3) present laterally on abdominal segment II (Fig. 9, dashed oval); dorsal gills only present at anterolateral position on segments II–IV, lateral gills absent, ventral gills only present at anterolateral position on segments II–IV (Fig. 12).

Case. Length 4.9-5.3 mm. Case of final instar larvae constructed of small sand grains, tusk-shaped; anterior opening with overhanging dorsal portion, posterior opening closed with silk (Fig. 1).