Aethaloptera dispar Brauer

Ogbogu, Sylvester Sunday, 2005, First report of Aethaloptera dispar Brauer 1875 (Trichoptera: Hydropsychidae) from Ile­Ife, southwestern Nigeria, West Africa, Zootaxa 1088, pp. 25-32 : 27-29

Aethaloptera dispar Brauer

Figs. 2–7

Aethaloptera dispar Brauer, 1875: 72 .

Diagnostic characters of larva

The larva of Aethaloptera dispar can easily be confused with other macronematine hydropsychids, Amphipsyche McLachlan species in particular, but the shape and arrangement of features in the head are useful in differentiating one from the other. When the head of A. dispar is viewed dorsally, the mandibles are almost entirely concealed by the clypeus. This is not the case with species belonging to the genus Amphipsyche .

Description of mature larva

Head: Broad and oval, no carina, frontoclypeal apotome triangular. Eyes black, medium­sized, situated well forward. Antenna minute, situated near the back of mandible. Anterior margin of frontoclypeus with an incision in front of seta no. 2 ( Fig. 2 ).

Thorax: Thoracic segments short, wide, pale yellow­brown in color. Thoracic sclerites without a long process; lateral and anterior margins of dorsal plates generally dark; the lateral margin with very black areas ( Fig. 3 ). Pronotum with transverse sulcus near posterior margin, mesonotum with faint brown stripes originating from lateral margin and extending diagonally and half way towards the middle; with median sickle­shaped black spot located centrally at posterior margin of mesonotum. Metanotum with brown stripes originating from lateral margin and extending down across shield; median boat­shaped black spot located centrally near posterior margin. Gill branches on mesosternum consist of long filaments, terminating with the origin of 2 or several short filaments.

Legs: Yellowish brown, darkened at the joints. Foreleg with spine on anterior surface of coxa. Long hairs present mostly at fringes of trochanter and anterior end of femur ( Fig. 4 ). Fore trochanter stout, shorter than coxa, with setae along its length and with many around distal area; thick brush of hairs present on surface of tibia and one side of tarsus; mid­ and hind legs less setose. Tarsal claws differ with leg; foretarsi with anterior tarsal claw bearing 2 sharp basal spines that are unequal in length; mid­and hind tarsal claws with only single basal spine ( Fig.5 ).

Abdomen: Rows of tracheal gills present on mesosternum, metasternum and abdominal segments;gill branches on mesosternum ending in 2 filaments. Segment VIII without ventral sclerite. Segment IX with 2 sub­ovate ventral sclerites bearing light and dark long setae, anterior area of the sclerites with light setae slightly larger than the posterior area with dark setae; segment IX with pair of central patches of setae. Anal proleg long with fairly smooth, plain, curved anal hooks ( Fig. 6 ).

Diagnostic characters of adult

Antenna golden brown, 95 segments and up to 50 mm long in male, 35 segments and 10 mm in female. Head and thorax yellowish brown, forewing pale green, 10–15 mm long in male and 8–10 mm in female. Detailed description of adult A. dispar was given by Barnard (1980).

Description of adult female

Head: Antennae golden brown with whitish band at the base. Vertex with distinct balllike wart covered with bristles, a 2nd wart below this is not well developed. Eyes large.

Wings: Forewing broad, 10.1 mm in length. Forewing fork R2 longer than its stem; R1 straight, free to the wing margin; R4+5 forming a triangle; M3 stalked; Sc and R1; straight apically. Hind wing 8 mm in length, triangular along hind margin; marginal hairs smooth at the edges, curved.

Legs: Tibial and tarsal segments of mesothoracic leg long, slender, with 3 or more short spines apically; 2 pairs of long lanceolate spurs at middle and at apical end of tibia ( Fig. 7 ).

Abdomen: Sclerites of sternite VIII without deeply excised posterior corners.

Figures

FIGURES 2 – 7. Aethaloptera dispar Brauer, 1875 (larva and adult female). 2, Anterior region of head of larva, dorsal view. 3, Larval pronotum, dorsal view. 4, Left foreleg of larva, dorsal view. 5, Tibia and tarsus of midleg of larva, dorsal view. 6, IXth sternite and proleg of larva, ventral view. 7, Adult female midleg showing pre­apical and apical tibial spurs.