Agapetus (Synagapetus) alarum, Gibon, 2017

Gibon, François-Marie, 2017, Presence of the Glossosomatidae in Madagascar, with description of two species (Trichoptera), Zootaxa 4317 (1), pp. 174-178 : 175

Agapetus (Synagapetus) alarum n. sp.

Figs 1 A–1E

Holotype: Male, mounted on six slides. MADAGASCAR: Fianarantsoa Prov., Andringitra National Park, Sahanivoraky River , 22°13'33"S, 47°0'41"E, 810 m a.s.l., 19.xi.1993, F.- M. Gibon leg. ( CBGP).

Paratypes: all specimens same data as holotype; 2 males in alcohol ; 1 male mounted on six slides; 1 male with genitalia on two slides and remaining parts in alcohol.

Diagnosis. Agapetus alarum n. sp. is similar to the other Malagasy species, A. ranohelae n. sp. They differ from one another by the inferior appendages (curved dorsad in A. alarum , but rectangular in A. ranohelae ) and by tergum X (longer than the inferior appendages and extended in a distal digitiform lobe in A. alarum , but as long as the inferior appendages and roughly triangular in A. ranohelae ). Both species belong to the A. (Synagapetus) agilis Group of Ross (1956). This group is not homogeneous; it includes the two southern African species: A. agilis , characterized by the absence of preanal appendages and the absence of a ventral process on sternite VI, and A. murinus , which is fairly similar to the Malagasy species but is distinguished by the slender and acute tergum X (stout and wide in the Malagasy species). Also the preanal appendages are finger-shaped in A. murinus , but short and wide in the Malagasy species. The other African species group ( Agapetus ungulatus Group) is clearly characterized and distinguished by two apomorphies: a single and apically curved preapical spur on each metatibia and a highly modified tergite X.

Description. Three ocelli. Tibial spurs 2/4/4. Maxillary palps each 5-segmented, segments 1, 2 and 5 short, segment 2 enlarged distally, segment 3 clearly longer. Labial palps each 3-segmented. Forewings each with length 4.1 mm, maximum width 1.4 mm; distal margin oval; forks 1, 2, 3, 4, and 5 present; forks 3 and 4 petiolate; Cu1 forked just beyond m-cu crossvein. Hindwings each with length 3.2 mm, maximum width 0.9 mm; smaller and narrower than forewing, venation reduced; forks 1, 2, 3, and 5 present; forks 1, 2, and 3 petiolate; R1 ending at R2+3; discoidal cell open; Cu1 forked just beyond m-cu crossvein. Sternite V with lateral fold and internal gland, similar to those described by Ross (1956) for A. cocandicus McLachlan 1875 . Sternite VI with ventral keel-shaped projection. Abdominal segment IX large and synsclerotized; tergum IX shorter than sternum. Preanal appendages short and wide, roughly rectangular. Inferior appendages each single-segmented, stout, thick, curved dorsad, with small setae but without sclerotized denticles, spines, or small bumps on inner face; 2/3 as long as tergum X. Tergum X almost entirely divided in pair of lateral elements; in lateral view each element composed of large, wide, almost rectangular basal part, ventrodistally elongated in short, acute ventral lobe and long distal finger-shaped lobe. Phallic apparatus long, slender, slightly curved ventrad.

Etymology. From the Malagasy: ala (forest), with reference to the magnificent pristine forests of the Andringitra.

Habitat and distribution. Collected from a small brook in pristine rainforest. Endemic to Madagascar and recorded from only Andringitra National Park ( Fig. 3 ).

Figures

FIGURE 3. Ecological profile and known locations of Agapetus alarum n. sp. (circles) and Agapetus ranohelae n. sp. (stars) in Madagascar.

FIGURE 1. 1 A – 1 E, Agapetus alarum n. sp.: 1 A, wings; 1 B, head, meso- and meta thorax, dorsal; 1 C, genitalia, left lateral; 1 D, genitalia, dorsal; 1 E, phallic apparatus, left lateral. Scale bars, wings: 1 mm; genitalia: 0.1 mm; head and thorax: 0.5 mm.