Acritoptila chiasma Kelley

Wells, Alice & Johanson, Kjell Arne, 2014, Review of the New Caledonian species of Acritoptila Wells, 1982 (Trichoptera, Insecta), with descriptions of 3 new species, ZooKeys 397, pp. 1-23 : 9-10

Acritoptila chiasma Kelley Figs 5-7, 27, 35

Acritoptila chiasma Kelley (1989: 192, figs 2, 11, 12).

Revised diagnosis.

Males of Acritoptila chiasma are similar to Acritoptila crinita and Acritoptila csavar , with which they share, in ventral view, the rather similar tongue-shaped form of the mid ventral genitalic structures interpreted as subgenital processes (Fig. 5). The males are distinguished from Acritoptila crinita by having spiny apical processes apico-laterally on tergite X (Fig. 6), which are hooked in Acritoptila csavar (Fig. 9), and simply curved in Acritoptila chiasma (Figs 6, 7). Neither Acritoptila chiasma nor Acritoptila csavar has the lateral setose processes seen on tergite X of Acritoptila crinita .

Male antennae each with 37-40 flagellomeres; forewing length, 2.0-2.1 mm (n = 3).

Material examined.

Holotype male: New Caledonia, mountain stream up Boulari River, (BPBM); 3 males (2 on slides), 4 females (1 on slide), Province Sud, lower part Rivière des Pirogues, 800 m WNW summit of Mont Imbaah, 4.7 km E Lucky Creek in Plum, 22°18.559'S, 166°41.227'E, 1.3 m, 1.xii.2003, light trap, loc#059, KAJ (NHRS); 1 male, Province Sud, Mt Dzumac, source stream of Ouinne River, at crosspoint to mountain track, 22°02.218'S, 166°28.566'E, 797 m, 18.xi.2003, light trap, loc#032, KAJ (NHRS).

Remarks.

The features separating Acritoptila chiasma from Acritoptila csavar are weak, but appear to be definitive. In the diagnosis of Acritoptila chiasma , Kelley (1989) states that species "is most closely related to Acritoptila crinita ", but has the tenth tergum "quite distinctive". However, Acritoptila chiasma more closely resembles Acritoptila csavar , both having gonopods of similar shape and stout spiny processes laterally on tergite X, whereas Acritoptila crinita has the gonopods forming a tight sphere and on tergite X has slightly sclerotized, weakly curved, lateral processes. Acritoptila chiasma differs from Acritoptila csavar in having in ventral the structure representing the fused gonopods more rounded, and in dorsal view the apical angles of tergite X acute and in lateral view the spine on tergite X curved ventrad, rather than dorsad. This species has been collected only in the far south of the island.