Acrotrichis exigua, Darby, Michael, 2014

Darby, Michael, 2014, Studies of Madagascan Ptiliidae (Coleoptera) 3: The genus Acrotrichis including twenty seven new species, Zootaxa 3866 (2), pp. 151-201 : 174

Acrotrichis exigua sp. n.

( Figs. 2 D, 15A–J)

Habitus Fig. 15A . Length 0.57 mm. Colour dark reddish brown, antennae and legs dusky yellow, the two basal segments of the antennae slightly lighter. Antennomeres 3–11 0.24 mm long Fig. 15 C. Mentum and submentum chaetotaxy Fig. 15 J. Width across eyes 0.23 mm. Pronotum 0.32 mm wide, 0.17 mm long, sides with a slight sinuation before the posterior angles Fig. 15 B. Elytra 0.34 mm long, 0.32 mm wide. Posterior margin of the mesoventral collar slightly sloped at shoulders and with a shallow median excision Fig. 15 F. Posterior margin of metaventrum and metacoxal plates Fig. 15 G. Pygidium without an apical tooth.

Male: ventrite six with +/- 7 spines Fig. 15 I; aedeagus Fig. 15 E.

Female: spermatheca Fig. 15 D.

Etymology. Johnson ms name.

Remarks. The smallest and apparently the most widespread of the small species. The spermatheca is the most reliable distinguishing feature though this is somewhat variable particularly in the size of the pump and the diameter of the duct.

Type data. Holotype: ♂, Ranomafana N.P., Vatoharanana RNF Sept 2012/09 GPS 209, sifting litter, Winkler app. extraction, S. 21˚16’ 59.7” E. 47˚25’ 30.3”, 1126 m, 5.x.2012, L.S.Rahanitriniaina ( BMNH). Paratypes: 96 examples, same data as holotype; 1♀, Ranomafana N.P., sifting, S.21˚14’51” E.47˚24’13”, 1079 m, 16–18.xi.2010, P. Banar ( BMNH); 30 examples, Ranomafana N.P., sifting, S.21˚15’ E.47˚25’, 970–990 m, 13–15.xi.2010, P. Banar ( BMNH); 2 examples, Ranomafana N.P., sifting, by stream close to main entrance, 17.xi.2010, P. Banar ( BMNH); 2♀, Ranomafana N.P., RNF/16/2011, sifting litter, Winkler app.extr., S.21˚14’57.9” E.47˚24’22.9”, 1138m, 16.iv.2011, L.S.Rahanitriniaina & R. Raveloson ( BMNH); 1♀, Ranomafana N.P., RNF/15/2011, sifting litter, Winkler app.extr., S.21˚15’06.0” E.47˚24’31.0”, 1197 m, 16.iv.2011, L.S.Rahanitriniaina & R. Raveloson ( BMNH); 3♂ 5♀, Ranomafana N.P., RNF/13.2011, sifting litter, Winkler app.extr., S.21˚15’13.5” E.47˚24’09.8”, 1158 m, 16.iv.2011, L.S.Rahanitriniaina & R. Raveloson ( BMNH); 93 examples, Ambohitantely Spec. Res., ABT/ 12/2011, sifting plant residues under palm tree, Winkler app. extr., S.18˚11’48.9” E.47˚17’10.5”, 1602 m, 19.iv.2011, L.S.Rhanitriniaina & R. Raveloson ( BMNH); 1♀, Ambohitantely Spec. Res., ABT/08/2011, sifting forest litter forest edge, Winkler app. extr., S.18˚11’51.8” E.47˚17’03.5”, 1523m, 19.iv.2011, P. Banar & R. Raveloson ( BMNH); 43 examples, Ambohitantely Spec. Res., ABT/ Nov/2011/11, sifting forest litter, Winkler app. extr., S.18˚10’52.6” E.47˚17’22.5”, 1497 m, 18.xi.2011, L.S.Rhanitriniaina ( BMNH); 1♀, Ambohitantely Spec. Res., ABT/ Nov/2011/19, sifting forest litter, Winkler app. extr., S.18˚10’56.9” E.47˚21’17.9”, 14974 m, 23.xi.2011, L.S.Rhanitriniaina ( BMNH); 2 examples, Ambohitantely Spec. Res., ABT/10/2011, sifting plant residues under Pandanus, Winkler app. extr., S.18˚11’39.2” E.47˚17’12.6”, 1674m, 19.iv.2011, L.S.Rhanitriniaina & R. Raveloson ( BMNH); 3 examples Ambohitantely Spec. Res., ABT/ Sept.2011/04, sifting litter by stream, Winkler app. extraction, S.18˚10’ 52.3” E.47˚17’21.3”, 1500 m, 2.ix.2011, L.S.Rahanitriniaina ( BMNH); 7 examples, Ambohitantely Spec. Res., ABT/ Sep.2011/11, sifting forest litter under palm tree close by water, Winkler app. extraction, S.18˚10’58.3” E.47˚17’22.2”, 1518m, 3.ix.2011, L.S.Rahanitriniaina ( BMNH); 4 examples, Ambohitantely Spec. Res., ABT/ Sep.2011/13, sifting forest litter under Pandanus and by big tree, Winkler app. extraction, S.18˚10’58.4” E.47˚17’22.6”, 1525 m, 3.ix.2011, L.S.Rahanitriniaina ( BMNH); 1♂ 2♀, Ambohitantely Spec. Res., ABT/10/2011, sifting plant residues under Pandanus, Winkler app.extr., S.18˚11’39.2” E.47˚17’ 12.6”, 1674 m, 19.iv.2011, L.S.Rahanitriniaina & R. Raveloson ( BMNH); 1# Ambohitantely Spec. Res., ABT/ Sept. 2011/25, sifting forest litter under Pandanus + palm tree, Winkler app. extraction, S..18˚11’43.6” E.47˚17’22.4”, 1642 m, 5.ix.2011, L.S.Rahanitriniaina ( BMNH); 2 examples, Ambohitantely Spec. Res., ABT/01/ 2011, sifting forest litter under Pandanus very dry material, Winkler app.extr., S.18˚10’51.7” E.47˚17’21.6”, 1593 m, 19.iv.2011, P. Banar & R. Raveloson ( BMNH); 3 examples, Ambohitantely Spec. Res., ABT/ Sep.2011/08, sifting forest litter (bamboo, Pandanus ), Winkler app. extr., S.18˚10’52.3” E.47˚17’21.3”, 1493 m, 2.ix.2011, L.S.Rahanitriniaina ( BMNH); 2 examples, Perinet, 928 m, 15.iv.1969, forest of transition, leg. H. Franz (MM); 8 examples, Plateau de Tampoketsa, 11.iv.1969, mountain forest, 1500m, leg H. Franz (MM) (note: Johnson ms indicates that further specimens from these collections may have been placed in the collection of H. Franz).

Figures

FIGURE 2. Skeletal features. A, A. barclayi, pronotum and scutellum / elytra x 465; B, A. exigua pronotum x 2480; C, A. truncata pronotum x 2220; D, A. exigua elytra x 4550; E, A. hammondi elytra x 2020; F, A. subafricana elytra x 2460; G, A. strenua metaventrum x 840; H, A. strenua mesoventrum x 840; I, A. barclayi, microtrichia on abdominal sclerites x 1640; J, A. subafricana, abdominal ventrites x 735; K, A. cuspida palisade fringe on abdominal sclerite x 1620; L, A. cuspida, spines on abdominalventrite 6 x 550.

FIGURE 15. A. exigua. A, habitus; B, side of pronotum viewed at 45 ˚; C, antennomeres 3 – 11; D, spermatheca; E, aedeagus; F, mesoventral collar x 760; G, metaventral posterior margin and metacoxal plates x 505; H, elytron; I, ventrite six; J, mentum and submentum.