Aenictus nesiotis Wheeler and Chapman

Shattuck, Steven O., 2008, Review of the ant genus Aenictus (Hymenoptera: Formicidae) in Australia with notes on A. ceylonicus (Mayr), Zootaxa 1926, pp. 1-19 : 11-13

Aenictus nesiotis Wheeler and Chapman , n. stat.

( Figs 7, 8 , 12–14 , 27 )

Aenictus (Aenictus) aratus subsp. nesiotis Wheeler, W.M. & Chapman , in Wheeler, 1930: 208.

Types. One syntype worker from Los Banos and 39 syntype workers from Dumaguete, Philippine Islands (MCZC, examined).

Diagnosis. Head capsule completely punctate; pronotum entirely sculptured with dense micro-reticulations. This species is most similar to A. aratus , but differs in the narrower head (CI <88 and HW <0.70mm compared to CI> 87 and HW> 0.70mm in A. aratus ) and the longer scapes (SI> 107 compared to <103 in A. aratus ).

Worker Description. Mandible triangular with numerous small teeth, those along the medial region of the masticatory margin ill defined; anterior clypeal border broadly convex, extending slightly anterior of frontal lobes; parafrontal ridges well developed, extending posteriorly approximately 1/3 length of head capsule; subpetiolar process broadly convex anteriorly, flat posteriorly; head entirely punctate; mesosoma uniformly punctate, generally with weak, ill-defined longitudinal rugae on dorsum of pronotum and lateral surfaces posterior of pronotum; body brown to black, anterior section of head sometimes lighter, distal antennae and legs always lighter.

Measurements. Worker (n = 15) - CI 82–88; HL 0.75–0.84; HW 0.64–0.70; MTL 0.67–0.79; ML 1.11– 1.24; SI 107–115; SL 0.70–0.78.

Material examined. Australia: Queensland: 20km N Cairns (Lowery,B.B.) ( ANIC); 4.5km NNW Cape Tribulation (Wild,A.L.) ( ANIC); 40 m. from Laceys Cr. (Taylor,R.W. & Feehan,J.E.) ( ANIC); Cape Tribulation (Kistner,D.H., Kistner,A.C., Nutting,W.L. & Nutting,R.D.) ( ANIC); Emmagen Ck., 5.0 km N of Cape Tribulation (Monteith,G.B., Yeates & Thompson) ( ANIC); Noah Creek, Cape Tribulation (Moneith,G.B.) ( ANIC); S2 Mission Beach (Cermak,M.) ( ANIC). Papua New Guinea: East Sepik: Yawasora nr. Wewak (Taylor,R.W.) ( ANIC): Morobe: Bulolo (Lowery,B.B.) ( ANIC); Ebabaang, Mongi Watershed, Huon Pen. (Wilson,E. O.) ( MCZC); Kua River, Laulaunung (Wilson,E. O.) ( MCZC); nr. Lae (Taylor,R.W.) ( ANIC); Northern: 3.2km N of Kokoda;(Lowery,B.B.) ( ANIC); Buna (Room,P.M.) ( ANIC); Kokoda Trail nr. Kokoda;(Lowery,B.B.) ( ANIC). Philippine Islands: Los Banos (Williams,F.X.) ( MCZC); Dumaguete (Chapman,J.W.; Schneira,T.C.) ( ANIC, MCZC); Iwahig Penal Colony (Lowery,B.B.) ( ANIC).

Comments. This is the widest spread Australian species of Aenictus with populations occurring in the Philippines and Papua New Guinea. The non-Australian material placed here shows only minor differences from Australian populations, none of which suggest separate species are involved. These differences include a slightly broader anterior petiolar face and less distinct sculpturing in Philippines specimens (especially those from Palawan) compared to most PNG /Australian specimens. However, both of these characters show considerable variation with essentially all morphologies found in both regions. Because of this all specimens are considered to belong to a single wide-ranging species. The larva described by Wheeler and Wheeler (1984) under the name A. aratus originated from the Philippines and had previously been identified as “ A. a. nesiotus var. fraterculus ” (an unavailable infrasubspecific name associated with A. aratus by Wilson, 1964). It is likely this larva belongs to A. nesiotus rather than A. aratus as A. aratus is not known to occur in the Philippines.

Figures

FIGURES 7 – 8. Fig. 7, Graph of head length versus head width. Fig. 8, Graph of scape length versus head width.

FIGURES 9 – 14. Aenictus diclops sp. n. worker. Fig. 9, front of head; Fig. 10, dorsal view of body; Fig. 11, lateral view of body. Aenictus nesiotis. worker. Fig. 12, front of head; Fig. 13, dorsal view of body; Fig. 14, lateral view of body.

FIGURES 24 – 30. Distribution of material examined during this study. Fig. 24, A. acerbus; Fig. 25, A. aratus; Fig. 26, A. diclops; Fig. 27, A. nesiotis; Fig. 28, A. philiporum; Fig. 29, A. prolixus; Fig. 30, A. turneri.