Citation: Staab M (2014) A new species of the Aenictus wroughtonii group (Hymenoptera, Formicidae) from South-East China. ZooKeys 391: 65–73. doi: 10.3897/zookeys.391.7213
A new species of army ant from the Aenictus wroughtonii group is described and illustrated based on the worker caste. Aenictus gutianshanensis Staab, sp. n. is known form a single colony collected in the subtropical mixed evergreen broad-leaved forest of the Gutianshan National Nature Reserve, South-East China. The new species is probably most closely related to A. vieti Jaitrong & Yamane, 2010 known from North Vietnam and Taiwan. It is suggested that the abundant records of A. camposi Wheeler & Chapman, 1925 from East and South-East China should be reevaluated, as they are probably A. gutianshanensis or A. vieti and not A. camposi, which is distributed in Sundaland, the Philippines, and the southernmost part of continental South-East Asia.
Aenictinae, Aenictus gutianshanensis, army ants, species description, taxonomy
The genus Aenictus, which is the only genus of the dorylomorph subfamily Aenictinae, is the largest genus of army ants. Army ants are characterized by several specialized morphological, behavioral, and ecological adaptations, such as a nomadic life style, highly specialized mating systems, and mass raiding for arthropod prey (
Until now, 179 species (9 synonyms, 2 unavailable) and 30 subspecies (13 synonyms, 2 unavailable) have been validly described (
The Aenictus wroughtonii species group has been revised in detail by
All morphological observations were made with a Leica SD6 stereomicroscope. Measurements were taken with an ocular micrometer. Images were produced using a Keyence VHX2000 (Osaka, Japan) digital microscope.
The general worker terminology follows
All measurements are expressed in millimeters. Abbreviations used for measurements and indices follow
CI Cephalic index, HW / HL × 100.
HL Maximum head length in full-face view, measured from the anterior clypeal margin (excluding the projecting clypeal teeth) to the midpoint of a line drawn across the posterior margin of the head.
HW Maximum head width in full face view.
ML Mesosomal length measured from the point at which the pronotum meets the cervical shield to the posterior base of the metapleuron in profile.
MTL Maximum length of mid tibia, excluding the proximal part of the articulation which is received into the distal end of the femur.
PL Petiole length measured from the anterior margin of the peduncle to the posteriormost point of tergite.
SI Scape index, SL / HW × 100.
SL Scape length excluding the basal constriction and condylar bulb.
TL Total length, measured roughly from the anterior margin of head to the tip of gaster in stretched specimens.
Head narrow; occipital margin lacking collar. Antenna long, consisting of 10 segments, with a strikingly long scape attaining or extending beyond posterolateral corner of head (but in one Vietnamese species the scape shorter, not reaching posterolateral corner of head). Anterior clypeal margin roundly convex with 5–10 denticles. Mandible triangular, with masticatory margin bearing 8–12 minute inconspicuous denticles in addition to large apical tooth with a sharp apex; basal margin of mandible lacking denticles. Frontal carina short; parafrontal ridge feeble and incomplete. Mesosoma narrow and elongate. Legs very slender. Subpetiolar process weakly developed or almost absent. Head and gaster entirely smooth and shiny. Nearly entire body clear yellow to yellowish brown; typhlatta spot absent.
http://zoobank.org/F14B8EED-1D2E-4931-A0AA-F3697502BEEF
http://species-id.net/wiki/Aenictus_gutianshanensis
Figs 1–5Worker from China, Zhejiang Province, Gutianshan National Nature Reserve, ca. 30 km NW of Kaihua, 29°12'54"N, 118°7'18"E, ca. 250 m above sea level, 28.VI.2009, leg. Andreas Schuldt, label: “CSP26/SW7(2009)”, deposited in IZAS.
Aenictus gutianshanensis sp. n. (holotype). 1 Head in full-face view 2 body in profile 3 body in dorsal view 4 propodeal junction petiole and postpetiole in profile.
Aenictus gutianshanensis sp. n. (holotype), sculpture of pronotal dorsum.
Five workers, same data as holotype. Three deposited in IZAS; one each deposited in ZMBH and CASC. All type specimens were collected in a single pitfall trap in a secondary mixed evergreen broad-leaved forest.
Holotype: TL 3.30, HL 0.68, HW 0.63, SL 0.70, ML 1.17, MTL 0.75, PL 0.30, CI 93, SI 112.
Paratypes (n=5): TL 3.10–3.30, HL 0.69–0.75, HW 0.60–0.65, SL 0.65–0.70, ML 1.17–1.25, MTL 0.69–0.83, PL 0.29–0.31, CI 87–91, SI 104–113.
Head in full-face view elliptical, slightly longer than broad, with convex sides and almost straight posterior margin of head. Antennal scape long, reaching posterior corner of head; antennal segments II-X each longer than broad; II as long as III, but longer than each of IV-VII; terminal segment (X) longer than each of II-IX; the last four segments forming an indistinct club. Frontal carina long, extending slightly beyond the posterior margin of antennal torulus. Clypeus short with its anterior margin slightly convex, bearing 7-8 bluntly rounded denticles. Mandible subtriangular, masticatory margin straight, with a large curved apical tooth which is followed by 9-10 minutes teeth on masticatory margin. With mesosoma in profile, pronotum dorsally convex, not distinctly separated from mesonotum by a promesonotal suture. Propodeum slightly lower than promesonotum, its dorsal outline gently sloping posteriorly; propodeal junction angulate; declivity of propodeum straight in the dorsal part, concave in the ventral part when viewed in profile, encircled by a thin rim. Petiole in profile as long as high, its node convex dorsally. Subpetiolar process present, its ventral margin almost straight, bearing a thin rim below, anteroventral corner angulate. Postpetiole slightly longer than petiole, its node convex dorsally in profile; ventral postpetiolar process developed, angulate, bearing a thin rim below, slightly projecting over the posterior part of the petiole.
Head including mandible smooth and shiny; antennal scape punctate. Entire mesosoma finely reticulate, dorsal face of pronotum finely reticulate but shiny, reticulation on mesopleuron, metapleuron and lateral face of propodeum finer than on pronotum, appearing almost punctate in magnification lower 64×. Entire petiole finely reticulate. Postpetiole finely reticulate, except the dorsum smooth and shiny. Gaster smooth and shiny. Coxae finely reticulate, femora densely punctate, tibiae sparsely punctate.
Body except anterior part of mesonotum with abundant standing hairs and interdispersed short hairs; length of longest hairs on dorsa of head and pronotum 0.20–0.30 mm. Antennal scape and legs with abundant standing hairs. Head, mandible, gaster and legs yellowish brown. Mesosoma, antennal scape, petiole and postpetiole reddish brown.
Male and female are unknown.
The scientific name is after the type locality, the Gutianshan National Nature Reserve (Fig. 6) in South-East China.
Typical mixed evergreen broad-leaved forest at the type locality, the Gutianshan National Nature Reserve.
South-East China; only known from the type series.
No direct biological information is available. The type series was collected in a single pitfall trap in a secondary mixed evergreen broad-leaved forest. Thus, the species probably lives and forages on and in the leaf-litter preying on small ants of the subfamily Formicinae, as it has been previously reported for species in the Aenictus wroughtonii group (
Aenictus is one of the most species-rich ant genera in China and worldwide (
Aenictus gutianshanensis can be easily distinguished from all other species of the Aenictus wroughtonii group by the pronotum, the petiole, and the side of the postpetiole completely finely reticulate (see
In China, Aenictus camposi has been recorded from several provinces in East and South-East China. (
There are probably several Aenictus species which still await discovery and description in the tropical and subtropical forests of the Oriental region. However, these forests are under high land-use pressure and are increasingly being cleared for agriculture (
I thank the administration of the Gutianshan National Nature Reserve for generously granting research permissions and Andreas Schuldt for collecting the type series. Helge Bruelheide, Bernhard Schmid, Sabine Both, Keping Ma, Xiaojuan Liu, and the entire team of BEF-China are gratefully acknowledged for their support. Ottmar Fischer and Anita Kiesel assisted with the recording of specimen images. Tamar Marcus improved the English. Valuable comments from two anonymous reviewers improved the manuscript. Funding by the German Research Foundation (DFG FOR 891, 891/2, KL 1849/6-1) is gratefully acknowledged.