Aenictus ceylonicus (Mayr)

Jaitrong, Weeyawat & Yamane, Seiki, 2013, The Aenictus ceylonicus species group (Hymenoptera, Formicidae, Aenictinae) from Southeast Asia, Journal of Hymenoptera Research 31, pp. 165-233 : 215-219

Aenictus ceylonicus (Mayr) Fig. 27A-E

Typhlatta ceylonica Mayr, 1866: 505 (combination in Aenictus by DallaTorre, 1893: 7). Type locality: Sri Lanka (Ceylon).

Aenictus ceylonicus var. latro Forel, 1901: 477. Type locality: India, Poona.

Aenictus ceylonicus : Wilson 1964: 452 (part); Bolton 1995: 59 (part); Shattuck 2008: 16 (part).

Type material examined.

Typhlatta ceylonica : Three syntype workers from Sri Lanka (NHMW, examined). One worker among them is selected as the lectotype ( Fig. 27E ). Aenictus ceylonicus var. latro: Six syntype workers from India, Poona (MHNG, examined).

Worker measurements

(lectotype and paralectotypes of Aenictus ceylonicus , n = 3). TL 3.15-3.20 mm; HL 0.63-0.70 mm; HW 0.58-0.63 mm; SL 0.48-0.53 mm; ML 1.00-1.03 mm; PL 0.25-0.28 mm CI 89-92; SI 83-84.

Worker description

(lectotype and paralectotypes of Aenictus ceylonicus ). Head in full-face view subrectangular, slightly longer than broad, sides convex and posterior margin almost straight or feebly concave. Antennal scape reaching 2/3 of head length; antennal segments II longer than broad and slightly longer than each of III-VI; III slightly longer than broad; IV-VI each almost as long as broad; terminal segment (X) almost as long as VII+VIII+IX. Frontal carina short, reaching the level of posterior margin of torulus. Parafrontal ridge absent. Anterior clypeal margin weakly concave, lacking denticles. Masticatory margin of mandible with 3 teeth, including a large apical tooth; basal margin weakly concave, lacking denticles. Maximum width of gap between anterior clypeal margin and mandibles about 1.8 times as broad as maximum width of mandible. Promesonotum convex dorsally and sloping gradually to metanotal groove; metanotal groove indistinct; metapleural gland bulla relatively large, its maximum diameter about 3.1 times as long as distance between propodeal spiracle and metapleural gland bulla. Propodeum in profile with feebly convex dorsal outline; propodeal junction angulated, nearly right-angled; declivity of propodeum wide, shallowly concave, and encircled with a distinct rim. Petiole sessile and short, almost as long as high, with its dorsal outline elevated posteriorly; subpetiolar process weakly developed. Postpetiole distinctly shorter than petiole and shorter than high, with its dorsal outline slightly elevated posteriorly.

Head entirely smooth and shiny. Mandible with fine longitudinal striation, except along masticatory margin smooth and shiny. Antennal scape smooth and shiny. Promesonotum smooth and shiny except anteriormost portion punctate; mesopleu ron, metapleuron and propodeum with several longitudinal rugae. Lateral faces of petiole and postpetiole microreticulate but the dorsal faces smooth and shiny. Legs smooth and shiny.

Head and mesosoma dorsally with relatively sparse standing hairs; longest pronotal hair 0.15-0.18 mm long. Head, mesosoma, petiole and postpetiole reddish brown; gaster, antennae and legs yellowish brown, paler than head, mesosoma and waist.

Distribution.

India and Sri Lanka.

Bionomics.

Aenictus ceylonicus is probably restricted to the western part of the Oriental region (India and Sri Lanka).

Remarks.

Aenictus ceylonicus is most similar to Aenictus watanasiti in having the mandible with only 3 teeth including apical tooth. It can be separated from the latter by the postpetiole being short and clearly shorter than high (mandible with more than 3 teeth and postpetiole almost as long as high or longer in the other members of the group). See also under Aenictus formosensis .

Figures

Figure 27. Aenictus ceylonicus (A, C paralectotype B, D, E lectotype). A Head in full-face view B body in dorsal view C body in profile; labels of lectotype E lectotype designated in this paper.