Stigmatomma zwaluwenburgi
Amblyopone zwaluwenburgi is a small brownish-yellow species with a square head, no eye facets and long slender mandibles. The mandibles are armed with a long pointed apical tooth, a minute subapical tooth, a strong third tooth and four minute basal teeth. Amblyopone zwaluwenburgi is only known from three islands in the Pacific: Christmas Island (Framenau & Thomas, 2008; Taylor, 1990), Fiji (Sarnat & Economo, 2012), and Hawaii (Williams, 1946). The species is evidently quite rare. It has not been seen in Hawaii since its original collection in 1945 (Reimer, 1994), and was collected only once in Fiji. The native range is not known, but Wilson and Taylor (1967) concurred with Brown’s (1960)prediction that, “…the species has been introduced into Hawaii from Melanesia or the East Indies.” Amblyopone zwaluwenburgi is evidently a hypogaeic ant that can tolerate disturbed habitats. The Hawaii collection was made from the soil of a sugar cane field (Williams, 1946), and the Fiji collection was made from a litter sample taken from coastal area with abundant populations of introduced and widespread species (Sarnat & Economo, 2012).
Amblyopone zwaluwenburgi is not considered to be a significant pest species. Low risk of incursion. Low risk of establishment. Low risk of invasiveness.
Diagnosis among workers of Antkey species. Antenna 11-segmented. Antennal club 3-segmented. Antennal insertions entirely exposed, not covered even partially by frontal lobes. Head with anterior margin of clypeus denticulate. Eyes absent. Mandibles long and linear with seven teeth (one apical, one sub-apical, and five basal). Metanotum not forming a prominent convexity bordered by distinct suture lines. Waist 1-segmented. Petiole broadly attached to gaster and lacking a posterior face. Subpetiolar process narrow and with fenestra absent. Gaster armed with sting, abdominal segment 4 lacking deep longitudinal furrows. Legs with hind coxa lacking dorsal spine. Body entirely brownish yellow.
Among the species treated here, Amblyopone zwaluwenburgi is most similar in appearance to its fellow amplyoponine Prionopelta antillana. Both species have a single waist segment with the petiole broadly attached to gaster and lacking a posterior face and entirely exposed antennal insertions. Amblyopone zwaluwenburgi is separated from P. antillana by the mandibles which are long and linear with seven teeth (versus tridentate), the eye which is small but distinct (versus entirely absent), and the subpetiolar process which is narrower and lacks a fenestra.
Prionopelta antillana
Native range: Unknown.
Introduced range: Hawaii (last seen 1945), Christmas Island, Fiji.