Strumigenys loriae

A few colonies included the parasitic Strumigenys yaleogyna (Wilson & Brown 1956). Known from rainforest habitats, S. loriae has been found in rotten wood, in soil under wood and in a litter sample.

Identification
Bolton (2000) - A member of the Strumigenys loriae-group. As well as the size-related variation mentioned above the measurements also express aspects of the polymorphism of this species. For instance, as HW increases CI also tends to increase, especially in the upper part of HW range; and the largest individuals have the lowest SI. Remarkably, MI remains very stable through the entire range of HL so that the relative length of the mandible always stays about the same, regardless of the size of the individual.

Of the seven species in this group Strumigenys pachycephala, Strumigenys chyzeri and Strumigenys odalatra are easily isolated. The first is the only one to lack a preapical tooth on the mandible; the second is the only one in which the preapical mandibular tooth arises from the dorsal surface of the mandible rather than from its inner margin; the third is the only member of the group to have erect long fine hairs freely projecting from the middle and hind basitarsi.

The remaining four fall into two species-pairs: Strumigenys festigona plus Strumigenys loriae, which have reticulate-punctate postpetiole discs and basigastral costulae that are at least as long as the postpetiole disc; and Strumigenys kyroma plus Strumigenys retothra in which the postpetiole discs are usually smooth and the basigastral costulae are distinctly shorter than the postpetiole discs.

As well as being polymorphic loriae separates from the monomorphic festigona on the shape of the preocular projection of the head’s ventrolateral margin. In loriae it is always blunt and more or less straight. In festigona it is acute and thorn-like, curved anteriorly and with a concave anterior margin and convex posterior margin. The bullae of the femoral and tibial glands of the hind leg also differ in the material available. The femoral gland bulla in loriae is minute or invisible, when visible always smaller and less distinct than the bulla of the tibial gland. In festigona the femoral gland bulla is always conspicuous and about equal in size to that on the tibia.

Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea.

Biology
One colony in a large rotting moss-covered log lying on the ground consisted of 1622 workers and 16 dealate queens, together with the parasitic Strumigenys yaleogyna. Host and parasite pupae were mixed together in several chambers. Dealate queens and workers of both species were distributed amicably throughout the nest. Trophallaxis was observed between adults.

Nomenclature

 *  loriae. Strumigenys loriae Emery, 1897c: 576, pl. 14, fig. 3 (w.) NEW GUINEA. Szabó, 1910a: 368 (q.). Senior synonym of excisa: Brown, 1949d: 15. See also: Bolton, 2000: 862.
 * excisa. Eneria excisa Donisthorpe, 1948d: 598, fig. 1 (w.q.) NEW GUINEA. Junior synonym of loriae: Brown, 1949d: 15.

Worker
Bolton (2000) - TL 3.1-5.1, H L 0.96-1.64, HW 0.82-1.60, CI 83-99, ML 0.40-0.67, MI 39-44, SL 0.52-0.88, SI 53-69, PW 0.37-0.55, AL 0.90-1.34 (polymorphic species, 25 measured). In full-face view side of head in front of preocular impression expanded and projecting laterally; in smallest workers the expansion a low rounded tumulus, in larger workers bluntly triangular, bluntly conical or thickly boss-like. Cephalic dorsum with fine rugulose sculpture overlying reticulate-punctation in larger workers; in smaller workers the rugulae reduced or sometimes absent. Dorsolateral margin of occipital lobe with a few short stiff projecting hairs that are apically blunt or slightly expanded. In profile cephalic dorsum with short stiff standing hairs present from just behind level of eye to occipital margin, but absent from concavity of transverse dorsal impression. Pleurae and side of propodeum reticulate-punctate; in smallest workers katepisternum may be less strongly sculptured than metapleuron and side of propodeum. Propodeal spines long and strong, with a tendency to be weakly upcurved. Bulla of femoral gland on hind leg usually invisible, when discernible small and inconspicuous, smaller than the conspicuous bulla of the hind tibial gland. Dorsal (outer) surfaces of middle and hind basitarsi without erect long fine simple hairs. Petiole node subconical in profile, the lateral spongiform lobe little more than an extension of the collar. Depth of ventral spongiform strip on petiole less than half depth of peduncle but extends whole length of petiole; often of about equal depth throughout its length. Petiole node in dorsal view distinctly broader than long. Disc of postpetiole reticulate-punctate. Basigastral costulae at least equal in length to disc of postpetiole, usually longer. Hairs on first gastral tergite stiff and apically blunt, either simple or somewhat flattened and expanded toward the apex. Strongly polymorphic species.

Type Material
Bolton (2000) - Syntype workers and queen, PAPUA NEW GUINEA: Madang ( = Friedrich-Wilhelrnshafen) (L. Biro) [examined].

Determination Clarifications
Bolton (2000) - In several collections workers of loriae have been found mounted upon the same pins as specimens of Strumigenys chyzeri.

References based on Global Ant Biodiversity Informatics

 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * CSIRO Collection
 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Donisthorpe H. 1948. A third instalment of the Ross Collection of ants from New Guinea. Annals and Magazine of Natural History (11)14: 589-604.
 * Emery C. 1897. Formicidarum species novae vel minus cognitae in collectione Musaei Nationalis Hungarici quas in Nova-Guinea, colonia germanica, collegit L. Biró. Természetrajzi Füzetek 20: 571-599.
 * IZIKO South Africa Museum Collection
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 * Lucky A., K. Sagata, and E. Sarnat. 2011. Ants of the Nakanai Mountains, East New Britain Province, Papua New Guinea, Chapter 1. In Richards, S. J. and Gamui, B. G. (editors). 2013. Rapid Biological Assessments of the Nakanai Mountains and the upper Strickland Basin: surveying the biodiversity of Papua New Guineas sublime karst environments. RAP Bulletin of Biological Assessment 60. Conservation International. Arlington, VA.
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 * Room, P.M. 1975. Relative Distributions of Ant Species in Cocoa Plantations in Papua New Guinea Relative Distributions of Ant Species in Cocoa Plantations in Papua New Guinea. Journal of Applied Ecology 12(1):47-61
 * Sagata, K., A.L. Mack, D.D. Wright and P.J. Lester. 2010. The influence of nest avaiability on the abundance and diversity of twig-dwelling ants in a Papua New Guinea forest. Insectes Sociaux 57:333-341
 * Snelling R. R. 1998. Insect Part 1: The social Hymenoptera. In Mack A. L. (Ed.) A Biological Assessment of the Lakekamu Basin, Papua New Guinea, RAP 9. 189 ppages
 * Snelling R. R. 2000. Ants of the Wapoga river area, Irian Jaya, Indonesia. In Mack, Andrew L. and Leeanne E. Alonso (eds.). 2000. A Biological Assessment of the Wapoga River Area of Northwestern Irian Jaya, Indonesia. RAP Bulletin of Biological Assessment 14, Conservation International, Washington, DC.
 * Szabó J. 1910. Formicides nouveaux ou peu connus des collections du Musée National Hongrois. [part]. Ann. Hist.-Nat. Mus. Natl. Hung. 8: 364-368.
 * Viehmeyer H. 1912. Ameisen aus Deutsch Neuguinea gesammelt von Dr. O. Schlaginhaufen. Nebst einem Verzeichnisse der papuanischen Arten. Abhandlungen und Berichte des Königlichen Zoologischen und Anthropologische-Ethnographischen Museums zu Dresden 14: 1-26.
 * Wilson E. O. 1958. Observations on the behavior of the cerapachyine ants. Insectes Sociaux 5: 129-140.
 * Wilson E. O. 1959. Some ecological characteristics of ants in New Guinea rain forests. Ecology 40: 437-447.
 * Wilson E. O., and W. L. Brown, Jr. 1956. New parasitic ants of the genus Kyidris, with notes on ecology and behavior. Insectes Soc. 3: 439-454.