Crematogaster foliocrypta

An arboreal species that constructs cryptic carton nests between leaves.

Identification
Longino (2003) - The general habitus of this species allies it with the limata complex (Crematogaster brasiliensis, Crematogaster carinata, Crematogaster limata, and Crematogaster tenuicula in Costa Rica). It shares with these species the abundant erect flexuous setae on the face, the moderate length to short propodeal spines that are posteriorly directed, and the elongate tapering petiole. In contrast to all other limata complex species, it has appressed rather than erect tibial pilosity.

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica, Ecuador.

Biology
Longino (2003) - Crematogaster foliocrypta is known from only four collections, all from Braulio Carrillo National Park on the Atlantic slope of Costa Rica. The habitat where the species occurs is 500m elevation rainforest. Two of the collections are workers obtained in mixed collections of foragers. One collection is from a cluster of very distinctive nests. The ants had constructed flat carton nests between leaves of small saplings, pulling two or more leaves together and sealing the edges, completely concealing the disk-like carton nest. I saw five of these nests in one small area. Often there were scale insects on the leaves inside the nest, and most nests I saw had spiders associated with them. The carton itself was composed entirely of filamentous material molded into passageways. The nests contained workers and brood, including some large larvae that were possibly queens, but none of the nests contained adult queens or males. A final collection was from the canopy of a Licania tree (Chrysobalanaceae). A small group of workers was in a dead stick, and other workers were scattered in small clusters throughout the crown.

G. B. Edwards of the Florida State Collection of Arthropods identified the spiders as immatures of the salticid genus Cotinusa. He and colleagues alerted me to the fact that a species of Cotinusa has been reported inhabiting a nest of Tapinoma melanocephalum (Shepard and Gibson 1972). These spiders have stridulatory organs, and it has been suggested that the stridulation may be related to communication with ants (Maddison 1987).

Nomenclature

 *  foliocrypta. Crematogaster foliocrypta Longino, 2003a: 73 (w.) COSTA RICA.

Worker
Holotype: HL 0.643, HW 0.723, HC 0.631, SL 0.686, EL 0.166, WL 0.789, SPL 0.169, PTH 0.171, PTL 0.307, PTW 0.156, PPL 0.178, PPW 0.173, CI 112, OI 26, SI 107, PTHI 56, PTWI 51, PPI 97, SPI 21.

Other specimens: HL 0.591, 0.563, 0.654; HW 0.673, 0.622, 0.730; HC 0.611, 0.537, 0.657; SL 0.664, 0.631, 0.688; EL 0.163, 0.152, 0.181; A11L 0.265; A11W 0.119; A10L 0.145; A10W 0.089; A09L 0.074; A09W 0.060; A08L 0.063; A08W 0.052; WL 0.743, 0.692, 0.786; SPL 0.158, 0.138, 0.161; PTH 0.168, 0.135, 0.178; PTL 0.281, 0.255, 0.321; PTW 0.143, 0.127, 0.171; PPL 0.166, 0.152, 0.162; PPW 0.167, 0.142, 0.184; CI 114, 110, 112; OI 28, 27, 28; SI 112, 112, 105; PTHI 60, 53, 55; PTWI 51, 50, 53; PPI 101, 93, 114; SPI 21, 20, 20; ACI 1.55.

Color red brown; workers monomorphic in size.

Mandibles smooth and shining; clypeus feebly striate, with 5 or more longitudinal carinulae, weakly convex, anterior margin straight; head about as long as wide, subcircular, with broadly convex sides and posterior border, posterior border with small, shallow median emargination; antenna with terminal two segments enlarged to form a club, third segment from end somewhat enlarged, blurring distinction between two and three-segmented club; scapes with abundant long erect setae; when scapes laid back from antennal insertions, they surpass margin of vertex; face largely smooth and shining, with variable extent of striated region between antennal insertion and eye, and whorled above antennal insertion; face covered with abundant long flexuous white setae, no appressed pubescence; in face view with moderately abundant suberect setae projecting from lateral and posterior margins.

Promesonotum in profile somewhat flattened dorsally, short anterior face of pronotum rises to dorsal face, dorsal faces of pronotum and mesonotum subequal in length, horizontal, forming single flat surface or meeting at a slightly produced angle, dorsal and posterior faces of mesonotum meeting at distinct angle, posterior face dropping to propodeal suture; propodeal suture deep in dorsal view but obscured in profile due to lateral carinulae that bridge the suture; lateral carinulae with or without minute triangular tooth at propodeal suture; propodeal spines medium length, projecting posteriorly; propodeum with differentiated dorsal and posterior faces; pronotal dorsum with sparse longitudinal carinulae, strongest laterally, becoming weaker medially, interspaces smooth and shining; anterodorsal face of mesonotum with weak, subparallel lateral carinae, these continue onto posterodorsal face as stronger carinae that converge posteriorly, interspace concave, smooth and shining; dorsal face of propodeum with a few coarse rugae, shining; posterior face smooth and shining; side of pronotum smooth and shining; katepisternum uniformly punctate; bulla of metapleural gland longitudinally carinulate, area around propodeal spiracle smooth and shining; mesosomal dorsum with a row of long flexuous white setae on anterior pronotum, a pair of long setae on anterior mesonotum, scattered shorter setae elsewhere, setae on pronotal humeri longest; femora and tibiae with abundant medium-length subdecumbent setae (unlike limata and relatives, which have long suberect setae).

Petiole in side view elongate, trapezoidal, shallowly but distinctly and uniformly punctate; anteroventral margin with a short right angle tooth; dorsal face of petiole smooth and shining, elongate, widest posteriorly, gradually tapering to gibbosities formed by petiolar spiracles, more abruptly constricted anterior to gibbosities, with two long flexuous setae along posterior border, sparse shorter setae on posterior border and sides; postpetiole with ventral margin flat, lacking anteroventral tooth, globular in dorsal view, with two long erect setae posteriorly, two medium-length setae anterodorsally, sparse short setae elsewhere; fourth abdominal tergite smooth and shining, with abundant long flexuous erect white setae, no appressed pubescence.

Type Material
Holotype worker. Costa Rica, Prov. Heredia, 22km N Volcan Barva, 500m, 10°20'N, 84°04'W, 11 Mar 1985 (Longino, collection code JTL0183), specimen code INBIOCRI002280524.

Paratypes. One worker, same data as holotype, specimen code JTLC000001387; same data , specimen code JTLC000001388; same data , specimen code JTLC000001389; same data , specimen code JTLC000001390]; same data , specimen code JTLC000001391; same data , specimen code JTLC000001392; same data , specimen code JTLC000001393.

Etymology
This species is named for its habit of constructing cryptic carton nests between leaves.