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Costa Rica (Atlantic and Pacific slopes), Honduras.
This is the only species of this genus known from the New World.
The first collection was made in February 2003, during the Project ALAS expeditions to the 500m site on the Volcan Barva transect (locality: Costa Rica, Prov. Heredia, 10km SE La Virgen, 10deg20'N 85deg04'W, 500m). The expeditions were based at the "El Ceibo" guard station, on the west bank of the Rio Peje. The station building itself is in pasture abutting mature rainforest. A few meters inside the forest a large tree had fallen sometime during the months prior to the expeditions. A few of the tree's leaves were still green; most were brown but still attached to branches. There were still extensive epiphyte mats covering the trunk and major branches. I collected from beneath these mats and found Bothriomyrmex workers and brood piles to be abundant beneath most of the mats. Large Margarodidae were also scattered amongst the Bothriomyrmex. Other ant species occurred under the mats and were somewhat interdigitated with the Bothriomyrmex, although much less abundant. These included Hypoponera opacior, a small yellow Solenopsis, and Tapinoma. Smaller nests or aggregations were also found of Crematogaster sotobosque and Pheidole biconstricta. One part of the tree, near the pasture edge, was being invaded by Solenopsis geminata. I found only workers and brood. Ronald Vargas of Project ALAS collected more from the same tree in April. His collections included two adult males.
Also in February of 2003 John Noyes of the British Museum was working in Costa Rica. He was taking large sweep samples from vegetation at several localities and extracting Encyrtidae, his primary focal taxon. He also separated ants and sent these samples to me, requesting a rough count of the number of ant species in each sample. Each sample contained hundreds to thousands of ants, including many alates. In the sample from Estacion Cacao (locality: Costa Rica, Prov. Guanacaste, Guanacaste Conservation Area, Estacion Cacao, 10deg55'N 85deg30'W, 1100m) I was surprised to find about a dozen males and a similar number of dealate queens of Bothriomyrmex! The habitat at Est. Cacao is a mosaic of mature montane moist forest with epiphyte-laden trees and abandoned pastures. This is a site on the Pacific slope of the northernmost cordillera in Costa Rica, 170km from the El Ceibo site on the Atlantic slope.
It was a great surprise to have two different collections taken at widely separated sites at more or less the same time. This suggests the species is relatively common in Costa Rica. Yet it has never been collected before, in spite of over a century of intensive ant collecting by many researchers. One possibility is that the species is recently introduced and has been quietly and rapidly spreading, and it is capable of invading mature forest habitats. The second possibility is that the species is so small and nondescript in all castes that it has simply been overlooked, and a fortuitous sequence of events resulted in the simultaneous occurrence of two collections. First, workers that live beneath epiphyte mats are not easily sampled by common methods such as baiting or canopy fogging. Second, my increasing nearsightedness has resulted in a slower collecting style that involves getting my nose very close to the substrate, and I can more easily see very small ants. Third, ant collectors rarely take or examine sweep samples, especially those taken by an encyrtid taxonomist dedicated to finding small Hymenoptera. When such samples are examined, often the emphasis is on workers and sexuals are ignored. Finally, having just discovered workers and males of Bothriomyrmex, I was primed to notice the males and diminutive queens in the sweep samples. Perhaps, like a new word one learns, I will start seeing them everywhere now.
The species was discovered in a cloud forest site in Honduras in 2010, during sampling by the LLAMA project. A dealate queen was in a beating sample, workers came to a bait sample on the ground, and Brendon Boudinot traced these baited workers to a nest. The nest was in a hard piece of rotting wood on the forest floor, and it contained abundant queens, males, workers, and brood.
Other species, and perhaps the genus as a whole, are temporary social parasites of the genus Tapinoma.
Dubovikoff, D. A., and J. T. Longino. 2004. A new species of the genus Bothriomyrmex Emery, 1869 (Hymenoptera: Formicidae: Dolichoderinae) from Costa Rica. Zootaxa 776:1-10.
Holotype queen: Costa Rica, Prov. Guanacaste, Guanacaste Conservation Area, Estacion Cacao GoogleMaps, 10°55'N 85°30'W, 1100m GoogleMaps, 22 Feb 2003, tropical montane moist forest GoogleMaps, sweep sample (J. S. Noyes), specimen barcode JTLC000004280 [INBio]. GoogleMaps
Paratypes: 3 queens and 3 males, same data as holotype [ZIN]; GoogleMaps queen and 2 males, same data as holotype [MCZC]; GoogleMaps 2 queens, same data as holotype [LACM, INBio]; GoogleMaps 5 workers, Costa Rica, Prov. Heredia, 11 km SE La Virgen , 10º20´N 84º04´W, 500m , 19 Apr 2003, coll. R. Vargas C., 05-RVC-007 [ZIN]; GoogleMaps 4 workers, same data [MHNG]; GoogleMaps 5 workers, same data but 16 Feb 2003, coll. J. Longino (JTL4938) [same colony] [CAS, INBio, LACM, UCDC, USNM] GoogleMaps.
Holotype measurements: HL 0.600; HW 0.526; SL 0.424; TL 0.697; TH 0.448; PH 0.227; TI 0.643; CI 0.876; SI 0.706.
Paratype measurements (average for 3 queens): HL 0.600; HW 0.543; SL 0.436; TL 0.700; TH 0.450; PH 0.257; TI 0.643; CI 0.905; SI 0.726.
Paratype measurements (average for 5 workers): HL 0.586; HW 0.520; SL 0.434; PH 0.239; CI 0.888; SI 0.742.
Paratype measurements (average for 3 males): HL 0.457; HW 0.479; SL 0.257; OL 0.171; PH 0.179; OI 0.667; CI 1.047; SI 0.563.
Etymology: named for the paradoxical occurrence of this species in the New World, when the genus was previously considered strictly Old World.
Diagnosis: Queen with short suberect setae on mesosoma and gaster; queen mesosoma short and high (TI> 0.64); worker mesosoma with impressed metanotal groove.
Description (queen): Palp formula 4:3; head oblong, with rounded posterolateral vertex margins; suberect hairs of variable length on genae (Fig. 2a); clypeus broad, width in center 0.2 mm (average for 4 queens), with curved setae on anterior margin; mandible long, with outer and basal margin subparallel, masticatory margin with three teeth and 4- 5 denticles; mesosoma short and high, with erect setae on dorsum and posterior face of propodeum; wings with closed cubital and radial cells (Fig. 1c); petiole with strongly developed ventral lobe, dorsal scale inclined anteriorly; gaster with many long setae on posterolateral margins of tergites; body dark brown; entire body with short suberect pubescence, distance between hairs subequal to length.
Description (worker): Palp formula 4:3; medial hypostoma absent (Fig. 3d); head with two long setae on the frons, two on the posterior clypeal margin, and many curved setae on the anterior clypeal margin; metanotal groove impressed (Fig. 3a); dorsal face of propodeum rounded, much shorter than posterior face; petiolar node scale-like, tall, inclined anteriorly; ventral margin of petiole with prominent lobe (Fig. 3c); gaster with long setae on posterior margins of tergites; pubescence short and dense over entire body; body dark brown, with lighter antennae and legs.
Description (male): Scape long, projecting beyond outer eye margin (in face view) by about half of its length; propodeum rounded, without differentiated dorsal and posterior faces; petiole with short anterior peduncle; petiolar node low, thin, vertical; ventral margin of petiole with small anterior denticle and strongly developed medial lobe (Fig. 4); sagitta thin, with apex weakly folded down.
Description (larva): Body with two protuberances on the prothorax, located ventrolaterally; hairs short; eight pairs of spiracles (Fig. 5).
Biology: Bothriomyrmex paradoxusHNS is known from two different collections from widely separated localities in Costa Rica (Fig. 1). One collection was made in February 2003, during the Project ALAS expeditions to the 500m site on the Volcan Barva transect. The expeditions were based at the "El Ceibo" guard station, on the west bank of the Rio Peje. The station building itself is in pasture abutting mature rainforest. A few meters inside the forest a large tree had fallen sometime during the months prior to the expeditions. A few of the tree's leaves were still green; most were brown but still attached to branches. There were still extensive epiphyte mats covering the trunk and major branches. Longino collected from beneath these mats and found BothriomyrmexHNS workers and brood piles to be abundant beneath most of the mats. Large Margarodidae (Hemiptera, Coccoidea) were also scattered amongst the BothriomyrmexHNS. Other ant species occurred under the mats and were somewhat interdigitated with the BothriomyrmexHNS, although much less abundant. These included Hypoponera opaciorHNS, a small yellow SolenopsisHNS, and TapinomaHNS. Smaller nests or aggregations were also found of Crematogaster sotobosqueHNS and Pheidole biconstrictaHNS. One part of the tree, near the pasture edge, was being invaded by Solenopsis geminataHNS. I found only workers and brood. Ronald Vargas of Project ALAS collected more from the same tree in April. His collections included two adult males.
The second collection was also made in February of 2003. John Noyes of The Natural History Museum (London) was taking large sweep samples from vegetation at several Costa Rican localities and extracting Encyrtidae, his primary focal taxon. He also separated ants and sent these samples to Longino. Each sample contained hundreds to thousands of ants, including many alates. In the sample from Estación Cacao were about a dozen males and a similar number of dealate queens of BothriomyrmexHNS. The habitat at Estacion Cacao is a mosaic of mature montane moist forest with epiphyte-laden trees and abandoned pastures. This is a site on the Pacific slope of the northern-most cordillera in Costa Rica, 170km from the El Ceibo site on the Atlantic slope.
Comments: Although it is typical to choose workers as holotypes of ant species, we have chosen a queen because queens exhibit much greater morphological differences among species in BothriomyrmexHNS. This is true of several dolichoderine genera, including AztecaHNS and TapinomaHNS. For example, Longino (1991) used queens as holotypes in taxonomic work on AztecaHNS.
The new species undoubtedly belongs to the genus BothriomyrmexHNS. It has all the traits typical of the genus: 4:3 palp formula, strongly reduced hypostomal margin, and a characteristic venation on the forewing of the queen (closed discoidal cell, RM-2 absent, and radius reaching costal margin of wing). The systematics of the genus BothriomyrmexHNS are complex, and the previous classification (Dubovikoff, 2002) is not complete. Bothriomymex paradoxusHNS belongs to BothriomyrmexHNS s.s. and not among the Asian and Australian species (Dubovikoff unpub.). However, it does not fit cleanly into one of the Palearctic species groups. The short suberect setae on the queen's mesosoma and gaster is a trait also found in members of the B. syriusHNS group ( B. syrius ForelHNS, B. turcomenicus EmeryHNS, B. communistus SantschiHNS, B. kusnezovi EmeryHNS and B. urartus DubovikoffHNS). However, B. paradoxusHNS differs from all species of this group by the higher and shorter mesosoma of the queen. TI of B. paradoxusHNS is 0.64, while other species have TI <0.50. Also, the impressed metanotal groove on the worker is a trait found in members of the B. gibbusHNS complex and not in the B. syriusHNS group.
This is the first collection of the genus BothriomyrmexHNS in the New World. The occurrence in mature forest habitats and the fact that it is not conspecific with any known Old World species suggest it is truly native and not a recent introduction. Bothriomyrmex paradoxusHNS may be a very old species, long isolated from the Palearctic species. Other putative relict species in Central America include Technomyrmex fulvus (WheelerHNS 1934) and Perissomyrmex snyderi (Longino and HartleyHNS 1995). Central America appears to be a refuge for several ancient lineages of ants.
In the Palearctic, BothriomyrmexHNS s. s. are temporary social parasites of monogynous TapinomaHNS. It is unknown whether B. paradoxusHNS is also a temporary social parasite of TapinomaHNS. Given its geographic isolation, elucidating the nest foundation behavior of B. paradoxusHNS would be particularly valuable.
Found most commonly in these habitats: 1 times found in wet forest treefall gap, 1 times found in tropical montane moist forest, 3 times found in mesophyll forest, 1 times found in wet forest.
Found most commonly in these microhabitats: 1 times under epiphytes, 1 times nest, 1 times at bait, 1 times under epiphytes on recent treefall, 1 times beating vegetation.
Collected most commonly using these methods: 3 times search, 1 times sweep net, 1 times Baiting, 1 times Beating.
Elevations: collected from 500 - 1340 meters, 824 meters average
Type specimens: holotype Bothriomyrmex paradoxus: jtlc000004280; paratype: casent0103277; Paratype Bothriomyrmex paradoxus: jtlc000003508, jtlc000003509, jtlc000003510, jtlc000003511, jtlc000003512, jtlc000004281, jtlc000004282