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Species: Pheidole scalaris   Wilson, 2003 

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Taxonomic History (provided by Barry Bolton, 2018)

Pheidole scalaris Wilson, 2003A: 643, figs. (s.w.) COSTA RICA. Neotropic. AntCat AntWiki HOL


   (According to curated Geolocale/Taxon lists)
Neotropical Region: Costa Rica, Ecuador, Nicaragua, Trinidad and Tobago, Venezuela

Distribution Notes:

Costa Rica (Atlantic and northern Pacific lowlands).


Natural History:

Occurs in both seasonal dry forest and lowland rainforest; recruits to baits; does not occur in Winkler samples, which implies that it neither nests nor forages in forest leaf litter.

Taxonomic Treatment (provided by Plazi)

Treatment Citation: Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press

Pheidole scalarisHNS new species

Types Mus. Comp. Zool. Harvard.

Etymology L scalarisHNS, of a ladder, alluding to the strong ladder-like pattern on the dorsum of the major head. diagnosis Close to transversostriataHNS but distinguished from it and other members of the transversostriataHNS group by the broad occipital zone of rugoreticulum on the dorsal surface of the head of the major, surmounting a wide "ladder" of parallel transverse carinulae that reach the frontal lobes, where they curve anteriorly to the ends of the lobes; also, the premesonotal dorsum is completely covered by transverse carinulae. Also, see the distinctive color of the minor (below).

This species is possibly synonymous with P. transversostriata var. nigridensHNS Forel of Colombia, which has been provisionally synonymized with transversostriataHNS; nigridensHNS has rugoreticula on the occipital corners and more carinulae on the pronotal dorsum, and is intermediate between scalarisHNS and transversostriataHNS. However, scalarisHNS also differs from transversostriataHNS by the more elongate head of the major (Head Length 1.3X Head Width versus 1.2X in transversostriataHNS) and smooth sides of the pronotum of the minor. Measurements (mm) Holotype major: HW 0.64, HL 0.84, SL 0.32, EL 0.10, PW 0.36. Paratype minor: HW 0.42, HL 0.46, SL 0.36, EL 0.08, PW 0.26. Color Major: concolorous medium yellow.

Minor: overall light brownish yellow, with medium brown vertex, occiput, and dorsum of promesonotum, and medium yellow appendages.

Range Atlantic and northern Pacific lowlands of Costa Rica; and Arima Valley, Trinidad.

Biology Longino (1997) found P. scalarisHNS in both seasonal dry forest and evergreen forest. The workers were recruited to baits on the forest floor.

Figure Upper: holotype, major. Lower: paratype, minor. COSTA RICA: La Selva Biological Station, near Puerto Viejo, Heredia (Stefan Cover). Scale bars = 1 mm.

Specimen Habitat Summary

Found most commonly in these habitats: 3 times found in SAT, 3 times found in 2nd growth dry forest, 3 times found in La Selva, 7 times found in tropical rainforest, some big trees, 2 times found in dry forest, 5 times found in tropical rainforest, with some big trees, probably a mix of primary and secondary forest, 1 times found in house clearing, 1 times found in Puesto19,158G. 10m., 3 times found in tropical rainforest, some big trees, primary forest, 3 times found in mature wet forest, ...

Found most commonly in these microhabitats: 14 times at bait, 3 times Hojarasca, 9 times ex sifted leaf litter, 2 times at bait on ground, 5 times Primary forest, 1 times nest in soil, 1 times in soil of clay bank, 3 times bajo de M/28, 1 times At baits on ground; primary forest along CES; part of project for OTS managed ec, 1 times Solanum adherens foliage, 1 times Parcelas susecionales, Suelo, ...

Collected most commonly using these methods: 16 times baiting, 4 times search, 4 times Winkler, 4 times bait, 7 times Berlese, 8 times miniWinkler, 5 times Lure/Bait, 4 times flight intercept trap, 2 times Malaise, 2 times Mini Winkler, 1 times Unknown, ...

Elevations: collected from 50 - 860 meters, 153 meters average

Type specimens: paratype Pheidole scalaris: jtlc000016522

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