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Species: Leptothorax calderoni   Creighton, 1950 

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Taxonomic History (provided by Barry Bolton, 2015)

Leptothorax (Mychothorax) canadensis ssp. calderoni Creighton, 1950a PDF: 276 U.S.A. Nearctic. AntCat AntWiki

Taxonomic history

(as junior synonym of septentrionalis) [First available use of Leptothorax acervorum canadensis calderoni Forel, 1914c PDF: 617 (w.q.); unavailable name.].
Revived from synonymy and raised to species: Ward, 2005 PDF: 13.


Previously misidentified by PSW as Leptothorax septentrionalis Wheeler. Given the temporary name of Leptothorax sp. CA-08 until PSW examined the types of L. calderoni Creighton, 1950A (= L. acervorum subsp. canadensis var. calderoni Forel, 1914C:617; unavailable).

Taxonomic Treatment (provided by Plazi)

Ward, P. S., 2005:
(Figure 5)
Leptothorax (Mychothorax) acervorum race canadensis var. calderoni Forel 1914c: 617. [Unavailable name.]
Leptothorax (Mychothorax) canadensis calderoni Creighton 1950a: 276. [First available use of name.] Three syntype workers, one syntype alate queen, Lake Tahoe , California , 6325' ( Calderon ) [ MHNG ] [Examined]
Comments. Leptothorax calderoni is a large, bicolored species with short standing pilosity and a robust petiole. In California it is sympatric with another species in the L. muscorum-complex , here called Leptothorax sp. CA-01 (this second species might correspond to L. canadensis Provancher ). In contrast to Leptothorax sp. CA-01, the petiole of L. calderoni has a less peaked appearance, with the anterior and dorsal faces forming a right angle in lateral view. The two pairs of standing hairs visible in profile on the dorsum of the petiole are separated by notably more than their lengths, whereas in L. sp. CA-01 they are separated by about their lengths or less (compare Figures 5 and 6). In addition, L. calderoni is larger (worker HW 0.66-0.81; n = 35) with disproportionately longer legs (worker FL 0.56-0.66; n = 35) compared to L. sp. CA-01 (worker HW 0.56-0.70, worker FL 0.44-0.56; n = 70). The mesosoma, petiole and postpetiole of L. calderoni are orangebrown, the head medium brown and gaster dark brown. Color contrasts tend to be less marked in L. sp. CA-01 .
Most records of L. calderoni come from coniferous forest at moderate to high elevations in the Sierra Nevada of California (1470-2680 m), with outlier populations in the northern Coast Ranges and in the San Bernardino Mountains of southern California. Colonies are found in cavities in hard, dead wood. Workers are often conspicuous as foragers on downed logs.
Bolton (1995b) incorrectly listed L. calderoni as an unavailable name, overlooking that fact that Creighton’s (1950a) treatment of it as a trinomen rendered it available. Creighton considered L. calderoni to be a subspecies of L. canadensis and a senior synonym of L. canadensis septentrionalis Wheeler (1917a). Actually L. c. septentrionalis would have seniority if the two were synonyms, but they are not conspecific. They have a similar color pattern but L. c. septentrionalis (described from Banff, Alberta and Emerald Lake, British Columbia) has longer setae, a more peaked petiole, and is smaller in size (syntype workers in MCZC examined).

Specimen Habitat Summary

Found most commonly in these habitats: 3 times found in pine/fir forest, 0 times found in Douglas fir-larch forest, 1 times found in mixed coniferous forest, 0 times found in Aspen forest, 0 times found in Mixed costal forest, 0 times found in Mixed transition forest, 0 times found in Montane forest, 1 times found in Sierran Meadow, 0 times found in Subalpine forest, 1 times found in wet meadow

Collected most commonly using these methods or in the following microhabitats: 3 times hand collecting, 0 times Log stage 3, 0 times Driftwood log on beach, 0 times Log stage 4, 1 times sweep net, 0 times Under bark, log stage 4

Elevations: collected from 21 - 2680 meters, 1740 meters average

Type specimens: syntype of Leptothorax calderoni: casent0909065

(-1 examples)

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