Camponotus maritimus Ward, 2005

Ward, P. S., 2005, A synoptic review of the ants of California (Hymenoptera: Formicidae)., Zootaxa 936, pp. 1-68 : 10-13

Camponotus maritimus Ward , sp. nov.

(Figures 1-4)

Camponotus maculatus subsp. vicinus var. maritimus Wheeler 1910g: 305. Unavailable name.

Camponotus vicinus ; Creighton 1950a, nec Mayr [in part].

Camponotus vicinus ; Snelling 1970, nec Mayr [in part].

Camponotus sp. near vicinus ; Wetterer et al. 2000.

Camponotus cf. vicinus ; Sanders et al. 2001.

Camponotus sp. near vicinus ; Ward 2005.

Holotype worker, Jasper Ridge , San Mateo Co., California, U.S.A., 150m , 37º24'N 122º14'W, 3.iv.2004, under stone, oak woodland , P.S.Ward #15202 [ MCZC]. Paratypes: series of workers, queens and males, same data and nest series as holotype [ BMNH, CASC, CDAE, LACM, MCZC, UCDC, USNM, WPMC].

Description, major worker. Medium-sized species, related to C. vicinus Mayr , but smaller on average and with a shinier appearance. Masticatory margin of mandibles with five teeth, the first four (counting from apex) acute, the proximal tooth truncate or weakly bifid, and subtended by a small tooth on the outer basal margin of mandible (dentition simpler -five acute teeth only -in smaller workers). Head as long as, or longer than, wide; sides of head weakly convex, diverging posteriorly, and rounding into concave posterior margin (in smaller workers sides of head subparallel and posterior margin convex). Eye about one-quarter of head length and not protruding from side of head in full-face view (breaking outline of head in smallest workers). Anterior clypeal margin crenulate, broadly convex in outline; median clypeal carina prominently developed. Scape relatively short (Figure 3); scape base subcylindrical, not strongly flattened or flared. Frontal carinae separated anteriorly by about one-fifth head width, flaring out posteriorly to about one-third of head width. Mesosoma dorsum convex in profile; dorsal face of propodeum longer than, and rounding into, declivitous face; propodeum markedly compressed from side to side. Petiole simple, scale-like in profile, with blunt summit, and convex in posterior view. Legs relatively short (Figure 4); in largest workers (HW 2.50-3.10 mm), LHT not exceeding3.00 mm. Body subopaque to sublucid, with a distinctly greater sheen than in workers of C. vicinus . Sculpture consisting of fine reticulations, with scattered punctures, coarser on head than on abdominal tergites. Pilosity moderately common on most of body, finetipped and golden-yellow; standing pilosity absent from scapes (except apices), external face of tibiae, and sides of head, present on clypeus, midline of head, venter of head, mesosoma, petiole and rest of metasoma. The following numbers of standing setae present on the indicated structures (counts include all sizes of workers): profemur 3-13, pronotum 2- 20, mesonotum 2-13, propodeum 3-10, petiole 5-11, abdominal tergite III (exclusive of posterior margin) 4-21, abdominal tergite III posterior margin 5-15, abdominal tergite IV (exclusive of posterior margin) 5-24, abdominal tergite III posterior margin 8-28. Fine, appressed pubescence present on most of body but not forming a dense mat; appressed hairs on abdominal tergites 3 and 4 (gastric tergites 1 and 2) relatively short and sparse and separated by about their lengths. Medium to dark brown, head and metasoma darker, legs, antennal segments 2-12, and scape base usually lighter.

Worker measurements (n = 30). HW 1.08-3.11, HL 1.44-3.17, SL 1.59-2.68, PW 0.93-1.97, LHT 1.78-3.01, CI 0.73-1.00, SI 0.79-1.54, REL 0.21-0.31, LHT/HW 0.94- 1.71.

DNA sequence data. The following GenBank sequences are available for Camponotus maritimus : 18S ribosomal RNA gene (AY867448), 28S ribosomal RNA gene (AY867464), wingless (AY867433), long wavelength rhodopsin (AY867495) and abdominal-A(AY867480). All sequences derive from a single worker taken from the same nest series as the holotype.

Comments. Wheeler’s maritimus has remained a quadrinomen, and hence unavailable, since the original description. Creighton (1950a) considered it to represent a synonym of the more widespread species Camponotus vicinus , but there are in fact two distinct sympatric species in California. Workers of what is here called C. maritimus can be distinguished from those of C. vicinus by the narrower scape base, shorter scape, shorter legs, more closely adjacent frontal carinae, shinier integument, and sparser pubescence on abdominal tergites 3 and 4 (appressed hairs separated by about their lengths in C. maritimus , by less than their lengths in C. vicinus ). Plots of SL by HW and LHT by HW separate all but the smallest workers of C. maritimus and C. vicinus (Figures 3-4), except in southern coastal California. In this latter region there are vicinus-like populations in chaparral and coastal sage scrub with atypically short scapes and legs. The workers of these populations can be separated from those of C. maritimus by the other characters, especially the duller integument of the head and abdominal tergites 3 and 4, and the denser pubescence on the latter. In addition workers of the southern coastal populations of vicinus are exceptionally hairy, with standing pilosity commonly present on the sides of the head, as seen in full-face view, and on the venter of the metafemur (standing pilosity generally absent on these structures in C. maritimus ).

C. maritimus occurs in coastal regions of California from Mendocino and Lake Counties to San Diego County (including the Channel Islands), and in the western foothills of the Sierra Nevada. Habitats from which it has been collected include chaparral, serpentine chaparral, serpentine grassland, oak woodland, mixed redwood forest, coniferous forest on serpentine, and coastal scrub. Colonies are most frequently found under stones, less commonly in or under rotten wood.

Localities cited by Wheeler (1910g: 305) in his description of Camponotus maculatus subsp. vicinus var. maritimus are Pacific Grove and San José (H. Heath) and Catalina Island (C. F. Baker). Old specimens collected by Baker, Heath and Wheeler, and placed by Wheeler under “maritimus” in the MCZ collection, belong to three species: C. maritimus (from Catalina Island and Palo Alto), C. semitestaceus Snelling (Palo Alto) and C. vicinus Mayr (Pacific Grove). Some of these specimens are labeled as maritimus “types” but none of them has true type status because maritimus Wheeler is an unavailable name.

For convenience I have chosen the holotype and paratypes of C. maritimus Ward from a nest series collected recently at Jasper Ridge near Palo Alto, rather than from the old specimens. Wheeler, it seems, correctly inferred the presence of more than one species but he did not distinguish them with 100% accuracy.