Strumigenys californica

Strumigenys californica was initially known from three alate queens that lacked any collection information other than locality and collector. C.F. Baker collected these specimens in Claremont, a small city located on the eastern edge of Los Angeles Co., California sometime before 1950 (Brown 1964). Brown (1950) noted the similarity of this species with the Japanese species Strumigenys rostrataeformis, and posited that it might be a non-native introduction. Since the first collection, several other smithistrumiform natives have been discovered as well as additional S. californica collections from Monterey, San Luis Obispo, and Los Angeles counties, supporting it being native (Ward 1988).

Strumigenys californica appears to be associated with more arid environments than many of the other more western native species, with two workers collected foraging on Eriogonum buckwheat (Ward 1988), and a mostly intact dead worker found among the middens of a Solenopsis xyloni colony. A dealate queen was collected in mid-October, suggesting a flight/dispersal period that is about a month later than eastern counterpart species and coinciding with the onset of winter precipitation. This dealate queen was collected in a chamise/Ceanothus chaparral near Claremont, Los Angeles Co. in 2010. (Booher, 2021)

Identification
Bolton (2000) - A member of the Strumigenys rostrata-group. Within the group the dentition and adiastemate condition of the mandible allies this species with Strumigenys arizonica and Strumigenys rostrata (see there). The apical sculpture of the gastral segments is unique in the group and immediately identifies californica.

Distribution based on Regional Taxon Lists
Nearctic Region: United States.

Nomenclature

 *  californica. Smithistruma (Smithistruma) californica Brown, 1950b: 40 (q.) U.S.A. Ward, 1988: 120 (w.). Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 116. See also: Brown, 1953g: 85; Bolton, 2000: 126.

Bolton (2000) - In the original description of the holotype queen Brown (1950b) mentions that the head has one or two transverse rows of elongate erect hairs near the occipital margin. Of the worker Ward (1988) says that the head has no sign of flagellate or linear hairs, and this also applies to workers from San Lucas. The LACM paratype queen, as well as having a few standing hairs near the occipital margin, has a short simple apicoscrobal curved hair, this latter hair not being recorded by either Brown or Ward. It is possible that these differences may reflect caste-specific characters, or that the workers may have had their longer cephalic hairs abraded. But it may imply that two sibling species are present. Material of californica is so sparse that no conclusion can be reached at present.

Worker
Bolton (2000) - HL 0.60-0.62, HW 0.38, CI 62, MI 16, AL 0.61 (measurements from Ward, 1988). Basal lamella of mandible followed without a diastema by the principal row of 5 acute teeth. First gastral tergite with sharply defined basigastral costulae that extend about one-quarter the length of the sclerite. Behind this the tergite smooth until the apical quarter or so, where there is a distinct transverse band of fine reticulate and longitudinally striate sculpture. Similar sculpture present at apex of first gastral sternite and at apices of tergites 2 and 3. Pronotal humeral hair long fine and flagellate.

Queen
Holotype. Total length (TL) 2.41, head length (HL) 0.64, cephalic index (CI) 67, mandibulo-cephalic index (MI) 17. Closely related to Sm. rostrata (Emery) and to the Japanese species rostrataeformis Brown and incerta Brown. Differs from rostrata in considerably smaller size and in the shorter, broader hairs of the free clypeal border, particularly those on the anterolateral "corners" of the clypeus. Humeral angles each with a distinctly flagelliform hair; gastric hairs flagelliform, erect, distinctly more numerous than are those of either worker or female of rostrata. Propodeal teeth short, compressed, subtended by convexly expanded infradental lamellae. Dorsum of petiole with sculpture more or less effaced, subopaque to weakly shining in varying lights. Mandibles shorter than those of rostrata, but appearing similarly toothed; no diastema evident, even in partially open mandible. Differs from the types of incerta (female and worker) and rostrataeformis in details of pilosity and in proportions of head, clypeus and mandibles. The anterior median clypeal emargination is present but very weak, not so well developed as in incerta, but perhaps a little stronger than in the majority of rostrata females. Color ferrugineous yellow; apex of gaster slightly darkened. Remnants of wings present.

Type Material
Holotype and single paratype (see below) taken at Claremont, California (C. F. Baker). The data go no farther, as might be wished in the case of the only certain record for a member of the genus from west of the Great Plains in North America. Whether this locality is in the irrigated, intensively cultivated region around Claremont or in one of the canyons near the city may make the difference between an ant introduced from the Orient or one native to California. The paratype, also a female with large parts of the wings remaining, unfortunately lacks a head. The two females were probably captured during or just after the nuptial flight. These two (holotype and paratype) specimens, now in the Museum of Comparative Zoology, are the basis for the record of rostrata from California. Wheeler made the original determination, and this record appeared in Smith's revision of 1931. Dr. W. S. Creighton has rightly called this record to question in his book on North American ants (1950).

Bolton (2000) - Holotype queen and paratype queens, U.S.A.: California, Claremont (C.F. Baker) [examined].

References based on Global Ant Biodiversity Informatics

 * Des Lauriers J., and D. Ikeda. 2017. The ants (Hymenoptera: Formicidae) of the San Gabriel Mountains of Southern California, USA with an annotated list. In: Reynolds R. E. (Ed.) Desert Studies Symposium. California State University Desert Studies Consortium, 342 pp. Pages 264-277.
 * Ward, P. S. 1988. Mesic Elemets in the Western Nearctic Ant Fauna: Taxonomic and Bilogical Notes on Amblyopone, Proceratium, and Smithistruma (Hymenoptera: Formicidae) Journal of the Kansas Entomological Society. 61:102-124