Genus Forelius (Dolichoderinae)

• Forelius Emery, 1888d: 389. Type species: Iridomyrmex mccooki Forel, by monotypy.
• Neoforelius Kusnezov, 1953c: 327. Type species: Neoforelius tucumanus Kusnezov, by monotypy. Synonymy: Shattuck, 1992c: 87.

• OVERVIEW.   This is a small New World genus with disjunct North and South American populations. Members of the genus are inhabitants of xeric habitats and are seldom found in forested or moist sites. This has resulted in the North and South American populations of Forelius being separated by the tropical regions of northern South America. Nests are in the ground under rocks or with small craters. Workers forage for honeydew and arthropods on the ground or in the trees. They are usually active during the warmer parts of the day, and they forage singly or in conspicuous columns (Shattuck, 1992c: 92, 94).
• ZOOGEOGRAPHICAL REGIONS.  New World.
• RECOGNITION.   Psammophore absent. Mandible with 5 teeth and 0 to 2 denticles. In profile, clypeus with 2 long hairs originating at or near the anterior margin that curve downward over anterior surface of closed mandibles. Pronotum with 2 long hairs (at least 1/3 longer than others on pronotum) and 1 to about 14 short hairs. Metanotal impression slight to moderate; in profile, mesonotum and propodeum not forming a continuous, smooth curve. Petiolar scale present though sometimes small. First gastral tergite projecting anteriorly and, in dorsal view, concealing the petiole.



Figure of Forelius from Smith, M.R. 1965.


• SIMILAR GENERA.   Member of genus Forelius are easily confused with other Nearctic dolichoderines. Tapinoma is distinguished by the absence of a petiolar scale although some Forelius specimens will have a small petiolar scale overhung by the gaster. Liometopum species are moderately polymorphic with mesosoma in profile evenly convex and lacking the metanotal impression of Forelius. Linepithema is most similar to Forelius.
  

  	Forelius	Linepithema
  Hairs on anterior margin of clypeus	Long and ventrally curved	Shorter and straight
  Basal margin of mandible	Without denticles	With denticles
  First gastral tergite	Overhanging petiole	Not overhanging petiole

• TRIBE.  Dolichoderini.
• REVISIONS.   Cuezzo, 2000: 199–277 (world revision, descriptions and figures for all species, key to world species) .
• TAXONOMY.   Smith, M.R. 1943e: 312 (diagnosis of m.) .— Smith, M.R. 1947f: 595, 597, pl. 17, fig. 63 (diagnosis of w., figure (lateral view) of w.) .— Creighton, 1950a: 343–345, pl. 46, figs. 1–4 .— Wheeler, G.C. & Wheeler, J. 1966: 729 (larva) .— Shattuck, 1992c: 87–95, figs. 75–80, table 5 (description of w.q.m., diagnosis of l., distribution map, comparison to Linepithema figures (full face and lateral views) w.q.m.) .— Bolton, 1994: figs. 32, 33 (SEMs (full face and lateral view) of w.) .— Shattuck, 1994: 91–97 (catalog) .

• mccooki. Iridomyrmex mccooki McCook, 1880: 187. [USA] Mayr, G. 1886d: 432 (q.m.) . Junior synonym of foetida Buckley: Wheeler, W.M. 1901c: 520, and hence first available replacement name for Formica foetida Buckley, 1866. Combination in Forelius: Emery, 1888d: 389. Current subspecies nominal plus keiferi. Note that the correct date of the original citation is 'McCook, 1880' not 'McCook, 1879' as in Bolton, 1995b: 190.
• foetida. Formica foetida Buckley, S.B. 1866: 167 (w.q.) . [USA, TX, (central)] Crozier, 1970a: 113 (k.) . Junior primary homonym of Formica foetida Linneaus, 1758 (now in Pachycondyla). The replacement name is Forelius mccooki McCook, 1880.
• mccooki. Iridomyrmex mccooki Forel, 1878c: 382 (footnote) . Nomen nudum. Synonymy: Bolton, 1995b: 190.
• andrei. Forelius maccooki r. andrei Forel, 1912i: 44 (w.) . [USA] Subspecies of foetidus: Smith, M.R. 1951c: 836. Junior synonym of foetidus: Wheeler, W.M. 1901c: 520; of mccooki: Smith, D.R. 1979: 1419. Synonymy: Smith, D.R. 1979: 1419.

• DISTRIBUTION. Ark., Kans., Okla., Tex., Colo. w. to Calif.; Mexico.
• TAXONOMY. Forel, 1886b: xxxix.— Smith, M.R. 1947f: pl. 17, fig. 53 (figure (lateral view) of w.) .— Creighton, 1950a: 345 .— Wheeler, G.C. & Wheeler, J. 1974b: 401, fig. 1 (larva of F. foetidus (Buckley)) .— Cuezzo, 2000: 249–253, figs. 13, 25, 36, map 6 (description w.q.m., figure of worker head, mesosoma, distribution, biology) .
• MISCELLANEOUS. Cole, A.C. 1937b: 137.— Mallis, 1941: 137.— Gregg, R.E. 1963: 434–436 (distribution in CO, as Forelius foetidus) .— Wheeler, G.C. & Wheeler, J. 1973e: 102–103.— Allred, 1982: 461 (distribution in UT, as F. foetidus) .— Van Pelt, 1983: table 1 (habitat and frequency in the Chisos Mts., Texas, as I. pruinosus analis ) .— Cokendolpher & Francke, 1990: 22–23 (distribution in TX, as F. foetidus) .— Rojas-Fernández & Fragoso, 1994: 59 (diagnosis of w., habitat, as F. foetidus) .

• pruinosus. Tapinoma pruinosum Roger, 1863a: 165 (w.) . [Cuba] Wheeler, G.C. & Wheeler, J. 1951: 185, pl. III, figs. 1–6 (l.) . Combination in Iridomyrmex: Wheeler, W.M. 1913b: 497; in Forelius: Wheeler, G.C. & Wheeler, J. 1986g: 13; Shattuck, 1992c: 95.
• anale. Tapinoma anale André, 1893b: 148 (w.) . [Mexico, Chihuahua, (Terraras)] Cuezzo, 2000: 222 (m.) . Combination in Iridomyrmex: Forel, 1908c: 62. Combination in Forelius: Wheeler, G.C. & Wheeler, J. 1986g: 13. Variety of pruinosis: Emery, 1895d: 333. Revived status as species: Forel, 1908c: 62; Emery, 1912a: 26. Variety / subspecies of pruinosis: Wheeler, W.M. 1913b: 497; Creighton, 1950a: 343. Junior synonym of pruinosus: Wheeler, G.C. & Wheeler, J. 1986g: 13. Subspecies of pruinosis: Shattuck, 1994: 96. Junior synonym of pruinosus: Bolton, 1995b: 190. Revived status as species: Cuezzo, 2000 Sociobiol. 35: 222. Synonymy: Ward, 2005a: 936.
• testaceus. Iridomyrmex pruinosus var. testaceus Cole, A.C. 1936b: 121 (w.q.) . [USA, ID, Twin Falls Co.; USNM, Cole Collection, Kennedy Collection] Synonymy: Creighton, 1950a: 343 .

• DISTRIBUTION. NY, s. to FL, w. to CA, n. to southern ID, e. to WI; Mexico, Guatemala, West Indies.
• TAXONOMY. Smith, M.R. 1929b: 241.— Santschi, 1930e: 81.— Eckert & Mallis, 1937: 8 (as F. analis) .— Cole, A.C. 1940b: 64–65.— Cole, A.C. 1942: 372– 373 (also biological notes) .— Creighton, 1950a: 342–343, pl. 45, figs 1–4 (figure (lateral view) w.q.m., figure (wing) q., in part as F. analis) .— Smith, M.R. 1965: 54–55, fig. 29 (diagnosis of w., natural history, figure (lateral view) w., as Iridomyrmex pruinosus) .— Wheeler, G.C. & Wheeler, J. 1966: 729 (revised description of larva) .— Petralia & Vinson, 1980: 386.— Cuezzo, 2000: 222–224, 261–263, figs. 10, 15, 22, 26, 37, 39, map 6 (description w.; figures of worker head and mesosoma; distribution; biology; in part as F.analis) .—Ward, 2005a: 936–937.
• MISCELLANEOUS. Wheeler, W.M. 1905j: 389 .— Wheeler, W.M. 1906i: 342 (as F. analis) .— Smith, M.R. 1924b: 83 (as F. analis) .— Smith, M.R. 1930a: 5.— Dennis, 1938: 294, 305 (as F. analis) .— Carter, 1962b: 191 (distribution in NC, natural history) .— Warter, Moser & Blum, 1962: 42–46 (correlation between night hawk feeding and nuptial flights of pruinosus pruinosus) .— Blum, Warter, Monroe, & Chidchester, 1963: 881–885 (chemical releasers of social behavior- methyl-n-amyl ketone) .— Gregg, R.E. 1963: 436–438 (brief natural history, distribution in CO, as F. analis) .— Wheeler, G.C. & Wheeler, J. 1963: 154–155.— Smith, M.R. 1965: 54–55 (economic importance) .— Cole, A.C. 1966b: 18 (Nevada Test Site, as F. analis) .— Wheeler, G.C. & Wheeler, J. 1973e: 101–102 (as F. analis) .— Bernstein, R.A. 1979: table 2 (temperature range for foraging) .— Van Pelt, 1983: table 1 (habitat and frequency in the Chisos Mts. Texas, as F. analis) .— MacKay, Lowrie, et. al. 1988: 102 (occurrence in NM, as F. analis) .— Cokendolpher & Francke, 1990: 23–24 (distribution in TX) .— Rojas-Fernández & Fragoso, 1994: 66–67 (diagnosis of w., habitat) .