Dolichoderinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Range
Mexico south to Uruguay, southern Brazil, northern Argentina; St. Thomas in Virgin Islands. Costa Rica: common in southern Pacific lowlands, becoming less common in northern Pacific lowlands, unknown from Atlantic slope.
Identification
Color black; scapes and mesosomal dorsum with abundant erect setae; dorsal and posterior faces of propodeum separated by a well-defined transverse flange; petiolar summit (anterior view) more or less transversely truncate, usually crenulate, with lateral margins well differentiated from those of spine.
Similar species: validus, curvilobus.
Natural History
From MacKay 1993:
This is one of the most common and widely distributed species in the genus, occurring especially in disturbed habitats (coffee, cacao plantations) in second growth forest, as well as virgin rain forests, up to 2100 meters. They are commonly found during quarantine on banana debris and on orchids. Dolichoderus bispinosus nests in cavities in trees or in hollow logs on the ground and occasionally in carton termite nests on branches of trees (Swain, 1977), especially those of Nasutitermes ephratae, N. columbicus and N. sp. (pers. obs.). This species also nests in myrmecophytes such as Cordia and Tillandsia. Myrmecophiles include cockroachs and thysanurans (both unidentified - Swain, 1977). Dolichoderus bispinosus is polygynous (Kempf, 1959; Swain, 1977); several de-alate females and workers are often found within series. It is also polydomous (Swain, 1977). A mature nest contains thousands of workers and sexuals (Swain, 1977). New nests are formed by fission (Swain, 1977). These ants are very aggressive, especially when the nest is disturbed (Mann, 1916; Wheeler, 1936; pers. obser.). Workers produce a strong odor similar to that of Liometopum spp. when they are disturbed. They look and act similar to Liometopum in the field under such circumstances. They often nest together with Crematogaster limata parabiotica and with Dolichoderus lamellosus. Worker specimens have been collected almost 50 meters inside the mouth of a cave in Yucat n. Workers have been found in extrafloral nectaries of Bixa orellana (Bentley, 1977) and in the facultative, myrmecophytic orchid, Caularthron bilamellatum (Fisher et al., 1990), as well as several other species of plants (Swain, 1977). This species tends scale insects on Prioria, coccids, membracids and rioninid larvae, and are also effective predators, especially of termites (Swain, 1977). They are preyed upon by ant eaters and armadillos. Swain (1977) presents much more detailed information on this species. Sexuals are commonly collected in light traps. Stray sexuals have been collected in Jan. (Venezuela), Apr. (Surinam), May (Mexico, Panama, Venezuela), June (Costa Rica), July (Mexico, Guiana, Venezuela), Aug. (Trinidad, Peru, Venezuela), Aug.-Sept. (Brasil), Sept.-Oct. (Panama) and Oct. (Ecuador). [MacKay Literature Cited]
In the field these may be easily confused with some species of Camponotus subgenus Myrmobrachys, which are of similar size, black, and diurnal. However, they are nothing alike in behavior or odor. Myrmobrachys are generally timid and will flee disturbance, and if they have any odor at all it is a weak acid odor. Dolichoderus bispinosus workers are extremely pugnacious, aggressively defending resources and nest areas. Workers will quickly run onto your hand and bite. They have a strong chemical defense that imparts a characteristic odor. This distinctive odor is shared with many other groups in the Dolichoderinae, including Azteca, Tapinoma, Dorymyrmex, and some but not all other species of Dolichoderus. Workers are very fond of carbohydrate resources and will cluster around extrafloral nectaries, aggregations of membracids, and Coccoidea. Some riodinid butterflies with myrmecophilous larvae have a specialized association with D. bispinosus. For example, adult females of Juditha molpe search for aggregations of D. bispinosus as oviposition sites. Larvae can be found on a wide variety of host plants, the common factor being the presence of extrafloral nectaries or other carbohydrate sources at which D. bispinosus have gathered. The butterfly is an ant specialist rather than a plant specialist!
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu
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