Rhopalothrix JTL-004 Longino ms. (cf. isthmica)

Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker lateral view

worker face view


Costa Rica (Atlantic lowland wet forest).


Gastral dorsum with at most one pair of spatulate setae a little over half way back, and a cluster near the apex; labrum deeply notched with lateral lobes rounded; side of head above antennal insertions with three subequal gibbosities, nearly aligned, giving the head a subquadrate aspect.

Natural History

The genus Rhopalothrix is a member of the monophyletic tribe Basicerotini (Bolton 1998). I assume that Rhopalothrix share the predaceous habits of other members of the tribe. The few basicerotines whose habits are known prey on small, soft-bodied arthropods (Wilson 1956, Brown and Kempf 1960, Wilson and Brown 1985).

I know this species from three Berlese samples from La Selva Biological Station.

Taxonomic notes

JTL-004 is similar to isthmica in size and in the deeply bilobed labrum. isthmica is described with the inner surface of the mandibles having 7 acute teeth alternating in two sizes. JTL-004 has a single, large, subquadrate tooth (probably two fused teeth). isthmica is described with spatulate setae on the posterior half of the gaster; on JTL-004 there are only a few clustered at the very apex. Weber's figure of the head shape of isthmica is intermediate between JTL-004 and weberi.

Acanthidris isthmicus Weber 1941:188. Holotype worker: Panama, Barro Colorado Island [Weber collection?]. Brown and Kempf also examined a USNM specimen from the same locality.

Literature Cited

Bolton, B. 1998. Monophyly of the dacetonine tribe-group and its component tribes (Hymenoptera: Formicidae). Bulletin of the Natural History Museum London (Entomology) 67:65-78.

Brown, W. L., Jr., Kempf, W. W. 1960. A world revision of the ant tribe Basicerotini. Stud. Entomol. (n.s.) 3:161-250.

Weber, N. A. 1941. Four new genera of Ethiopian and Neotropical Formicidae. Ann. Entomol. Soc. Am. 34:183-194.

Wilson, E. O. 1956. Feeding behavior in the ant Rhopalothrix biroi Szabo. Psyche (Camb.) 63:21-23.

Wilson, E. O., Brown, W. L., Jr. 1985 ("1984"). Behavior of the cryptobiotic predaceous ant Eurhopalothrix heliscata, n. sp. (Hymenoptera: Formicidae: Basicerotini). Insectes Soc. 31:408-428.

Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu

Date of this version: 9 November 1999
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