Myrmelachista cooperi

Myrmelachista cooperi
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Formicinae
Tribe:	Myrmelachistini
Genus:	Myrmelachista
Species:	M. cooperi
Binomial name
	Myrmelachista cooperi; (Gregg, 1951) Specimen Labels

Longino (2006) - Prior to this study M. cooperi was known only from the holotype queen, taken with no associated biological data near Turrialba. I rediscovered the species in the Peñas Blancas Valley, east of Monteverde in the Cordillera de Tilarán. The habitat was mature wet forest at 800m elevation. I found nests in live stems of a small lauraceous tree. A voucher specimen of this tree was obtained (William Haber collection #10708) but it has not been identified. At this field site O. dendrodaphne and atirrensis were common in the understory, inhabited by Myrmelachista flavocotea and Myrmelachista nigrocotea. The tree species inhabited by M. cooperi was distinctly larger than these and much less common. I found several trees and they all contained M. cooperi in the live stems. One of the branches contained alate queens and males in addition to workers. One of the branches contained a dealate queen and workers.

Identification

Longino (2006) - Worker antenna 9-segmented; maxillary palpus 6-segmented; color black. Queen black, antenna 10-segmented, head elongate and strongly flattened, mandible falcate.

The strongly falcate mandibles, the enlarged labrum covering the mouthparts, the shiny surface, and the diminutive thorax and abdomen in relation to the head are similar to other species known to be temporary social parasites (the parasite syndrome, see Hölldobler & Wilson 1990). The suite of characters suggests that queens of cooperi may use some form of social parasitism to establish colonies.

This is the only Myrmelachista species I know in which the workers and queens differ in number of antennal segments: workers with 9 and queens with 10 (based on examination of three queens and dozens of workers). The male genitalia are very similar to Myrmelachista zeledoni, and very different from any of the other species with 9-segmented antenna. This suggests that cooperi is derived from a zeledoni-like ancestor, the 9-segmented antennal count in the workers may be independently derived relative to other 9-segmented species, and it may not be particularly closely related to the other Lauraceae-inhabiting species.

Keys including this Species

Distribution

In Costa Rica known from two mid-elevation sites on the Atlantic slope.

Latitudinal Distribution Pattern

Latitudinal Range: 15.106° to 10.31666667°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Costa Rica (type locality), Panama.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Castes

Worker

Images from AntWeb


Worker. Specimen code casent0624259. Photographer J. Longino, uploaded by University of Utah.	Owned by JTLC.

Queen

Images from AntWeb


Queen (alate/dealate). Specimen code jtlc000002753. Photographer J. Longino, uploaded by University of Utah.	Owned by JTLC.

Male

Images from AntWeb


Male (alate). Specimen code jtlc000002752. Photographer J. Longino, uploaded by University of Utah.	Owned by JTLC.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

cooperi. Camponotus (Myrmostenus) cooperi Gregg, 1951: 80, figs. 2, 3 (q.) COSTA RICA. Longino, 2006a: 14 (w.m.). Combination in Aphomomyrmex: Gregg, 1954a: 104; in Neaphomus: Kempf, 1972a: 152; in Myrmelachista: Snelling & Hunt, 1976: 110.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Longino (2006):

Description

Worker

HL 0.761–0.881, HW 0.750–0.853, SL 0.398–0.457, EL 0.157–0.178, CI 94–100 (n=3).

Antenna 9-segmented; maxillary palpus 6-segmented; mandible with teeth 4 and 5 (counting from apex) separated by a wide diastema, teeth 1-4 more closely and evenly spaced; dorsal surface of mandible striatopunctate near masticatory margin, grading to smooth and shining basally; clypeus strongly bulging medially, some workers with longitudinal median carina; face with superficial reticulate sculpture, becoming denser on clypeus and anterior malar spaces; in full face view, with abundant short erect setae projecting from rear margin of head, absent from sides of head; ventral surface of head with short sparse appressed pubescence, no erect setae; scapes with abundant erect to subdecumbent setae, longer setae subequal to width of scape; HW of large worker 0.76mm; outer surface of hind tibia with abundant erect setae, longer setae about 2/3 width of tibia; color black.

Queen

HL 1.684, HW 1.123, SL 0.613, EL 0.330, OW 0.081, OD 0.251, CI 67, OI 29, OcI 5 (n=1).

Antenna 10-segmented; maxillary palpus 6-segmented; labrum a large shiny plate that completely covers and closes the buccal cavity and other mouthparts (in other Myrmelachista the labrum is shorter, not covering the buccal cavity); mandible falcate, with three apical teeth and a series of small denticles; dorsal surface of mandible striatopunctate near apex, grading to smooth and shining basally; clypeus with large cone-like projection; face smooth and shining; in full face view, with abundant erect setae projecting from rear margin of head, much shorter erect setae on sides of head; ventral surface of head with long suberect pubescence; scapes with abundant erect to subdecumbent setae, longer setae subequal to width of scape; outer surface of hind tibia with abundant erect setae, longer setae about 2/3 width of tibia; petiole elongate, with very long, low node; color black. See also description of Gregg (1950).

Male

Antenna 11-segmented; maxillary palpus 6-segmented; pygostyles present, sclerotized, setose; basiparamere lobe and paramere short, robust, broadly triangular; cuspis robust, spatulate, with an apicodorsal field of small teeth at the apical contact point with the digitus; digitus short, dorsal margin forming an abrupt right angle, apex of digitus a ventrally directed triangular lobe; penial valve short and broad, apex blunt, with dorsally-directed short triangular tooth, apodeme of penial valve strongly developed, at right angle to the rest of valve.

Type Material

Holotype queen: Costa Rica, Turrialba (Cooper).

References

Gregg, R. E. 1951. Two new species of exotic ants. Psyche. 58:77-84. (page 80, figs. 2, 3 queen described)
Gregg, R. E. 1954a [1953]. Taxonomic notes on the ant, Camponotus cooperi Gregg. Psyche. 60:102-104. (page 104, Combination in Aphomomyrmex)
Kempf, W. W. 1972b. Catálogo abreviado das formigas da regia~o Neotropical. Stud. Entomol. 15: 3-344 (page 152, Combination in Neaphomus)
Longino, J.T. 2006. A taxonomic review of the genus Myrmelachista in Costa Rica. Zootaxa. 1141:1-54.
Snelling, R. R. and Hunt, J. H. 1975. The ants of Chile (Hymenoptera: Formicidae). Rev. Chil. Entomol. 9: 63-129 (page 110, Combination in Myrmelachista)

References based on Global Ant Biodiversity Informatics

Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
Gregg R. E. 1951. Two new species of exotic ants. Psyche (Cambridge) 58: 77-84.
INBio Collection (via Gbif)