Eutetramorium mocquerysi

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to: navigation, search
Eutetramorium mocquerysi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Eutetramorium
Species: E. mocquerysi
Binomial name
Eutetramorium mocquerysi
Emery, 1899

Eutetramorium mocquerysi casent0005927 profile 1.jpg

Eutetramorium mocquerysi casent0005927 dorsal 1.jpg

Specimen Label

At a Glance • Ergatoid queen  
 

E. mocquerysi has queens that cannot be distinguished from workers without ovarian dissections (Heinze et al. 1999). Based on the number of ovarioles, however, two types of females can be distinguished: females (queen) with six ovarioles and a spermatheca which can mate and produce diploid offspring and females (workers) with only two ovarioles and no spermatheca but can lay unfertilized eggs.

Identification

Bolton and Fisher (2014) - This rainforest species is closely related to Eutetramorium monticellii but easily separated from it by the keyed characters. In addition, mocquerysi is larger than monticellii, has slightly longer scapes, different sculpture, distinctly larger eyes (compare measurements), and has the first gastral tergite with superficial reticular patterning everywhere on the dorsum. E. mocquerysi has queens that cannot be distinguished from workers without ovarian dissections (Heinze et al. 1999).

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Colonies consist of 35±18 adults (sample of 18 colonies) nesting inside moist decaying wood lying on the forest ground.

Castes

Colonies have more ergatoid gynes than workers (Sébastien, Peeters & Fisher 2010). A single ergatoid queen was mated in each colony, and had active ovaries with "yellow bodies". Scanning electron microscopy failed to reveal differences in the thoracic structure between queens and workers. The mated, egg-laying ergatoid queen was always behaviourally dominant (high-on-legs posture, and performance of antennal boxing). The workers and virgin ergatoids behaved as nurses and foragers.


Ergatoid queens have 6 ovarioles and a spermatheca (A: mated and active ovaries; B: virgin and undeveloped ovaries), unlike workers with 2 ovarioles and lacking a spermatheca (C: virgin and active ovaries; D: virgin and undeveloped ovaries). Photo by Alexandra Sébastien
Marked colony used to study dominance interactions among ergatoid queens and workers. Only the alpha individual can mate and lay eggs. Photo by Christian Peeters


Sébastien, A., Peeters, C. & Fisher, B. 2010. Behavioural regulation of monogyny among ergatoid queens in Eutetramorium mocquerysi, an ant from Madagascar. Poster IUSSI, Copenhagen


Worker

Male

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • mocquerysi. Eutetramorium mocquerysi Emery, 1899f: 281, figs. (w.) MADAGASCAR. Wheeler, G.C. & Wheeler, J. 1980: 537 (l.).

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

Description

Bolton and Fisher (2014):

Worker

TL 9.8–10.4, HL 2.08–2.18, HW 1.82–1.92, CI 86–89, SL 1.40–1.56, SI 76–83, PW 1.36–1.46, WL 2.84–3.04 (6 measured).

Palp formula 4,3. Mandible finely and densely longitudinally costulate. Cephalic dorsum longitudinally coarsely costate medially, the costae diverging posteriorly; spaces between costae with superficial ground sculpture. Sides of head with foveate pits, the spaces between which are densely shagreenate. Similar pits occur near the posterior margin of the dorsum. Eyes about at midlength of head in full-face view, EL 0.40–0.42 (EL/HW 0.21–0.22). Sides of head without projecting setae, but a few short coarse pubescence hairs may be present, appressed or nearly so. Mesotibia and metatibia each with a conspicuous simple spur. MfL 2.28–2.44 (MfL/HW 1.24–1.32). Legs covered with fine superficial reticular sculpture, superimposed upon which are scattered larger, shallow, semi-effaced punctures. Mesonotum in profile abruptly truncated posteriorly, descending almost vertically to the deeply impressed metanotal groove. Mesopleuron with a broad transverse sulcus that is unsculptured or very nearly so. Dorsal surfaces of entire mesosoma, petiole and postpetiole lack standing setae. Side of pronotum and entire dorsum of mesosoma foveate, the surfaces between foveae densely and strongly shagreenate. Propodeal spines long, slender and acute, in profile the spine 3.30–4.00 × longer than the maximum width of the propodeal lobe. Petiole in profile with a very small anteroventral process, spiracle located just anterior of the midlength of the peduncle. Postpetiole node broader than long, its width 0.70–0.74; dorsum of postpetiole shallowly foveate, the foveae less sharply defined than on the pronotum and the spaces between them punctulate-shagreenate. First gastral tergite with minute, superficial reticular patterning, and with scattered, minute, appressed pubescence, without setae. Full adult colour black, with dull brown to reddish brown legs.

Queen

Bolton and Fisher (2014) - (gyne). Extreme ergatoid (e.g. CASENT0217042). Indistinguishable from worker without ovarian dissection.

Male

Bolton and Fisher (2014) - See genus diagnosis of male for main features. Smaller than worker, HL 1.44, HW 1.36, CI 94, SL 0.42, SI 31, PW 1.36, WL 2.64, MfL 2.08 (MfL/HW 1.53), EL 0.68 (EL/HW 0.50) (1 measured). Length of first funiculus segment 0.14, of second 0.40. Maximum length of petiole 0.60, of postpetiole 1.10; maximum width of postpetiole 0.57. Dorsum of head transversely costulate behind the ocelli. Mesoscutum irregularly finely rugulose; sculpture similar but more longitudinal on mesoscutellum. Legs densely minutely punctulate on almost all surfaces, but the posterior face of the metafemur more shiny and notably less densely sculptured than the anterior face.

References

  • Bolton, B. & Fisher, B.L. 2014. The Madagascan endemic myrmicine ants related to Eutetramorium (Hymenoptera: Formicidae): taxonomy of the genera Eutetramorium Emery, Malagidris nom. n., Myrmisaraka gen. n., Royidris gen. n., and Vitsika gen. n. Zootaxa 3791, 1–99.
  • Emery, C. 1899e. Formiche di Madagascar raccolte dal Sig. A. Mocquerys nei pressi della Baia di Antongil (1897-1898). Bull. Soc. Entomol. Ital. 31: 263-290 (page 281, figs. worker described)
  • Fisher, B. L. 1997a. Biogeography and ecology of the ant fauna of Madagascar (Hymenoptera: Formicidae). J. Nat. Hist. 31: 269-302 (see also)
  • Heinze, J. Ḧolldobler, B. and Alpert, G. 1999. Reproductive conflict and division of labor in Eutetramorium mocquerysi, a myrmicine ant without morphologically distinct female reproductives. Ethology. 105:701–717.
  • Wheeler, G. C.; Wheeler, J. 1980. Supplementary studies on ant larvae: Ponerinae, Myrmicinae and Formicinae. Trans. Am. Entomol. Soc. 106: 527-545 (page 537, larva described)