Myrmecocystus baja

Myrmecocystus baja
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Formicinae
Tribe:	Lasiini
Genus:	Myrmecocystus
Species:	M. baja
Binomial name
Myrmecocystus baja Sankey-Alamilla, Hernandez-Jimenez, Lopez-Reyes & Ceccarelli, 2024

In coastal dunes such as Punta Mazo where the ecosystem is divided between coastal dune (on west side) and inland coastal dune with coastal scrub vegetation (on east side), ants tended to prefer the west side. Ants were where climatic conditions are more adverse (referring mainly to wind speed and amounts of shadows). On the west side, competition with other species was less and the soil had less clay, so anthills have weaker structure compared to other species of the same genus. Myrmecocystus baja was relatively abundant in this habitat and generally easy to find foraging during the day (mainly in early hours of the day). The species is generally not considered aggressive, worker ants from Punta Mazo were aggressive to each other on one occasion. Although replete workers were common in most, if not all, species of Myrmecocystus (Snelling 1976) for Myrmecocystus baja, no replete workers were found in any of the seven anthills. Ants were observed to be constantly digging up sand, building nests during the day; nests generally have one entrance, although nests with two or three entrances were also found. The entrance of the nest is a small, round hole, and the nests consist of few tunnels and small chambers. The chambers with pupae were a few centimeters from the surface, while eggs and queens were in chambers at depths 10 to 20 cm from the surface.

Photo Gallery

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  Sankey-Alamilla et al. (2024), Figs. 3-4. Myrmecocystus baja worker. 3) lateral view, scale = 1 mm. 4) head in frontal view; scale = 0.5 mm.
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  Sankey-Alamilla et al. (2024), Figs. 5-8. Myrmecocystus baja female. 5) lateral view, scale = 1 mm. 6) head in frontal view, scale = 0.5 mm. 7) forewing, scale = 1 mm. 8) hindwing, scale = 1 mm.
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  Sankey-Alamilla et al. (2024), Figs 9-12. Myrmecocystus baja male. 9) lateral view, scale = 1 mm. 10) head in frontal view, scale = 0.5 mm. 11) forewing, scale = 1 mm. 12) hindwing; scale = 1 mm.
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  Sankey-Alamilla et al. (2024), Figs. 13-16. Typical habitats. 13) coastal dunes of Punta Mazo and 14) coastal dunes of Guerrero Negro, and 15) 16) nest entrances of Myrmecocystus baja.

Identification

Worker. Head with HW less than 0.93. Femur with small erect hair scattered (about 40 in frontal view), few short and erect hairs in pronotum, small erect hairs in second tergum, and uniform pronotal hairs. Small head, orbiculate to semi-square.

Females and males. Abundant hair on head, especially in malar area, smooth thorax of upper part, males shinier than females. Antennal sockets in females and funiculus of males orange, noticeably lighter than rest of body.

Following the keys for Myrmecocystus species proposed by Snelling (1976, 1982), morphology of the new ant leads to identification as Myrmecocystus intonsus, mainly in relation to size [HL 0.97-1.07 (1.03), HW 0.86-0.93 (0.88), and WL 1.47-1.99 (2.02)]. It differs from M. intonsus by having less pilosity. Close phylogenetic relation to Myrmecocystus wheeleri found by Kronauer et al. (2004) warrants comparison, yielding notable differences in size between M. wheeleri and M. baja, with the former notably larger. M. wheeleri is uniformly orange-ferruginous (Snelling 1976) while in M. baja a dark, reddish color dominates and in the head, the reddish color gradually darkens from the mandibles (reddish/orange) to the occiput (brown/dark).

Keys including this Species

• Key to Myrmecocystus species

Distribution

This species is distributed in coastal dunes of the Pacific Ocean of the peninsula of Baja California, Mexico, where it is endemic (restricted distribution between coordinates Latitude: 30.424333°N, Longitude: -116.012529°W in its northernmost distribution and Latitude: 26.719174°N, Longitude: -113.559251°W in its southernmost distribution).

Latitudinal Distribution Pattern

Latitudinal Range: 30.4° to 26.7°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: Sankey-Alamilla et al., 2024

Distribution based on type material

Mexico (type locality).

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.

Castes

Known only from workers.

Nomenclature

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

• baja. Myrmecocystus baja Sankey-Alamilla et al., 2024: 77, figs. 3-12 (w.q.m.) MEXICO (Baja California).

Type Material

• Holotype worker, allotype and eight worker ants, two female and two male paratypes: MEXICO, Baja California, Punta Mazo coastal dunes (San Quintín Municipality), 30.424333°N, -116.012529°W, 10.iii.2023 (S.A. Hernández, E. Lopez, L.A. Sankey, A. Rincon coll.). Additional paratypes: 48 workers, same locality, 15.viii.2021 (E. Lopez, L.A. Sankey coll.). Type material deposited in the Museo de Artrópodos de Baja California, CICESE, Ensenada and at Orma J. Smith Museum of Natural History, The College of Idaho (CIDA; one female, one male, and 10 worker paratypes).

References

• Sankey-Alamilla, L.R.A., Hernandez-Jimenez, S.A., Lopez-Reyes, E., Ceccarelli, F.S. 2024. New species of honeypot ant of the genus Myrmecocystus from Pacific coastal dunes of Baja California, Mexico. Southwestern Entomologist 49(1), 71-87 (doi:10.3958/059.049.0107).