New species of Tetramorium Mayr (Hymenoptera: Formicidae) from Puebla State, Mexico

SYSTEMATICS, MORPHOLOGY AND PHYSIOLOGY

New species of Tetramorium Mayr (Hymenoptera: Formicidae) from Puebla State, Mexico

M Vásquez-Bolaños^I; G Castaño-Meneses^II,III; R Guzmán-Mendoza^IV

^IEntomología, Centro de Estudios en Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Univ de Guadalajara, Zapopan Jalisco, México

^IIEcología y Sistemática de Microartrópodos, Depto de Ecología y Recursos Naturales, Facultad de Ciencias, Univ Nacional Autónoma de México, México, DF

^IIIUnidad Multidisciplinaria de Docencia e Investigación, Facultad de Ciencias, Univ Nacional Autónoma de México, Juriquilla, Querétaro, México

^IVEstudiante de Doctorado en Ciencias Biológicas, UAM, Depto de Biología, Univ Autónoma Metropolitana Iztapalapa, México

^{Correspondence}

ABSTRACT

Tetramorium notomelanum sp. n. is described from the Tehuacán Valley, state of Puebla, México. Its distribution and relation with other species of the tortuosum-group is discussed. The new species of Tetramonium is described from workers, and distinguished from others of the group by several characters: i) black coloration of the body; ii) size: T. notomelanum sp. n. is smaller than T. hispidum (Wheeler), T. mexicanum Bolton and T.spinosum (Pergande), but larger than T. bicolorum Vásquez-Bolaños and T. placidum Bolton; iii) length of the hairs of the dorsal of the head are equal to the diameter of eye; iv) the length of the hairs on the scape and tibiae less than the width of the appendage where they are located. This is the second species of the tortuosum group of Tetramorium found in the State of Puebla, and the fourth recorded in Mexico.

Keywords: Taxonomy, Tehuacán Valley, Myrmicinae, Tetramoriini, tortuosum group, Zapotitlán Salinas

Introduction

The genus Tetramorium Mayr belongs to the tribe Tetramoriini of the Myrmicinae ants and is widespread in the World, currently comprising 459 nominal species (Bolton et al 2006) worldwide. There are twelve species recorded in several groups in the New World. Of these, only the five species of the tortuosum group are native to the Americas and include: T. bicolorum Vásquez-Bolaños, T. hispidum (Wheeler), T. mexicanum Bolton, T. placidum Bolton and T. spinosum (Pergande). The remaining seven species are all introduced and belong to different groups. The species of the tortuosum-group are distinguished from the all introduced species because they present only eleven antennal segments (Bolton 1979). In Mexico, four of the five native American species are found: T. bicolorum known from Jalisco state, T. mexicanum and T. placidum recorded in Jalisco and Nayarit states, the three species having Neotropical distribution. Tetramorium spinosum, with both Nearctic and Neotropical distribution, has been reported in several Mexican states: Baja California, Coahuila, Durango, Hidalgo, Jalisco, Michoacán, Nayarit, Nuevo León, Puebla, San Luis Potosí, Sonora, Tamaulipas and Zacatecas. Finally, T. hispidum has a more Nearctic distribution and is known only in the central southern states of the United States, Texas and Arizona (Vásquez-Bolaños 2007).

In the present work, we report and describe a new species of Tetramorium of the tortuosum-group from the Tehuacán Valley, Puebla State, in central Mexico.

Material and Methods

The specimens were obtained from a sampling with a series of pitfall traps (Guzmán-Mendoza et al 2010) carried out in "Helia Bravo" Botanical Garden, in the Zapotitlán Salinas area at the southwestern border of the Tehuacán Valley (18º11' - 18º25' N, 97º39' - 97º22'W), in Puebla State, Mexico (Fig 1a). The elevation range in the Valley varies between 1280 m and 2720 m. The climate of the region is semiarid type, with two periods of rain (May to June, and September),with average annual precipitation of 400 mm and mean annual temperature ranging from 18ºC to 22ºC. The dominant vegetation is represented by xerophytic shrub (Rzedowski 1978).

The samples were exclusively composed of workers. After the review of the collected specimens according with the genus revision of Bolton (1979), and comparing with the specimens of Tetramorium deposited at the Entomological Collection of the Centro de Estudios en Zoología, Universidad de Guadalajara (CZUG), we concluded that the specimens represented a new species.

We used the following measurements and indices (in mm), according with Bolton (1979): TL- total length, HL - head length in full face view, HW - maximum head width in full face view, SL - maximum straight-line length of antennal scape seen in profile, PNW - maximum width of pronotum from above in full dorsal view, AL - alitrunk length seen in profile, LE - eye length in full face view, and WE - eye width in full face view. Indices used were the cephalic index : ;CI = HL / HW x 100, and the scape index: SI = SL / HL x 100.

Results

Tetramorium notomelanum sp. n. (Fig 1a-c)

Material examined. All the specimens from Mexico, State of Puebla, Tehuacán Zapotitlán Salinas: Type series. Holotype, worker, labeled with the following data, 17 – 21.XII.2003, pitfall tramp 5, sitio El Llano, Jardín Botánico Helia Bravo, Zapotitlán Salinas, Tehuacán, Puebla. Paratypes: three workers, labels with as follow: 17-21.XII.2003, pitfall tramp 5, sitio El Llano, Jardín Botánico Helia Bravo, Zapotitlán Salinas, Tehuacán, Puebla; one worker: VIII 2003, pitfall 5, sitio El Llano, Jardín Botánico Helia Bravo, Zapotitlán Salinas, Tehuacán, Puebla. Holotype and two paratypes deposited at CZUG (Entomological Collection of the Centro de Estudios en Zoología, Universidad de Guadalajara); one paratype deposited in the Ant Collection of the Laboratorio de Ecología y Sistemática de Microartrópodos (LESM), Facultad de Ciencias, Universidad Nacional Autónoma de México, and one paratype deposited in the Collection of William and Emma Mackay Collection (CWEM), University of Texas, El Paso, Texas.

Supplementary material. Three specimens were used for scanning electron microscopy observation.

Diagnosis

Workers (Fig 1a-c). Antenna with 11 segments. Mandibles showing longitudinal ridges and seven well defined teeth (Fig 1b). Frontal carinae extending beyond the upper level of the eyes. Small eyes, about 0.22 mm long. Propodeal spines relatively long and sharp. Dorsal surface of alitrunk and petiole with reticulate sculpturing (Fig 1c). Head and postpetiole with longitudinal ridges. Dorsal pilosity of body straight, length similar to diameter of eyes. Hairs of the tibiae and scape longer than the diameter of the corresponding appendage. Head, alitrunk, petiole, postpetiole, gaster and appendages black.

Measurements (mm) and indices (data for holotype in parenthesis): TL 3.8-4.0 (3.9), HL 0.94-0.98 (0.98), HW 0.84-0.88 (0.88), CI 88.7-91.6 (89.7), SL 0.80 (0.80), SI 81.6-85.1 (81.6), PNW 0.70-0.74 (0.72), AL 1.20-1.26 (1.20).

Queen and males. Unknown.

Derivatio nominis. This species is named by the color of the body according with the Greek roots notos that means back, and melás that means black.

Distribution and ecology. This species is known only from the type locality, Zapotitlán Salinas, Puebla, México.

Biology. The specimens were collected in an area with sparse vegetation and low floral diversity. Solitary foraging ants were observed in search of seeds and waste plant tissues of leguminous plants (Prosopis laevigata, Cercidium praecox and Mimosa luisana), which represent an important resource in this area and especially during the dry season. The collection area also has been subject to anthropogenic and natural disturbance, suggesting that this is an early colonizer species because it was not found in undisturbed areas within the Botanical Garden.

Key to the species of genus Tetramorium tortuosum -group from the New World (modified from Vásquez-Bolaños 2007)

1.

Hairs length of antennal scape and external surface of metatibia distinctly longer than maximal diameter of corresponding appendage. Scape Index (SI) 94-99 (Mexico: Jalisco and Nayarit) ............................ T. mexicanum Bolton

-

Hairs length of antennal scape and external surface of metatibia distinctly shorter than maximal diameter of corresponding appendage. Scape Index (SI)
79-90 .............................................................................................. 2

2.

Petiolar dorsal suface without sculpture. Small ants, range of head width (HW range 0.66-0.72 mm; México: Jalisco and Nayarit) ............. T. placidum Bolton

-

Petiolar dorsal surface with sculpture. Large ants, head width (HW) between 0.77 mm and 1.0 mm .......................................................................... 3

3.

Large eyes, maximal diameter greater than a quarter of the head width. Hairs length on pronotal dorsal surface and frontal carinae, shorter than maximal eye diameter; small and erected hairs
(USA: Arizona and Texas) ........................................ T. hispidum (Wheeler)

-

Small eyes, maximal diameter less than a quarter of the head width. Hairs length on pronotal dorsal surface and frontal carinae equal or greater than maximal eye diameter; longer hairs, fine and curved .................................. 4

4.

Dorsum of body with longitudinal ridges (Mexico: Baja California, Coahuila, Durango, Hidalgo, Jalisco, Michoacán, Nayarit, Nuevo León, Puebla, San Luis Potosí, Sonora, Tamaulipas and Zacatecas) .............. T. spinosum (Pergande)

-

Dorsum of body reticulated .................................................................. 5

5.

Postpetiole dorsum without ridges. Total length from 3.4 mm to 3.8 mm (Mexico: Jalisco) ......................................... T. bicolorum Vásquez-Bolaños - Postpetiole dorsum with ridges. Total length from 3.8 mm to 4.0 mm (Mexico: Puebla) ................................................................ T.notomelanum sp. n.

Discussion

The species described here clearly belongs to the tortuosum-group. In common with described species, the antennae have 11 segments, the petiole is sculptured and nodiform, the propodeum is armed with spines, the mandibles are striate and the gaster unsculptured (Bolton 1977). This species is easily recognized from others of the genus Tetramorium by its coloration pattern. Tetramorium bicolorum is bicolored: dark brown on head while gaster is lighter brownish on alitrunk, petiole and postpetiole; the remaining species of the group (T.hispidum, T.mexicanum, T.placidum and T.spinosum) show pale to dark brown homogeneous coloration all over the body, while T.notomelanum sp. n. is completely dark black. Also, T. notomelanum sp. n. is smaller than T.hispidum, T.mexicanum and T.spinosum, but larger than T.bicolorum and T. placidum. The length of the hairs of the head and pronotum is equal or smaller to the maximal diameter of the eye, a character shared with T.bicolorum and T.spinosum. Other diagnostic characters of T. notomelanum sp. n. are the reticulated body sculpture and the acuminate propodeal spines relatively longer than that of the other species of the group.

Acknowledgements

Scanning electron microphotographs were obtained by Dr Silvia Espinosa-Matías (Microscopía de Barrido, Science Faculty, Universidad Nacional Autónoma de México). Dr José G. Palacios (Science Faculty, Universidad Nacional Autónoma de México) and Dr Robert Jones (Natural Sciences Faculty, Universidad Autónoma de Querétaro), kindly review the manuscript and gave invaluable suggestions.

Received 11 August 2010 and accepted 01 March 2011

Edited by Roberto A Zucchi – ESALQ/USP

• Bolton B (1977) The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Oriental and Indo-Australiannn regions, and in Australia. Bull British Mus (Nat Hist), Entomol Series 36: 67-151.
• Bolton B (1979) The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Malagasy region and in the New World. Bull British Mus (Nat Hist), Entomol series 38: 129-181.
• Bolton B, Alpert G, Ward PS, Naskrecki P (2006) Bolton's catalogue of ants of the World: 1758-2005. Harvard University Press, Cambridge, Massachussets, CD-Rom.
• Guzmán-Mendoza R, Castaño-Meneses G, Herrera-Fuentes MC (2010) Variación espacial y temporal de la diversidad de hormigas en el Jardín Botánico del valle de Zapotitlán de las Salinas, Puebla. Rev Mex Biodiv 81: 427-435.
• Rzedowski J (1978) La vegetación de México. México, Limusa, 432p.
• Vásquez-Bolaños M (2007) Una especie nueva del género Tetramorium Mayr (Hymenoptera: Formicidae) de Mascota, Jalisco, México. Dugesiana 14: 93-97.

Publication Dates

• Publication in this collection
  14 Sept 2011
• Date of issue
  Aug 2011

History

• Received
  11 Aug 2010
• Accepted
  01 Mar 2011