Lenomyrmex
| Lenomyrmex | |
|---|---|
| |
| Lenomyrmex colwelli | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Formicidae |
| Subfamily: | Myrmicinae |
| Tribe: | Attini |
| Genus: | Lenomyrmex Fernández & Palacio, 1999 |
| Type species | |
| Lenomyrmex mandibularis | |
| Diversity | |
| 7 species (Species Checklist, Species by Country)
| |
| Evolutionary Relationships |
| Based on Ward et al. (2014), Blaimer et al. (2018) and Li et al. (2018). |
Lenomyrmex species have been collected from elevations close to sea level to 1800m but seem to be mainly restricted to mid-elevations (1100–1500m). Queen-worker dimorphism is weak, suggesting small colony sizes and absence of claustral independent colony foundation (Delsinne and Fernandez 2012).
Contents
Identification
The genus is characterized by elongate manidbles bearing a series of minute peg-like denticles that arise behind the masticatory margin, by frontal lobes that are poorly expanded laterally, by large and deep antennal fossae, and by pedunculate petiole, with a poorly defined node.
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See images of species within this genus |
Keys including this Genus
Keys to Species in this Genus
Distribution
Mid to high elevation rain-forests in southern Central and northwestern South America.
Distribution and Richness based on AntMaps
Species by Region
Number of species within biogeographic regions, along with the total number of species for each region.
| Afrotropical Region | Australasian Region | Indo-Australian Region | Malagasy Region | Nearctic Region | Neotropical Region | Oriental Region | Palaearctic Region | |
|---|---|---|---|---|---|---|---|---|
| Species | 0 | 0 | 0 | 0 | 0 | 7 | 0 | 0 |
| Total Species | 2837 | 1734 | 3036 | 929 | 832 | 4375 | 1686 | 2823 |
Biology
Delsinne and Fernandez (2012) - Lenomyrmex ants seem always locally rare and our collection of 34 workers (evergreen lower montane forest litter samples in an area near Podocarpus National Park at 1420m, Zamora-Chinchipe province, Ecuador in the Eastern Cordillera of the South-Ecuadorian Andes) is the first time that such a concentration of specimens have been collected within a relatively small area (400m2). A thorough inspection of the dead wood laying on the ground and of soil samples failed to uncover any nest of L. inusitatus. This and the fact that both workers and dealate queens were extracted from the leaf litter (Winkler method) may indicate that this species nests and forages in the leaf litter. The unusual morphology of the mandibles suggests that Lenomyrmex is a specialist predator on an unknown prey. This habit is possibly linked to its apparent rarity and restricted elevational distribution.
Two additional workers were found within a soil sample, at slightly higher elevation (1500 m), than the location where the the winkler sampled workers were found. The two workers were maintained alive during six days. They moved relatively slowly and feigned death when disturbed. They did not feed on any offered food items (alive and dead termites, millipedes, mites, various insect parts, sugar/water, tuna, biscuits).
Rabeling et al. (2016) - Lenomyrmex ants are rare in museum collections and the majority of the specimens have been collected sporadically in leaf-litter samples (Fernández and Palacio 1999, Fernández 2001, Longino 2006, Delsinne and Fernández 2012). So far only colonies of Lenomyrmex mandibularis have been collected manually because this species constructs nests in stems of a Palicourea species in the plant family Rubiaceae and in rotten logs (Fernández and Palacio 1999). In addition to systematic leaf litter sampling and hand collecting, the examination of stomach contents of leaf-litter foraging amphibians is a valuable source of cryptic and rarely collected ant species (Weber 1938, Delsinne and Fernández 2012, Sosa-Calvo 2015). Many species of amphibians and non-avian reptiles specialize on ant feeding and some species are predominantly myrmecophagous (Solé et al. 2002, Darst et al. 2005, Esteves et al. 2008). In the Neotropical poison frog family Dendrobatidae, myrmecophagy evolved at least twice, possibly three times independently (Santos et al. 2003, Darst et al. 2005), and the frogs sequester the skin alkaloids mostly from their ant and mite diet (McGugan et al. 2016). In addition to ants and mites, other arthropods, such as beetles and millipedes, are considered alkaloid sources for poison frogs (Dumbacher et al. 2004, Saporito et al. 2003, 2004, 2007).
To study the feeding ecology of the Little Devil poison frog, Oophaga sylvatica, the stomach contents of more than 300 individuals from different populations in Ecuador have been examined recently (McGugan et al. 2016, O'Connell, Sosa-Calvo et al., unpublished data). The majority of the frogs' diet consisted of ants, constituting between 40 and 86 % of diet volume in different frog populations. Of the more than 3000 examined prey items, 44 different ant genera could be identified, representing nine different subfamilies (Sosa-Calvo, O'Connell et al., unpublished data). The majority of the eaten ant genera belong to the subfamily Myrmicinae, including the rarely collected genus Lenomyrmex, with a total of nine specimens belonging to two species, Lenomyrmex hoelldobleri (the holotype worker) and Lenomyrmex foveolatus (seven workers and one gyne). Other cryptic and rarely collected ant genera include Leptanilloides, Stigmatomma, and Cerapachys, among others. To sample stomach contents of amphibians and other vertebrates solely for nutritional studies, it is not necessary to kill the animals. Stomach flushing methods have been developed and successfully applied in numerous studies, which avoids killing individuals of the study species (Solé et al. 2005). To conclude, the study of vertebrate stomach contents is not only a way of studying the trophic ecology of vertebrates themselves, but also an interesting source of cryptic and new arthropod species, including ants.
Life History Traits
- Mean colony size: ? (Greer et al., 2021)
- Compound colony type: not parasitic (Greer et al., 2021)
- Nest site: hypogaeic; arboreal (Greer et al., 2021)
- Diet class: ? (Greer et al., 2021)
- Foraging stratum: subterranean/leaf litter; arboreal (Greer et al., 2021)
Castes
Morphology
Worker Morphology
• Antennal segment count: 11 • Antennal club: 2 • Palp formula: 2,2 • Total dental count: 10-12 • Spur formula: 0,0 • Eyes: 11-100 ommatidia • Pronotal Spines: absent • Mesonotal Spines: absent • Propodeal Spines: present • Petiolar Spines: absent • Caste: none or weak • Sting: present • Metaplural Gland: present • Cocoon: absent
Male Morphology
• Caste unknown
Nomenclature
The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.
- LENOMYRMEX [Myrmicinae: Lenomyrmecini]
- Lenomyrmex Fernández & Palacio, 1999: 8. Type-species: Lenomyrmex mandibularis, by original designation.
References
- Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 237, Lenomyrmex as genus)
- Boudinot, B.E. 2019. Hormigas de Colombia. Cap. 15. Clave para las subfamilias y generos basada en machos. Pp. 487-499 in: Fernández, F., Guerrero, R.J., Delsinne, T. (eds.) 2019d. Hormigas de Colombia. Bogotá: Universidad Nacional de Colombia, 1198 pp.
- Branstetter, M.G., Longino, J.T., Reyes- López, J.L., Brady, S.G., Schultz, T.R. 2022. Out of the temperate zone: A phylogenomic test of the biogeographical conservatism hypothesis in a contrarian clade of ants. Journal of Biogeography 00, 1-14 (doi:10.1111/jbi.14462).
- Cantone S. 2018. Winged Ants, The queen. Dichotomous key to genera of winged female ants in the World. The Wings of Ants: morphological and systematic relationships (self-published).
- Delsinne, T. & Fernández, F. 2011. First record of Lenomyrmex inusitatus in Ecuador and description of the queen. Psyche 2012:5 pp. Article ID 145743. (doi: 10.1155/2012/145743.) PDF
- Fernández C., F.; Palacio G., E. E. 1999. Lenomyrmex, an enigmatic new ant genus from the Neotropical region (Hymenoptera: Formicidae: Myrmicinae). Syst. Entomol. 24: 7-16 (page 8, Lenomyrmex as genus)
- Fernández, F. 2001. Hormigas de Colombia. IX: Nueva especie de Lenomyrmex (Formicidae: Myrmicinae). Rev. Colomb. Entomol. 27: 201-204 (page 203, all species key)
- Fernandez, F., Guerrero, R.J., Sánchez-Restrepo, A.F. 2021. Sistemática y diversidad de las hormigas neotropicales. Revista Colombiana de Entomología 47, 1–20 (doi:10.25100/socolen.v47i1.11082).
- Hanisch, P.E., Sosa-Calvo, J., Schultz, T.R. 2022. The last piece of the puzzle? Phylogenetic position and natural history of the monotypic fungus-farming ant genus Paramycetophylax (Formicidae: Attini). Insect Systematics and Diversity 6 (1): 11:1-17 (doi:10.1093/isd/ixab029).
