Strumigenys kraepelini

Strumigenys kraepelini
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Strumigenys
Species:	S. kraepelini
Binomial name
	Strumigenys kraepelini; Forel, 1905 Specimen Labels

Known from wet forest and rainforest litter-samples.

Identification

Bolton (2000) - A member of the feae complex in the Strumigenys mayri-group. As currently understood this species shows considerable variation in size and relative dimensions of head and scape. This, coupled with variation in sculpture of the dorsal alitrunk, leads me to believe that more than one real species may be included here. The question cannot be resolved at present because material representing the varying forms is too sparse. It is certain that the original type-material of kraepelini has long ceased to exist. While I am convinced that Forel’s taxon resides in kraepelini as defined here, designation of a neotype should await the more detailed analysis of variation that is necessary. See notes under Strumigenys barylonga and Strumigenys exilirhina.

Keys including this Species

Key to Strumigenys of East Asia

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 5.016666667° to -6.584°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo, Indonesia (type locality), Malaysia, Singapore.
Oriental Region: Thailand.

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

Explore Overview of Strumigenys biology

Strumigenys were once thought to be rare. The development and increased use of litter sampling methods has led to the discovery of a tremendous diversity of species. Many species are specialized predators (e.g. see Strumigenys membranifera and Strumigenys louisianae). Collembola (springtails) and other tiny soil arthropods are typically favored prey. Species with long linear mandibles employ trap-jaws to sieze their stalked prey (see Dacetine trap-jaws). Larvae feed directly on insect prey brought to them by workers. Trophallaxis is rarely practiced. Most species live in the soil, leaf litter, decaying wood or opportunistically move into inhabitable cavities on or under the soil. Colonies are small, typically less than 100 individuals but in some species many hundreds. Moist warm habitats and micro-habitats are preferred. A few better known tramp and otherwise widely ranging species tolerate drier conditions. Foraging is often in the leaf litter and humus. Workers of many species rarely venture above ground or into exposed, open areas. Individuals are typically small, slow moving and cryptic in coloration. When disturbed individuals freeze and remain motionless. Males are not known for a large majority of species.

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Castes

Nomenclature

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

kraepelini. Strumigenys kraepelini Forel, 1905c: 8 (w.) INDONESIA (Java). See also: Bolton, 2000: 885.

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

Description

Worker

Bolton (2000) - TL 2.7-3.0, HL 0.70-0.88, HW 0.38-0.50, CI 52-60, ML 0.32-0.40, MI 42-48, SL 0.45-0.60, SI 110-129, PW 0.27-0.28, AL 0.70-0.85 (18 measured).

Characters of the feae-complex. Preapical tooth short-triangular, its length half or less of the width of mandible at point where tooth arises, always shorter than maximum width of mandible. Outer margin of mandible in full-face view shallowly convex from close to base to level of preapical tooth. With head in full-face view anteriormost point of eye is located just posterior to 0.50 X HL (behind midlength of head). Upper scrobe margin with two freely laterally projecting long flagellate hairs, the posterior one in apicoscrobal position. Cephalic dorsum with 4-6 erect flagellate hairs along the occipital margin, a similar but usually shorter pair present at highest point of vertex. Preocular notch absent, ventrolateral margin of head extremely shallowly evenly concave immediately in front of eye and straight anteriorly. Maximum diameter of eye usually slightly greater than maximum width of scape, rarely less. Pronotal humeral hair flagellate. Pronotal dorsum varying from weakly reticulate-punctate to almost entirely smooth. Pronotal dorsum without standing hairs, mesonotum with 2 pairs of erect flagellate hairs. Dorsal surfaces of waist segments and first gastral tergite with long flagellate hairs. Pleurae and side of propodeum smooth; in profile the mesothorax long and constricted in its anterior half. One or two long fine erect flagellate hairs present on the dorsal (outer) surface of the hind basitarsus and another 1-2 on the hind tibia; similar pilosity present on the other legs. Petiole in profile long and low, node with a strongly differentiated anterior face. Dorsum of node long and low, shallowly convex, much longer than anterior face. In dorsal view petiole node at least as long as broad, usually longer than broad, reticulate-punctate; disc of postpetiole smooth. Basigastral costulae shorter than disc of postpetiole.

Type Material

Bolton (2000) - Holotype worker, INDONESIA: Java, Bogor ( = Buitenzorg), iii.1904 (K. Kraepelin) (holotype lost (probably destroyed in World War II), not in Zoologisches Institut und Zoologisches Museum der Universität Hamburg or Musee d'Histoire Naturelle Genève).

References

Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 885, redescription of worker)
Emery, C. 1924f [1922]. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [concl.]. Genera Insectorum 174C: 207-397 (page 321, catalogue)
Forel, A. 1905f. Ameisen aus Java. Gesammelt von Prof. Karl Kraepelin 1904. Mitteilungen aus dem Naturhistorischen Museum in Hamburg 22: 1-26. (page 8, worker described)
Khachonpisitsak, S., Yamane, S., Sriwichai, P., Jaitrong, W. 2020. An updated checklist of the ants of Thailand (Hymenoptera, Formicidae). ZooKeys 998, 1–182 (doi:10.3897/zookeys.998.54902).
Musfira, S.H., Rafi, M., Gusti, M., Putri, D.H., Satria, R. 2022. New data on the genus Strumigenys (Hymenoptera: Formicidae) from Sumatra. Zoosystematica Rossica 31(1): 74–86 (doi:10.31610/zsr/2022.31.1.74).
Tang, K. L., Guénard, B. 2023. Further additions to the knowledge of Strumigenys (Formicidae: Myrmicinae) within South East Asia, with the descriptions of 20 new species. European Journal of Taxonomy 907, 1–144 (doi:10.5852/ejt.2023.907.2327).
Wang, W.Y., Soh, E.J.Y., Yong, G.W.J., Wong, M.K.L., Benoit Guénard, Economo, E.P., Yamane, S. 2022. Remarkable diversity in a little red dot: a comprehensive checklist of known ant species in Singapore (Hymenoptera: Formicidae) with notes on ecology and taxonomy. Asian Myrmecology 15: e015006 (doi:10.20362/am.015006).

References based on Global Ant Biodiversity Informatics

Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
Forel A. 1905. Ameisen aus Java. Gesammelt von Prof. Karl Kraepelin 1904. Mitt. Naturhist. Mus. Hambg. 22: 1-26.
Pfeiffer M., and D. Mezger. 2012. Biodiversity Assessment in Incomplete Inventories: Leaf Litter Ant Communities in Several Types of Bornean Rain Forest. PLoS ONE 7(7): e40729. doi:10.1371/journal.pone.0040762
Pfeiffer M., and D. Mezger. 2012. Biodiversity Assessment in Incomplete Inventories: Leaf Litter Ant Communities in Several Types of Bornean Rain Forest. PLoS ONE 7(7): e40729. doi:10.1371/journal.pone.0040911
Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
Woodcock P., D. P. Edwards, R. J. Newton, C. Vun Khen, S. H. Bottrell, and K. C. Hamer. 2013. Impacts of Intensive Logging on the Trophic Organisation of Ant Communities in a Biodiversity Hotspot. PLoS ONE 8(4): e60756. doi:10.1371/journal.pone.0060756
Woodcock P., D. P. Edwards, T. M. Fayle, R. J. Newton, C. Vun Khen, S. H. Bottrell, and K. C. Hamer. 2011. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants. Phil. Trans. R. Soc. B. 366: 3256-3264.
Woodcock P., D.P. Edwards, T.M. Fayle, R.J. Newton, C. Vun Khen, S.H. Bottrell, and K.C. Hamer. 2011. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants. Phil. Trans. R. Soc. B 366: 3256-3264.