Strumigenys dryas

Strumigenys dryas
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Strumigenys
Species:	S. dryas
Binomial name
	Strumigenys dryas; Bolton, 2000 Specimen labels

The few collections of this species have been from litter samples in lowland forest.

Identification

Bolton (2000) - A member of the lyroessa complex in the Strumigenys lyroessa-group. Seven species of the lyroessa-complex have a pronotal humeral hair, see under Strumigenys arrogantia.

Of these dryas is by far the most densely hairy. The other six species all lack erect hairs on the cephalic dorsum anterior to the occipital margin and lack pronotal pilosity except for the humeral hair; on the mesonotum they have only 3 pairs of erect hairs at most, located on the dorsolateral margins.

Keys including this Species

Key to Strumigenys of East Asia

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 6.734778° to 6.734778°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Indo-Australian Region: Indonesia (type locality), Philippines, Sulawesi.

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.

dryas. Strumigenys dryas Bolton, 2000: 869 (w.) INDONESIA (Sulawesi).

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

Description

Worker

Holotype. TL 2.5, HL 0.72, HW 0.57, CI 79, ML 0.20, MI 28, SL 0.30, SI 53, PW 0.34, AL 0.68. Characters of lyroessa-complex. Hairs on leading edge of scape narrowly spatulate. Dorsolateral margin of head with numerous short simple hairs that freely project laterally; these hairs arise from close behind frontal lobes to corner of occipital margin. Hair in apicoscrobal position not differentiated from the others in its vicinity on the margin. Cephalic dorsum with short erect stubbly hairs present from level of highest point of vertex to occipital margin. Minute near-erect ground-pilosity present among the stubbly erect hairs and also present anteriorly from level of highest point of vertex to level of frontal lobe. Promesonotal dorsum and dorsolateral margins with numerous short erect simple hairs; similar hairs also present on waist segments. Pronotal humeral hair stiff and simple, only slightly longer than others that follow it on dorsolateral margin of promesonotum. First gastral tergite with abundant short simple erect stubbly hairs.

Paratypes. TL 2.4-2.5, HL 0.70-0.72, HW 0.55-0.57, CI 76-79, ML 0.20, MI 28-29, PW 0.32-0.34, AL 0.65-0.68 (3 measured).

Type Material

Holotype worker, Indonesia: Sulawesi Utara, Dumoga-Bone N. P., ii.1985, 2 m2 sample of litter, lowland forest, 200-400 m., BB3 (P. M. Hammond) (The Natural History Museum). Paratypes. 5 workers with same data as holotype; 2 workers with same data but BB10 (BMNH, Museum of Comparative Zoology, Musee d'Histoire Naturelle Genève).

References

Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 869, worker described)