Dorylus orientalis

My Ceylon collection was made in disturbed rain forest in the Udawaddatekele Sanctuary (Garden of the Kandy kings), at Kandy. Workers were found dispersed in the soil to a depth of at least 12.5 cm. None were found above ground. Our limited records indicate that the species is generally subterranean and occurs in a wide range of habitats, including cultivated land. (Wilson 1964)

Image Gallery


Workers from Kerala, India. Photo by Kalesh Sadasivan.

Identification
Wilson (1964) - A single series from Kandy, Ceylon varied in HW 0.55-1.37mm, or as much as all the other series together. Antenna always 9-segmented. The species is only moderately polymorphic. As in other Oriental Dorylus, the mandibular dentition shows great variation which is in part allometric. Concolorous yellowish brown.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia. Oriental Region: Bangladesh, India, Myanmar, Nepal, Sri Lanka, Thailand, Vietnam. Palaearctic Region: China.

Biology
Wilson (1964) - Green (1903) claimed that orientalis is vegetarian, attacking potatoes, dahlias, and roots of the common sunflower. But Mukerji (1933) doubted this. He studied the worker mouthparts in detail and found them " better adapted for feeding on animal food than on plants. The mandible is similar to that of the species Dorylus (Typhlopone) labiatus Schuck., which is carnivorous in habit. The sharp-pointed bristles, spines, and setae on the 1st and 2nd maxillae, can well pierce the skin of the victim, and draw out the nutritive fluid from the body of their prey, which they suck by their mobile tongue." This conclusion is supported by certain limited observations. "Examples of this species were found within the college compound at Ballygunge, Calcutta, engaged in feeding on a dead earthworm, underneath an earthern seedling pot. On digging the adjoining turf a large number of these blind ants were found below the surface of the earth, a few being busy in attacking a live grub of a beetle. Evidently they reached the bottom of the seedling pot by tunneling through the ground to hunt the prey, as none of them were seen on the surface of the lawn. These specimens were then collected in live condition, and were kept in an earthern vessel half filled with moist earth. They settled down there, and made nests in the earth. I fed them with small live earthworms, but they did not partake of any vegetable food which was given to them."

Nomenclature

 *  orientalis. Dorylus orientalis Westwood, 1835: 72 (m.) INDIA. Forel, 1901a: 463 (w.). Combination in D. (Alaopone): Emery, 1895j: 731. Senior synonym of curtisii (and its junior synonym oberthueri): Forel, 1901a: 463; of longicornis: Bingham, 1903: 4; Wilson, 1964a: 442; of fuscus: Wilson, 1964a: 442. Current subspecies: nominal plus obscuriceps.
 * curtisii. Labidus (Typhlopone) curtisii Shuckard, 1840b: 265 (w.) SRI LANKA. Combination in Dorylus: Dalla Torre, 1893: 10; in D. (Alaopone): Emery, 1895j: 730. Senior synonym of oberthueri: Emery, 1895j: 730. Junior synonym of orientalis: Forel, 1901a: 463; Bingham, 1903: 4.
 * longicornis. Dorylus longicornis Shuckard, 1840c: 321 (m.) INDIA. Combination in D. (Alaopone): Emery, 1895j: 731. Subspecies of orientalis: Dalla Torre, 1893: 13; Emery, 1895j: 731. Junior synonym of orientalis: Bingham, 1903: 4. Revived from synonymy as subspecies of orientalis: Forel, 1907e: 17; Santschi, 1924c: 97. Junior synonym of orientalis: Wilson, 1964a: 442.
 * oberthueri. Alaopone oberthueri Emery, 1881a: 274, fig. (w.) INDIA. Combination in Dorylus: Dalla Torre, 1893: 12. Junior synonym of curtisii: Emery, 1895j: 730.
 * fuscus. Dorylus fuscus Emery, 1889b: 487 (m.) MYANMAR. Combination in D. (Alaopone): Emery, 1895j: 731. Subspecies of orientalis: Dalla Torre, 1893: 13; Emery, 1895k: 453; Bingham, 1903: 5; Emery, 1910b: 15. Junior synonym of orientalis: Wilson, 1964a: 442.