Trichomyrmex destructor

A tramp species that has spread throughout the world.

Identification
Monomorium destructor is very similar to the closely related Monomorium robustior, but is lighter in color and the eyes tend to be less elongate. Workers within nests also show more allometric variation than is found in M. robustior (Heterick 2006).

Distribution
This taxon was described from India. It is also found in Mozambique, Australia, Philippines, Ecuador, Brazil, New Guinea, Colombia, United States, Dominican Republic, Puerto Rico, Nepal, South Africa, Israel, Eritrea, Kenya, Comoros, Seychelles, Mayotte, Mauritius, Madagascar, Japan, Iran (Islamic Republic of), Afghanistan, Sri Lanka, Bangladesh, Thailand, Indonesia, Singapore, Kuwait, Saudi Arabia, Oman, United Arab Emirates, Spain, Fiji, Guam, Samoa, Niue, Barbados, Canary Islands, Kiribati, Micronesia (Federated States of), Northern Mariana Islands, Trinidad and Tobago and United Kingdom of Great Britain and Northern Ireland.

Biology
As reported from issg database:

Nest outdoors or in buildings, depending largely on whether they occur in tropical, semitropical or temperate regions. In northern Western Australia they do not live far from houses where they live above the ground in wall and roof cavities. They are present in some tropical, irrigated, lowland rice fields in the Philippines, and coconut plantations in Sri Lanka. In Florida they nest in soil (lawns) or buildings. On Tiwi Island and in Australia's Northern Territory, M. destructor nests were only associated with urban areas; while there was some spread into surrounding bush land, they appear to be unable to establish in undisturbed habitat. In the United Arab Emirates the ants are present in a wide range of habitats, especially irrigated gardens and disturbed habitats close to water. In the Caribbean they were found nesting in trees in citrus orchards (in hollow twigs and branches) and on the ground (Collingwood et al. 1997; and Harris et al. 2005).

M. destructor is a tramp ant, renowned for transportation via human commerce and trade. It is associated with a wide range of freight types, making it difficult to target any particular pathways. This ant also spreads naturally from established colonies in two ways: colony budding, where queens walk on foot accompanied by workers to a new nesting site; and winged dispersal of inseminated queens to uninfested areas where they start a new colony. This latter mechanism needs to be confirmed; it is most likely colony budding is the primary natural dispersal method (Harris et al. 2005).

Nomenclature

 *  destructor. Atta destructor Jerdon, 1851: 105 (w.) INDIA. Bingham, 1903: 209 (q.m.). Combination in Monomorium: Dalla Torre, 1893: 66; in M. (Parholcomyrmex): Wheeler, W.M. 1922a: 874. Senior synonym of ominosa (and its junior synonym atomaria): Dalla Torre, 1893: 66; of basalis: Forel, 1894b: 86; of vexator: Donisthorpe, 1932c: 468; of gracillima: Bolton, 1987: 324. See also: Smith, D.R. 1979: 1382; Bolton, 1987: 324; Heterick, 2006: 96.
 * basalis. Myrmica basalis Smith, F. 1858b: 125 (w.) SRI LANKA. Combination in Monomorium: Mayr, 1865: 92. Junior synonym of destructor: Forel, 1894b: 86.
 * atomaria. Myrmica atomaria Gerstäcker, 1859: 263 (w.) MOZAMBIQUE. [Also described as new by Gerstäcker, 1862: 518.] Junior synonym of ominosa: Roger, 1863b: 31.
 * ominosa. Myrmica ominosa Gerstäcker, 1859: 263 (w.) MOZAMBIQUE. [Also described as new by Gerstäcker, 1862: 517.] Combination in Monomorium: Roger, 1863b: 31. Senior synonym of atomaria: Roger, 1863b: 31. Junior synonym of destructor: Dalla Torre, 1893: 66.
 * gracillima. Myrmica gracillima Smith, F. 1861a: 34 (w.) ISRAEL. Emery, 1877b: 369 (footnote) (q.m.). Combination in Monomorium: Mayr, 1862: 753; in M. (Parholcomyrmex): Emery, 1915i: 190. Subspecies of destructor: Forel, 1913d: 437. Junior synonym of destructor: Bolton, 1987: 324.
 * vexator. Myrmica vexator Smith, F. 1861b: 47 (w.) INDONESIA (Ternate I.). Junior synonym of destructor: Donisthorpe, 1932c: 468.

Worker
Heterick (2006) - HEAD: Head square; vertex planar or weakly concave; frons longitudinally finely striolate anteriad (striolae curving inwards around antennal insertions), smooth and shining posteriad, except for a few transverse rugulae on upper vertex; pilosity of frons consisting mainly of appressed and decumbent setulae with a few erect setae on vertex. Eye large, eye width 1.5× greater than greatest width of antennal scape to moderate, eye width 1–1.5× greatest width of antennal scape; (in full-face view) eyes set below midpoint of head capsule; (viewed in profile) eyes set around midline of head capsule; eye elliptical, curvature of inner eye margin may be more pronounced than that of its outer margin. Antennal segments 12; antennal club three-segmented. Clypeal carinae indicated by multiple weak ridges; anteromedian clypeal margin broadly convex to straight; paraclypeal setae moderately long and fine, curved; posteromedian clypeal margin extending slightly beyond level of posterior margin of antennal fossae. Anterior tentorial pits situated nearer antennal fossae than mandibular insertions. Frontal lobes sinuate, divergent posteriad. Weak psammophore present. Palp formula 2,2. Mandibular teeth three, plus minute, basal denticle or angle; mandibles with sub-parallel inner and outer margins, striate; masticatory margin of mandibles approximately vertical or weakly oblique; basal tooth a small to minute denticle or angle, much smaller than t3 (four teeth present).

MESOSOMA: Promesonotum shining and smooth on dorsum, lower mesopleuron strongly punctate; (viewed in profile) promesonotum broadly convex anteriad, convexity reduced posteriad; promesonotal setae seven to twelve; standing promesonotal setae a mixture of well-spaced, distinctly longer, erect and semi-erect setae which are curved distally and often paired, interspersed with much shorter, incurved, decumbent setae; appressed promesonotal setulae well-spaced over entire promesonotum. Metanotal groove strongly impressed, with distinct transverse costulae. Propodeum uniformly finely striolate, some punctation on metapleuron; propodeal dorsum flat throughout most of its length; propodeum smoothly rounded or with indistinct angle; standing propodeal setae variable in number and arrangement, when present usually one prominent pair at propodeal angles or at midlength, with other shorter setae very sparse or absent; appressed propodeal setulae well-spaced and sparse; propodeal spiracle equidistant from metanotal groove and declivitous face of propodeum. Vestibule of propodeal spiracle distinct in some specimens. Propodeal lobes present as vestigial flanges or small strips of cuticle only.

PETIOLE AND POSTPETIOLE: Petiolar spiracle lateral or laterodorsal and situated within anterior sector of petiolar node or just at front of node; node (viewed in profile) conical, vertex rounded; appearance of node shining and smooth throughout; ratio of greatest node breadth (viewed from front) to greatest node width (viewed in profile) between 1:1 and 3:4; anteroventral petiolar process absent or vestigial; ventral petiolar lobe absent; height ratio of petiole to postpetiole between 1:1 and 3:4; height–length ratio of postpetiole between 4:3 and 3:4; postpetiole shining and smooth; postpetiolar sternite without anterior lip or carina, or this structure vestigial.

GASTER: Pilosity of first gastral tergite consisting of well-spaced, erect and semi-erect setae interspersed with a few appressed setulae.

MESOSOMA: Color yellow-orange to brownish-orange, gaster chocolate with or without yellowish area on anterior sector of first gastral tergite. Worker caste monophasically allometric, i.e., with variable size, but not morphology among workers from same nest.

LECTOTYPE MEASUREMENTS (M. basale): HML 1.70 HL 0.66 HW 0.58 CeI 88 SL 0.48 SI 83 PW 0.34.

LECTOTYPE MEASUREMENTS (M. vexator): HML 1.78 HL 0.68 HW 0.62 CeI 91 SL 0.50 SI 81 PW 0.36.

OTHER WORKER MEASUREMENTS (non-types): HML 1.31–1.92 HL 0.49–0.76 HW 0.38–0.68 CeI 78–89 SL 0.39–0.52 SI 76–103 PW 0.25–0.40 (n=20).

Queen
Heterick (2006) - HEAD: Head rectangular; vertex weakly concave or planar; frons shining and smooth except for piliferous pits and striolae around antennal sockets, frontal carinae and below the eyes, and fine rugulae near posterior margin of vertex; frons consisting mainly of decumbent setae, with two longitudinal, parallel rows of erect setae straddling the midline. Eye elongate, elliptical and oblique; (in full-face view) eyes set above midpoint of head capsule; (viewed in profile) eyes set posteriad of midline of head capsule.

MESOSOMA: Anterior mesoscutum smoothly rounded, thereafter more-or-less flattened; pronotum, mesoscutum and mesopleuron shining and mainly smooth, vestigial striolae, if present, confined to anterior katepisternum; length–width ratio of mesoscutum and scutellum combined between 7:3 and 2:1. Axillae a strip of thin cuticle separating mesoscutum and scutellum, each individual axilla indistinct. Standing pronotal/mesoscutal setae a mixture of well-spaced, distinctly longer, erect and semi-erect setae which are curved distally, interspersed with much shorter, incurved, decumbent setae; appressed pronotal, mescoscutal and mesopleural setulae abundant, particularly on mesoscutum. Propodeum shining and smooth, with a few weak striolae on metapleuron; always smoothly rounded; propodeal dorsum convex; standing propodeal setae consisting of one pair anteriad, with or without another pair posteriad; propodeal spiracle nearer metanotal groove than declivitous face of propodeum; propodeal lobes present as vestigial flanges only, or absent.

WING: Wing not seen (queen dealated).

PETIOLE AND POSTPETIOLE: Petiolar spiracle lateral and situated slightly anteriad of petiolar node; (viewed in profile) node conical, vertex rounded; appearance of node shining and smooth; ratio of greatest node breadth (viewed from front) to greatest node width (viewed in profile) about 1:1. Anteroventral petiolar process absent or vestigial; height ratio of petiole to postpetiole between 4:3 and 1:1; height–length ratio of postpetiole between 4:3 and 1:1; postpetiole shining, with vestigial sculpture; postpetiolar sternite with anterior and posterior margins convergent, forming a narrow wedge.

GASTER: Pilosity of first gastral tergite consisting mainly of appressed setae with a few erect and semi-erect setae.

GENERAL CHARACTERS: Color of foreparts tawny-yellow, gaster brown. Brachypterous alates not seen. Ergatoid or worker-female intercastes not seen.

QUEEN MEASUREMENTS: HML 3.22–3.46 HL 0.83–0.84 HW 0.76–0.80 CeI 92–95 SL 0.60–0.62 SI 78 PW 0.68–0.89 (n=2).

Type Material
Heterick 2006 - Atta destructor Jerdon 1851:105. Syntype ☿'s, INDIA [no types known to exist]. Myrmica basalis Smith 1858:125. Syntype ☿ (lectotype here designated), SRI LANKA [examined].

Additional References

 * Heterick, B. E. 2006. A revision of the Malagasy ants belonging to genus Monomorium Mayr, 1855 (Hymenoptera: Formicidae). Proceedings of the California Academy of Sciences. 57:69-202.