Monomorium destructor (Jerdon)

Type location India (Atta destructor, N.S., Jerdon, 1851: 105, worker); junior synonyms basalis (Myrmica basalis, F Smith, 1858b: 125, worker) from Sri Lanka, gracillima (Myrmica gracillima, F Smith, 1861a: 34, worker; Emery, 1877b: 369, footnote, queen & male) from Israel, ominosa (and its junior synonym atomaria; both Gerstaecker, 1859: 263, worker) from Mozambique; and vexator (Myrmica vexator, F Smith, 1861b: 47, worker) from Indonesia .

Jerdon's (1851) description is at . Gerstaecker's (1859) descriptions of ominosa and atomaria are at ; the sole difference in these brief description appears to be the size. Emery (1877b: 369) gave a brief description and illustration of the British Museum specimen; this is at . Bolton's modern description (1987) is at

WORKER - TL 3.1-3.4 mm; distinguishing features as in key (Bolton, 1987: 324, illustrated, petiole and postpetiole only).

In addition to Bolton's illustration and my own of Nigeria specimens (below), I draw attention to the example in the Japanese Ant Color Image Database; from where the description reads - TL of workers around 3 - 3.5 mm. A relatively large Monomorium species, variable in size. Body yellowish brown to reddish brown from head to postpetiole; gaster blackish brown. Mandibles each with 4 teeth, the basalmost sometimes obscure. Eyes large, each with around 20 facets. Median paired carinae of clypeus obscure. Metanotal groove distinct. Propodeum with angulate posterodorsal border; the area of petiolar insertion carinate. Ventral outline of petiole less convex than in other species. Postpetiole 1.1 -1.2 times as long as broad. Mesopleuron and sections of lateral surfaces of propodeum with fine puncturation; dorsal surface of propodeum with transverse rugae.

A tramp species probably of Indian origin; Wheeler (1922) listed it (as gracillimum) from Guinea (Mamou, F. Silvestri). Well known as a destructive species, a nuisance in heated buildings, gnawing into the likes of telephone cables.

The photomontage of the vexator type from Indonesia, is collated from http://www.antweb.org/specimen.do?name=casent0008623

Nigeria specimen (Monomorium species G in Taylor, 1980a: 31). WORKER. TL 1.90 mm, HL 0.50, HW 0.47, SL 0.34, PW 0.25

Colour dark yellow-brown, gaster near black; antennae, tibiae and tarsi yellow; unsculptured and shiny. Erect hairs long and moderately abundant. Clypeal carinae well developed and running into the anterior margin of the clypeus. SI 72.

In Nigeria, my team and I found this form to be the commonest member of the genus on cocoa at CRIN, being quite often encountered, nesting in dead wood on living trees, and tending Homoptera (Taylor, 1981). We also encountered it on native trees and on kola.

Elsewhere, it was found in Ghana, on cocoa canopy and mistletoe, as well as on open ground, at the Mampong Cemetery farm by Room (1971). He also collected it in 18 of 168 canopy samples in his farm survey and reported an apparent negative association with Crematogaster clariventris and a positive association with Oecophylla longinoda. Found on cocoa at Kade by Majer (1975, 1976b), using pkd, with 7-9 workers per sample.

Even allowing for the variability in oscaris described in Bolton (1987), this I find a great quandary. The colour is quite distinctive and matches that of destructor, which was one of the separation points given by Bolton "oscaris is uniformly coloured, unlike destructor". However, for workers the size of that illustrated (the only size which I encountered in quite numerous collections at CRIN) the SI for destructor would be expected to fall in the range SI 97-85. The puzzle is deepened by the report by Majer (1975) of finding it in 23 of 144 25 m² pkd samples from cocoa at Kade, Ghana; specimens were identified as Monomorium species G by Bolton. So we had a relatively common species, clearly an arboreal forest dweller, and yet one which could not be readily identified from Bolton (1987).

TThe photomontage is of specimens from Egypt, Port Said, E 32°18' N 31°16'; 26.viii.2003, collector Mostafa Sharaf. Other images can be seen in the folders at - and

Monomorium destructor has the type location India but is described as a successful tramp species, throughout the tropical zones and in heated temperate buildings. From Africa, Bolton examined only specimens from South Africa, although Wheeler (1922) reported it from Zaïre (ssp. despectum, at Sankisia, by J. Bequaert). Generally omnivorous (Bolton, 1987).

Monomorium oscaris size range is TL 1.6-3.8 mm; the Monomorium destructor size range is TL 1.8-3.5 (Bolton, 1987: 324). In the key of Bolton (1987) destructor and oscaris are in the same couplets (65, 87) and are separable on pedicel shape, the petiole and postpetiole being rather broader in the former; oscaris also features in a couplet (9) with emeryi but that has the head and alitrunk all over coarsely sculptured.

Monomorium mayri is also within the group of near identical species, separated from destructor by its being uniformly dark brown (other characters apparently being near identical); it is recorded from the Sahel countries of western Africa, plus across to Egypt and onwards to West Malaysia. Now (2004), I have decided that the specimen I drew from the CRIN collection and labelled as Monomorium species A or F998 probably was mayri.

Bolton (1987) also preserved the species status of Monomorium epinotale Santschi.