|The Ants of
SUBFAMILY FORMICINAE - Genus Pseudolasius
|Contents - Formicinae - FORMICINAE Introduction|
In Tribe LASIINI, previously PRENOLEPIDINI.
Diagnostic Features - Polymorphic. Antennae 12-segmented; with their insertions virtually confluent with the posterior clypeal margin. Mandibles with five-six teeth, some with 7-8 teeth, set upon an oblique border. Palpi short. Major workers with small eyes, on the dorsum of the head, at or near the midlength. Minors without eyes. Petiole a scale which may be inclined forwards. Dorsal surfaces without distinct paired hairs.
Bolton (1973a) describes them as small depigmented to yellowish ants, nesting in or under very rotten wood, or in the soil at the base of trees. Normally avoid light but can be found on the soil surface at night. Bernard (1952) stated that 6 species were known from Africa and thought that they might well be common in the subsoil; adding that they raise Homoptera on roots in the same way as Lasius ants in Europe.
Emery gave four species, the former Lasius familiaris Sm. and the former Prenolepis sumatrensis Mayr; plus descriptions of Pseudolasius pheidolinus, from Java, and Pseudolasius breviceps, from Amboina. All were eyeless.
Note - the following paper appeared to alter the
LaPolla, Brady &
Shattuck (2010: 123) considered that the African Pseudolasius were anomalous and
should be separated from the essentially South Asian genus.
On what seem to be very tenuous grounds they placed the
African species, weissi and bufonus,
in their new genus Paraparatrechina.
They commented "One difference between the two is that Ps. bufonus has several erect setae on the mesosoma [alitrunk]", a characteristic that differs from the 2.1.1 pattern of most Paraparatechina. This suggests weissi does not have such hairs, which is wrong, although the erect hairs are smaller and semi-decumbent.
It has to be said that their SEM images show Pseudolasius that are almost indistinguishable from the two African species. The Pseudolasius they show, by deduction P. australis, has small but much larger eyes than the original members of Emery's eyeless genus.
African species have highly reduced or no eyes, whereas all known Paraparatrechina have well
developed eyes. Whilst the data provided to accompany their paper shows
they studied P. weissi but
that was the sole African species, other than the tramp P. longicornis.
Their reference to P. weissi as BLF2139 does not gel with the Antweb list where the sole specimens imaged are a queen and a male from Gabon, with unimaged workers from Kenya (accessed 7.iii.2011; unchanged 18.iii.2012). Antweb, however, shows a major worker, BLF4000 (CASENT0406725), from the Central African Republic, as "Pseudolasius undet.". Whilst the queen was described by Santschi (1910c) the male has never been reported. Santschi gave the queen as TL 6.5-7 m, whereas the Antweb queen has TL ca 8.5 mm.
In a further paper from the Prenolepis-group
study, LaPolla, Kalla & Brady (2012) provided a revised key to the
genera. The opening couplets have:
1. Maxillary palps with five or fewer segments; species often strongly polymorphic, with as major and minor caste expressed ..... 2
2. Polymorphic Afrotropical species ....... Paraparatechina (weissi species-group).
The specimen they included in their list of species from
genomic DNA analysis as studied is given as USNM00756224. The
list included no other species endemic to Africa. The Zatania male shown in their paper is quite different from P. weissi male shown on Antweb (see above), with a different shaped head and genitalia, with dense pilosity.
Note - References:
LaPolla, J. S., Kalla, R.J. & Brady, S.G. (2012) A new ant
genus from the Greater Antilles and Central America, Zatania (Hymenoptera: Formicidae),
exemplifies the utility of male and molecular character systems. Systematic Entomology, 37, 200-214.
With a range of fresh specimens from Cameroun and the availability of type images from the MCZ and Antweb, now (2011), I have reviewed the situation and agree with LaPolla's synonymy into two distinct species. However. it is clear gowdeyi is a junior synonym of bufonus and not of weissi. It appears also that the bufonus and gowdeyi types were media and minor workers. Note: the majors of bufonus I have from Cameroun do not have erect hairs on the legs or scapes; as stated by Wheeler, 1922: 1922: 223, for gowdeyi
Bernard (1952) noted from Mt. Nimba, Guinea, a single small eyeless worker (labelled Nimba, Lamotte), with a squarer head and more claviform antenna than the known species, but declined to define a new species on the basis of a sole minor worker.
Many workers were found in Ghana, in leaf litter (270) and soil samples (4) under primary forest at Bobiri, a logged area at Atewa Forest Reserve, primary and secondary forest at Bunso, and under cocoa at Ofinso, by Belshaw & Bolton (1994).
© 2007, 2011 - Brian Taylor CBiol FSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.