Ants of Singapore #02 - Myrmoteras (iriodum, arcoelinae)

Myrmoteras 

Myrmoteras is a genera of ants belonging to the subfamily Formicinae. Formicines have an acidopore rather than a sting and can spray formic acid. Myrmoteras is known as a lowland tropical rainforest and montane forest species. What is so unique about these ants is that it has a very long elongated mandible, unlike the many other ants. Further, these mandibles can open 270 degrees. These specimens are by far rare, and little is known about their biology. What made them develop such huge eyes, if they're primarily leaf-litter dwelling, and what are the long mandibles used for? Nests have been found in dead twigs of leaf litter. [1]

Also, about its taxonomy -- there are two subgenera within the genera, namely Myrmoteras and Myagroteras that are geographically separated, and delineated respectively by the Wallace line and Weber's line. They're strictly an Indomalayan genera.

Species accounts

Myrmoteras iriodum

A specimen -- Myrmoteras iriodum collected in Singapore

Myrmoteras cf. arcoelinae

A Myrmoteras cf. arcoelinae found on a leaf of a shrub (surprise, surprise) - not leaf litter where it is usually spotted. This was also observed by Agosti (1992). Found at one of the trails at Kinabalu National Park (1500m) which is a lower montane forest. The individual was moving sluggishly and did not seem aggressive.  Credit and thanks to Chui Shao Xiong for this wonderful photograph!

References
[1] Agosti, D.. 1992. Revision of the ant genus Myrmoteras of the Malay Archipelago (Hymenoptera: Formicidae). Revue sueisse Zoologie 99(2): 405-429.

Ants of Singapore #01 - Cataulacus (granulatus)

Hi everyone, will be starting a series on the 'Ants of Singapore'. My interest with respect to Singapore's biodiversity are insects, and more specifically, ants (family Formicidae). Ants are a group of insects within the order Hymenoptera (meaning membranous wings). Because of Singapore's position in the tropics, we have a great diversity of ants.

Personally, I don't pronounce to know a lot about these creatures but I am working to familiarize myself with their life history and taxonomy because they're such interesting, and also very beautiful insects.

Cataulacus

Species accounts

Cataulacus granulatus

Today's choice of ants will be none other than Cataulacus granulatus. Ants from the genera Cataulacus are strictly old world, and they look very similar to the New World ants Cephalotes. Cephalotes are known to be able to glide when dropped from a high distance, and I wonder if Cataulacus can do the same. All arthropods (which means jointed-legs) have an exoskeleton but the Cataulacus ant seems to have an exoskeleton even harder than the rest. Perhaps it's a protective adaptation that this group of insects have.

When disturbed, these ants like to take cover but they are also capable moving pretty fast, though not as fast as other ants. Lastly, these ants are arboreal, meaning primarily forage and live in trees!  

Cataulacus granulatus on a leaf.