Macrotermes carbonarius

Macrotermes carbonarius
Soldiers and workers
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Blattodea
Infraorder:	Isoptera
Family:	Termitidae
Genus:	Macrotermes
Species:	M. carbonarius
Binomial name
Macrotermes carbonarius (Hagen, 1858)

Macrotermes carbonarius, also known as Kongkiak in Malay, is a large black species of Macrotermes termite in the subfamily Macrotermitinae. The species is one of the most conspicuous of the Macrotermes found in the indomalayan tropics, forming large foraging trails that extend several meters in length. M. carbonarius is unusually aggressive in comparison to other Macrotermes species, with the soldiers notably possessing large curved mandibles that easily pierce skin. It is found in Cambodia, Indonesia, Malaysia, Myanmar, Singapore, Thailand and Vietnam.

Identification

Soldiers, workers and imago of this species are easily distinguished from others due to the almost jet-black coloration of their exoskeleton.

Like other Macrotermes species of the region, M. carbonarius has a dimorphic worker and soldier caste, with the largest soldiers commonly reaching lengths of 15 - 18 mm.

Biology

M. carbonarius is confined to elevations below 160 metres and primarily inhabits the tropical to subtropical lowland forests of Southeast Asia. It can be found across a wide variety of forested flat lands, most commonly in Dipterocarp forests and coastal forests as well as rural areas and plantations.

The nests are large and conspicuous, broad and irregular in shape. No obvious ventilation system exists within the mound walls. The walls of the mound are thick and compact, varying 11-18 in width, and the height of the mound ranges from 30-48 cm. Majority of the colony and the fungus gardens resides either just slightly below or above ground level or entirely within the mound itself.

M. carbonarius is amongst the most free-ranging of Macrotermes species found in the indomalayan tropics. It forages above the ground from numerous large subterranean tunnels that can extend as much as 33 metres from the nest before emerging onto the surface. Foraging trails may also then extend several metres above the surface and can be readily distinguished by the positioning of a large amount of soldiers at the flanks. Workers primarily forage for leaf litter which constitutes the principal diet of this species, although readily taking decaying hardwood when available. Other sources such as palm fronds or dried blades of grass are also occasionally taken. These termites are more readily tolerant of dessication, and can therefore forage for longer in areas that experience more harsher conditions than most other Macrotermes species. They are primarily active during the night and early morning or late evening, although foraging activities may continue for longer in more favorable weather such as humid and overcast conditions.

This species displays complex defensive behaviors when a breach of the mound occurs. In shallow breaches, a few minor and major soldiers rush out to face any threats, a normal behavior common to other Macrotermes species in the region. However in the case of a deep breach, soldiers assume defensive positions around the perimeter of the breach and begin hammering their heads against the walls of the mound, creating a rhythmic rattling noise. It is believed this behavior evolved due to predation by vertebrates.

The fungus comb of this species is notably less complex than that of its relatives, with a less defined airy grooved pattern common to other Macrotermitinae. After the completion and maturation of a fungus comb, the termites will consume all of it without continuously building it with new substrate. After being fully consumed a new comb is constructed.

Reproduction

Nuptial flights occur during daylight in the late afternoon, usually ~30 minutes before sunset. Windless, hot and dry conditions in the absence of rain after a day of heavy rain is preferred.

Horizontally elongated openings known as flight holes are constructed and opened around midday. If favorable conditions persist up to the late afternoon, massive nuptial flights consisting of hundreds or thousands alates are released by colonies. Flights are short in duration and last around 4-10 minutes. Flights may also occur as early as mid October and peaking in November, with shorter transient flights occurring from December to January.

References

• Media related to Macrotermes carbonarius at Wikimedia Commons
• Data related to Macrotermitinae at Wikispecies