Voluntary Self-Sacrifice Tendencies In Exploding Ants Found In KBFSC

Scientists were long intrigued by the extraordinary behaviour of “exploding ants” of the Camponotus(Colobopsis) cylindricus (COCY). In territorial combat with enemy ants or other arthropods, these remarkable insects sacrifice themselves by exploding sticky and irritant contents of their enlarged mandibular glands in order to kill rivals.


This extraordinary group of ants is found in the tropical rainforests of Southeast Asia, including the lowland dipterocarp rain forest at the Kuala Belalong Field Studies Centre (KBFSC). Dr Kamariah Abu Salim from UBD’s Faculty of Science worked with an interdisciplinary research team from Vienna, Austria, to reveal evolutionary advantages of autothysis of exploding ants.


In November 2015, two members of the team – Alexey Kopchinskiy (Technical University Vienna) and Alice Laciny (Natural History Museum Vienna) – visited KBFSC for several weeks to observe COCY ants in their natural habitat. While they inspected previously known colonies, they also worked with live animals to study the ants’ defensive and feeding behaviours in experimental settings, which are expected to be greatly valuable for acquiring a better understanding of these fascinating animals.


Voluntary self-sacrifice (autothysis) is very rare in nature, undoubtedly due to attendant fitness losses. It is known in eusocial insects such as termites and honeybees, whose effective deployment in defence of nest and colony may leave self-sacrificing workers with indirect fitness.


Unlike other insects with this defensive mechanism, COCY most often commit autothysis (self-destruction) far from the nest and queen to protect the foraging territory rather than the colony itself. Additionally, it is known that the ants collect microbes (that are found on leaf surfaces - phylloplane) into pellets that are digested in the buccal chamber of the head. Together, these observations suggest that autothysis possibly evolved to prevent territorial intruders from contaminating the foraging grounds with their "unwelcomed" microorganisms.


COCY ants have long intrigued chemists, microbiologists and entomologists, who hope to answer numerous questions about their biology and evolution. Analytic chemistry will determine the ingredients of mandibular gland secretions used in suicidal fighting, chemical analysis and morphometry are combined to reveal phylogenetic relationships among members of the clade and microbiological methods are applied to study microbiomes associated with COCY, such as fungal spores found in the ants’ foraging territories and within their buccal pellets.


This study expanded from Professor Dinah Davidson’s studies at the University of Utah, USA, who worked at KBFSC for many years, beginning in 2002, and who discovered most of the relevant species – many of them probably endemic to Brunei - right at the Centre’s doorstep, along the Ashton and Engkiang Trails. The interdisciplinary approach and the focus on the actual exploding and feeding behaviour make this study the first of its kind.

KBFSC in Ulu Temburong National Park  is located in one of the three hotspots of endemic plants in Brunei Darussalam. Recent surveys found over 300 species of butterflies and moths, over 200 bird species, more than 60 species of amphibians among other animal species in Kuala Belalong. Due to this, KBFSC has attracted researchers from all over the world to visit the research centre and collaborate with UBD scientists on a variety of studies ranging from climate change, forest management, soundscapes and energy studies.

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