Colobopsis explodens sp. n., model species for studies on “exploding ants” (Hymenoptera, Formicidae), with biological notes and first illustrations of males of the Colobopsis cylindrica group

Abstract

A taxonomic description of all castes of Colobopsis explodens Laciny & Zettel, sp. n. from Borneo, Thailand, and Malaysia is provided, which serves as a model species for biological studies on “exploding ants” in Southeast Asia. The new species is a member of the Colobopsis cylindrica (COCY) group and falls into a species complex that has been repeatedly summarized under the name Colobopsis saundersi (Emery, 1889) (formerly Camponotus saundersi). The COCY species group is known under its vernacular name “exploding ants” for a unique behaviour: during territorial combat, workers of some species sacrifice themselves by rupturing their gaster and releasing sticky and irritant contents of their hypertrophied mandibular gland reservoirs to kill or repel rivals. This study includes first illustrations and morphometric characterizations of males of the COCY group: Colobopsis explodens Laciny & Zettel, sp. n. and Colobopsis badia (Smith, 1857). Characters of male genitalia and external morphology are compared with other selected taxa of Camponotini. Preliminary notes on the biology of C. explodens Laciny & Zettel, sp. n. are provided. To fix the species identity of the closely related C. badia, a lectotype from Singapore is designated. The following taxonomic changes within the C. saundersi complex are proposed: Colobopsis solenobia (Menozzi, 1926), syn. n. and Colobopsis trieterica (Menozzi, 1926), syn. n. are synonymized with Colobopsis corallina Roger, 1863, a common endemic species of the Philippines. Colobopsis saginata Stitz, 1925, stat. n., hitherto a subspecies of C. badia, is raised to species level.

Population genomics revealed cryptic species within host-specific zombie-ant fungi (Ophiocordyceps unilateralis)

“…saundersi were previously classified in the genus Camponotus before a recent resurrection of the genus Colobopsis (Ward et al, 2016) and both are cryptic species with unclear taxonomy (Laciny et al, 2018). The genetic clusters found within described Ophiocordyceps species in our study could actually be associated to different ant species in agreement with the one ant-one fungus hypothesis.…”

The Evolution of Mass Cell Suicide in Bacterial Warfare

“…Left: A minor Colobopsis cylindricus (“exploding ant”) worker has ruptured her body to release a sticky yellow substance, killing both herself and her opponent, the larger worker of another ant species ( Camponotus sp. ) [6,55]. Middle: Honey bee ( Apis mellifera ) workers sting in defense of their colony, which often results in the worker’s death as the sting gets pulled out of her body [7].…”

Depression as a civilization-deformed adaptation and defence mechanism

“…Thanatosis can also be considered in the sense used by ethologists ie where people exposed to intolerable stress for example may "self-destruct" as was described above in the case of animal auto-detonation [9]. that an analogous mechanism operates for animals in which it operates as a defence-adaptive mechanism, simulating death to confuse a predator [8]. However, in some cases there is a lethal outcome resembling that devastating expression of Thanatosis in humans-namely suicide.…”

“…However, in some cases there is a lethal outcome resembling that devastating expression of Thanatosis in humans-namely suicide. An example of the auto-elimination mechanisms in animals which favour the community are" body explosions" in ants, who individually in defence of the colony secrete poisonous substances with great violence and in so doing-expire [8,9].…”