Fontanellar gun
The fontanellar gun is a termite defense mechanism in the form of a horn-like frontal projection (nasus) on the head of the soldier caste which is capable of expelling chemical weaponry at a distance, a trait exclusive to the subfamily Nasutitermitinae. It is primarily used to ward off predators such as ants.[1][2][3]
Physiology and usage
The "gun" is a gland with a duct on the front of the head. It operates by a chemical reaction triggered when the termite contracts its mandibular muscles. The termite is "able to eject the frontal gland material over a distance of many centimeters".[4] The gland material is forced out through the front of the internal nose and its pores, which covers much of the termite's head. Termites have been shown to be extremely accurate with the gun, even though they are blind. The exact nature of how termites retain such accuracy and are able to orient themselves toward their enemy is currently unknown, but it is believed that the ability is "olfactory or auditory" in nature.[4]
The fired material is glue-like and sticks to objects that it hits, causing the legs of an attacking enemy to become stuck to the ground. Most often, though, a number of termite soldiers will fire upon the enemy and the combined force of the "bullets" will kill the enemy along with covering it in the glue-like substance. It has also been observed that, for those that survive the force of the material, it also causes varying negative effects, likely because of the
Chemical composition
The secretion from
In other termites
The Syntermitinae, which were once classified within the Nasutitermitinae in a clade known as the mandibulate nasute termites, are now recognized to be a distinct and not closely related lineage which convergently evolved a nasus that is superficially analogous but not functionally homologous to the nasus of true nasute termites. Unlike true nasutes, all Syntermitinae exhibit soldiers with highly developed mandibles which are physiologically incapable of expelling their frontal gland secretions from the nasus. No other known termite has a frontal apparatus as functionally and morphologically similar to the Nasutitermitinae as the Syntermitinae.
References
- S2CID 40048208.
- PMID 20223240.
- PMID 10902684.
- ^ ISBN 9780674000896. Retrieved July 22, 2011.
- ^ .