ItalianTermiteMan
Arachnosquire
- Joined
- Jul 23, 2023
- Messages
- 146
While the vast majority of termites are no pest and just benefical actors for their habitats, some of course do cause quite a lot of headaches for us humans and today i'll talk about one of the worst: Cryptotermes brevis!
This small termite, just around 4/5 mm in the sterile castes and little more in the royals, belong to the family Kalotermitidae and is by far its most widespread member mainly thanks to two key factor: its secluded and cryptic lifestile and its extreme resistance to water deprivation. C. brevis form small colonies of up to around 1000 member (but usually less, though multiple colonies can live side by side in a single piece of wood) that reside exclusively inside the wood they inhabit, which can be something as small as a picture frame, and never leave it to forage outside or underground or build visible strucutes like shelter tubes; they do bore some small kickout holes (kept sealed most of the time) from which expel small quantities of their hexagonal pelletized frass but due to its very tiny size that's quite easily mistaken for sawdust or simply blown/scattered away. This make their presence extremely difficult to notice, in fact they are often spotted only during their swarming events many years after the founding and when the colony is already well developed, with some of the former swarmers likely already settled all around aswell. Even more importantly, they are also very well adapted to conditions of extreme drought and capable of living in fully dry wood on nothing more than metabolically produced water, even sporting three pairs of specialized rectal glands employed to squeeze every last bit of the precious liquid from their frass before excretion. It's hence easy to understand how these adaptable critters managed to exploit human wood commerce and seafaring, hitchhik rides inside lumber, boats and furniture to achieve a truly impressive global distribution: probably native to western parts of Chile and Perù they can now be found from the southern US to Hong Kong, from Australia to South Africa, without forgetting southern Europe (Italy included), a feat unattainable by other more moisture-dependent species of Cryptotermes. These critters are very damaging to human activities, but their status as an allochtonous species is quite peculiar as in non-native areas they are generally found only in anthropized environements, infesting man-made structures and never venturing out in wild habitats. In Italy C. brevis have been reported from the capital of Rome but also various other cities like Naples and Palermo and also in the region of Liguria, always restricted to human structures. In the US they're common in Hawaii, the coastal southeastern regions and Florida, where they cause severe damage.
Like every Kalotermitidae Cryptotermes brevis lacks a true caste of workers and reliy instead on pseudergates, sausage-shaped totipotent juvenile forms that act exactly like the workers proper but keep moulting throughout their lives and present an exceptional developmental plasticity: with a moult they will usually remain pseudergates, but if the situation calls for it they can differentiate into soldiers (passing through a presoldier stage in which they will already sport the soldier morphology but are still white and unsclerotized) or reproductives, both primaries and neotenics; the latters differentiate from pseudergates in a single moult, while primaries grows wing buds and becomes nymphs before maturity. The neotenics (which appears in number if the pseudergates are separated from the primary couple) are lightly sclerotized and pigmented (yet darker than the pseudergates themselves) and remain in the parent colony to assure its continuity by mating among them; the primaries are more sclerotized, have bigger eyes and sport two pair of membraneous wing that allow them to partecipate in a swarming event to found their own colonies, often near to their parents. I've read than unlike all other castes, which are very slow moving due to their small limbs, they are particularly fast runners. Even in a mature colony the queen exhibit only slight physogastry.
But the soldiers are the most interesting caste and a textbook example of phragmotic defence, the technique of blocking an intruder's way with you own body: they are equipped whit a short, truncated and extremely thickly-armored head that they use like a plug to block the narrow wood-bored tunnels that make up large parts of their nest structure and are just above the soldier's head own width. They antennae are also short to decrease their vulnerability to be grabbed. This defense it's not purely passive, for in the case of particularly insistent intruders these soldiers can still deliver powerful bites to anything in reach thanks to their stout, toothed mandibles. Another particularity is their low number: they make up only the 1-2% of the nest population. This means that a well matured, large colony (around 1000 individuals) sports an average of little more than a dozen soldiers! Still, since this species always live inside their own wood galleries in solid wood even so few soldiers are capable of defending their colonies well enough, for a single one of them planted in a narrow tunnel can effectively block off large number of would-be predators.
And now some pics, all of them shot by David Mora del Pozo and shared with permission:
Here we can see various castes of Cryptotermes brevis from a mature colony: the king and queen (light brown, note the light physogastry of the queen on the left), nymphs, many pseudergates and two soldiers with dark, truncated heads. They are no neotenics in this pic.
A group of C. brevis soldiers: those you see here might very well be the entire soldier complement of a mature colony!
A detail of the truncated, heavily sclerotized head of a C. brevis soldier seen from the front... an excellent portable door!
This small termite, just around 4/5 mm in the sterile castes and little more in the royals, belong to the family Kalotermitidae and is by far its most widespread member mainly thanks to two key factor: its secluded and cryptic lifestile and its extreme resistance to water deprivation. C. brevis form small colonies of up to around 1000 member (but usually less, though multiple colonies can live side by side in a single piece of wood) that reside exclusively inside the wood they inhabit, which can be something as small as a picture frame, and never leave it to forage outside or underground or build visible strucutes like shelter tubes; they do bore some small kickout holes (kept sealed most of the time) from which expel small quantities of their hexagonal pelletized frass but due to its very tiny size that's quite easily mistaken for sawdust or simply blown/scattered away. This make their presence extremely difficult to notice, in fact they are often spotted only during their swarming events many years after the founding and when the colony is already well developed, with some of the former swarmers likely already settled all around aswell. Even more importantly, they are also very well adapted to conditions of extreme drought and capable of living in fully dry wood on nothing more than metabolically produced water, even sporting three pairs of specialized rectal glands employed to squeeze every last bit of the precious liquid from their frass before excretion. It's hence easy to understand how these adaptable critters managed to exploit human wood commerce and seafaring, hitchhik rides inside lumber, boats and furniture to achieve a truly impressive global distribution: probably native to western parts of Chile and Perù they can now be found from the southern US to Hong Kong, from Australia to South Africa, without forgetting southern Europe (Italy included), a feat unattainable by other more moisture-dependent species of Cryptotermes. These critters are very damaging to human activities, but their status as an allochtonous species is quite peculiar as in non-native areas they are generally found only in anthropized environements, infesting man-made structures and never venturing out in wild habitats. In Italy C. brevis have been reported from the capital of Rome but also various other cities like Naples and Palermo and also in the region of Liguria, always restricted to human structures. In the US they're common in Hawaii, the coastal southeastern regions and Florida, where they cause severe damage.
Like every Kalotermitidae Cryptotermes brevis lacks a true caste of workers and reliy instead on pseudergates, sausage-shaped totipotent juvenile forms that act exactly like the workers proper but keep moulting throughout their lives and present an exceptional developmental plasticity: with a moult they will usually remain pseudergates, but if the situation calls for it they can differentiate into soldiers (passing through a presoldier stage in which they will already sport the soldier morphology but are still white and unsclerotized) or reproductives, both primaries and neotenics; the latters differentiate from pseudergates in a single moult, while primaries grows wing buds and becomes nymphs before maturity. The neotenics (which appears in number if the pseudergates are separated from the primary couple) are lightly sclerotized and pigmented (yet darker than the pseudergates themselves) and remain in the parent colony to assure its continuity by mating among them; the primaries are more sclerotized, have bigger eyes and sport two pair of membraneous wing that allow them to partecipate in a swarming event to found their own colonies, often near to their parents. I've read than unlike all other castes, which are very slow moving due to their small limbs, they are particularly fast runners. Even in a mature colony the queen exhibit only slight physogastry.
But the soldiers are the most interesting caste and a textbook example of phragmotic defence, the technique of blocking an intruder's way with you own body: they are equipped whit a short, truncated and extremely thickly-armored head that they use like a plug to block the narrow wood-bored tunnels that make up large parts of their nest structure and are just above the soldier's head own width. They antennae are also short to decrease their vulnerability to be grabbed. This defense it's not purely passive, for in the case of particularly insistent intruders these soldiers can still deliver powerful bites to anything in reach thanks to their stout, toothed mandibles. Another particularity is their low number: they make up only the 1-2% of the nest population. This means that a well matured, large colony (around 1000 individuals) sports an average of little more than a dozen soldiers! Still, since this species always live inside their own wood galleries in solid wood even so few soldiers are capable of defending their colonies well enough, for a single one of them planted in a narrow tunnel can effectively block off large number of would-be predators.
And now some pics, all of them shot by David Mora del Pozo and shared with permission:
Here we can see various castes of Cryptotermes brevis from a mature colony: the king and queen (light brown, note the light physogastry of the queen on the left), nymphs, many pseudergates and two soldiers with dark, truncated heads. They are no neotenics in this pic.
A group of C. brevis soldiers: those you see here might very well be the entire soldier complement of a mature colony!
A detail of the truncated, heavily sclerotized head of a C. brevis soldier seen from the front... an excellent portable door!
