Other Common Names
White Ants
(1) (though they are unrelated to ants)
Synonyms and other taxonomic changes
=Isoptera
used to be treated as a separate order Isoptera
Explanation of Names
Termite: from New Latin
termes (genitive
termit-), from Classical Latin
tarmes 'a wood-worm', prob. derived from
terere 'to rub'
(1)
Identification
Termite alates (‘swarmers’) are often confused with ants, webspinners, certain rove beetles and occasionally earwigs.
Alates possess a well developed distinct pronotum, two pairs of (more or less) equal sized wings, which detach along a suture. This leaves behind two pairs of ‘wing scales’. The wings are an elongated and extend significantly in length, oten times being equal to twice as long as the termite.
See also:
Keys
Range
Our area; diversity increases towards the southern latitudes, with Termitidae predominantly making up the diversity in the Southwest while Kalotermitidae and Rhinotermitidae in the Southeast. Termites have been recorded in every state except Alaska.
In Canada termites are found in British Columbia, Southern Alberta, Winnipeg Manitoba and Southern Ontario.
Worldwide; diversity increases towards the equator and maximum diversity is equatorial (half of that diversity falls between 18°N and 30°S)
(5)
The official record of the northernmost and southernmost latitude termites are 54°N and 48°S. These records are held by
Zootermopsis angusticollis and
Porotermes quadricollis respectively.
(6)(7)(8)Habitat
All termites live in colonies. Colony size and nest size may vary. Termites can be classified into three different nesting types: single-piece nesting (Group I), intermediate nesters (Group II) and separate piece nesters (Group III)
Single piece nesting involves individuals who nest within their food (wood) and otherwise do not leave said wood.
Intermediate nesters nest within their food (wood) but also forage to seek more food to nest in.
Separate piece nesters do not nest within their food and must leave their nest and forage to find it.
Archotermopsidae Group I nesting. These termites are behaviorally primitive, and are typically found in decaying dead damp wood. The majority of species occupy the temperate humid coniferous forests, often in montane environments (i.e the mountains of Vietnam, northern India, Japan and western North America).
Kalotermitidae Primarily Group I nesting. The majority of species in this family are found sound dead dry or damp wood or live wood, such as human structures, fallen logs, heartwood and dead branches. Members are the most specialized at single piece nesting, often specializing in certain plant species or environments, leaving very little evidence of their existence. Accumulated frass/fecal pellets are packed into unused chambers and/or is expelled via ‘kickout’ holes, which is typically how infestations are identified.
Rhinotermitidae Primarily Group II and Group III nesting. In North America, species typically construct diffuse subterranean networks in which they forage in and use to access food sources. Additional constructions may include carton nests/combs and ‘mud tube’ like structures over exposed surfaces, which are used to forage above ground to reach food sources not directly in contact with the soil, while protecting against predators and unfavourable conditions.
Termitidae Primarily Group III nesting. Their diversity drastically increases towards the tropics. Unparalleled in diversity, these species have just as varied diets and behaviour. They are responsible for the amazing termite mounds and other structures seen in other parts of the world.
In North America, the native species (primarily the Termitinae, distributed mostly to the deserts and grasslands of the Southwest and Texas) are best known for encrusting vegetation to feed on (Gnathamitermes). They are subterranean in nature and rarely encountered by humans nor do they pose much economic concern. Little is known of their biology.
Season
In North America, termites are most active in times corresponding to rain and warmth. Triggering of swarming and swarming behaviour is quite variable, even down to the population level. However, typically they correspond with rising temperatures, rain, a combination or non.
Food
Termites feed off of organic material, primarily containing cellulose. Termites are split between the so called “lower termites” and “higher termites” aka Termitidae.
Termitidae have lost the protozoans (flagellates) associated with termites. Instead they posses a highly compartmentalized gut and additionally a highly diverse gut fauna composed of bacteria and archaea. Although termites may have arisen around 150MYA, Termitidae are relatively recent, arising around ~50MYA.
(5) It is thought that the loss of the symbiotic flagellates allowed them to exploit new niches leading to adaptive radiation. Consequently Termitidae are known to feed on lichen, soil, humus, leaf litter, grass, live plants, roots, and wood. Some are even inquillines feeding off of the nest material of other termites and others opportunistically scavenge carrion. The subfamily Macrotermitinae has evolved to cultivate fungus, similar to
fungus growing ants.
Lower termites include the remaining subfamilies, all of these possess symbiotic flagellates, which in turn possess symbiotic bacteria. With the exception of the harvester termites (Hodotermitidae) all other families within predominantly feed on wood and woody materials (i.e tree roots).
Life Cycle
All termites are
eusocial. Unlike other eusocial groups (e.g.
ants,
Apidae,
Vespidae) termites do not have
haplodiploid genetics, and both males and females are required to found a colony.* Likewise, the non reproductive castes consist of both male and female individuals, with some species having a bias towards either sex or sex specific castes. In contrast to ants which undergo complete metamorphosis, termites undergo
simple metamorphosis. As a result, while all ant castes are terminal (do not molt further, adults), some termite castes constitute immature individuals who are capable of further molting into another caste. Regardless, termite castes can generally be characterized as into three categories: reproductives, soldiers and workers.
Reproductives
Termites have a variety of reproductive forms but they can mainly be separated into two groups: primary and secondary reproductives (also known as neotenics). Most if not all species possess a primary reproductive caste, referred to as an alate (or imago). These are the sclerotized, winged, dispersing individuals that found new colonies. Unlike the other castes they are not
neotenous, retaining various features typically not seen in the other castes such as compound eyes, ocelli, wings, etc.
Neotenics and their subtypes are extremely diverse in termites, but they can be grouped into three groups:
apterous neotenics/ergatoids - descended from the pseudergate ("worker") caste
brachypterous/nymphoid neotenic - descended from the nymphal line (would be queens and kings)
adultoid neotenic - equal in development to the alates (swarmers), largely identical, but may be underdeveloped in certain aspecis (i.e lacking pigment or stunted wings.)
All three types of reproductives are found in lower and higher termites. But lower termites typically produce the first two, higher termites typically produce none or one of the latter two.
Soldiers
Soldiers are perhaps the most ubiquitous and distinct termite caste, emerging early on in their evolution and are found in the majority of species. Only to be lost recently in certain higher termites (Mainly the Apicotermitinae although three Australian Termitinae genera have also lost them). Soldiers possess highly modified anatomy and morphology (particularly to the head) adapted for colony defense. Typically characterized by their well developed mandibles and a sclerotized pigmented head. Many termites (particularly the Neoisoptera) have also evolved a variety of chemical defenses employing a number of glands. Soldiers cannot feed themselves and usually do little else other than responding to threats, although in certain species they may be important for colony immune function. Certain species have multiple soldier castes.
Workers
Most termites possess something akin to a worker caste; the wingless, non reproducing, non soldiers which comprise most of the colony and do most of the work in maintaining it. Workers are typically classified into two categories: pseudergates ("false workers") and true workers. Pseudergates are essentially juveniles and retain developmental plasticity and may or may not do work to varying degrees, while true workers are a sterile terminal specialized caste in carrying out colony labour.
Elaboration on termite workers
While genera typically possess one or the other, the relationship between pseudergates, true workers and a "worker caste" complicated and limited by terminology. Since termites undergo simple metamorphosis, various instars can specialize in different tasks to the point where they can be considered a distinct caste in terms of function, in addition to polyethism within any defined caste. Hence, the degree of specialization in colony labour done by pseudergates varies significantly from limited/no specialization and/or limited/no labour in certain species to highly specialized in others. Likewise, termites with true workers or pseudergates might not share a common ancestor, with lineages possibly gaining and losing them.
The peculiarity of the termite worker caste arises from how early the irreversible split is between the nymphal line (future reproductives) and sterile apterous (=wingless) line (future soldiers and/or true workers) occurs during development. In the more "primitive" termites which are confined within their food such as Kalotermitidae, Archotermopsidae and Stolotermitidae, such split occurs very late and there is limited distinction -both in terms of morphology and division of labour- between pseudergates and nymphs. Development as a result is mainly linear with progressive, stationary and regressive molts between egg → larvae → pseudergate ↔ pseudergate ↔ nymph → alate. Certain individuals will molt into soldiers or neotenics along certain points during this development, usually from late pseudergate instars and early nymphal instars, but the majority will molt into alates and disperse to found new colonies; a necessity as the food they nest in is gradually depleted.
In contrast, the Termitidae and Hodotermitidae for example, have only true workers and low developmental plasticity, development is bifurcated, the developmental pathway branches early on into two branches between individuals who can become alates and those which can become soldiers and workers. Although in certain Termitidae, workers retain the ability to molt into apterous neotenics. Various intermediate developmental pathways can be found in termites however, notably the Rhinotermitidae; for example in Psammotermes the developmental pathway is similar to the aforementioned primitive termites, being largely linear and lacking true workers, but with distinct division of labour among certain instars. In others the bifurcation occurs early but the terminal castes are soldiers such as in Coptotermes, with late instars specializing as workers. In Rhinotermitinae, the developmental pathway is very similar to Termitidae, with low developmental plasticity and true workers. In Reticulitermes, there is evidence that both "pseudergates" and true workers are present in a colony in addition to regressive molting by nymphs.
*A few species are capable of
parthenogenesis, with a minority capable of establishing entire colonies asexually.
