Pterotermes occidentis
This record describes Pterotermes occidentis (species). Recorded family: Kalotermitidae. Recorded order: Blattodea.
Identification and Appearance
See: Kalotermitidae Largest Kalotermid of its region. Alates posses large circular black eyes, the ocelli are white, prominent and raised, right above eye. Compared to other Kalotermids of the region, the pronotum is more or less flat and does not wrap around extensively on the sides, and with no corners. Orange in colour. Soldiers of Pterotermes occidentis can be easily distinguished from other Kalotermitidae by the clear V-shaped concave anterior margin of their massive pronotum and the presence of prominent wingbuds. The head is rounded, and flat dorsally, with the mandibles attached at an angle. Eye spots are prominent whereas they are usually not noticeable on most other termites of the region. Despite their intolerance to moisture individuals have been recorded to enthusiastically and readily drink free water (i.e water droplets). Although prolonged exposure to moisture inevitably results in colony death and eventual takeover by microbes. It is possible that this not only represents a behavioural adaptation to capitalize on water but an anti-microbial adaptation. The same behaviour and outcome has been observed in the Kalotermid Incisitermes minor , the western drywood termite. Castes Worker caste : Lack of true worker caste; pseudergates. Eyespots present but without wingpads. Nymphs : Differs from pseudergates by possession of wingbuds, molts into alates. Reproductive castes Imago: Derived from the nymphs Neotenic: Brachypterous, very pigmented (brownish in colour). Derived from the pseudergates. Soldier caste : May possess wingbuds. Derived from the pseudergate caste. Comprises around 2% of the colony population. Soldiers are likely only employed to plug exits to the outside world (i.e kickout holes or flight holes) and not predominantly used in intercolonial warfare. Interaction with other organisms Marginitermes hubbardi Colonies have been recorded in wood simultaneously infested with Marginitermes hubbardi . Paraneotermes simplicornis The two species attack palo verde trees but do not occupy the same part of a host, with P. simplicornis occupying near the roots and P. occidentis colonizing via the branches. Saguaro cacti occupied by P. occidentis is not occupied by P. simplicornis . Intraspecific Aggression is variable between colonies. Colony on colony encounters likely result in fusion with the possible deaths of some or all of the current reproductives. In this regard their behaviour is similar to other dampwood and drywood termites such as Cryptotermes and Zootermopsis .
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Blattodea (Cockroaches and Termites)
- Superfamily
- Blattoidea
- Family
- Kalotermitidae (Drywood and Dampwood Termites)
- Genus
- Pterotermes
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Habitat
This species has been noted for its extreme tolerance to desiccation and its intolerance to moisture. It is thus restricted to the Sonoran desert and other desert habitats due to heavier rainfall outside of the desert. Nests P. occidentis constructs extensive haphazard galleries and often uses galleries left by other termites and beetles. Typically the tunnels are no smaller than 3x5 mm. The galleries are irregular chambers, with a characteristically rough surface. Although the galleries remain mostly free of fecal pellets, abandoned chambers are used to store fecal pellets or store deceased members in outbreaks of microbial infection due to moisture. Like other drywood termites they construct “kick out holes” to expel unwanted fecal pellets. Semi-wet fecal pellets are used to seal up holes or exits to the outside world or used to wall off abandoned chambers.
Geographic Range
Southern Arizona and Western Texas. Also found in Baja California and Mexico; occupies the Sonoran desert.
Seasonal Activity
This species flies during the night from mid-July to August, during the rainy season of the Southwest.
Diet and Behavior
Diet: As typical with other Kalotermids, they practice single piece nesting. They can live their entire lives within their food without making contact with the ground. P. occidentis occupies a niche of colonizing extremely dessicated vegetation, dominating long after competing insects -including termites- have departed. Vegetation occupied by P. occidentis has often times been damaged extensively by other termites (Namely Heterotermes aureus , M. hubbardi and possibly Amitermes sp.) as well as beetle larvae ( Cerambycidae and Buprestidae ). In the case of the latter group, P. occidentis likely feeds off of the tightly packed sawdust of the larval galleries. Although colonization likely starts before these optimal dessicated conditions. Hosts This species has been recorded in the following plant species: And various records in dead and alive “Palo verde trees (Most likely Parkinsonia spp.)” and “Yucca”.
Life History
See: Termites: Lifecycle P. occidentalis has long been regarded as one of the most primitive drywood termites, especially behaviorally. As such mature colonies devote the majority of their resources to alate production. Alates disperse in somewhat localized intervals throughout their flight season and a single colony does not tolerate more than one reproductive pair. Egg production of established colonies declines during the fall and comes to a halt during winter, resumes during the spring, around April or May. As with other basal termites colonies remain flexible with alate production and mature colonies devote most of their resources towards alate production. Swarming Alates search for nesting sites separately, and do not seem to rely on pheromones nor do they engage in tandem running. Often flying from host to host. Once a suitable crevice or hole is discovered, it is inspected, resulting in settlement or continued searching. Wing removal occurs either by the act of inspecting a hole or are manually removed via bodily movements. P. occidentis has never been recorded to bore into wood but will dig into an already existing cavity. After around 12 - 72 hours of digging the holes are plugged with a gut contents. This plug which seems distinct from normal semi-wet frass has also been noted and employed the same way in other Kalotermids. Infestation likely occurs before optimal desiccation has been achieved. Founding Initial egg production and colony founding is tediously slow, even among desert drywood termites. Colonies number from zero to a dozen offspring during the first year.
Additional species information
Species notes from the sources
Etymology: Pterotermes occidentis Walker, 1853
About Cockroaches and Termites: the wider group
Order-level background for Blattodea, the group containing Pterotermes occidentis. Species-specific details appear above.
Group overview
Blattodea includes ~4,600 cockroach species and ~3,000 termite species. Only about 30 cockroach species are associated with human habitats - less than 1% of all species.
Ecological role of the group
Termites contribute ~40% of soil arthropod biomass globally, far exceeding ants at ~10%. Cockroaches are ancient insects dating back 320 million years and are critical decomposers in tropical forest ecosystems, recycling leaf litter and dead wood.
Economic and practical significance of the group
Termites cause $5-30 billion in damage to structures in the U.S. annually. They damage approximately 600,000 American homes each year, with average repair costs of $3,000-$17,000. A subterranean termite colony can consume one pound of wood per day.
Recorded sources for this group: USDA, Orkin, Today's Homeowner, PNAS soil biomass study. Imported estimates may describe particular regions or reporting periods.
Frequently Asked Questions About Pterotermes occidentis
What is Pterotermes occidentis?
Pterotermes occidentis is a species in the family Kalotermitidae, within the order Blattodea.
How do you identify Pterotermes occidentis?
See: Kalotermitidae Largest Kalotermid of its region. Alates posses large circular black eyes, the ocelli are white, prominent and raised, right above eye. Compared to other Kalotermids of the region, the pronotum is more or less flat and does not wrap around extensively on the sides, and with no corners. Orange in colour. Soldiers of Pterotermes occidentis can be easily distinguished from other Kalotermitidae by the clear V-shaped concave anterior margin of their massive pronotum and the presence of prominent wingbuds. The head is rounded, and flat dorsally, with the mandibles attached at an angle. Eye spots are prominent whereas they are usually not noticeable on most other termites of the region.
Where is Pterotermes occidentis found?
| Feature | Details |
|---|---|
| Habitat | This species has been noted for its extreme tolerance to desiccation and its intolerance to moisture. It is thus restricted to the Sonoran desert and other desert habitats due to heavier rainfall outside of the desert. Nests P. occidentis constructs extensive haphazard galleries and often uses galleries left by other termites and beetles. Typically the tunnels are no smaller than 3x5 mm. The galleries are irregular chambers, with a characteristically rough surface. Although the galleries remain mostly free of fecal pellets, abandoned chambers are used to store fecal pellets or store deceased members in outbreaks of microbial infection due to moisture. Like other drywood termites they construct kick out holes to expel unwanted fecal pellets. Semi-wet fecal pellets are used to seal up holes or exits to the outside world or used to wall off abandoned chambers. |
| Range | Southern Arizona and Western Texas. Also found in Baja California and Mexico; occupies the Sonoran desert. |
What does Pterotermes occidentis eat?
The diet of the Pterotermes occidentis includes As typical with other Kalotermids, they practice single piece nesting. They can live their entire lives within their food without making contact with the ground. P. occidentis occupies a niche of colonizing extremely dessicated vegetation, dominating long after competing insects -including termites- have departed. Vegetation occupied by P. occidentis has often times been damaged extensively by other termites (Namely Heterotermes aureus , M. hubbardi and possibly Amitermes sp.) as well as beetle larvae ( Cerambycidae and Buprestidae ). In the case of the latter group, P. occidentis likely feeds off of the tightly packed sawdust of the larval galleries. Although colonization likely starts before these optimal dessicated conditions. Hosts This species has been recorded in the following plant species: And various records in dead and alive Palo verde trees (Most likely Parkinsonia spp.) and Yucca..
When is Pterotermes occidentis active?
Pterotermes occidentis: seasonal activity - This species flies during the night from mid-July to August, during the rainy season of the Southwest..
What is the life cycle of a Pterotermes occidentis?
See: Termites: Lifecycle P. occidentalis has long been regarded as one of the most primitive drywood termites, especially behaviorally. As such mature colonies devote the majority of their resources to alate production. Alates disperse in somewhat localized intervals throughout their flight season and a single colony does not tolerate more than one reproductive pair. Egg production of established colonies declines during the fall and comes to a halt during winter, resumes during the spring, around April or May. As with other basal termites colonies remain flexible with alate production and mature colonies devote most of their resources towards alate production. Swarming Alates search for nesting sites separately, and do not seem to rely on pheromones nor do they engage in tandem running. Often flying from host to host. Once a suitable crevice or hole is discovered, it is inspected, resulting in settlement or continued searching. Wing removal occurs either by the act of inspecting a hole or are manually removed via bodily movements. P. occidentis has never been recorded to bore into wood but will dig into an already existing cavity. After around 12 - 72 hours of digging the holes are plugged with a gut contents. This plug which seems distinct from normal semi-wet frass has also been noted and employed the same way in other Kalotermids. Infestation likely occurs before optimal desiccation has been achieved. Founding Initial egg production and colony founding is tediously slow, even among desert drywood termites. Colonies number from zero to a dozen offspring during the first year.