Coptotermes

Coptotermes Wasmann (Isoptera: Rhinotermitidae) is one of the most economically important subterranean termite genera and some species are successful invaders. However, despite its important pest status, the taxonomic validity of many named Coptotermes species remains unclear. In this study, we reviewed

The efficacy of bistrifluron, a chitin synthesis inhibitor, in cellulose bait pellets was evaluated on the mound-building subterranean termite, Coptotermes acinaciformis (Froggatt). Three concentrations of the bistrifluron were used: 0 (untreated control), 0.5, and 1.0% over an 8 wk period. Both doses of bistrifluron bait eliminated (viz. termites absent from nest or mound) termite colonies: 83% of colonies (10 of 12) were either eliminated or moribund (viz. colony had no reproductive capacity and decreased workforce) after 8 wk, compared with none of the control colonies. The remaining two treated colonies were deemed to be in decline. Early signs that bistrifluron was affecting the colonies included: 3 wk after baiting mound temperatures showed a loss of metabolic heat, 4 wk after baiting foraging activity in feeding stations was reduced or absent, and dissection of two mounds at 4 wk showed they were moribund. Colony elimination was achieved in around half or less the time, and with less bait toxicant, than other bait products tested under similar conditions in the field, because of either the active ingredient, the high surface area of the pellets, or a combination of both. This suggests the sometimes long times reported for control using baits may be reduced significantly. The use of a mound building species demonstrated clearly colony level effects before and after termites stopped foraging in bait stations.

Termites are typically marked by forcing them to eat fat-soluble stains in paper – a procedure that generally requires a week. A new and faster method that forces termites to drink a water solution of the same fat-soluble stains is described and tested. Coptotermes acinaciformis and C. lacteus (Rhinotermitidae) were ‘fast’ marked within 24 h with ~95% success and survivorship; this level was maintained for a week post-marking. This was significantly better than typical ‘slow’ marking, which had ~90% success and survivorship after the week-long marking period, a level which declined to ~70% after one week. More importantly, the ‘fast’ method reduced termite laboratory and handling time, which may be the cause of delayed mortality. As there were no apparent advantages of the ‘slow’ marking method over the ‘fast’ method, a switch to this new method is advocated.

Termites are difficult to detect reliably and many detection methods are destructive to property or disturbing to the termites (which may interfere with remedial treatment). The reliability of Termatrac™ a new device designed to detect termites in a nondestructive and non-disturbing manner, based on novel microwave technology, was tested in the field by assessing termite presence as indicated by the device in119 aggregation stations. There were 90% correct assessments: 56.5%of aggregation stations were correctly assessed as having termites and33.5% were correctly assessed as not having termites. The incorrect assessments were: 1.5% assessed as having termites when there were none (due to the presence of other insects) and 8.5% as not having termites when they were present (due to high moisture levels in aggregation stations, i.e. absorption of the microwaves). Ants could be distinguished from termites as they produced significantly different signals (as displayed on the LCD screen) from termites. With appropriate training and experience in interpreting termite (vs. other insect)signals, Termatrac™ should increase termite detection with decreased effort and disturbance in many situations.

The movement of foragers of two species of Australian, subterranean, mound building termites, Coptotermes lacteus (Froggatt) (Rhinotermitidae) and Nasutitermes exitiosus (Hill) (Termitidae), was investigated in their natural habitat using artificial feeding sites along trenches dug to mimic natural forager tunnels that radiate out from the central mound-nests. Termites were dyed by self-feeding on cardboard soaked with histological fat-stains on one or two trenches and then termites were collected from other feeding sites at two and four weeks after the fat-stains were placed. At two and four weeks after marking commenced, 60–75% of marked termites were found in trenches containing the marked paper, and 2–16% were found in trenches on the opposite side of the nest. The proportion of marked termites in a sample was three to eight times greater in the trenches containing the marked paper relative to other trenches. Although difficulties with fat-stains used as markers might explain some of the observed patterns, it is evident that C. lacteus and N. exitiosus foragers do not move randomly between feeding sites in their natural habitat.

"Forager population sizes of colonies of Coptotermes lacteus (Froggatt) in New South Wales were estimated using two methods: mark–recapture and constant removal, in two disturbed habitats: a pine plantation and cleared farmland. Mark–recapture population estimates were unrealistic and unreliable: they could be improbably large, over 200 million foragers, and they varied enormously between samples for each colony without any pattern. The constant removal population estimates could also be unrealistic: they could be negative or quite different when calculated using regression and maximum likelihood methods. However, the unrealistic results could be predicted reliably, and explained by the lack of re-contact with the sampling devices (bait stations) – a violation of an assumption of the method. This happened more frequently in the plantation than in the farmland, probably because of the greater abundance of alternative food sources in the plantation. Of the two methods, constant removal provided reasonable forager population estimates, relative to direct counts, at least some of
the time, plus a mechanism by which reliability could be tested, whereas mark–recapture provided neither. Further refinement and testing of constant removal methods are urged to provide a more reliable population estimation technique for termites."

Although mark-recapture protocols produce inaccurate population estimates of termite colonies, they might be employed to estimate a relative change in colony size. This possibility was tested using two Australian, mound-building, wood-eating, subterranean Coptotermes species. Three different toxicants delivered in baits were used to decrease (but not eliminate) colony size, and a single mark-recapture protocol was used to estimate pre- and post-baiting population sizes. For both species, the numbers of termites retrieved from bait stations varied widely, resulting in no significant differences in the numbers of termites sampled between treatments in either the pre- or post-baiting protocols. There were significantly fewer termites sampled in all treatments, controls included, in the postbaiting protocol compared with the pre-, suggesting a seasonal change in forager numbers. The comparison of population estimates shows a large decrease in toxicant treated colonies compared with little change in control colonies, which suggests that estimating the relative decline in population size using mark-recapture protocols might to be possible. However, the change in population estimate was due entirely to the significantly lower recapture rate in the control colonies relative to the toxicant treated colonies, as numbers of unmarked termites did not change between treatments. The population estimates should be treated with caution because low recapture rates produce dubious population estimates and, in some cases, post-baiting mark-recapture population estimates could be much greater than those at pre-baiting, despite consumption of bait in sufficient quantities to cause population decline. A possible interaction between fat-stain markers and toxicants should be investigated if mark-recapture population estimates are used. Alternative methods of population change are advised, along with other indirect measures.

The efficacy of baiting as a pest control method relies on the bait appealing to the pest species. In the case of wood-eating termites, bait stations should be designed to encourage termite presence and to maximize their consumption of bait matrix in order to expedite control in minimal time. A field experiment examined the effect of bait size (one large bait or four small baits of equivalent total size, with commensurate inspection and replacement schedules), compaction (tightly rolled or loosely folded) and composition (paper only or paper plus wood) on termite presence and on untreated bait paper removal rates over four months. All three factors were significant, with bait size the most important factor, followed by compaction and then composition. The least effective baits were small, compacted (rolled) paper-only baits with monthly inspections; these had the highest abandonment rate (70%) and had the least paper removed (mean of 24 g). The most effective baits were large, folded paper-plus-wood baits with inspections at two months; these had the lowest abandonment rate (20%) and had the highest paper removal (mean of 112 g). The more than four-fold difference between these baits types demonstrates that bait efficacy can be altered considerably merely by changing bait design without adding new ingredients to the bait matrix.

The termite genus Coptotermes (Rhinotermitidae) is found in Asia, Africa, Central/South America and Australia, with greatest diversity in Asia. Some Coptotermes species are amongst the world's most damaging invasive termites, but the genus is also significant for containing the most sophisticated mound-building termites outside the family Termitidae. These mound-building Coptotermes occur only in Australia. Despite its economic and evolutionary significance, the biogeographic history of the genus has not been well investigated, nor has the evolution of the Australian mound-building species. We present here the first phylogeny of the Australian Coptotermes to include representatives from all described species. We combined our new data with previously generated data to estimate the first phylogeny to include representatives from all continents where the genus is found. We also present the first estimation of divergence dates during the evolution of the genus. We found the Australian Coptotermes to be monophyletic and most closely related to the Asian Coptotermes, with considerable genetic diversity in some Australian taxa possibly representing undescribed species. The Australian mound-building species did not form a monophyletic clade. Our ancestral state reconstruction analysis indicated that the ancestral Australian Coptotermes was likely to have been a tree nester, and that mound-building behaviour has arisen multiple times. The Australian Coptotermes were found to have diversified $13 million years ago, which plausibly matches with the narrowing of the Arafura Sea allowing Asian taxa to cross into Australia. The first diverging Coptotermes group was found to be African, casting doubt on the previously raised hypothesis that the genus has an Asian origin.

Coptotermes Wasmann (Isoptera: Rhinotermitidae) is one of the most economically important subterranean termite genera and some species are successful invaders. However, despite its important pest status, the taxonomic validity of many named Coptotermes species remains unclear. In this study, we reviewed all named species within the genus and investigated evidence supporting the validity of each named species. Species were systematically scrutinized according to the region of their original description: Southeast Asia, India, China, Africa, the Neotropics, and Australia. We estimate that of the currently 69 named species described by accepted nomenclatural rules, only 21 taxa have solid evidence for validity, 44 names have uncertain status, and the remaining species names should be synonymized or were made unavailable. Species with high degrees of invasiveness may be known under additional junior synonyms due to independent parochial descriptions. Molecular data for a vast majority of species are scarce and significant effort is needed to complete the taxonomic and  phylogenetic revision.
of the genus. Because of the wide distribution of Coptotermes,
we advocate for an integrative taxonomic effort to establish the
distribution of each putative species, provide specimens and
corresponding molecular data, check original descriptions and
type specimens (if available), and provide evidence for a more
robust phylogenetic position of each species. This study embodies
both consensus and contention of those studying Coptotermes
and thus pinpoints the current uncertainty of many species.
This project is intended to be a roadmap for identifying those
Coptotermes species names that need to be more thoroughly
investigated, as an incentive to complete a necessary revision
process.

The termite genus Coptotermes (Rhinotermitidae) is found in Asia, Africa, Central/South America and Australia, with greatest diversity in Asia. Some Coptotermes species are amongst the world’s most damaging invasive termites, but the genus is also significant for containing the most sophisticated mound-building termites outside the family Termitidae. These mound-building Coptotermes occur only in Australia. Despite its economic and evolutionary significance, the biogeographic history of the genus has not been well investigated, nor has the evolution of the Australian mound-building species. We present here first phylogeny of the Australian Coptotermes to include representatives from all described species. We combined our new data with previously generated data to estimate the first phylogeny to include representatives from all continents where the genus is found.We also present the first estimation of divergence dates during the evolution of genus. We found the Australian Coptotermes to be monophyletic and most closely related to the Asian Coptotermes, with considerable genetic diversity in some Australian taxa possibly representing undescribed species. The Australian mound-building species did not form a monophyletic clade. Our ancestral state reconstruction analysis indicated that ancestral Australian Coptotermes was likely to have been a tree nester, and that mound-building behaviour has arisen multiple times. The Australian Coptotermes were found to have diversified 13 million years ago, which plausibly matches with the narrowing of the Arafura Sea allowing Asian taxa to cross into Australia. The first diverging Coptotermes group was found to be African, casting doubt on the previously raised hypothesis that the genus has an Asian origin.

The effects of starvation on mortality, cannibalism, caste-specific cannibalism, and body weight loss were investigated in laboratory groups of the Formosan subterranean termite, Coptotermes formosanus Shiraki. Groups of50 termites (80% workers and 20% soldiers) were tested under starvation or with access to a filter paper food source. At the end of a 40-d test, starved and fed groups showed a mortality of 90.5% and 23.2%, respectively. The cannibalism rate was about 62.0% when starved and 23.0% when food was provided. Starved groups lost about 7.7% of body weight and fed groups lost 2.3%. Termite mortality was mainly a result of starvation-induced cannibalism during the first 30 d, but some termites died solely from starvation after 30 d. Caste-specific cannibalism was observed between 1 to 20 d when starvingworkers preferred to eat more soldiers (36.0%) than workers (16.0%), and resulted in a solider/worker ratio of 3.0% at 40 d. Our data indicate a refined surviving starvation strategy in this termite species. Under starvation conditions, workers may first rely on their own metabolic stores in addition to occasional non-caste-specific cannibalism. If the starvation continues, workers begin to eat more soldiers to mitigate the trophic burden soldiers place on them. Such practice stops when the soldier/worker ratio declines to some point to maintain a proportional caste composition. Our tests on necrophagy and entombment indicate that starving workers not only cannibalized live nestmates but also termite carcasses. Workers with or without food had a similar propensity to burying carcasses.

In 2009 an outbreak of the termite Coptotermes gestroi caused major damage to buildings and vegetation in Fiji. Termite control is most commonly performed using synthetic insecticides, although many botanically-derived toxins are also being evaluated. The woody legume, Abrus precatorius, contains the toxic protein abrin, and has been investigated previously for insecticidal properties. The current study used laboratory experiments to evaluate extracts of A. precatorius as potential control agents for C. gestroi. In Petri dish assays, exposure to water- and methanol-based extracts of leaf and seed material significantly increased mortality and shortened time to death of C. gestroi. The results suggest that extracts of A. precatorius have potential for use as control agents of C. gestroi and should be evaluated further to determine their mode of action and efficacy under field conditions.

The efficacy of baiting as a pest control method relies on the bait appealing to the pest species. In the case of wood-eating termites, bait stations should be designed to encourage termite presence and to maximize their consumption of bait matrix in order to expedite control in minimal time. A field experiment examined the effect of bait size (one large bait or four small baits of equivalent total size, with commensurate inspection and replacement schedules), compaction (tightly rolled or loosely folded) and composition (paper only or paper plus wood) on termite presence and on untreated bait paper removal rates over four months. All three factors were significant, with bait size the most important factor, followed by compaction and then composition. The least effective baits were small, compacted (rolled) paper-only baits with monthly inspections; these had the highest abandonment rate (70%) and had the least paper removed (mean of 24 g). The most effective baits were large, folde...

Integrative taxonomy, including molecular, morphological, distributional and biological data, is applied in a review of the taxonomy of the Australian species of the pest termite genus Coptotermes. The validity of the previously described species is discussed, and two new species, Coptotermes nanus, sp. nov. and Coptotermes cooloola, sp. nov., are described from the Kimberley region of Western Australia and southeast Queensland respectively. Their delimitation is based on morphological and distributional data, and the results of generalised mixed Yule-coalescent analysis of mitochondrial DNA sequence data. Images of the external view of the two new species are provided, as well as a key, based on soldier characters, for all Australian species of Coptotermes.

Task-switching between foraging and building in workers of Nasutitermes exitiosus (Termitidae), a subterranean termite, was followed using mark-recapture. Foragers were collected from wood-filled drums and marked with Nile blue (ca. 12,500 per colony), whereas builders were collected from damaged sections of mounds and marked with Neutral red (ca. 18,500 per colony). Two protocols were followed: the first marked foragers and then damaged the mound; the second reversed this order. In the first protocol few foragers switched to building, i.e. blue-marked workers in mound samples, measured either as numbers (81 ± 28) or proportion of originally marked (0.66 ± 0.20 %); whereas more than double blue-marked foragers remained foraging (222 ± 64 workers or 1.76 ± 0.44 %). In the second protocol few builders had switched to foraging, i.e. red-marked workers found in the first drum sample (82 ± 33 workers or 0.29 ± 0.09 %). Up to eight drums were sampled for foragers over about 80 days; the numbers of blue-marked workers decreased slowly (ca. 1.6 workers per day) whereas those of red-marked workers increased slowly (ca. 2.4 workers per day). These results suggest that relatively few termite workers switch directly between foraging and building. The possibility of builders being recruited from other tasks is discussed.

The exploration of sand-filled arenas by workers of an entire colony of the Australian, subterranean foraging, tree-nesting termite, Coptotermes frenchi Hill was investigated under laboratory conditions. The first experiment tested whether termite exploration of sand was influenced by the presence of gaps or objects in the sand. Gaps and objects were chosen to represent soil heterogeneity in the urban environment: gaps to represent tunnels dug by other animals, perspex strips to represent cables and pipes, and wood strips to represent roots. Termites always chose to explore gaps thoroughly before they began tunnelling in the sand. Significantly more and longer tunnels were excavated from the end of gaps at the far end of the arenas, and relatively little tunnelling occurred around and along objects. Termite density was significantly greater around and along wood compared with perspex blocks. The second experiment tested whether termite exploratory tunnelling was influenced by soil moisture. The termites tunnelled slowly in dry sand, but after discovering a patch of wet sand, increased tunnelling five-fold until it was completely explored, after which activity declined. Energy and water conservation may be behind these patterns of exploratory tunnelling as well as those seen in large field studies, but caution is urged when interpreting small scale laboratory experiments to explain large scale field data.