Populations Of Subterranean Termites Research Articles

Molecular identification of the invasive subterranean termite Reticulitermes grassei (Blattodea: Rhinotermitidae) outside its known distribution: introduction routes and implications for pest management strategies.

Despite providing important ecosystem services, termites are also serious pests of wooden structures. Termites are highly adaptive organisms that cause concern as an invasive species. Predictions of the future spread of their distribution range due to factors such as climate change, urban growth, and global trade present new challenges to our capacity to protect our wood and wood-based materials and structures effectively. Reticulitermes grassei Clément, 1978 (Blattodea: Rhinotermitidae) is a subterranean termite native to the Iberian Peninsula and France, whose global distribution has widened over recent years. This article updates the distribution range of this species, confirming its identification in the Azores, Madeira, and Morocco through molecular analysis. The origin and consequences of these putative invasive populations are discussed in light of previously available data. The resulting network showed a highly structured base consisting of many haplotypes from the southern and southwestern Iberian Peninsula (Spain and Portugal), including those from Morocco (in natural landscapes) and Switzerland (in infrastructures). The more derived part of the network includes the haplotypes from southwest France, the northwest Iberian Peninsula, the United Kingdom, Azores, and Madeira, the last 3 being linked probably to human-mediated transportation events. The potential impacts of invasive subterranean termite populations expanding into new regions are concerning, especially in urban environments, and remain uncertain in natural areas. The challenges posed by these termites could be especially worrying in island ecosystems. Hence, it is crucial to implement early warning systems and monitoring programs in regions susceptible to subterranean termite invasions.

Chemical Ecology, Detection and Identification of Subterranean Termites Based on Electronic-Nose Volatile Emissions Analysis

The effective monitoring and identification of existing subterranean termite populations within coarse woody debris and infested wood in service depend on accurate detection. These insects are often concealed within logs, wooden support structures, walls, and floorboards of buildings. In the absence of external mud tubes, termite infestations normally must be discovered through the destructive exploration of wooden structures to reveal the physical presence of these insect pests. Subterranean termite species are difficult to identify due to similarities in morphological features, but they may be readily distinguished by differences in volatile emissions from which they are divided into chemotaxonomic groups. Consequently, a more effective and nondestructive approach for detection and identification is to take advantage of unique species-specific emissions of volatile organic compounds (VOCs) from termite bodies which easily pass through wooden structures, allowing for detection without physical damage to wood and avoiding expensive DNA analysis. Electronic aroma detection analyses were conducted with an Aromascan A32S electronic-nose (e-nose) instrument, fitted with a 32-sensor conducting polymer (CP) sensor array, for discrimination between four common subterranean termite species based on differences in volatile emissions. Principal component analysis (PCA) of whole-body volatiles effectively distinguished between four termite species with the first two principal components accounting for more than 98% of sample variance (p < 0.01). Unique electronic aroma signature patterns (smellprints) were produced from e-nose sensor array outputs that allowed for the effective identification of termite species based on distinct differences in volatile metabolites released from their bodies. The e-nose methods were determined to be an improved means for rapidly detecting and monitoring termite species in wood. The method is cheaper than conventional detection methods and allows for the timelier discovery of species-specific termite infestations necessary for better management. The e-nose capability of detecting the Formosan termite in indoor living spaces was particularly significant due to the production of naphthalene, a volatile hazardous gas causing many adverse human health effects in enclosed environments.

Efficacy of Minimum Application of Chlorfluazuron Baiting to Control Urban Subterranean Termite Populations of Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae)

Simple SummaryThe termite baiting system has emerged as a popular option for controlling subterranean termites. The effectiveness of termite baiting depends on the foraging of the termites to encounter the bait, feed on the bait, and the horizontal transfer of residual insecticide deposits between nestmates. However, termite baiting can be costly and time consuming. Thus, this study looks to minimize the termite baiting application which leads to the total colony elimination. Overall, this study found that a termite colony population can be eliminated by selective termite baiting treatment.Termite infestations in urban areas are a serious problem because they cause negative economic effects, reduce the esthetic value of buildings, damage crops, and require household repairs. Chemical controls are the most common method used against subterranean termites, and baiting has emerged as one of the prominent control methods. The goal of this research was to determine the efficacy of termite baiting by treating one of six active termite stations (selective baiting) with chlorfluazuron baits to eradicate six populations of subterranean termites. This work shows that the placement of chlorfluazuron baits in one of the active stations was sufficient to destroy a colony that was interconnected with multiple chlorfluazuron-free stations. In general, it requires an average of 4–8 weeks for a quantity of less than 300 g of chlorfluazuron bait to remove a termite infestation at the study site.

Sustainable Management of Subterranean Termite Populations (Isoptera: Rhinotermitidae) in Armstrong Park, New Orleans, With Durable Baits.

Durable baits, Recruit HD, were installed in 45 Sentricon stations between September 2010 and July 2014 in the 32-acre Armstrong Park, New Orleans. After eliminating all detectable termite colonies in the Park, 6-12 mo elapsed before new activity was detected. Newly invading termite colonies were usually found near the Park border or were smaller colonies that originated from recently paired alates. After colony elimination, Recruit HD baits were left in the stations to intercept newly invading colonies of subterranean termites, leading to their elimination, and multiple cycles of such interception and elimination events were recorded. Because the presence of Recruit HD baits continues to eliminate incoming colonies with little effort in maintaining and resupplying baits in the target areas, the bait system offers an economically sustainable option for managing subterranean termite populations in a large area. The 32-acre Armstrong Park is a manageable size to carry out an area-wide (AW) project. If the number of such AW projects is gradually increased over time in selected metro areas of New Orleans, we predict that we may be able to turn the tide against the ever-increasing populations of C. formosanus in the entire city.

Sodium Fluoride for Protection of Wood Against Field Populations of Subterranean Termites.

Sodium fluoride (NaF) is a wood preservative with fungicidal activity and antifeedant activity against termites. In this study, wood blocks of Pinus massoniana were treated with a 0.5% (wt/wt) aqueous solution of NaF, and placed in soil contact under field conditions to evaluate leachability of NaF and resistance to Reticulitermes flaviceps (Oshima). Fluoride leachate levels in soil from wood-soil locations were also determined. After 12-mo outdoor exposure, 91.54% of fluoride was leached from NaF-treated wood and fluoride retention of the wood was 154.28 μg/g wood. In NaF-treated wood-soil locations, soil fluoride residues were significantly higher than locations with the water-treated negative control. Termite activity (presence or occupation) on NaF-treated blocks was 6.25% which was significantly less than 40.00% activity on water-treated control blocks. The mass lost from the wood of NaF-treated blocks was 17.46% which was significantly less than the 45.21% loss from the water-treated blocks. The results show that fluoride is readily leachable from treated wood into surrounding soil. NaF treatment can reduce termite damage to wood under field conditions, and this compound should receive further consideration as a wood preservative to protect timber from termite damage.

Survey of Metabolic Reserves, Stored Uric Acid, and Water Content from Field Populations of Subterranean Termites (Isoptera: Rhinotermitidae) from Georgia

Total levels of uric acid, soluble proteins, lipid, glycogen, and body water were determined for Reticulitermes flavipes (Kollar) workers 24-72 h after field collection. In addition, levels of biological molecules were compared for termites collected from the same inspection ports within 24 h after field collection, and after laboratory captivity of 6 or 9 mo. Uric acid content, described in a previous study as steadily accumulating in R. flavipes termites in captivity, was found to be low or undetectable in workers tested after 6 or 9 mo in the laboratory.

Foraging Populations and Control Strategies of Subterranean Termites in the Urban Environment, with Special Reference to Baiting

This paper reviews the literature on foraging populations, and control of subterranean termites with special reference to baiting. Studies on foraging populations of subterranean termites generally involved population characterization and estimation of foraging territories. Population characterization was normally conducted using mark-recapture techniques (single or triple) by trapping subterranean termites in underground monitoring stations, followed by marking the insects using histological dyes. Methods of studying foraging territories of subterranean termites involved the use of radio isotopes, direct excavation, histological dyes, flourescent paints and conducting agonistic behavioral experiments. Subterranean termite control strategies included chemical, biological and physical control methods. The soil treatment and baiting methods were common chemical methods, while the use of specific sand or granite particles, and stainless steel mesh are recent advances in physical exclusion method. Baiting is a relatively popular method which takes the advantage of social nature and foraging behaviour of subterranean termites where food sharing among the workers and nestmates through trophallaxis could enable the transfer of slow-acting toxicant to the whole colony. Many potential active ingredients as bait toxicants had been evaluated including metabolic inhibitors, fungi (bioagents) and insect growth regulators (IGRs), but only the latter has been

Control of subterranean termite populations at San Cristóbal and El Morro, San Juan National Historic Site

Populations of Coptotermes havilandi and Heterotermes sp. were detected in soil and structures of San Cristóbal and El Morro of the San Juan National Historic Site. This was the first record of C. havilandi in Puerto Rico. Baits containing a chitin synthesis inhibitor, hexaflumuron, were applied using in-ground and aboveground bait stations. It took 2–8 months to eliminate three populations of C. havilandi, but 13–15 months were required to eliminate four populations of Heterotermes sp. Due to the vast area of the San Juan National Historic Site, there are probably many more unseen populations of subterranean termites. There is a need for a routine monitoring program for early detection of subterranean termite infestations so that baits can be applied to eliminate detectable populations before severe and irreversible damage occurs to this historic site.

Estimating relative decline in populations of subterranean termites (Isoptera: Rhinotermitidae) due to baiting.

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 postbaiting 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 postbaiting 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, postbaiting mark-recapture population estimates could be much greater than those at prebaiting, 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.

Elimination of Subterranean Termite Populations from the Statue of Liberty National Monument Using a Bait Matrix Containing An Insect Growth Regulator, Hexaflumuron

Infestation by the eastern subterranean termite, Reticulitermes flavipes (Kollar), was found throughout the two ground floors of the pedestal of the Statue of Liberty National Monument. Termite activity in soil was also detected in two locations outside the monument walls. In total, four clusters of termite activity were identified. The widespread infestation suggested that termites had been in the monument for several years before they were noticed in 1994 and were probably introduced during the restoration project in the mid-1980s. Baits containing an insect growth regulator, hexaflumuron, were applied using above- and in-ground stations in mid-1996. By October 1997, all four infestations were eliminated after consuming a total of 1.8 g hexaflumuron. Monitoring stations remained in the soil to detect residual or new populations of subterranean termites on Liberty Island.

Elimination of Subterranean Termite Populations from the Statue of Liberty National Monument Using a Bait Matrix Containing an Insect Growth Regulator, Hexaflumuron

Elimination of Subterranean Termite Populations from the Statue of Liberty National Monument Using a Bait Matrix Containing an Insect Growth Regulator, Hexaflumuron

Remedial Baiting with Hexaflumuron in Above-Ground Stations To Control Structure-Infesting Populations of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae)

Above-ground bait stations composed of reclosable plastic bags containing bait matrices impregnated with hexaflumuron were placed directly over active infestations of the Formosan subterranean termite, Coptotermes formosanus Shiraki. Of the 5 colonies tested, 2 each of aerial colonies and ground-based colonies were eliminated. The population of 1 ground-based colony was reduced from >2,000,000 to 155,000 foragers. The results demonstrated the feasibility of introducing baits into active areas of infestation of subterranean termites. In addition to the in-ground baiting system, the above-ground bait station may offer another option for bait delivery to affect the structure-infesting populations of subterranean termites.

Comparison of Tunneling Responses into Insecticide-Treated Soil by Field Populations and Laboratory Groups of Subterranean Termites (Isoptera: Rhinotermitidae)

Tunneling responses of laboratory groups and field populations of subterranean termites into soil treated with 1of the 3 insecticides, chlorpyrifos, cypermethrin, or permethrin, were compared to validate laboratory evaluation techniques. Because of the diverse response exhibited by field populations, no statistical difference (P > 0.05) was detected between laboratory and field data for both the Formosan subterranean termite, Coptotermes formosanus Shiraki, and the eastern subterranean termite, Reticulitermes flavipes (Kollar).The results indicated that the overall tunneling behavior exhibited by field populations into insecticide- treated soil is essentially the same as that of laboratory groups of 80 foragers. But in some instances, the threshold concentrations (the lowest concentration to stop termite penetration totally) recorded from field populations were higher than those observed from laboratory groups.

Monitoring/Baiting Station To Detect and Eliminate Foraging Populations of Subterranean Termites (Isoptera: Rhinotermitidae) Near Structures

Commercial prototype monitoring/baiting stations were used to detect, bait, and elminate field populations of the Formosan subterranean termite, Coptotermes fornwsanus Shiraki, and the eastern subterranean termite, Reticulitermes flavipes (Kollar), near structures. Because of the durable plastic housing, the station can be used by pest control professionals for ongoing monitoring and baiting programs to provide continuous protection of structures from subterranean termites.

Termite control with microencapsulated permethrin

AbstractBait methods with microencapsulated active ingredients are proposed for controlling local populations of subterranean termites. The foraging workers will take up the microcapsules, transport them to the nest and pass them to their nestmates.In laboratory tests microencapsulated formulations of permethrin had lethal effects on Heterotermes indicola Wasman and Reticulitermes flavipes (Kollar) depending on the amount of active ingredient applied. The time interval between the application of the capsules and the occurrence of insecticidal effects could be modified by changing the wall thickness of the capsules. Tests revealed that the microcapsules were transmitted from donors to recipients by trophallaxis. Microencapsulated formulations from which the solvent used during the manufacturing process had been removed did not reveal any repellent effects in several tests.

Penetration of Sized-Particle Barriers by Field Populations of Subterranean Termites (Isoptera: Rhinotermitidae)

Barriers of seven single-sized and two mixed-sized particles were exposed to field populations of the Formosan subterranean termite, Coptotermes formosanus Shiraki, and the eastern subterranean termite, Reticulitermes flavipes (Kollar) for 1-3 mo. Compared with previous laboratory results, field populations of subterranean termites were generally more successful in penetration of sand barriers composed of sized particles. Barriers of particles in sizes 2.00-2.36 and 2.36–2.80 mm were least penetrated by soilborne colonies of C. formosanus . Three single-sized barriers (1.70–2.00, 2.00–2.36, and 2.36–2.80 mm) and two mixed-sized barriers (1.18–2.80 and 1.70–2.36 mm) were most effective against field populations of R. flavipes . In areas where both C. formosanus and Reticulitermes spp. occur, the two single-sized particle barriers (2.00–2.36 and 2.36–2.80 mm) appeared to be the most effective exclusion devices against field populations of these subterranean termites.

Fungi Associated with the Subterranean Termite Reticulitermes flavipes in Ontario

In a survey of the mycoflora associated with Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) subterranean termite populations in Ontario, Canada, forty species of fungi were isolated. These included both cellulolytic fungi and potential pathogens. Twenty-one fungal species were cultured from living termites. Observations of isolates from field collections, and the low diversity of fungi in declining laboratory termite colonies, suggest that interactions among fungi may suppress pathogenic effects and promote termite survival.

Fungi Associated with the Subterranean TermiteReticulitermes Flavipesin Ontario

In a survey of the mycoflora associated with Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) subterranean termite populations in Ontario, Canada, forty species of fungi were isolated. ...

Studies on a Wood-Feeding Termite Community in Ghana, West Africa

Following the partial clearance of farm scrub some termite species became locally extinct or scarcer, some were not affected, whilst others were adversely affected but became re-established and increased their activity. Wood-feeding termites in the moist semi-deciduous forest zone of Ghana consume about 0.2 kg m-2 yr-1 of woody material. This weight accounts for about 20 percent of the litter fall or about 8 to 10 percent of the annual primary production of the deciduous forest and a rather greater proportion of the lower production of more open sites. There is a spatial heterogeneity in the species distribution. Although water, clay, silt and sand contents of soil, and temperature, sunshine, and sunflecks were measured, the only significant correlations are of these parameters with Microtermes subhyalinus, which is more frequent in the moister areas with higher silt and lower sand content, and also shows a temperature preference. The lack of significance in correlation and principal component analyses is attributed to the observations being made away from the unknown location of the underground nest, and the ability of termites partially to modify their environment. The several coexisting wood-feeding species show slight micro-environment preferences leading to some spatial separation, and also show a series of size differences. The species show different responses to potential food resources, some apparently preferentially attacking wood in which fungal decomposition has begun and others not. TERMITES (Isoptera) are an important component of the fauna of tropical soils. Their efficiency in utilizing many food sources has meant that some species have become pests of crops or timber, and a few species have attacked a great variety of manmade materials. Because of their economic importance, the majority of studies of tropical termites have concentrated on the pest species and their control. The species known to attack crops have been reviewed by Harris (1961, 1969), whilst Sands (1960) has reviewed the species destroying timber and crops in West Africa. Further, Harris (1970) has listed all the species known to attack structural timbers, whilst Small et al. (1960) have described the effect of termites upon West African timbers. There have been relatively few studies on the populations of tropical termites. The relations between termites and soil have been reviewed by Lee and Wood (1971), though much of their detailed work was undertaken in Australia where the Macrotermitinae, the termites with perhaps the greatest population density in Africa, are absent. A general review of African termites is given by Bouillon (1970). Sands (1965b) attempted to sample subterranean termite populations during studies on the effect of human interference with vegetation communities in the West African savanna. However, later Sands (1972) drew attention to the extreme difficulty of obtaining estimates of the population density of truly subterranean, as opposed to moundbuilding, termite species. The work described here gives an indirect estimate of the population size and impact of a woodfeeding termite community, the majority of whose members are subterranean. These studies were undertaken during the development of a termite test site, mainly designed for conducting 'graveyard'-type tests. The Ghanaian Council for Scientific and Industrial Research wished the site to be developcd in an area of farm scrub near the village of Fumesua, about 10 km east of Kumasi (6?40'N, 1?35'W), in the Ashanti Region of Ghana. Since no previous work has been undertaken on the termite fauna of the area, the present study was designed to cover the first year of the creation of the test site, prior to any tests being carried out. It was thought important to know the ecological characteristics of the termites potentially able to attack the test samples, and the community structure of the termites that might be killed by chemical treatments of soil or wood.

Desert Subterranean Termites: A Method for Studying Foraging Behavior 1 , 2

Subterranean termites are among the most abundant but cryptic of animals, a factor making behavioral studies very difficult. Consequently little is known of their foraging behavior or general activity patterns. Previous studies have been restricted mainly to mound builders (Bouillon and Lekie 1964) or harvesters which forageopenly on the soil surface (Bouillon 1970, Nel 1968). A few estimates of subterranean termite populations have been based on baiting with attractive materials or soilcore sampling (Sands 1972).