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Alternative control strategies for termites
Abstract
The relative efficacy of five detection and 12 control methods for termites is reviewed. Chemical and nonchemical control methods are included. Discussions of the latest advances in detection and control focus on seven species: Cryptotermes brevis (Walker), Incisitermes minor (Hagen), I. snyderi (Light), Coptotermes formosanus Shiraki, Heterotermes aureus (Snyder), Reticulitermes flavipes (Kollar), and R. hesperus Banks. These species were chosen because they have great economic importance as pests and because studies have been published on alternative control strategies. Tables and discussions recount the historical development as well as strengths and limitations for most termite detection and control methods. Differences between whole-structure and localized treatments also are discussed. Chemical methods are the most predominant termite treatment application. However, uses of alternative methods that emphasize least-toxic and nonchemical applications are increasing. Technological advances in detection are needed to enhance all termite control methods, especially those directed at localized applications. Prospects for the development and public acceptance of alternative termite controls appear good, although population reduction of termites from structures may be a more attainable and realistic goal than elimination as new technologies are developed. The greatest challenges ahead in improving and developing existing and new termite detection and control strategies will be to secure funds for research and to identify mechanisms for rapid dissemination of evolving information to pest control operators and consumers.
... In the last 25 years, numerous review articles on the science behind termite control have been published [3][4][5][6][7][8][9][10]. The goal of this paper is to highlight the evolution of termite control by reviewing methods considered alternatives to the standard practice of the time, while noting the coevolution of regulatory processes that consider human health, environmental health, and product efficacy in contrast to home remedies and products that are not required to meet performance standards for structural protection. ...
... Baits, wood treatments, particle size barriers, marine-grade stainless-steel mesh, and polyethylene sheets with and without termiticides are being used as alternatives to, or in conjunction with, soil termiticides and they have been thoroughly reviewed [3,5,7,10,69,[101][102][103][104][105][106][107][108][109][110][111][112]. What has not been discussed is how these products may differ in regulatory aspects. ...
The global economic impact of termites is estimated to be approximately USD 40 billion annually, and subterranean termites are responsible for about 80% of the total impact. Twenty-eight species of termites have been described as invasive, and these termites are spreading, partially due to global trade, making effective control methods essential. Termite control is complex, as is the biology and behavior of this social insect group. In the U.S., termite prevention and control (with claims of structural protection) is regulated by more than one industry (pest control and building construction), and at the federal and state levels. Termite prevention has historically relied on building construction practices that do not create conducive conditions for termite infestations, but as soil termiticides developed, heavy reliance on pesticides became the standard for termite control. The concern for human and environmental health has driven the development of termite control alternatives and regulation for products claiming structural protection. Product development has also provided unprecedented opportunities to study the biology and behavior of cryptobiotic termites. Technological advances have allowed for the re-examination of questions about termite behavior. Advances in communications via social media provide unrestricted access to information, creating a conundrum for consumers and science educators alike.
... However, some subterranean termite species within Coptotermes (Wasmann) (Blattodea: Rhinotermitidae) have an important structural pest status Su 2012, Chouvenc et al. 2016a) and over the past decades, an extensive number of studies have focused on minimizing their negative impact on manmade structures and wood commodities (Su and Scheffrahn 1998, Osbrink et al. 2011, Su 2019. Historically, liquid termiticides have been implemented in soils to create a chemical barrier around a structure, to provide protection from potential subterranean termite damage (Su and Scheffrahn 1990, Lewis 1997, Su 2002, Mao et al. 2011, Keefer et al. 2012, Vargo and Parman 2012. However, while currently used nonrepellent termiticides formulations can temporarily exclude termite activity for relatively short distances from the treated area, long term impact on surrounding colonies may be limited owing to the emergence of secondary repellency that prevents further termite foraging activity near treated areas and can directly increase the environmental impact of such invasive termite species , Su 2005, Saran and Rust 2007, Shelton 2013, Chouvenc 2018, Chouvenc and Foley 2018. ...
... This delayed mode of action is fundamental for the success of bait programs because it results in a time to kill that is dose-independent (Su 1994, Su andLees 2009). It also gives time for the CSI active ingredient to be transferred to the rest of the colony before mortality starts occurring (Lewis andForschler 2017, Kakkar et al. 2018), and as workers come back to the central part of the nest to molt, it prevents the occurrence of secondary repellency at the bait station (Su 2005, Chouvenc 2018. Ultimately, baited colonies are often eliminated between 70 and 90 d after the initiation of feeding on the CSI bait formulation Su 2017a, Chouvenc 2021). ...
Subterranean termite control methods using chitin synthesis inhibitors (CSIs) aim at eliminating colonies that feed upon a bait formulation. Several benzoylurea active ingredient formulations are currently commercially available as alternative termite management strategies to liquid termiticides. Individual workers need to molt on a regular basis and CSIs interfere with such molting process, allowing sufficient time for the acquisition of a colony-wide lethal dose prior to widespread mortality. As workers progressively die, the colony eventually collapses, leaving only soldiers and primary reproductives that starve to death. One common observation is that young workers often die early owing to their relatively short molting cycle. However, the absence of brood in dying colonies raises questions about the potential fate of eggs laid by the queen. This study aims to determine if CSI baits also terminate the ability of a colony to produce a new cohort of workers by disabling the ongoing brood development. Incipient termite colonies were used to test the impact of noviflumuron on the queen’s ability to lay eggs and on the eggs' ability to hatch. Our results showed that queens in colonies exposed to CSI not only initially laid less eggs than the control queens, but eggs also did not develop and were progressively cannibalized, eventually leading to colony establishment failure. This result implies that queens of mature colonies exposed to CSI would lose the ability to lay viable eggs as the colony collapses, leading to an absence of worker replacement, aiding in colony elimination.
... In addition to timber and wood products they also attack growing trees, leather rubber and wool as well as agriculture crops (Malaker SLO, 1983). Significant damage is caused by termites to manmade fibres, polythenes, plastics, metal foils, books, furniture, wooden poles, insulators of electric cables (Malaker SLO, 1996;Lewis VR, 1997). ...
... Together with different alternatives development in the field of wood protection, anti-termite barriers for buildings became serious candidates for termite management. Since the early development of particle barriers, different strategies have been envisaged, such as physical (particle, metal, shield) and physico-chemical (a matrix associated with a termicidal ingredient) barriers (Ahmed and French, 2008;Lewis, 1997). Anti-termite barriers present the advantages to be non-invasive systems, excluding termites from the buildings, protecting the structure, fittings and contents. ...
... Random forest run number Z-score Arinana Philippines et al., 2016;Lewis, 1997;Lewis et al., 1997;Nanda et al., 2018b). Therefore, various sophisticated termite detection devices have been designed based on termites' signals (Farkhanda, 2013;Mankin et al., 2011). ...
The termite detection system has been studied intensively in both industry and academia. However, the devices currently in the market are only used to detect the presence of termites. Therefore, this research aims to develop a termite detection system capable of detecting the presence of termites and predicting their population size. This research focuses on the extraction and the relevant feature selection processes on acoustic and temperature signals, which complement the new system's design. To this end, the Boruta package was employed to identify relevant feature sets in the signals that can be used to significantly distinguish the different termite population sizes. The sample consists of 40 acoustic and 10 temperature features extracted and integrated with the Boruta package. However, after proper numerical analysis, an identified total of 25 relevant features consisting of 21 acoustic and 4 temperature features were used. Therefore, by reducing the dimensionality of the data set with the Boruta package, the computational burden of the termite detection system can be decreased. This study confirms that implementing relevant features to the termite detection system provides better performance due to its detection accuracy of 97.167% and ability to predict termites population size with a root mean squared error (RMSE) of 98.316.
... Los métodos curativos consisten en la aplicación de tratamientos qulmicos y no quimicos, como por ejemplo, la utilización de dióxido de carbono (Delate el. al, 1995), aire caliente (Woodrow y Grace, 199B), nitrógeno liquido (Lewis 1997). Los tratamientos quimicos en áreas localizadas consisten en la perforación y posterior inyección de insecticida en las galerias construidas por las termitas. ...
El Departamento de Ingeniería de la Madera de la Universidad de Chile ha desarrollado una línea de investigaciones tendiente a detectar y controlar la termita subterránea, utilizando técnicas no destructivas como son la aplicación de ondas sónicas y ultrasónicas. Los resultados presentados en este artículo se enmarcan en esta línea de investigación. El objetivo de este estudio es determinar el efecto de ondas sónicas en el comportamiento de termitas subterráneas durante el proceso de infestación en el interior de piezas de madera de pino radiata (Pinus radiata D.Don) de diferentes escuadrías.
... Globally, approximately 2800 termite species are identified. In India, out of 300 species, 35 are known for their damaging effects (Lewis 1997). The highly susceptible crops of various regions of India have been recorded for the severe losses (Rajagopal 2002). ...
Termites are one among the pests that pose serious threat to live plants as well as cause harm to plant-based products. The urban environment and agriculture are most threatened by them as they are the most challenging pests. The annual and perennial crops face significant losses, and in the semiarid and subhumid tropics around the globe, wooden components are also destroyed by them. Among the successful methods, chemical control is of great importance, but the side effects of such chemicals lead to the production of serious health issues, especially respiratory problems, if present in the environment. Plant-based natural products are promising replacements for these chemical pesticides. Botanicals used for pest remediation especially the one derived from essential oils are target-specific. A safe environment and food free from residues are attained by their use as they are required in little amount and also possess a quick decomposition. The mode of action of these herbal pesticides may vary. Some may act as direct toxicant, while others might act upon as antifeedant, repellent or behavior modifiers, morphogenetic agents, or phagostimulants. The current chapter aims to discuss the different aspects of various natural herbal plants parts and their potential application in the management of pest particularly termites. A sneak peek to their mechanism of action will also be taken into consideration. Essential oil-bearing plants being abundantly grown for various purposes become a possible herbal alternate to chemical pesticides.
... These chemicals are efficient, but are highly toxic to humans and contaminate the environment (Milano & Fontes 2002). In the last several years, with the aim of elaborating less noxious methods, studies were developed based on the use of baits that take into account the social behavior of termites (Su 1994;Lewis 1997). ...
In this study, we found that N. corniger manifests a preference for determined species of wood. In the first experiment, termites from a single nest that were kept under laboratory conditions were released in a foraging arena containing blocks of wood (5.0 x 2.0 x 2.0 cm) of (I) Pinus elliottii Engelm. (Pinaceae) (low density), (II) Eucalyptus grandis Hill (ex Maiden) (Myrtaceae) (medium density), and (III) Manilkara huberi Ducke (ex Chevalier) (Sapotaceae) (high density). One hour after the tests began the termites present in each type of wood were removed, separated by castes, counted and weighed. In another experiment, the wood consumed of these three species was determined when they were offered to the termites in a foraging arena during seven days. Both experiments were carried out with 20 replications, five times with each of the four colonies of termites utilized in the experiments. The total number of termites recruited was greater in E. grandis (183.2±33.8) than in P. elliottii (76.8±19.0) and M. huberi (41.3±11.0) (F 6.48 = 140, p< 0.001). The termites also consumed more dry matter of E. grandis (880.5±154.4 mg) than of P. elliottii (477.0±83.8 mg) and M. huberi (112.5±42.2 mg) which was the wood least consumed (F 6.48 =13.56, p<0.001). It was found that N. corniger can show preference for the species of wood and that the increase in preference was not determined exclusively by the density of the wood.
Forests harbour most of the known insects, and they perform multiple functions in forest ecosystems. Their ubiquitous presence in diversified forest habitats proves their adaptive behaviour, which makes them the most successful. Their roles in forests are so diverse that they can be seen in all the trophic systems, as herbivores, detritivores, parasites, predators, pollinators, etc. The classification as beneficial and harmful insects is because of their functional diversity, which is more or less the same as in other terrestrial or aquatic ecosystems. The cultural, aesthetic, and nutritional values of forest insects are seldom valued and made use of. The status issues on diversity are more or less parallel to the type of forests and the topographical and climatic regimes. The issues are mostly related to plant diversity and the diverse roles that insects play. Challenges are mainly the management of pests, their spread potential, and outbreaks due to disruption of natural balances. The major challenge is their multiplication rate and devastation potential. Unlike in agriculture, natural mechanisms of biological control play a major role in pest regulation. However, anthropogenic interventions in forest management and maintenance disrupt the natural functions and create skewed outcomes, which lead to pest outbreaks and uncontrollable damage to specific ecosystems. The invasive alien species, especially weeds, sometimes cause unmanageable population buildups so that the native plants get affected badly. The natural and manmade climatic changes add to the imbalance in the natural balance of floral and faunal components, but the capacity of forests to build resilience comes to the rescue of the faunal components, especially the insects. The population shifts in distribution often save them from extinction. The insects in forests are really a mystery still, and it may take many more years to unravel the hidden treasures of insect life in forests. This chapter deals with the forest insect groups from a trophic level perspective, the functionality, habits of living, adaptation behaviour, and their ecosystem services.KeywordsTrophic levelHerbivoresParasitesPredatorsPollinatorsClimate changeBio control
Termites are major pests of houses and buildings, and also living plants such as agricultural crops, trees in forests, urban areas and gardens. However, in Japan, the basic ecology of termites nesting in living trees is not fully understood. In this study, we observed 255 colonies (nests) of the drywood termite Neotermes sugioi, collected in the field on Okinawa Island, and reported the frequency composition of the reproductive castes, the size of wood with termite gallery, the population size of colonies, and the relative position of the reproductive and non-reproductive castes within nests. Most colonies were headed by a primary queen and a primary king. However, colonies headed only by primary queens, primary kings, or neotenic kings, each accounted for approximately 5% of the colonies. A colony size of 1,000– 4,000 individuals (2058.2 ± 1695.0 [mean ± SD]) was common and the average length of colony branches was less than 100 cm. Queens and kings were found in the same or nearby nest areas, and more predominantly in the central or root side of nest wood areas. The termites may experience colony fragmentation and reproductive loss as a consequence of typhoons. Incipient colonies (i.e., colonies at an early stage of development) were found on 11.3% of branches of Leucaena leucocephala that did not show any obvious signs of infestation. In future research, it will be necessary to update the list of trees damaged by this termite species, compare the damage by tree species, and evaluate the economic impact.
The neem tree, Azadirachta indica, is a source of natural compounds with potent insecticidal, feeding deterrent and insect growth regulator activity. However, little information is available on the effects of these natural products on termites. We assessed the effects of mulches made from ground neem branches and roots on survival of the Formosan subterranean termite, Coptotermes formosanus, and compared termite feeding and survival on neem wood and bark to that on susceptible Pseudotsuga menziesii wood. Termite survival was fairly low in both P. menziesii heartwood and neem mulches over the 14 day test period, and did not differ significantly among those treatments. However, termites exposed to either P. menziesii wood, neem wood, or neem bark for 4 weeks fed significantly less on neem wood and bark. Feeding on neem bark caused significant termite mortality (56.4%) in comparison to that induced by feeding on
neem wood (27.1 %) or P. menziesii wood (12.5%). Thus, although neem is not entirely resistant to termite attack, the antifeedant properties of its wood and bark and the toxicity of neem bark support the use of neem trees for arboriculturein areas where termites are a problem.
Formosan subterranean termites, Coptotermes formosanus Shiraki, were exposed to ⩾ 95% or 50% carbon dioxide atmospheres for intervals of 24-120 h at 26(±3)°C. A 24-h exposure to ⩾ 95% carbon dioxide caused significant termite mortality, but 60 h were required for complete mortality. Exposure to 50% carbon dioxide for 60 h resulted in approximately 70% termite mortality, while complete mortality was recorded after 120 h. When termites were sealed in wooden blocks (90 × 90 × 152 mm), 72-96 h exposure to ⩾ 95% carbon dioxide was necessary for complete control. A limited study with Cryptotermes brevis (Walker) suggested that this drywood termite is also susceptible to carbon dioxide fumigation, although slightly longer exposures may be required than with C. formosanus. Carbon dioxide-modified atmospheres are a viable alternative to conventional fumigants for vault fumigation of termite-infested materials, and may also be applicable to larger-scale fumigations to control structural pests.
A cooperative project between Forest Products Laboratories in the United States and Canada, initiated in 1966 to study the control effectiveness of an insecticide-treated termite attractant, is reported. It represents a bait method of control being developed to eradicate relatively large pockets of infestation.
Wooden bait blocks decayed by Lenzites trabea (Pers.) Fr., which attracts termites, with and without poison coating (Mirex insecticide) were installed in experimental plots at Oxley, Ont. An abrupt suppression of termite foraging occurred in plots where insecticide was used. Observations will be continued and work extended to determine whether the poison will prevent subterranean expansion of colonies and to assess its degree of effectiveness in eliminating localized pockets of infestation.