Termite Biology Research Articles

Lethal disruption of the bacterial gut community in Eastern subterranean termite caused by boric acid.

The Eastern subterranean termite, Reticulitermes flavipes (Kollar) (Blattodea: Rhinotermitidae), is a significant pest, causing extensive damage to structures that amount to substantial economic losses. Boric acid is widely used for wood preservation due to its stability and broad-spectrum insecticidal properties, yet its impact on termite gut microbiomes and the implications of such effects remain understudied. Our study evaluates the dose-dependent mortality of R. flavipes upon being provided boric acid treated filter papers and investigates the resulting dysbiosis within the termite gut microbiome. Consistent with reports from other insects, mortality increased in a dose-dependent manner, with the highest boric acid concentration (203.7 µg/cm2 of filter paper) significantly reducing termite survival. 16S rRNA gene sequencing of the gut bacterial microbiome revealed notable shifts in composition, indicating boric acid-induced dysbiosis. Aside from an overall decrease in bacterial diversity, the relative abundance of some symbionts essential for termite nutrition decreased in response to higher boric acid concentrations, while several opportunistic pathogens increased. Our findings extend the understanding of boric acid's mode of action in termites, emphasizing its ability to significantly modulate the bacterial symbiont community, which can have dire effects on termite biology. Considering its ability to protect wood from further termite consumption, our study supports the continued use of boric acid and related compounds for termite-resistant treatments for wood.

Investigation of termite attack, Macrotermes gilvus Hagen (Termitidae: Blattodea), to cocoa (Theobroma cacao)

Macrotermes gilvus is a major pest in the cocoa cultivation industry in Indonesia, with huge productivity. The success of a termite control technology is largely determined by the availability of information about the biology of termites which are pests. Investigating M. gilvus attacks was surveyed on polyculture cocoa plantations in Pidie, Aceh Tamiang, and Southeast Aceh Districts, Aceh Province. We found various levels of termite attacks characterized by mounds (nests) and galleries on the cocoa. The presence of nests and galleries damages the pith tissue and creates empty spaces, which are later filled with soil. Lack of land sanitation can trigger termite attacks on the plantations.

Role of Molecular tools in unravelling the cryptic characteristics of termites

Termites, as cryptic organisms, pose significant challenges to traditional methods of species identification and behavior analysis due to their morphological similarities, hidden habitats, and complex social structures. Molecular tools have emerged as transformative techniques for unraveling the cryptic characteristics of termites, aiding in taxonomy, phylogenetics, and population genetics. This research paper explores the pivotal role of molecular approaches, such as DNA barcoding, mitochondrial markers, and genome sequencing, in uncovering termite species diversity and evolutionary relationships. Molecular tools not only enhance the identification of cryptic species but also provide insight into caste differentiation, social behavior, and colony structure. Advanced techniques like transcriptomics and genomics have shed light on termite physiological adaptations, such as cellulose digestion and symbiosis with gut microbes, which are critical for their ecological roles. Additionally, molecular diagnostics offer innovative solutions for termite pest management by identifying genetic markers linked to pesticide resistance and targeting specific species for control measures. This paper reviews key molecular methodologies applied to termites, discusses case studies, and explores future directions in termite research, emphasizing the significance of these tools in understanding termite biology and ecological impact.

Introduction to the special section on Biology of Termites

As descendants of social cockroaches, termites have an intriguing biology that makes them highly suitable study subjects in a wide variety of fields, such as eusocial evolution, ageing mechanisms, wood decomposition, ecosystem engineering, and pest management. This special section presents four studies ranging from the role of chemical compounds in foraging behaviour and food digestion to genetics and physiology of reproduction. Taken together, these studies offer new insights and ample suggestions for future work on these fascinating insects.

Nan-Yao Su: Good Lucky Me

When Nan-Yao Su immigrated from Japan to the United States in 1978, he could not have imagined that he would one day stand on Ellis Island as a naturalized citizen responsible for protecting the most iconic symbol of American freedom—the Statue of Liberty—from termites. Currently a distinguished professor of entomology at the University of Florida, Su revolutionized termite control with his invention of Sentricon, the world’s first commercial termite baiting system. Su earned B.S. (1975) and M.S. (1977) degrees, both in sericultural science, from the Kyoto Institute of Technology, Kyoto, Japan, and a Ph.D. (1982) in entomology from the University of Hawaii, Honolulu. After spending two years as a postdoctoral associate studying the behavioral ecology and control of subterranean termites at Louisiana State University with Jeffrey La Fage, he joined the faculty of the University of Florida in 1985. Su is internationally respected as an authority on subterranean termite biology, ecology, and behavior. His depth of knowledge and seminal research with these destructive pests served as the foundation for developing the Sentricon system. Commercialized in 1995, the system used a monitoring–baiting approach to identify and then treat the termite colony with hexaflumuron, an insect growth regulator (IGR). This slow-acting chemical allows the termite workers to pass the IGR to one another via trophallaxis, subsequently eliminating the entire colony, including the queen.

A Review of the Evolution of Termite Control: A Continuum of Alternatives to Termiticides in the United States with Emphasis on Efficacy Testing Requirements for Product Registration.

Simple SummaryTermites are structurally destructive pests that can infest a consumer’s most important investment, their home. The evolution of termite control is complex, involving people’s understanding of termite biology and behavior, building construction, the use of soil termiticides, baits, wood treatments, and physical barriers, as well as regulations from different industries (pest control and building construction). Soil termiticides have been the standard method of treatment for decades, but the concern for human and environmental health has driven the development of alternatives. This article discusses the evolution of termite control methods that were alternatives to the standard of the time and the regulatory structure that provides a level of consumer protection for some products.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.

Termite Testing Methods: A Global Review

Abstract The protection of wood against termites is a major global problem, especially in the tropics and subtropics, and has been the subject of considerable research to understand termite biology and to develop effective mitigation methods. Field trials are useful for this purpose, but they often lack the degree of control and reproducibility needed. As a result, many researchers use laboratory methods when evaluating new wood preservatives or the suitability of timber for specific uses. These methods have developed over many years and in many regions with differing termite species and risks. Some methods differ only slightly from one another, but others use dramatically different approaches based upon the behavior and biology of a given termite species. The range of methods can make it difficult to make comparisons in terms of termite behavior, timber species preferences, or treatment efficacy. This review assembles the methods used for evaluating termite attack, explaining the underlying termite biology connected with each method, and identifying commonalities that might facilitate comparisons between various data sets, or potentially standardizing the standards. Understanding the essential characteristics of test methodologies can help identify the most appropriate methods for assessing the effectiveness of a given treatment, but it may also help compare results from different approaches, thereby avoiding redundant tests.

Some special aspects of the biology of termites of Hospitalitermes spр. in Southern Vietnam

Two species of the genus Hospitalitermes (H. bicolor and H. luzonensis) were discovered as new inhabitants in South Vietnam. Observations on these two species have shown their open activity during the year cycle at any time of the day/night. H. luzonensis build paper nests of average size, while H. bicolor prefers nomadic life activity and does not build long-term nests. Termite activity on the open surface is provided by the dark color of their bodies, strongly chitinized. An enormous amount of the soldiers provide absolute security for the workers during the open foraging. The article contains data on the composition of termite colony. The population of the two nests of H. luzonensis is calculated, the average amount of individuals in H. bicolor nest is estimated.

Worker Defensive Behavior Associated with Toxins in the Neotropical Termite Neocapritermes braziliensis (Blattaria, Isoptera, Termitidae, Termitinae).

Termite societies are abundant in the tropics, and are therefore exposed to multiple enemies and predators, especially during foraging activity. Soldiers constitute a specialized defensive caste, although workers also participate in this process, and even display suicidal behavior, which is the case with the species Neocapritermes braziliensis. Here we describe the morphology, mechanisms of action, and proteomics of the salivary weapon in workers of this species, which due to the autothysis of the salivary glands causes their body rupture, in turn releasing a defensive secretion, observed during aggressiveness bioassays. Salivary glands are paired, composed of two translucent reservoirs, ducts and a set of multicellular acini. Histological and ultrastructural techniques showed that acini are composed of two types of central cells, and small parietal cells located in the acinar periphery. Type I central cells were abundant and filled with a large amount of secretion, while type II central cells were scarce and presented smaller secretion. Parietal cells were often paired and devoid of secretion. The gel-free proteomic approach (shotgun) followed by mass spectrometry revealed 235 proteins in the defensive secretion, which were classified into functional groups: (i) toxins and defensins, (ii) folding/conformation and post-translational modifications, (iii) salivary gland detoxification, (iv) housekeeping proteins and (v) uncharacterized and hypothetical proteins. We highlight the occurrence of neurotoxins previously identified in arachnid venoms, which are novelties for termite biology, and contribute to the knowledge regarding the defense strategies developed by termite species from the Neotropical region.

Termite Ecology in the First Two Decades of the 21st Century: A Review of Reviews.

Termite ecology came of age in 1978 with the seminal review of Wood and Sands which by considering the quantitative contributions made by termites to the carbon cycle at the landscape level concluded that they were major players in tropical ecosystems. Subsequent field work in the succeeding two decades was summarised in 2000 by Bignell and Eggleton, the most recent review which attempted to cover the entire topic in detail, which included 188 listed references and has been extensively cited for almost 20 years. Subsequent summaries more narrowly defined or in some cases more superficial are listed in the bibliography. In this overview, the main and subsidiary headings in Bignell and Eggleton are revisited and reclassified in the light of 186 selected articles added to the relevant literature since 2000, and some earlier work. While the literature on termite ecology remains buoyant, it has declined relative to publications on other aspects of termite biology. Overall, the thesis that termites have a major impact on, and are major indicators of soil health and landscape integrity in the tropics and sub-tropics is maintained, but the drivers of local diversity, abundance and biomass remain complex, with many biographical, edaphic and optimum sampling issues not completely resolved. The large increase in diversity and abundance data from Neotropical biomes can also be noted.

Diversity of Termite Breeding Systems.

Termites are social insects that live in colonies headed by reproductive castes. The breeding system is defined by the number of reproductive individuals in a colony and the castes to which they belong. There is tremendous variation in the breeding system of termites both within and among species. The current state of our understanding of termite breeding systems is reviewed. Most termite colonies are founded by a primary (alate-derived) king and queen who mate and produce the other colony members. In some species, colonies continue throughout their life span as simple families headed by the original king and queen. In others, the primary king and queen are replaced by numerous neotenic (nymph- or worker-derived) reproductives, or less commonly primary reproductives, that are descendants of the original founding pair leading to inbreeding in the colony. In still others, colonies can have multiple unrelated reproductives due to either founding the colonies as groups or through colony fusion. More recently, parthenogenetic reproduction has shown to be important in some termite species and may be widespread. A major challenge in termite biology is to understand the ecological and evolutionary factors driving the variation in termite breeding systems.

Phylogenetic reconstruction of Syntermitinae (Isoptera, Termitidae) based on morphological and molecular data.

The subfamily Syntermitinae comprises a group of Neotropical termites with 18 genera and 101 species described. It has been considered a natural group, but relationships among the genera within the subfamily remain uncertain, and some genera appear to be non-monophyletic. Here, we provide a comprehensive phylogeny including six Neotropical species of Termitinae as outgroup, 42 Syntermitinae species as ingroup, 92 morphological characters (from external and internal anatomy of soldier and worker castes) and 117 molecular sequences (109 obtained for this study and 8 from GenBank) of 4 gene regions (41 and 22 from Cytochrome Oxidase I and II respectively, 19 from Cytochrome b, and 35 from 16S rDNA). Morphological and molecular data were analyzed in combination, with the Bayesian inference method, and the important aspects of termite biology, defense and feeding habits are discussed based on the resulting tree. Although useful for providing diagnostic characters, the morphology of the soldier caste reveals several cases of convergence; whereas the feeding habit shows indications of evolutionary significance.

Lower Termite Associations with Microbes: Synergy, Protection, and Interplay.

Lower-termites are one of the best studied symbiotic systems in insects. Their ability to feed on a nitrogen-poor, wood-based diet with help from symbiotic microbes has been under investigation for almost a century. A unique microbial consortium living in the guts of lower termites is essential for wood-feeding. Host and symbiont cellulolytic enzymes synergize each other in the termite gut to increase digestive efficiency. Because of their critical role in digestion, gut microbiota are driving forces in all aspects of termite biology. Social living also comes with risks for termites. The combination of group living and a microbe-rich habitat makes termites potentially vulnerable to pathogenic infections. However, the use of entomopathogens for termite control has been largely unsuccessful. One mechanism for this failure may be symbiotic collaboration; i.e., one of the very reasons termites have thrived in the first place. Symbiont contributions are thought to neutralize fungal spores as they pass through the termite gut. Also, when the symbiont community is disrupted pathogen susceptibility increases. These recent discoveries have shed light on novel interactions for symbiotic microbes both within the termite host and with pathogenic invaders. Lower termite biology is therefore tightly linked to symbiotic associations and their resulting physiological collaborations.

Optimization of termite in-ground monitoring stations: An evaluation trial

Subterranean termites are serious pests of wood in service in much of the world. One of the most popular techniques for monitoring and controlling termites is the use of in-ground monitoring stations. Different cellulosic matrices were evaluated in terms of mass loss, moisture content variation and termite presence, accounting for spatial coordinates and monitoring station conditional variables, including: type of cellulosic matrix, matrix treatment and meteorological conditions, during one year in field conditions, both in Portugal and in the USA. A multivariate redundancy analysis was performed resulting in 60.4% of data variability being explained by the variables considered in this analysis. Spatial variables were responsible for the highest amount of variance observed in the response variables monitored for the termite monitoring stations, followed by the type of cellulosic matrix, from which cellulose and Hevea brasiliensis were the most influential variables. The optimization of termite in-ground monitoring stations should be performed through correct evaluation of termite feeding preferences and decay resistance, in order to choose an adequate bait matrix and a proper bait design. The termite species biology and the geographical location where control programs will be applied should also be taken into account.

Omic research in termites: an overview and a roadmap.

Many recent breakthroughs in our understanding of termite biology have been facilitated by “omics” research. Omic science seeks to collectively catalog, quantify, and characterize pools of biological molecules that translate into structure, function, and life processes of an organism. Biological molecules in this context include genomic DNA, messenger RNA, proteins, and other biochemicals. Other permutations of omics that apply to termites include sociogenomics, which seeks to define social life in molecular terms (e.g., behavior, sociality, physiology, symbiosis, etc.) and digestomics, which seeks to define the collective pool of host and symbiont genes that collaborate to achieve high-efficiency lignocellulose digestion in the termite gut. This review covers a wide spectrum of termite omic studies from the past 15 years. Topics covered include a summary of terminology, the various kinds of omic efforts that have been undertaken, what has been revealed, and to a degree, what the results mean. Although recent omic efforts have contributed to a better understanding of many facets of termite and symbiont biology, and have created important new resources for many species, significant knowledge gaps still remain. Crossing these gaps can best be done by applying new omic resources within multi-dimensional (i.e., functional, translational, and applied) research programs.

Investigation of Age Polyethism in Food Processing of the Fungus-Growing Termite Odontotermes formosanus (Blattodea: Termitidae) Using a Laboratory Artificial Rearing System.

Laboratory rearing systems are useful models for studying Rhinotermitid behavior. Information on the biology of fungus-growing termites, however, is limited because of the difficulty of rearing colonies in the laboratory settings. The physical structure of termite nests makes it impossible to photograph or to observe colonies in the field. In this study, an artificial rearing system for field-collected colonies of the fungus-growing termite Odontotermes formosanus (Shiraki) was developed to facilitate observation in the laboratory. We recorded colony activity within the artificial rearing system and documented a variety of social behaviors that occurred throughout the food processing of the colony. This complex miniature ecosystem was cooperatively organized via division of labor in the foraging and processing of plant materials, and the observed patterns largely resembled the caste and age-based principles present in Macrotermes colonies. This work extends our insights into polyethism in the subfamily Macrotermitinae.

Termites as targets and models for biotechnology.

Termites have many unique evolutionary adaptations associated with their eusocial lifestyles. Recent omics research has created a wealth of new information in numerous areas of termite biology (e.g., caste polyphenism, lignocellulose digestion, and microbial symbiosis) with wide-ranging applications in diverse biotechnological niches. Termite biotechnology falls into two categories: (a) termite-targeted biotechnology for pest management purposes, and (b) termite-modeled biotechnology for use in various industrial applications. The first category includes several candidate termiticidal modes of action such as RNA interference, digestive inhibition, pathogen enhancement, antimicrobials, endocrine disruption, and primer pheromone mimicry. In the second category, termite digestomes are deep resources for host and symbiont lignocellulases and other enzymes with applications in a variety of biomass, industrial, and processing applications. Moving forward, one of the most important approaches for accelerating advances in both termite-targeted and termite-modeled biotechnology will be to consider host and symbiont together as a single functional unit.

A Taxonomic Index, with Names of Descriptive Authorities of Termite Genera and Species: An Accompaniment toBiology of Termites: A Modern Synthesis(Bignell DE, Roisin Y, Lo N, Editors. 2011. Springer, Dordrecht. 576 pp.)

Biology of Termites: A Modern Synthesis (Bignell DE, Roisin Y, Lo N, (Editors), Springer, Dordrecht, 576pp, ISBN 978-90-481-3976-7, e-ISBN 978-90-481-3977-4, DOI 10.1007/978-90-481-3977-4) was published in 2011. With the agreement of the publishers, we give a taxonomic index of the book comprising 494 termite entries, 103 entries of other multicellular animal species mentioned as associates or predators of termites, with 9 fungal, 60 protist, and 64 prokaryote identities, which are listed as termite symbionts (sensu stricto). In addition, we add descriptive authorities for living (and some fossil) termite genera and species. Higher taxonomic groupings for termites are indicated by 25 code numbers. Microorganisms (prokaryotes, protists, and fungi) are listed separately, using broad modern taxonomic affiliations from the contemporary literature of bacteriology, protozoology, and mycology.

Foraging in subterranean termites (Isoptera: Rhinotermitidae): how do Heterotermes tenuis and Coptotermes gestroi behave when they locate equivalent food resources?

A previous research suggests that when subterranean termites locate equivalent food they consume the initial food resource. However, little is known about the movement of foragers among these food sources. For this reason, this study analyzed the feeding behavior of Heterotermes tenuis and Coptotermes gestroi in the presence of equivalent foods. The experimental arenas were composed of a release chamber connected to food chambers. The consumption of each wood block and percentage of the foraging individuals recruited for the food chambers were observed in relation to the total survival rate. The results showed that in the multiple-choice tests, wood block consumptions and the recruitment of individuals did not differ between replicates of each termite species. However, in different tests of tenacity, the chambers with the first food presented higher feeding rates by both H. tenuis and C. gestroi and resulted in a higher recruitment of workers and soldiers. In these conditions, it may be concluded that foragers of either species do not concentrate their efforts on the consumption of only one food resource when they are able to reach multiple cellulosic sources simultaneously. Additionally, the data concerning tenacity tests suggest that there is a chronologic priority of consumption in relation to the discovery of available food sources. Knowledge about the foraging biology of subterranean termites is important for future studies of their feeding behavior, and it is indispensable for improving control strategies.

Measuring the Impact of Termite Prevention Curricula in Hawaii Public Schools in an Area-Wide Extension Program

The efficacy of Educate to Eradicate, a K-12 service-learning science curricula developed as part of a statewide, community-based Extension effort for termite prevention, was evaluated. The curricula use termite biology and control as the basis for science education and have been implemented in over 350 Hawaii public school classrooms with more than 12,530 students from 2001 to present. Student surveys and work samples were used to measure changes in student knowledge, behavior, and engagement. Use of school curricula in Extension programs reaches a large public audience and encourages long-term continuation of community pest prevention efforts.