Subterranean termites are a major pest of human structures throughout tropic and sub-tropic climate zones, causing billions of dollars in damage worldwide. Most control systems, in the past, have employed extensively applied chemical agents. Because of severe unintended effects of these chemicals, many will no longer be available in the near future. The focus of research on subterranean termites must now turn to finding more "environmentally friendly" termite control methods. In order to develop new possibilities for more acceptable termite controls, it will be necessary to have a clear understanding of their life history, including reproduction, division of labor, foraging, intra-specific and inter-specific interaction, and environmental influences. Once this understanding is better achieved more efficient and more effective alternative control strategies can be developed. The purpose of this article is to assemble the current research on the behavior of subterranean termites in order highlight ongoing research related to development of alternative biological control methods and to begin to identify areas in need of further study.
 

It has been estimated that termites cause over 3 billion dollars in damage to wooden structures annually throughout the United States with at least 80% of that attributable to subterranean termites (Lewis, 1997 and references therein). Costs attributable to Coptotermes formosanus, in the Hawaiian Islands alone, are greater than 60 million Dollars (Delate, 1995 and references therein). These estimates show that subterranean termites are some of the most economically important insects to humans. The main focus of past research was on chemical methods for control with an obvious lack of attention placed on understanding behavior and natural history. This trend has changed over recent years because of concerns over side effects caused by the use of these chemicals. The direction being taken by many researchers is towards alternative non-toxic and biological methods of control. These newer methods that are being investigated include baiting, asphyxiant gases, extreme temperatures, barriers of various types, and biological control organisms (Lewis, 1997 and references therein). There is a need for more research in all of these areas. Research is also needed to analyze the feasibility of eradication as opposed to control of a population size and its affect on human structures. The use of multiple combined strategies to prevent termite damage to wooden structures or living plants seems to be indicated. While, the total eradication of a population of termites seems to be unfeasible at the current time using alternative non-chemical methods.

Some of the most economically important species of subterranean termites are in the genera Coptotermes and Reticulitermes (Lewis, 1997 and references therein). These species can be viewed as "ecological equivalents" (Chen & Henderson, 1997). Coptotermes sp. originated in the Orient and were transported around the world, probably as infestations in the hulls of wooden boats and in lumber. Coptotermes species have now invaded many sites in the southern United States where they occur sympatrically with many Reticulitermes species. Because of similarities in Phenotypic ratio, reproduction, and environmental requirements it would seem relevant to discuss them together when considering alternative strategies of control. Each aspect of subterranean termite behavior discussed here will be considered in the light of current research on both Coptotermes and Reticulitermes species. Discussion involving alternative control methods will address both similarities and differences in these taxa and possible ways to exploit this knowledge.

Early studies on polyethism within the Isoptera indicated a strong resemblance to the caste system of the social Hymenoptera, which has been thoroughly investigated. The caste system proposed for Isopteran workers was one involving temporal polyethism. Current investigations have supported this theory with some modifications for specific Isopterans. This has lead to the use of a new term for the system described here: temporal polymorphism (Crosland et. al., 1998 and references therein). Research has indicated that some Reticulitermes species go through 7-11 larval and worker instar stages. These instars can be difficult to distinguish in the later stages (Crosland et al., 1997 and references therein). A classification system was devised, based upon difference in size, dividing workers into 5 distinct groups: Small Larvae (SL), Large Larvae (LL), Small Workers (SW), Medium Workers (MW), and Large Workers (LW)(Crosland et al., 1997 and references therein). Division of labor in the worker caste Reticulitermes fukienensis has been the subject of several extensive studies (Crosland & Traneillo, 1997)(Crosland et al.,1997)(Crosland et al., 1998.) Behavioral assays showed a clear division in labor among these groups. The behaviors examined include tunnel construction, tunnel elongation, covered gallery construction, food consumption, exploratory behavior, care of brood and queen, corpse burying, alarm signaling, and time spent stationary. For all tasks that were investigated, LW performed the labor more efficiently and more extensively than any other group (Crosland et al., 1997, 1998). MW were able to perform all of the tasks but not nearly as well, except in the case of gallery repair which was performed equally as well. SM were even less efficient and could not perform several tasks. SL and LL were totally dependent upon larger castes. Current knowledge indicates a need for research on foraging behaviors. Little is known about dependence of each caste upon foraging and the transport of food back to the colony from foraging tunnels and covered galleries (Crosland et al., 1998). There was evidence to support the greater dependence of younger termites upon trophallaxis as a source of food (Crosland et. al., 1997)(Crosland et al., 1998). There was also evidence that a colony deprived of a large portion of their older workers could survive (Crosland et. Al., 1998). Assays done on the incipient growth of Reticulitermes flavipes colonies in the laboratory by Thorne at al. (1997) suggest that developing colonies can produce smaller sized workers to perform the same tasks as larger workers in older colonies. The results of Thorne et al. (1997) seem to fit the pattern of flexibility in the system of temporal polymorphism described for Reticulitermes fukienensis by Crosland et al. (1997), Crosland & Traneillo (1997) and Crosland et al. (1998). Field studies by Grace et al. (1995) on Coptotermes formosanus Shiraki revealed that individual worker body weight increased over a 16-year period while population decreased exponentially. This relationship could allow an estimate to be made for the age of Coptotermes formosanus colonies based on population sampling over several years(Grace et al., 1995). Perhaps the trend towards employing smaller workers in the early stages of colony development of these similar species would indicate the possibility of a division of labor in some Coptotermes species, C. formosanus in particular. Further research seems to be needed into the division of labor in Coptotermes species.

Reproduction in subterranean termites has been demonstrated to be quite variable in adaptations to different environments. Myles (1999), in a recent review of secondary reproduction of termites, included Coptotermes and Reticulitermes in the xylophagous foragers to describe the common capability of these Isopterans for opportunistic resource budding through secondary neotenics derived from nymphs. A recent study of Reticulitermes flavipes by Grace (1996) found high aggregations of nymphs in stumps during the summer in the northern part of its range in North America. There is a notably low occurrence of the winged alate form in this part is the termites' range as opposed to it's relatively frequent occurrence in the southern parts of North America (Grace, 1996 and references therein). These findings show the ability of these termites to adapt to a range of climactic conditions with success. Myles (1996) states that primary reproductives, queens and kings derived from flown alates after dispersal, exist in harmony with numerous secondary neotenics as supplemental sources for colony reproduction. This is consistent the findings of Chen & Henderson (1997) showing that Coptotermes formosanus will readily connect tubes under construction with those of their own colony or a neighboring colony of a different lineage. With the frequent occurrence of neotenics within the nest these termites are able to survive and reproduce when a part of the colony is cut off from the primary reproductives. Myles (1996) states that one of the primary factors for differentiation of nymphs to secondary neotenics is the occurrence of orphaning and speculates on a pheromone based inhibitor mechanism. Myles (1999) also states that other factors including population diffusion, seasons, and newly discovered resources also stimulate the differentiation of secondary reproductives and the development of new distinct colonies. This highly flexible, opportunistic approach to reproduction makes subterranean termites an incredibly successful pest upon human structures and agriculture. This ability also increases the difficulty of eliminating termites from an area completely therefore enhancing the need for control measures aimed at control of foraging preference along with control of population size. Physogastry is a trait also common to these subterranean termites (Myles, 1999). Primary reproductives are capable of the highest extent of physogastry. This should result in higher fecundity in the primary reproductives with further results of larger more successful colonies in most cases (Myles, 1999). The results of Grace (1996) seem to show that in cooler climates secondary reproductives are much more successful in Reticulitermes flavipes. The termite Coptotermes havilandi, in a study by Costa-Leonardo & Barsotti (1998), displays a very different reproductive style in South America. Swarms of alates occur throughout the warm, dry summer. These alates are released in short bursts of many individuals that issue from holes in the nest under the defense of Soldiers stationed around the opening. These alates pair, build nuptial chambers and begin reproducing. C. havilandi has been devastatingly successful in its invasion of the live heartwood of trees in Brazil. A further understanding of the dynamics of reproductive styles of subterranean termites should enable control measures to be developed for curbing reproduction. Costa-Leonardo & Barsotti (1998) site a need for research into factors involved in nest site selection.

Subterranean termites within the Rhinotermitidae form diffuse networks of tunnels connecting food sources to the nursery and reproduction chambers. These tunnels may be underground or above ground in the form of covered galleries. Reinhard et al. (1997) found that Reticulitermes santonensis creates a net of regularly branched trails when foraging in search of wood and refers to research that describes a similar system in Reticulitermes flavipes. During foraging the termites lay down an exploratory trail which will be covered with a tunnel extending in that direction. Once food is located, a recruitment trail is laid down back to the nest (Reinhard et al., 1997)(Grace et al., 1995 and references therein). Termites are capable of orienting themselves laterally and longitudinally along this trail using mechanisms of chemotaxis and chemokinesis (Grace et al., 1995 and references therein) Chen et al.(1998) demonstrated that some of the chemicals used for trail following are non-pheromone chemicals that can be synthesized. Reinhard et al. (1997) demonstrates that labial gland secretions in R. santonensis cause gnawing and feeding activity in other workers. The possibility was suggested that this activity is enhanced by the action of digestive enzymes on the food source. Field sampling tests by Henderson et al. (1998) found a much higher rate of foraging in close proximity to known existing colonies demonstrating the need for some knowledge of termite behavior and of the area of infestation in order to achieve better efficiency in baiting termites. In laboratory bioassays, Reinhard et al. (1997) also found a strong orientation towards wood in the branching direction and tunnel length by foraging R. santonensis indicating detection of some volatile chemicals within the wood. Applications of attraction and repulsion by wood extracts to termite control are discussed below. Reinhard et al. (1997) state that only workers initiate foraging behavior. The role of soldiers is to defend foraging worker and to defend intrusions into the existing galleries and tunnels until they can be repaired. These soldiers make up a small percentage (1-5%) of the population. Cornelius & Grace (1997) described a similar role for soldiers in Coptotermes formosanus which as defending the colony from predatory ants. In contrast to R. santonensis, 10-20% of the colony's population consists of soldiers in C. formosanus. Sornnuwat et al. (1996) estimated populations of Coptotermes gestroi at over 2.5 million. A smaller population in one study group located in a river basin was thought to have more disturbances such as flooding and competition. Several other studies have shown foraging population decline due to flooding. Forschler & Henderson (1995) discussed the reduction of populations of Reticulitermes flavipes and R. virginicus in Georgia due to excessive rainfall. In laboratory bioassays Forschler & Henderson (1995) showed the unwillingness of R. flavipes, R. virginicus, and C. formosanus to leave flooded chambers and their ability to survive long submersions in water indicating that a prolonged exposure to saturated conditions would be necessary to cause a decline in population. The population estimates of Coptotermes gestroi closely matched estimates of Coptotermes formosanus and Reticulitermes flavipes occurring in eastern North America (Sornnuwat et al., 1996 and references therein). This shows the extent of success the introduced species C. formosanus and the possible application of controls developed throughout the world. Variation between worker stages of R. fukienensis in their dependence upon trophallaxis as a food source (Crosland et al. 1998) Forschler (1996) demonstrated an unpredictable pattern of feeding in R. flavipes feeding on color treated cellulose and by trophallaxis or coprophagy over a period of several days. Large R. fukienensis workers were seen to have eaten more often and to have eaten many times the quantity of younger workers. These characteristics make the choice of a toxicant for a bait system very difficult because of the necessity for an even distribution of the toxicant.

Subterranean termites in the family Rhinotermitidae are extremely successful xylophagous foragers in most temperate and tropical climate zones. The Coptotermes have been extremely successful at invading North and South America. A recent introduction of Coptotermes havilandi to southern Florida shows that this species is continuing to spread (Su et al. 1997). C. havilandi is a wide spread pest of live trees and wooden structures in Brazil. It's swarming has been described in detail by Costa-Leonardo & Barsotti (1998) in the city of Rio Clara, SP, Brazil. A study of alate swarming in New Orleans, Louisiana by Henderson (1996) showed tremendous growth in the introduced population of Coptotermes formosanus there over a seven year period.

Henderson et al. (1998) demonstrate the need for a sound knowledge of termite foraging behavior when applying baiting techniques for control. In a review of alternative termite control strategies Lewis (1997) states that there is more variation in success with baiting than with any other method. He sites the need for research on delivery systems and better active ingredients. This need is emphasized in the above discussion of erratic feeding patterns in Reticulitermes fukienensis and R. flavipes (Crosland et al., 1998)(Forschler, 1996). Cardboard is being investigated as a conduit system to guide termites into traps with great success (Grace et al. 1995)(Kirton et al.,1998) This could have applications to improving the efficiency of baiting systems. Strong research is being done on the attraction and repellence of volatiles from trees to subterranean termites. Reinhard et al. (1997) described the ability of Reticulitermes santonensis to orient its foraging efforts towards wood suggesting the volatiles from the wood as the source of attraction. Chen & Henderson (1996) found that Coptotermes formosanus is attracted and preferentially feeds upon the amino acids glutamic acid and aspartic acid. These could be used to improve the effectiveness of baiting systems. Grace (1997) showed that many of the chemicals causing attracting and avoidance in several tree species are polar molecules. Doi et al. (1998) found that steaming of the heartwood of the Japanese larch degraded or removed the chemicals responsible for the inhibition of termite attack. Grace & Yamamoto (1994) showed that Alaska cedar, redwood and teak are resistant to termite attack. Neem was found to be a strong repellent to Coptotermes formosanus and was suggested as a barrier tree to protect more vulnerable plants (Delate & Grace, 1995). Naturally resistive woods and wood extractive have great promise for prevention of termite attack. Fungus has been shown to be of importance to subterranean termites both as a pathogen and as an attractant. Rust et al. (1996) showed that Reticulitermes hesperus is attracted to extracts of the fungus, Gloeophyllum trabeum. Pathogenic fungi have been recently studied in their affects on Coptotermes formosanus. This research shows that various isolates of the fungi Metarhizium anisopliae and Beauveria bassiana have potential for future use in control programs (Delate et al., 1995)(Wells et al.,1995)(Jones et al.,1996). Belitz & Waller (1998) show that environmental influences affect the digestion of cellulose in the termite hindgut by symbiotic protozoans. The food is quickly digested after a period of starvation. With more information about feeding patterns this research will help design protozoicide treatments for controlling termite population.

Some of the newer least toxic methods for controlling termites include: asphyxiant gases, extreme temperature biological control agents, and physical barriers (Lewis, 1997) Delate et al. (1995) describe the successful use of high levels of carbon dioxide for extended period in controlling termites in a contained space. The use of heated air to kill termites has shown to be successful in laboratory bioassays (Woodrow &Grace, 1998). Liquid nitrogen has also been shown to be effective at eliminating termites in the laboratory (Lewis, 1997). These temperature based are showing great promise but need more field studies on effectiveness in a natural setting. Inundation with water was shown to cause a decline in foraging worker population in studies by Forschler & Henderson (1995). This could indicate possible applications to control, for example the controlled flooding the territories of specific termite colonies to reduce damage by foraging termites. Barriers to foraging termites that are being test include: sand, crushed granite, glass splinters, and metal shields. These methods have had mixed success pointing to the need for more research in this area (Lewis, 1997).

With the changes in public opinion and scientific findings on the use of traditional chemical control methods, alternative, less toxic methods of control must be found for subterranean termites. Research has been lacking, in the past, on termite behavior. Research has been done recently to bring about understanding of subterranean termite life history. This research has revealed that relatively little is understood about many aspects of termite life. There are specific arenas of study that need special study in the near future. The division of labor in the Coptotermes seems to need to be better defined. Flexibility in modes of reproduction needs further studies. Nesting site choices are another little understood part of termite life style. Influences on foraging patterns are an area of constant need of study because of the direct affect on human structures and agriculture. Research into the attractive and repellent properties of new woods and wood extracts promises to allow some control of termite foraging patterns in the future. Biological and least-toxic methods are the areas in need of the most research because of their relative harmlessness. The use of pathogenic fungi and possibly predatory ants for control are valuable areas of research. Research into better physical barriers would be worthwhile also. These new areas of research will become stronger and produce more varied approaches to subterranean termite control.

Belitz LA, Waller DA (1998) Effects of Temperature and Termite Starvation on Phagocytosis by Protozoan Symbionts of the Eastern Subterranean Termite Reticulitermes flavipes Kollar. Microbial Ecology 36:175-180

Chen J, Henderson G (1996) Determination of Feeding Preference of Formosan Subterranean Termite (Coptotermes formosanus Shiraki) for Some Amino Acid Additives. Journal of Chemical Ecology 22:2359-2369

Chen J, Henderson G (1997) Tunnel and Tube Convergence of Formosan Subterranean Termites (Isoptera: Rhinotermitidae) in the Laboratory. Sociobiology 30:305-318

Chen J, Henderson G, Laine RA (1998) Isolation of 2-Phenoxyethanol from a Ballpoint Pen Ink as a Trail-Following Substance of Coptotermes formosanus Shiraki an Reticulitermes sp. Journal of Entomological Science 33:97-105

Chen J, Henderson G, Grimm CC, Lloyd SW, Laine RA (1998) Naphthalene in Formosan Subterranean Termite Carton Nests. Journal of Agricultural and Food Chemistry 46:2337-2339

Cornelius ML, Grace JK (1994) Behavioral Respoces of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae) to Semiochemicals of Seven Ant Species. Environmental Entomology 23:1524-1528

Cornelius ML, Grace JK (1994) Semiochemicals Extracted from a Dolichoderine Ant Affects the Feeding and Tunneling Behavior of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae). Journal of Economic Entomology 87:705-708

Cornelius ML, Grace JK (1995) Laboratory Evaluations of Interactions of Three Ant Species with the Formosan Subterranean Termite (Isoptera: Rhinotermitidae). Sociobiology 26:291-298

Cornelius ML, Grace JK (1996) Effect of Two Species (Hymenoptera: Formicidae) on the Foraging and Survival of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae). Environmental Entomology 25:85-89

Cornelius ML, Grace JK (1997) Effect of Termite Soldiers on the Foraging Behavior of Coptotermes formosanus (Isoptera: Rhinotermitidae) in the Presence of Predatory Ants. Sociobiology 29:247-253

Cornelius ML, Grace JK, Ford PW, Davidson BS (1995) Toxicity and Repellency of Semiochemicals Exracted from a Dolichoderine Ant (Hymenoptera: Formicidae) to the Formosan Subterranean Termite (Isoptera: Rhinotermitidae). Environmental Entomology 24:1263-1269

Crosland MWJ, Lok CM, Wong TC, Shakarad M, Traniello (1997) Division of Labour in a lower termite: the majority of tasks are performed by older workers. Animal Behavior 54:999-1012

Crosland MWJ, Ren SX, Traneillo JFA (1998) Division of Labour amoung Workers in the Termite, Reticulitermes fukiensis ( Isoptera: Rhinotermitidae). Ethology 104:57-67

Crosland MWJ, Traniello (1997) Behavioral Plasticity in Division of Labor in the Lower Termite Reticulitermes fukienensis. Naturwissenchaften 84:208-211

Costa-Leonardo AM, Barsotti RC (1998) Swarming and Incipient Colonies of Coptotermes havilandi (Isoptera, Rhinotermitidae). Sociobiology 31:131-142

Davis RW, Kamble ST (1994) Low Temperature Effects on Survival of the Eastern Subbterranean Termite (Isoptera: Rhinotermitidae). Environmental Entomology 23:1211-1214

Delate KM, Grace JK (1995) Susceptibility of neem to attack by the Formosan Subterranean Termite, Coptotermes formosanus Shir. (Isopt., Rhinotermitidae). Journal of Applied Entomology 119:93-95

Delate KM, Grace JK, Armstrong JW (1995) Carbon Dioxide as a Potential Fumigant for Termite Control. Pesticide Science 44:357-361

Delate KM, Grace JK, Tome CHM (1995) Potential use of pathogenic fungi in baits to control the Formosan subterranean termite (Isopt., Rhinotermitidae). Journal of applied Entomology 119:429-433

Doi S, Takahashi M, Yoshimura T, Kubota M, Adachi A (1998) Attraction of Stemed Japanese Larch (Larix leptolepis (Sieb. Et Zucc.) Gord.) Heartwood to the Subterranean Termite Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). Holzaforschung 52:7-12

Forschler BT, Henderson G (1995) Subterranean Termite Behavioral Reaction to Water and Survival of Inundation: Implications for Field Populations. Environmental Entomology 24:1592-1597

Forschler BT (1996) Incidence of Feeding by the Eastern Subterranean Termite (Isoptera: Rhinotermitidae) in Laboratory Bioassay. Sociobiology 28:265-273

Grace JK (1996) Temporal and Spatial Variation in Caste Proportions in a Northern Reticulitermes flavipes Colony (Isoptera: Rhinotermitidae). Sociobiology 28:225-231

Grace JK (1997) Influence of Tree Extractives on Foraging Preferences of Reticulitermes flavipes (Isoptera: Rhinotermitidae). Sociobiology 30:35-42

Grace JK, Wood DL, Kubo I, Kim M (1995) Behavioral and chemical investigation of trail pheromone from the termite Reticulitermes hesperus Banks (Isiopt., Rhinotermitidae). Journal of Applied Entomology 119:501-505

Grace JK, Yamamoto RT, Tamashiro M (1995) Relationship of Individual Worker Mass and Population Decline in a Formosan Subterranean Termite Colony (Isoptera: Rhinotermitidae). Environmental Entomology 24:1258-1262

Grace JK, Yamamoto RT (1994) Natural resistance of Alaska-cedar, redwood, and teak to Formosan subterranean termites. Forest Products Journal 44:41-44

Grace JK, Yates JR, Tome CHM (1995) Modification of a Commercial Bait Station to Collect Large Numbers of Subterranean Termites (Isoptera:Rhinotermitidae). Sociobiology 26:259-268

Henderson G (1996) Alate Production, Flight Phenology, and Sex-Ratio in Coptotermes formosanus Shiraki, an introduced Subterranean Termite in New Orleans , Louisiana. Sociobiology 28:319-326

Jones WE, Grace JK, Tamashiro M (1996) Virulence of seven Isolates of Beauveria basiana and Metarhizium anisopliae to Coptotermes formosanus (Isoptera: Rhinotermitidae). Environmental Entomology 25:481-487

Kirton LG, Brown VK, Azmi M (1998) A New Method of Trapping Subterranean Termites of the Genus Coptotermes (Isoptera:Rhinotermitidae) for Field and Laboratory Studies. Sociobiology 32:451-458

Lewis VR (1997) Alternative Control Strategies for Termites. Journal of Agricultural Entomology 14:291-307

Myles TG (1999) Review of Secondary Reproduction in Termites (Insecta: Isoptera) with Comments on its Role in Termite Ecology and Social Evolution. Sociobiology 33:1

Polizzi JM, Forschler BT (1998) Inrta- and interspecific agonism in Reticulitermes flavipes (Kollar) and R. virginicus (Banks) and effects of arena size in laboratory assays. Insectes Sociaux 45:43-49

Reinhard J, Hertel H, Kaib M (1997) Feeding Stimulation Signal in Labial Gland Secretion of the Subterranean Termite Reticulitermes santonensis. Journal of Chemical Ecology 23:2371-2381

Reinhard J, Hertel H, Kaib M (1997) Systematic search for food in the subterranean termite Reticulitermes santonensis De Feytaud (Isoptera, Rhinotermitidae). Insectes Sociaux 44:147-158

Rust MK, Haagsma K, Nyugen J (1996) Enhancing Foraging of Western Subterranean Termites (Isoptera: Rhintermitidae

Sornnuwat Y, Tsunoda K, Yoshimura T, Takahashi M, Vongkaluang C (1996) Foraging Populations of Coptotermes gestroi (Isoptera: Rhinotermitidae) in an Urban area. Journal of Economic Entomology 89:1485-1490

Shelton TG, Grace JK (1997) Impact of Low Temperature Conditioning on Intercolonial Agonism in Coptotermes formosanus (Isoptera: Rhinotermitidae). Sociobiology 30:197-211

Shelton TG, Grace JK (1997) Suggestion of an Environmental Influence on Intercolony Agonism of Formosan Subterranean Termites (Ispotera, Rhinotermitidae). Environmental Entomology 26:632-637

Su NY, Scheffrahn RH, Weissling T (1997) A New Introduction of a Subterranean Termite Coptotermes havilandi Holmgren (Isoptera: Rhinotermitidae) in Miami Florida. Florida Entomologist 80:408-411

Thorne BL, Breisch NL, Traniello JFA (1997) Incipient Colony Development in the Subterranean Termite Reticulitermes flavipes (Isoptera: Rhinotermitidae) Sociobiology 30:145-159

Waller WA (1996) Feeding Interactions between the Subtereanean Termite Reticulitermes (Isoptera; Rhinotermitidae) and the Wood Roach Cryptocercus punctulatus (Blattaria; Cryptocercidae). Sociobiology 28:45-52

Wells JD, Fuxa JR, Henderson G (1995) Virulence of Four Fungal Pathogen to Coptotermes formosanus (Isoptera: Rhinotermitidae) Journal of Entomological Science 30:208-215

Wiltz BA, Henderson G, Chen J (1998) Effect of Naphthalene, Butylated Hydroxytoluene, Dioctyl Phthalate, and Adipic Dioctyl Ester, Chemicals Found in the Nests of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae) on a Saprophytic Mucor sp. (Zygomycetes: Mucorales). Environmental Entomology 27:936-940

Woodrow RJ, Grace JK (1998) Thermal Tolerances of Four Termite Species (Isoptera: Rhinotermitidae, Kalotermitidae) Sociobiology 32:17-25