Fluid bait formulations and their use with active termite infestation

Abstract

The subject invention provides fluid formulations for use in controlling a population of a pest once it has been detected. Specifically, the subject invention pertains to a fluid bait formulation comprising a feed medium impregnated with at least one active ingredient and a liquid carrier. The invention is based on the concept of providing a unique fluid bait formulation that can be injected into a termite infestation site, where an effective amount of AI(s) is presented to the termite population, even following dehydration of the formulation, to control the termite population.

Claims

1. A fluid form bait formulation having a viscosity between 1 and 100 Pa.Math.s, the formulation comprising a particulate feed medium impregnated with at least one active ingredient (AI) and suspended in a liquid carrier selected from methylcell solution, agar solution and gel solution; wherein the feed medium is impregnated with the AI such that following dehydration of the formulation, a slow-acting and non-repellent concentration of the AI is present in the feed medium; and wherein the AI is one or more insecticides selected from the group consisting of insect growth regulators and metabolic inhibitors.

2. The formulation of claim 1, where the feed medium comprises any one or more of the following materials selected from the group consisting of: -cellulose, wood flour, and milled paper, wherein the feed medium is in fine powder form.

3. The formulation of claim 1, wherein the feed medium further comprises an attractant.

4. The formulation of claim 3, wherein the feed medium comprises fine powder form of wood materials decayed with brown-rot fungi or white-rot fungi.

5. The formulation of claim 3, wherein the attractant is a synthetic termite phagostimulant.

6. The formulation of claim 1, wherein the AI is selected from the group consisting of: hexaflumruon, noviflumuron, diflubenzuron, lufenuron, chlorfluazuron, bistrifluron, and triflumruon, and the ecdysone agonist is a ecdysteroid.

7. The formulation of claim 1, wherein the metabolic inhibitor is selected from the group consisting of: borates, sulfluramid, hydramethylnon, ivermectin, fipronil, imidacloprid, and thiamethoxam.

8. The formulation of claim 1, wherein the feed medium is -cellulose, the liquid carrier is methylcell solution and the active ingredient is hexaflumuron.

9. The formulation of claim 1, wherein the viscosity of the formulation is between about 1-50 Pas.

10. The formulation of claim 1, wherein the viscosity of the formulation is between about 50-100 Pas.

11. The formulation of claim 1, wherein the impregnated feed medium is suspended in the liquid carrier to yield a 15-20% dry weight feed medium in 0.5% methylcell solution.

12. The formulation of claim 1, wherein the impregnated feed medium is suspended in the liquid carrier to yield a 10% dry weight feed medium in 1% methylcell solution.

13. The formulation of claim 1, wherein the insect growth regulator is a chitin synthesis inhibitor, juvenoid, or ecdyson agonist.

14. A method for controlling a termite infestation wherein said method comprises: providing a fluid form bait formulation according to claim 1; and injecting the fluid form bait formulation into a void in a structures created by termites.

15. The method of claim 14, wherein the fluid form bait formulation has a viscosity between about 1-50 Pa.Math.s.

16. A kit for preparing a fluid bait formulation having a viscosity of between 1 and 100 Pa.Math.s, wherein the kit comprises: a particulate feed medium impregnated with at least one active ingredient (AI), a liquid carrier to be mixed with the AI(s)-impregnated feed medium wherein the liquid carrier is selected from methylcell solution, agar solution and gel solution; wherein the feed medium is impregnated with the AI such that following dehydration of the formulation, a slow-acting and non-repellent concentration of the AI is present in the feed medium; and wherein the AI is one or more insecticides selected from the group consisting of insect growth regulators and metabolic inhibitors.

17. The kit of claim 16, further comprising an apparatus for injecting the liquid bait formulation into a termite infestation site.

18. The kit of claim 17, wherein the apparatus is a syringe.

19. The kit of claim 11, wherein the feed medium comprises 90% -cellulose and 10% wood flour decayed with G. trabeum and is impregnated with hexaflumuron at 0.5% (AI wt/wt), wherein the liquid carrier is 1% methylcel solution.

20. The kit of claim 16, wherein the fluid form bait formulation has a viscosity between about 1-50 Pa.Math.s.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a depiction of a cross section of wood (or other similar material) damaged by termites.

(2) FIG. 2 illustrates an arena composed of spruce boards colonizing termites to which an embodiment of the invention was applied.

(3) FIG. 3 illustrated changes in termite activities in drilled hole on tree trunk and in the in-ground monitoring stations (represented by the % wood consumption and the number of workers collected), following the application (arrows) of liquid baits (treated with 0.5% hexaflumuron) in trees infested with C. formosanus. Untreated control tree, also infested with C. formosanus, received similar liquid baits without hexaflumuron.

DETAILED DESCRIPTION

(4) The subject invention provides fluid formulations for use in controlling a population of a pest once it has been detected. Specifically, the subject invention pertains to a fluid bait formulation comprising a feed medium impregnated with at least one AI and a liquid carrier. The invention is based on the concept of providing a unique fluid bait formulation that can be injected into a termite infestation site, where an effective (i.e., a lethal AI concentration that is slow-acting and non-repellent) amount of AI(s) is presented to the termite population, even following dehydration of the formulation, to control the termite population.

(5) The subject invention provides a fluid bait formulation that presents to termites within a colony a feed medium impregnated with AI(s) that is toxic to the termites. Preferably, the fluid bait formulation should be delivered into voids created by termite tunneling or feeding or into natural voids (such as internal wall cracks or tree hollows) where termites will likely enter so as to prevent termite infestation.

(6) The fluid bait formulation of the invention has a viscosity that allows it to be injectable. The viscosity of the fluid bait formulation must allow it to flow into and adhere onto the inner surface of voids in structures created by termite tunneling or chewing (also referred to herein as termite galleries). In a specific embodiment, the viscosity of a fluid bait formulation must allow it to be deployed from a syringe or a caulking gun.

(7) In certain embodiments, the viscosity of the fluid bait formulation is between about (3-4)10.sup.3 Pa.Math.s to about 100 Pa.Math.s. Preferably, the viscosity of the fluid bait formulation of the subject invention is between about 1-100 Pa.Math.s; more preferably, the viscosity is between about 50-100 Pa.Math.s. In more preferred embodiments, the viscosity is between about 50-60 Pa.Math.s, 60-70 Pa.Math.s, 70-80 Pa.Math.s, 80-90 Pa.Math.s, or 90-100 Pa.Math.s. In alternate embodiments, the viscosity of the fluid bait formulation of the subject invention is between about 1-50 Pa.Math.s. In more preferred embodiments, the viscosity is between about 1-10 Pa.Math.s, 10-20 Pa.Math.s, 20-30 Pa.Math.s, 30-40 Pa.Math.s, or 40-50 Pa.Math.s.

(8) Materials to be used as feed medium may include -cellulose, wood flour, milled paper or any cellulosic materials in fine powder forms. The particle size or cellulose fiber length, however, have to be large or long enough to contain sufficient quantity of AI(s) after impregnation, and can be fed by termites. A preferred cellulose-containing feed medium is sawdust or wood flour which is not repellent to target termite species.

(9) Suitable AIs that are slow-acting and non-repellent insecticides include insect growth regulators and metabolic inhibitors. The preferred active ingredient will be lethal at concentrations that do not repel the termites. The preferred active ingredient is also capable of being impregnated in the feed medium as described herein. For example, the feed medium may be soaked in AI(s) prior to mixture with a liquid carrier.

(10) Contemplated AIs include, but are not limited to, any one or more of the following: insect growth regulators and metabolic inhibitors. Insect growth regulators may include a broad class of benzoylphenylurea as disclosed in U.S. Pat. No. 5,886,221 (which is incorporated herein by reference in its entirety). Examples of insect growth regulators include chitin synthesis inhibitors such as hexaflumruon, noviflumuron, diflubenzuron, lufenuron, chlorfluazuron, bistrifluron, and triflumruon. Other insect growth regulators include juvenoids or ecdyson agonists, such as those disclosed in U.S. Pat. No. 7,998,496 (which is incorporated herein by reference in its entirety). Slow-acting metabolic inhibitors may include, but are not limited to, borates, sulfluramid, hydramethylnon, ivermectin, fipronil, imidacloprid, and thiamethoxam.

(11) Liquid carriers to be combined with AI(s)-impregnated feed medium can be any liquid useful for suspending powder forms of feed medium. For example, a liquid carrier may include, but is not limited to, water, a methylcell solution, agar solution and/or a gel solution. The final product has to remain in fluid form instead of past-like consistency so that the liquid bait can be injected though a small diameter syringe or a caulking gun. A fluid form is defined here as an entity that does not hold its shape when left in the open, while a past is the one that holds its shape when left in the open. Due to the relatively large particle size and long fiber length of the feed medium, a formulation without sufficient fluid-like consistency tends to clog the injection tip. When the feed medium is made of -cellulose (average fiber length of ca. 0.06 mm), for example, baits with past-like consistency are squeezed into a solid block when the pressure concentrates at the injection tip, making it impossible to place a sufficient quantity of baits into termite galleries.

(12) Preferably, the fluid carrier, when combined with the AI(s)-impregnated feed medium provides a formulation that does not repel target termites.

(13) In certain embodiments, the subject formulations may include materials for stabilizing and/or maintain the formulation environment. For example, a fluid bait formulation may include a humectant to regulating the moisture content of the formulation. An appropriate humectant can have hygroscopic characteristics.

(14) In certain embodiments, the subject formulations may also include a termite attractant. The termite attractant can be a natural or synthetic product. For example, pheromone mimics, such as brown-rot fungi (Gloeophyllum trabeum) extract and its analogs can be used to attract termites to the formulation and feed medium.

(15) In certain embodiments, the subject formulations may also include preservatives for preventing unwanted decay of the feed medium.

(16) An example of the invention disclosed herein uses a fluid bait formulation comprising a feed medium of 90% -cellulose and 10% wood flour decayed with G. trabeum. The feed medium is impregnated with hexaflumuron by mixing acetone solution of hexaflumuron and constantly stirred in a mixer until the total evaporation of acetone so as to yield the final produce of feed medium with 0.5% hexaflumuron (AI wt/wt). Nine parts of the impregnated feed medium are then mixed with one part of 1% methylcel solution to yield 10% dry weight feed medium in 1% methylcel solution. The 1% methylcel solution was viscous enough to suspend particles of feed medium yet remained fluid enough to be injected into termite galleries by using syringes or caulking guns.

(17) According to one embodiment of the invention, a feed medium already impregnated with AI(s) is provided to the user in a kit. The kit could further comprise any one or more of the following: a liquid carrier to be mixed with the AI(s)-impregnated feed medium; an instruction pamphlet with a description regarding how to prepare the fluid bait formulation of the invention; and/or an apparatus for injecting the fluid bait formulation into a termite infestation site.

(18) In a preferred embodiment, a kit is provided comprising a feed medium of 90% -cellulose and 10% wood flour decayed with G. trabeum, where the feed medium is impregnated with hexaflumuron at 0.5% (AI wt/wt), a liquid carrier that is 1% methylcel solution, and an instruction pamphlet providing instructions for mixing the hexaflumuron-impregnated feed medium with the liquid carrier.

(19) In another embodiment, provided is a fluid bait formulation comprising: a feed medium impregnated with AI(s) and a liquid carrier, that is sterilized and/or packaged.

(20) In certain embodiments, where the fluid bait formulation is to be used immediately after it is mixed with a liquid carrier, the feed medium particles do not have to be suspended for a prolonged period, and a lower viscosity liquid carrier, such as 0.5% methylcel or even water, may be used. The proportion of feed medium in the formulation may be increased to 15-20% when the liquid bait formulations are to be injected by using larger diameter apparatuses such as caulking guns.

(21) The subject invention specifically provides a method for controlling a population of termites comprising: providing a fluid bait formulation comprising a feed medium impregnated with at least one AI and a liquid carrier; and injecting the fluid bait formulation into voids in structures created by termites. The termite population may have been detected, for example, following monitoring for termite activity.

(22) With this method, a termite infestation is controlled as a result of termite ingestion and/or contact with an AI(s)-impregnated feed medium that was provided via the fluid bait formulation.

(23) The present fluid termiticide bait formulation can be used against termite pests of family Rhinotermitidae, Kalotermitidae, or Termitidae, but especially desirable against subterranean termite species whose colonies tend to build extensive gallery system, including but not limited to Coptotermes formosanus, C. gestroi, C. acinaciformis, C. lacteus, C. frenchi, C. crassus, C. niger, Heterotermes aureus, H. tenuis, Odontotermes formosnaus, Reticulitermes flavipes, R. virginicus, R. hageni, R. hesperus, R. speratus, R. flaviceps, R. chinensis, R. fukiensis, R. lucifugus, Nasutitermes exitiosus, N. corniger, and N. costalis.

(24) FIG. 1 provides an example of one method of using a fluid bait formulation of the invention. FIG. 1 is a cross section of wood damaged by termites. The surface of the wood 5 rarely shows signs of termite infestation. Within the wood, termites often construct an extensive gallery system 10 comprised of many voids. A syringe or caulking gun 15 may be used to inject a fluid bait formulation 20 of the invention into the termite gallery 10. Hence the liquid bait formulation has to be fluid enough to be injected through a syringe and yet has to be of sufficient viscosity to be retained within the void to allow termite access to AI(s)-impregnated feed medium and enable termites to spread the feed medium to nestmates to eliminate the colony.

(25) Following is an example that illustrates a system and method for practicing the invention. This example should not be construed as limiting. All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.

Example I

(26) Materials and Methods

(27) Efficacy of the fluid bait formulation was tested in an arena composed of a stack of five spruce (Picea sp.) boards (30 cm by 9 cm by 0.4 cm thick each) covered with a sheet of transparent Plexiglas (30 cm by 9 cm by 0.2 cm thick) and tightly secured with eight screws through two steel L-brackets, as shown in FIG. 2. Large washers were placed beneath the crew heads to prevent damaging the Plexiglas, and the steel brackets prevent wooden boards from warping when soaked wet. A 0.5 cm wide main tunnel (0.5 cm deep) 25 was pre-cut at the center of the upper two boards through the entire 30 cm length with four branch tunnels (3 cm long) 30 emerging alternately on both sides at 51 from the main tunnel. The tunnel pattern was provided to simulate that of the subterranean termite galleries (Su et al. 2004). One end of the main tunnel was connected with a Tygon tubing (5 cm by 0.5 cm ID) 35 to a snap-cap plastic container (4 cm by 10.5 cm by 11.5 cm) 40 filled to the 5 cm depth with moistened sand. The other end of the main tunnel 45 was capped with a wooden plug. The arena-container assembly was placed in a large plastic container (42 cm by 17 cm by 12 cm) provisioned with moistened paper at the bottom. The test was done for two subterranean termite species, the Formosan subterranean termite, C. formosanus, and the dark southern subterranean termite, R. virginicus. Two-hundred fifty workers (plus 25 soldiers for C. formosanus, and 3 soldiers for R. virginicus) were placed in the snap-on plastic container to allow them to move into the artificial tunnel through the Tygon tubing 35. C. formosanus termites were collected from five field colonies (three from New Orleans, La., two from Broward County, Fla.) for testing. Termites of R. virginicus collected from three field colonies in Broward County, Fla., plus one colony that has been maintained in the laboratory for over two years were used. Colony origin was used as the replicate, totaling five and four replicates for C. formosanus and R. virginicus, respectively. The entire assembly was then covered with a plastic lid to maintain moisture, and kept at 251 C. for 1-2 weeks before the fluid bait formulations were injected into the arena.

(28) Feed medium comprised of 90% -cellulose and 10% fine-ground Summon (FMC corp., Princeton, N.J.) was impregnated with 0.5% hexaflumuron (AI wt/wt) and homogeneously mixed with 1% methylcel solution to yield 10% dry weight feed medium in the resultant fluid termiticide bait formulation. Control fluid formulations were also prepared by using acetone-treated feed medium, i.e. 90% -cellulose and 10% fine-ground Summon impregnated with acetone.

(29) One to two weeks after placing termites in the arena, the wooden plug at the opposite end 45 of the Tygon tubing connection was removed and approximate 5-10 grams of the fluid bait formulation was injected into the main tunnel by using a syringe (0.3 cm diameter and 5 cm long). The injected quantity usually resulted in filling approximately 10-15 cm of the main tunnels with the fluid bait formulation.

(30) Fifteen experimental units each were prepared for both treated and untreated control for C. formosanus, totaling 30 units. For R. virginicus, 12 experimental units each were prepared for both treated and untreated control, totaling 24 units. The experimental units were kept at 251 C. At 4, 6, and 8 weeks, each replicate of treated and untreated control was disassembled to count the number of surviving workers. Percent moralities were transformed to log (X+1) and subjected to t-test to compare the difference between treated and untreated control groups separately at 4, 6, and 8 week for each species.

(31) Results

(32) One to two weeks after being introduced into the arena, termites extensively fed on wood by expanding the provided tunnels as illustrated in FIG. 2. Termites were present in most of the tunnels when the fluid bait formulations were injected at one end 45, and some were trapped in the injected fluid bait, but most were able to free themselves the following day when the wood absorbed substantial amount of liquid and the feed medium became more solid. In the initial weeks after injecting the fluid bait formulation into the arena, termites moved the feed medium throughout the tunnel system, and by 3.sup.rd week, some workers in treated arenas began to show symptoms of hexaflumuron effects, i.e., marbled coloration with sluggish movement. At the 4.sup.th week, dead workers were found in the tunnels of treated arenas, and mortality was ca. 36% and 73% for C. formosanus and R. virginicus, respectively, which were significantly higher than untreated control groups (Table 1). The timing of the appearance of these symptoms and mortality was similar to the previous laboratory study with hexaflumuron baits (Su and Scheffrahn 1993). By 6.sup.th week, mortalities for both species exceeded 90%. Control mortality of one R. virginicus colony exceeded 30% at 8.sup.th week and data of this colony was excluded from the analysis. Mortality of the treated C. formosanus at 8.sup.th week was 100%. Mean mortality of R. virginicus exposed to hexaflumuron at 8 week was ca. 96%, with a few survivors exhibiting hexaflumuron-affected symptoms, and eventually died after 8 weeks (Table 1).

(33) The results showed that the fluid bait formulation being injected at one part of the tunnel system can be spread to the rest of the experiment unit to cause 90-100% mortality 6-8 weeks later. As demonstrated in previous laboratory and field studies (Su and Scheffrahn 1993, Su 1994, Su et al. 1995), the 6-8 weeks latent effect of hexaflumuron is long enough to enable termites to spread the AI-impregnated feed medium amongst the termites of the colony and eliminate the field colony that may extend to several hundred feet. When injected into an active gallery of termites in a structure, a tree or in soil, termites in the active sites should be able to carry the feed medium from the fluid bait formulation to feed the nestmates, leading to the elimination of a termite colony.

(34) TABLE-US-00001 TABLE 1 Termite mortalities 4, 6, and 8 weeks after feeding on injectable baits treated with 0.5% hexaflumuron in laboratory arenas C. formosanus R. virginicus Weeks Control Treated Control Treated 4 15.4 0.7a 36.1 3.8b 17.4 1.7a 73.2 3.4b 6 19.4 1.4a 94.6 3.9b 23.7 2.9a 92.6 6.0b 8 16.7 1.9a 100.0 0.0b 17.2 2.4a 96.4 1.2b

Example II

(35) Materials and Methods

(36) Field efficacy of the fluid bait formulation was tested against a colony of C. formosanus infesting a tree (Sweetgum, Liquidambar styraciflua) in New Orleans. The infested tree was used as a surrogate of an above-ground infestation. Six holes (ca. 1.3 cm diameter) were drilled into the tree trunk at eye level to intercept termite galleries within. A fiber-optic scope was used to confirm termite presence in the holes. An in-ground monitoring station similar to that of Su and Scheffrahn (1986) was installed in soil near the tree. The station consisted of a plastic collar (18.5 cm diameter by 19 cm high) inserted into the ground and contained a feeding block composed of 18 spruce (Picea sp.) slices (13.4 cm by 8.3 cm by 0.4 cm) bound together with wires. Stations were examined monthly or bi-monthly to visually estimate % wood consumption, and the infested blocks were collected to count the number of termites. Numbers of drilled holes with live termites, % wood consumption and the number of workers in the in-ground station were used to represent termite activities.

(37) Fluid baits were placed in plastic tubes (6 cm diameter and 17 cm long) and injected through two drilled holes on the tree by using caulking guns while termite activities were monitored from the other four drilled holes. Another tree (Bold cypress, Taxodium distichum), also infested by C. formosanus in New Orleans, served as the untreated control. Three drilled holes of the control tree intercepted termites, and one hole received fluid bait without hexaflumuron, while the other two drilled holes served as the monitoring loci. At the 3.sup.rd inspection in September 2012 when continuous termite activities were confirmed in the infested trees, liquid baits were applied.

(38) Results

(39) Through fiber-optic scope, live termites were found in all six holes (two received baits and four did not) up until December 2012, but wood consumption declined substantially in October; only one month after bait application (FIG. 3). The large fluctuation in the number of workers collected from the in-ground station resulted from the abandonment of station when, on some occasions, the feeding blocks were totally consumed. The overall trends of wood consumption rates and the numbers of collected termites, however, showed a general decline in termite activities in the station, as indicated by the low termite in the spring of 2013 when temperature began to rise (FIG. 3). The numbers of drilled holes with live termites also showed the same trend, i.e. a decline from six holes in December 2012 to 1-2 in the spring of 2013. Since May 2013, no live termites have been found in any of the six drilled holes or in the in-ground monitoring station with the feeding block untouched by termites. The trend of decline in treated tree was in sharp contrast with the termite activities recorded form the untreated tree. After the application of untreated baits in September 2012, termite activities (wood consumption rate and number of collected termites) did not change substantially except for a dip in December 2012 when the temperature fell (FIG. 3). As the temperature rose in the spring and summer of 2013, termite activities recovered with occasional fluctuation in the numbers of termites (i.e., due to station abandonment after the total consumption of feeding blocks), and live termites were found in all three drilled holes throughout the field trial period (FIG. 3). It is concluded that the application of treated fluid baits in September 2012 eliminated the C. formosanus colony by April of 2013.

(40) All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

(41) It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.

REFERENCES

(42) Esenther, G. R., T. C. Allen, J. E. Casida, and R. D. Shenefer. 1961. Termite attractant from fungus-infected wood. Science 134: 50. Cornelius, M L, and A. Lax. 2005. Effect of Summon Preferred Food Source on feeding, tunneling, and bait station discovery by the Formosan subterranean termite (Isoptera: Rhinotermitidae). J. Econ. Entomol. 98:502-08 Rust, M. K., K. Haagsma, and J. Nyugen. 1996. Enhancing foraging of western subterranean termites (Isoptera: Rhinotermitidae) in arid environment. Sociobiology 28: 275-286. Su, N.-Y. 1994. Field evaluation of a hexaflumuron bait for population suppression of subterranean termites (Isoptera: Rhinotermitidae). J. Econ. Entomol. 87: 389-397. Su, N.-Y. 2007. Hermetically sealed baits for subterranean termites (Isoptera: Rhinotermitidae). J. Econ. Entomol. 100: 475-482 Su, N.-Y. and M. Lees. 2009. Biological activities of a bait toxicant for population management of subterranean termites. In. C. Perterson & D. Stout [eds.], pp. 87-96, Household, Structural and Residential Pest Management. Oxford University Press, NY. Su, N.-Y., and R. H. Scheffrahn. 1986. A method to access, trap, and monitor field populations of the Formosan subterranean termite (Isoptera: Rhinotermitidae) in the urban environment. Sociobiology 12: 299-304. Su, N.-Y. and R. H. Scheffrahn. 1993. Laboratory evaluation of two chitin synthesis inhibitors, hexaflumuron and diflubenzuron, as bait toxicants against Formosan and eastern subterranean termites (Isoptera: Rhinotermitidae). J. Econ. Entomol. 86: 1453-1457. Su, N.-Y., E. M. Thoms, P. M. Ban, and R. H. Scheffrahn. 1995. A monitoring/baiting station to detect and eliminate foraging populations of subterranean termites (Isoptera: Rhinotermitidae) near structures. J. Econ. Entomol. 88: 932-936. Su, N.-Y, P. M. Ban, and R. H. Scheffrahn. 1997. Remedial baiting with hexaflumuron in above-ground stations to control structure-infesting populations of the Formosan subterranean termite (Isoptera: Rhinotermitidae). J. Econ. Entomol. 90: 809-817. Su, N.-Y., P. M. Ban, and R. H. Scheffrahn. 2001. Control of subterranean termites (Isoptera: Rhinotermitidae) using commercial prototype aboveground stations and hexaflumuron baits. Sociobiology 37: 111-120 Su, N.-Y., B. M. Stith, H. Puche, and P. Bardunias. 2004. Characterization of tunneling geometry of subterranean termites (Isoptera: Rhinotermitidae) by computer simulation. Sociobiology 44: 471-483.