Progress 12/08/00 to 11/30/05
Outputs
Termites are difficult to detect in structures. Dogs were able to differentiate termites from other insects. Properly trained and handled dogs were 96% accurate in finding termites with a 4% false indication rate. As a result, canines have been commercialized as a termite detection service. Subterranean termites usually enter buildings by tunneling from their colonies in the soil. Subterranean termite tunneling behavior in soil was determined to be affected by the number of termites in a colony and by soil compaction, with reduced tunneling in compacted soil. Tunneling is energy expensive for termites so once a tunnel is established they only do minor modifications to it. Therefore, a termite tunnel network would be more extensive in disturbed soil, especially in areas around buildings and underground utilities. A common way to control subterranean termites is to apply a residual soil treatment underneath and around houses. Soil around houses with brick veneer had high
soil pH due to the mixture of spilled cement in the soil. Residual soil termite treatments degraded in high soil pH caused by spilled cement. Another common subterranean termite control treatment technique is termite bait placed in stations in the ground. Diflubenzuron bait was evaluated for its potential as a termite bait, and was shown to protect houses from termite infestation. The product was commericalized and is available to pest controllers. A survey of houses in three Florida counties indicated that home construction practices affect infestation rates of subterranean termites. Placement of landscape shrubs, trees, irrigation, downspouts, and air conditioning condensate lines within 2 feet of the structure was found to increase the rate of termite infestations in houses. As a result of the survey, Florida building codes were modified with termite protection code language to solve the problems with termite foraging guidelines from plants roots and sources of water for termites.
Cockroaches are important pests in structures. Cockroaches were found to follow fecal trails from harborages to food and water. Fecal extracts were shown to enhance sprays for cockroach control, and location of trails in buildings allows pest controllers to place baits close to cockroach activity. The new bait active ingredients, indoxacarb and emamectin benzoate were evaluated for control of bait averse German cockroaches. Indoxacarb is now registered and available to pest controllers and emamectin benzoate is being commercialized. The interaction of enteric bacteria with the cuticle of American cockroaches and pharaoh ants was investigated. Salmonella and E. coli O157-H7 were found to embed in the cuticular waxy layer and remain viable. This indicates that cockroaches and ants can be important transmitters of bacterial food poisoning organisms. Carbon dioxide is often used to immobilize colonized cockroaches for counting into experiments. Carbon dioxide was found to affect bait
feeding experiments for up to 48 hours after cockroach recovery. As a result most researchers now have modified cockroach handling techniques to allow cockroaches to adequately recover and behave normally.
Impacts
The results of this research are being used by pest managers to reduce insecticide usage and manage urban pests. Canine termite detectors were proven capable of reliably detecting termites. By finding termites more efficiently, termiticide use can be targeted to locations where they are entering buildings. Movement of termites and cockroaches is dictated by their response to their environment. Our discoveries about termite tunneling help us understand where termites enter structures and termiticide treatments should be placed. We discovered that cockroaches follow trails from harborage to food and water sources. Until this work was published pest controllers thought that cockroach movement was random, and consequently placed bait and spray treatments throughout the structure. Cockroaches are important urban pests as causative agents of asthma. Human pathogens, Salmonella and E. coli O157:H7, were found on the exterior cuticle of cockroaches and ants for days after the
bacteria were applied. We found the waxy layer of cockroaches is very liquid and mobile, allowing the flagellated bacterial cells to swim through the waxy layer and attach to the cuticle. New insecticides for pest control were evaluated for commercial development. A new termite bait containing diflubenzuron was found to protect houses from subterranean termites. New German cockroach baits containing indoxacarb or emamectin benzoate were evaluated for control of bait averse cockroaches. Both indoxacarb and emamectin benzoate baits overcame bait aversion and were effective in controlling German cockroaches
Publications
- Richman, D.L., C.L Tucker, and P.G. Koehler. 2006. Influence of Portland cement amendment on soil pH and residual soil termiticide performance. Pest Management Sci. 62(2006): 1216-1223.
- Branscome, D. 2004. Interactions of enteric bacteria with american cockroaches (periplaneta americana) and pharaoh ants. PhD dissertation, University of Florida, Gainesville, FL.
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Progress 10/01/04 to 09/30/05
Outputs
New bait containing diflubenzuron products were evaluated for control of subterrantean termites in field situations. These tests are ongoing and will continue for several years. Neonictotinoid termiticides and combinations with pyrethroids were evaluated for activity against subterranean termites. Residual treatments for pest ant control were evaluated. Fipronil was found to kill queens and was an effective insecticide for residual ant control. Two new cockroach bait products were evaluated. Emamectin and indoxacarb were found to be effective new products for control of bait aversive and insecticide resistant cockroaches. New products were evaluated for fly control. Attractants for fly traps were evaluated, and residual fly insecticides were tested for activity against house flies.
Impacts
New products for control of household pests will allow pest management professionals and homeowners to effectively and safely manage pest infestations. These new methods will assist the public to control cockroaches, ants, termites, and flies.
Publications
- Influence of carbon dioxide gas on German cockroach (Dictyoptera: Blattellidae) knockdown, recovery, movement and feeding. Branscome, D.D.; Koehler, P.G.; Oi, F.M., Physiological entomology., vol. 30, no. 2, pp. 144-150, June 2005
- Tunnel formation by different numbers of eastern subterranean termites (Isoptera: Rhinotermitidae) in laboratory arenas. Tucker, C.L.; Koehler, P.G.; Oi, F.M., Sociobiology., vol. 45, no. 3, pp. 731-744, 2005
- Influence of soil compaction on tunnel network construction by the Eastern Subterranean termite (Isoptera: Rhinotermitidae). Tucker, C.L.; Koehler, P.G.; Oi, F.M., Journal of economic entomology., vol. 97, no. 1, pp. 89-94, Feb 2004
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Progress 10/01/01 to 10/01/02
Outputs
Dogs were trained to detect eastern subterranean termites (EST) using the United States Customs method of scent detection dog training modified with a food reward. Dogs were tested with various numbers and species of termites placed in vented PVC containers. Trained dogs were 95.93% accurate in finding >40 EST workers and incorrectly indicated the presence of termites in 2.69% of the containers without termites. Dogs trained to locate EST were also 100% accurate in finding R. virginicus, 98.89% accurate in finding C. formosanus, 97.33% accurate in finding C. cavifrons, and 88.89% accurate in finding I. snyderi. Dogs were able to discriminate live termites from non-termite material. Trained dogs' false response rate was 25.33% to EST damaged wood, 6.67% to American cockroaches, and 2.67% to carpenter ants. Tunneling of various numbers of EST was investigated in sand of various compaction levels was investigated. Tunneling was significantly fastest in low compaction
soil and at high termite densities. Minimum diameters of tunnels allowed 2 termites to pass. Tunnels were in a geometric pattern and angles between primary and secondary tunnels remained constant for all termite densities and soil compaction levels. Termite survival was lowest for low termite densities and high soil compaction. The amount of wood moisture necessary for EST survival was determined by placing termites in wood blocks of 20-30% wood moisture. At 20% wood moisture the LT-90 was 12.6 days, but was 105 days at 30% wood moisture. Wood moisture above 25% was sufficient to allow termites to survive for extended periods of time. To determine typical wood moisture content of EST-infested wood located in termite stations, moisture content was determined with a 2-prong moisture meter. The mean moisture content of infested wood was 53% and was significantly higher than the content of non-infested wood (44%). Carbon dioxide anesthesia is used to knock down cockroaches before many
laboratory experiments. Susceptibility of 4 cockroach strains to CO-2 anesthesia was determined. Cockroaches were knocked down in 7-45 sec; presumptive recovery occurred in 398-587 s. Although presumptively recovered from knockdown, cockroaches exited harborages to forage for food more slowly than for compressed air controls. In addition, food consumption was less, and, consequently, bait consumption was also reduced. As a result, Co-2 exposed cockroaches died significantly more slowly after consuming baits than control cockroaches.
Impacts
For the first time, dogs as termite detectors have been scientifically proven to be capable of accurately detecting hidden termite infestations in buildings. The training and handling method was shown to be very important. As a result, trainers and handlers are now forming a canine termite detection association with high standards of performance, similar to police dog standards. The knowledge of termite tunnel construction will allow better placement of termite baits around structures to obtain control. Because termites prefer tunneling in soil of low compaction, it may be possible to aerate soil around bait stations to encourage termite activity around control devices. Termite survival in wood of various moisture contents allows inspectors after treatment to determine whether termite survival in wood is due to faulty treatments or whether more time is needed to kill the termites. The knowledge that termites will die with 2 weeks in wood moisture of less than 20% will
enhance inspections. Also the knowledge that termites will survive for more than 6 months in wood of 30% will prevent retreatments with expensive termiticides. Cockroach researchers need to be aware that cockroach recovery from carbon dioxide anesthesia may take long periods of time and may affect experimental results. Cockroaches presumably recover from anesthesia within minutes. But foraging and feeding behavior of cockroaches can be suppressed for many hours.
Publications
- Tucker, C. L. 2002. Construction of tunnel network components by subterranean termites, Reticulitermes flavipes (Kollar), in soils of various compaction levels. M.S. Thesis. University of Florida, Gainesville, FL. 112 pp.
- Brooks, S. E. 2001. Canine termite detection. M.S. Thesis. University of Florida, Gainesville, FL. 66 pp.
- McManamy, K. D. 2002. The effect of biotic and abiotic factors on the survivorship of the eastern subterranean termite, Reticulitermes flavipes (Kollar). M.S. Thesis. University of Florida, Gainesville, FL. 68 pp.
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Progress 10/01/00 to 10/01/01
Outputs
German cockroaches live in structures and forage for food and water. by following chemical trails. German cockroaches exhibited trail-following behavior by following chemicals in cockroach feces. Trail-following accuracy varied among the cockroach groups. The mean distance from the fecal trail ranged from 18.45 to 110.05 cm with adult males less than or equal to adult females less than or equal to late instars < gravid females. Fecal trails are not thought to be actively deposited. Rather, the passive distribution of fecal material within the home range results in the accumulation of trails along frequently traveled routes (i.e., between resources and the cockroach harborage). The efficacy of chlorpyrifos and boric acid formulations was tested with and without the addition of fecal extracts. The addition of the aqueous extract produced significantly greater cockroach mortality. Termiticides are applied to soils under houses to protect them from subterranean termites.
The ability of eastern subterranean termites to penetrate various concentrations and treatment thicknesses ranging from 1.0 to 50.0 mm of Dursban TC and Premise 75 was evaluated in a laboratory bioassay. Termites penetrated only a few millimeters into 500 ppm Dursban TC-treated soil at all thicknesses and died as a result of contact. Termites were found to be able to detoxify insecticides. Three alpha-naphthyl acetate hydrolyzing esterase isozymes were purified from microsomes prepared from Reticulitermes flavipes workers.
Impacts
Cockroaches and termites are very difficult to control in infested structures. The discovery of trail following in German cockroaches will improve the efficacy of insecticides, reduce the amounts needed to control infestations, and allow targeting of applications to surfaces cockroaches frequently travel. Some soil termiticides repel termites rather than kill them. Imidacloprid and fipronil were found to be non-repellent and killed termites rather than repelling them. This information is critical for understanding the mode of action of these commonly used termiticides. Also, the discomvery of hydrolizing enzymes in termites was the first discovery of detoxification systems in termites.
Publications
- GAHLHOFF, J.E. Jr. and P.G. KOEHLER. 2001. Penetration of the eastern subterranean termite into soil treated at various thicknesses and concentrations of Dursban TC and Premise 75. J. Econ. Entomol. 94: 486-491.
- MILLER, D.M. and P.G. KOEHLER. 2000. Trail-following behavior in the German cockroach (Dictyoptera: Blattellidae). J. Econ. Entomol. 93: 1241-1246.
- STRONG, C.A., VALLES, S.M., KOEHLER, P.G., BRENNER, R.J. 2000. Residual efficacy of blatticides applied to surfaces contaminated with German cockroach (Dictyoptera: Blattellidae) feces. Fla. Entomol. 83: 438-445.
- MILLER, D.M., KOEHLER, P.G., NATION, J.L. 2000. Use of fecal extract trails to enhance trap catch in German cockroach (Dictyoptera: Blattellidae) monitoring stations. J. Econ. Entomol. 93: 865-870.
- MILLER, D.M. and P.G. KOEHLER. 2000. Novel extraction of German cockroach (Dictyoptera: Blattellidae) fecal pellets enhances efficacy of spray formulation insecticides. J. Econ. Entomol. 93: 107-111.
- VALLES, S.M., OI, F.M., and STRONG, C.A. 2001. Purification and characterization of trans-permethrin metabolizing microsomal esterases from workers of the eastern subterranean termite, Reticulitermes flavipes (Kollar). Insect Biochem. & Molec. Biol. 31: 715-725.
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