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The western subterranean termite, Reticulitermes hesperus Banks, exposed to temperature gradients of 26–47°C, preferred temperatures between 29–32°C. Termites were never found at temperatures >40°C. When exposed to temperature gradients of 5·8–43·6°C, workers preferred temperatures between 14 and 19°C. Soil temperatures varied with depth, exposure to sunlight, and season of the year. Surface soil temperatures in the sunlight exceeded 40°C only during post meridian readings from April through to October. Soil temperatures to a depth of 120 cm exceeded 14°C from April through to October, indicating adequate temperatures for foraging activity. Surface soil temperatures were below optimal foraging temperatures from November through to March, especially during the night and early morning. No thermal shadows existed at the 0800 h reading. Within 4 h, the soil underneath the centre of the stone was significantly cooler than was the soil at the edge or exposed to sunlight. By late afternoon even the soil under the centre of the stone had increased to above 40°C. Thermal shadows provide refuge for surface foraging termites to avoid high temperatures.

To assess the capability of passive decay heat removal systems of an advanced pool-type liquid-metal cooled reactor, natural circulation experiments have been performed to investigate the in-vessel cooling modes caused by the position and number of decay heat exchangers in operation. The rather simple slab test facility AQUARIUS is equipped with an electrically heated core and decay heat exchangers. Four different arrangements of heat exchangers are under consideration to study the temperature distribution and the flow behavior in the apparatus during both symmetrical and asymmetrical heat removal. The experiments have been carried out in water under laminar flow conditions. Temperatures have been measured under quasi-steady-state conditions. The observed flow paths have been documented photographically. In case of asymmetrical heat removal, especially when a single heat exchanger is operated in one of both upper plena, the temperature distribution and the flow behavior are different from symmetrical cooling modes. A comparison of analytically predicted temperatures using the COMMIX-2(V) computer program with experimental data shows reasonably matches the findings. The results of the numerically determined velocity fields are in good agreement with the visual observations.

Adult cat fleas, Ctenocephalides felis (Bouché), marked with orange-red or green fluorescent dye were released on one cat to study movement to another cat over a 7-d period. When the cats were separated, 3-8% of the marked fleas moved to the other cat. When the cats were allowed to remain together, 2-15% of the fleas moved. The percentage of fleas unaccounted for ranged from 8-47%. When both cats lived together, 8-15% movement occurred no matter which cat was infested. The percentage of female and male fleas unaccounted for was 8-32 and 30-47%, respectively, highlighting the importance of host grooming. Significantly fewer female cat fleas moved from one host to another than did males. The likelihood of establishing new infestations by adult fleas transferring from one host to another exists. However, visitations to environments capable of supporting immature stages of fleas seem a more important source of flea infestations.

Intensive residential use of insecticides has resulted in their ubiquitous presence as contaminants in urban surface streams. For pest eradication, urban hard surfaces such as concrete are often directly treated with pesticides, and wind/water can also carry pesticides onto hard surfaces from surrounding areas. This study expanded on previous bench-scale studies by considering pesticide runoff caused by irrigation under dry weather conditions and rain during the wet season, and evaluated the effects of pesticide residence time on concrete, single versus recurring precipitations, precipitation intensity, and concrete surface conditions, on pesticide transferability to runoff water. Runoff from concrete 1 d after pesticide treatment contained high levels of bifenthrin (82 μg/L) and permethrin (5143 μg/L for cis and 5518 μg/L for trans ), indicating the importance of preventing water contact on concrete after pesticide treatments. Although the runoff transferability quickly decreased as the pesticide residence time on concrete increased, detectable residues were still found in runoff water after 3 months (89 d) exposure to hot and dry summer conditions. ANOVA analysis showed that precipitation intensities and concrete surface conditions (i.e., acid wash, silicone seal, stamping, and addition of microsilica) did not significantly affect the pesticide transferability to runoff. For concrete slabs subjected to natural rainfalls during the winter wet season, pesticide levels in the runoff decreased as the time interval between pesticide application and the rain event increased. However, bifenthrin and permethrin were still detected at 0.15–0.17 and 0.75–1.15 μg/L in the rain runoff after 7 months (221 d) from the initial treatment. In addition, pesticide concentrations showed no decrease between the two rainfall events, suggesting that concrete surfaces contaminated by pesticides may act as a reservoir for pesticide residues, leading to sustained urban runoff contamination.

Although on-animal topical treatment with compounds such as imidacloprid has revolutionized the control of the cat flea, Ctenocephalides felis (Bouche) (Siphonaptera: Pulicidae), the development of insecticide resistance is a continuing threat. As part of a highly co-ordinated and unprecedented resistance monitoring programme for C. felis, 1437 flea isolates were collected by veterinary clinics in Australia, Germany, France, the U.K. and 29 states in the U.S.A. from 2002 to 2009. About 65% of the collections were made from June to October each year and 71% of the collections were from cats. Collections of flea eggs were sent to one of five different laboratories, where they were tested with a diagnostic dose of imidacloprid (3 p.p.m.) applied to larval flea-rearing medium. Of the 1437 collections received, 1064 contained adequate numbers of eggs for testing. Of these isolates, untreated eggs failed to hatch in 22.7% and were not considered valid bioassays. Survival rates > 5% and development of adult fleas (a threshold for further testing) occurred in only 22 isolates. They were re-tested with the same diagnostic dose and none produced > 5% adult emergence. Complete dose-response bioassays were performed on three of the isolates that had triggered a second test and produced slopes, intercepts and LC(50) values similar to those for existing susceptible laboratory strains. Results confirmed sustained susceptibility of C. felis to imidacloprid, despite its widespread use for over a decade.

Sands treated with solvent systems used to formulate commercially available termiticides, except for isofenphos, were toxic to western subterranean termites, Recticulitermes hesperus Banks, killing 24-86% after a 24-h exposure to sand air dried for 1 d. After air-drying deposits for 7 d, no solvent systems were still toxic. Irrigating solvent-treated sands with the equivalent of 1.27 cm of rainfall removed all toxicity, except for permethrin and cypermethrin solvent systems. After a second irrigation, all sands treated with the solvent systems were not toxic. Sands treated with solvent systems of all termiticides tested were repellent, except for that of isofenphos, and remained repellent after being air dried for 7 d. The loss of toxicity, but not repellency, after air drying suggests different chemical bases for the two effects or a concentration dependent effect. None of the termiticides tested were repellent after two rinses with water (equivalent of 2.54 cm rainfall). The effects of solvents must be considered when evaluating the repellency and toxicity of soils treated with commercially available termiticides.

To address the capability of passive decay heat removal systems of an advanced liquid-metal-cooled nuclear reactor, natural circulation experiments were performed to investigate the bouyancy-driven backflow phenomenon in the mixed convection flow of a cooling channel. In the AQUARIUS half-slab test facility, the core is represented by a vertical channel formed by two parallel electrically heated walls. At the top end, the channel is connected to an upper plenum where the fluid is cooled by an immersion cooler. Fluid velocities and temperatures were measured under quasi-steady-state laminar conditions. The experiments indicate that for low heat flux densities and large channel widths, cold water from the upper plenum flows down and penetrates the heated channel where the flow direction is upward. A comparison of analytical predictions using the COMMIX-2(V) three-dimensional computer code against experimental AQUARIUS data shows reasonable overall agreement. The numerical results reflect that backflow effects were not predicted for the investigated problem.

BACKGROUND: Insecticides are commonly used for ant control around residential homes, but post-treatment runoff may contribute to contamination of surface water in urban watersheds. This study represents the first instance where runoff of insecticides was directly measured after applications around single family residences. During 2007, houses were treated with bifenthrinorfipronilsprays following standardpractices. During 2008,pin streamapplicators, spray-freezones andrestricting sprays to the house foundation were considered as management options. RESULTS: During 2007, the resulting runoff from the bifenthrin spray in the irrigation water had a mean concentration of 14.9 µ gL −1 at 1 week post-treatment and 2.5 µ gL −1 at 8 weeks, both high enough to be toxic to sensitive aquatic organisms. In comparison, treatments with bifenthrin granules resulted in no detectable concentrations in the runoff water after 8 weeks. The mean concentration for fipronil used as a perimeter spray was 4.2 µ gL −1 at 1 week post-treatment and 0.01 µ gL −1 at 8 weeks, with the first value also suggesting a potential for causing acute aquatic toxicity to sensitive organisms. During 2008, insecticide runoff was reduced by using spray-free zones and pin stream perimeter applications. CONCLUSIONS: It is shown that insecticide runoff from individual home treatments for ants can be measured and used to improve techniques that minimize runoff. The pin stream application and applications limited to the house foundation should be further evaluated for their potential to reduce pesticide runoff from residential homes. c � 2010 Society of Chemical Industry

In a previous experimental study, recluse spiders Loxosceles reclusa Gertsch and Mulaik and Loxosceles laeta (Nicolet) (Araneae: Sicariidae) preferred small cardboard refugia covered with conspecific silk compared with never-occupied refugia. Herein, we investigated some factors that might be responsible for this preference using similar cardboard refugia. When the two Loxosceles species were given choices between refugia previously occupied by their own and by the congeneric species, neither showed a species-specific preference; however, each chose refugia coated with conspecific silk rather than those previously inhabited by a distantly related cribellate spider, Metaltella simoni (Keyserling). When L. laeta spiders were offered refugia that were freshly removed from silk donors compared with heated, aged refugia from the same silk donor, older refugia were preferred. Solvent extracts of L. laeta silk were chosen approximately as often as control refugia when a range of solvents (methylene chloride:methanol, water, and hexane) were used. However, when acetone was used on similar silk, there was a statistical preference for the control, indicating that there might be a mildly repellent aspect to acetone-washed silk. Considering the inability to show attraction to chemical aspects of fresh silk, it seems that physical attributes may be more important for selection and that there might be repellency to silk of a recently vacated spider. These findings are discussed in regard to pest management strategies to control recluse spiders.

Publisher Summary This chapter expands on the use patterns of insecticides in and around structures to control the major urban insect pests. Environmental and health concerns have become an important consideration in urban pest management, especially as it relates to water quality issues. The detection of pesticides, particularly pyrethroids, in urban waterways has raised concerns about their use, especially for ant control. There has been an increased awareness of the potential hazards of pesticides in urban environments and demand for more integrated pest management (IPM) and so-called green pest control. Even though green pest control lacks a clear definition and is largely a marketing tool, it has generated considerable attention. It has revitalized urban IPM, especially strategies that utilize a smaller amount of insecticides, and has stimulated the development of several different training programs for pest management professionals (PMPs). There is an increasing database and public awareness of the medical importance and role of cockroaches and other arthropods in inducing asthma and related health issues. This development will likely result in major regulatory changes and use patterns of insecticides around urban structures and present challenges to the PMP and homeowner. The use of botanicals, fragrance oils, and inorganic compounds has increased dramatically. Other new chemistries such as the neonicotinoids, phenylpyrazoles, and pyrroles have largely replaced the organophosphate and some traditional uses of pyrethroid insecticides.

Topical toxicity of cypermethrin (LD50 = 1.6 μg/g) was approximately three times greater to Reticulitermes hesperus Banks than chlorpyrifos (LD50 = 4.5 μg/g) and ≈35 times greater than chlordane (LD50 = 56.8 μg/g) after 7 d. Water rinsed from soil treated with chlorpyrifos produced significantly greater kill than did soil treated with an aqueous rinse hom soil h’eated with cypermethrin. The rinse water from soil treated with chlordane did not produce significant kill when redeposited on untreated soil. Termiticidal amounts of chlorpyrifos, chlordane, or cypermethrin moved to soil depths of at least 30,7, and 7 cm, respectively. With cypenrmethrin, sublethal effects were detected to a depth of 42 cm.

Photoperiod affected the production of cat flea eggs by cats infested with cat flea, Ctenocephalides felis (Bouché). Cat flea eggs have a smooth chorion and do not adhere to the host. About 60% of fluorescing eggs placed in the pelage were recovered in collecting trays underneath the host in 2 h. An average of 87.7 eggs per cat was laid during the last 8 h of the scotophase compared with 49.9 and 59.1 eggs during the other 8-h periods. Significant variation in the number of eggs collected daily existed among the six cats. The activity budgets were similar for all the cats with the maximum sleep period during the photophase. The possible adaptive advantages of synchronizing egg production with photoperiod are discussed.

The oral toxicity of boron compounds to the Argentine ant, Linepithema humile (Mayr), was evaluated in laboratory tests. The ants were provided 25% sucrose water containing 0.5 and 1% boric acid, disodium octaborate tetrahydrate, and borax. Lethal times of these solutions were a function of the concentration of boron. In field tests, the ants showed no discrimination between disodium octaborate tetrahydrate and boric acid. There was a significant reduction in consumption of sucrose water with >1% boric acid.

Experiments tested the ability of newly emerged spiderlings of a black widow spider, Latrodectus hesperus Chamberlin & Ivie (Araneae: Theridiidae), to crawl through brass screen of various mesh size. The purpose was to determine whether immatures of these medically important spiders could be excluded from buildings. In horizontal orientation, black widow spiderlings were able to easily pass through mesh with openings of 0.83 mm and were prevented from passing in four of five tests with mesh of 0.59-mm openings. Spiderlings also readily pass through 0.83-mm mesh in vertical orientation. Our laboratory studies indicate that the mesh size sufficient for exclusion is too small for practical use in most cases, although there are some specialized situations where such small mesh might be useful. The results are discussed in regard to actual conditions found in typical commercial building situations.

Publisher Summary This chapter discusses cat fleas, which are small (2 mm), dark, reddish brown, wingless, bloodsucking insects. The cat flea is a cosmopolitan, eclectic species, having been recorded from more than three dozen species, including opossums, raccoons, kangaroos, and even birds. This wide host range explains this flea’ s ability to repopulate domestic animals after suppression efforts. Because it lacks host specificity and tends to feed on humans, the cat flea is a pest of both companion animals and humans with whom they share their abode. Once adult cat fleas locate a host, they tend to remain on that animal unless dislodged. They feed readily and mate on the host. Female fleas lay eggs while on the host and because the eggs are not sticky, they readily fall off into the host's environment, with large numbers accumulating in areas frequented by the animal. From the eggs emerge small, white, eyeless, legless larvae with chewing mouthparts. Flea larvae have three instars that, under favorable conditions, can be completed in as little as 10 days. The third instar voids its gut approximately 24 hours before initiation of cocoon construction. Within its cocoon, the prepupa molds to the pupa and continues metamorphosis to the adult flea within about 4 days, under favorable conditions. Because fleas must have blood from a mammalian host to survive, treating host animals is the most efficient and effective means of suppressing fleas.

Publisher Summary This chapter discusses how urban habitats are conducive to insect pest problems such as mosquitoes, flies, cockroaches, fleas, termites, and wooddestroying pests. In addition, crowding and waste also lead to vertebrate pest problems such as rats, mice, and pigeons. For example the Formosan subterranean termite, Coptotermes formosanus, has spread by marine commerce to semitropical and tropical seaports throughout the world. Once ashore, railroad ties provide a rapid method of moving and establishing large colonies of termites. The vast majority of insects, however, are not capable of adapting to the artificial and unnatural conditions created by humans in urban environments. A few pests such as the German cockroach, cat flea, and house fly have readily adapted, have been able to survive in close proximity to humans, and now are cosmopolitan. Humans can directly attribute the need for urban pest management in and around structures to the dislike of insects and arthropods. Some pests such as cockroaches, fleas, flies, and mosquitoes represent potential health risks. Others such as termites and wooddestroying pests can cause serious economic damage to structures. Pantry and fabric pests cause damage to foods, fabrics, and items made with furs, skins, and feathers.

A blanket design concept using Pb17Li eutectic alloy as both breeder material and coolant is described. Such a self-cooled blanket for the boundary conditions of a DEMO-reactor is under development at the Kernforschungszentrum Karlsruhe (KfK) in the frame of the European blanket development program. Results of investigations in the areas of design, neutroncs, magneto-hydrodynamics, thermo-mechanics, ancillary loop systems, and safety are reported. Based on recent progress, it can be concluded that the boundary conditions of a DEMO-reactor can be met, tritium self-sufficiency can be obtained without using beryllium as an additional neutron multiplier, and tritium inventory and permeation are acceptably low. However, to completely judge the feasibility of the proposed concept, further studies are necessary to obtain a better understanding of the magneto-hydrodynamic phenomena and their effects on the thermal-hydraulic performance of a fusion reactor blanket.

We developed a laboratory method to determine the potential efficacy of baits formulated for control of the Argentine ant, Iridomyrmex humilis (Mayr). Possible effects as insect growth regulators were not examined. Of the 10 formulated baits tested, only mirex applied to granulated silkworm pupae had delayed toxicity. Hydramethylnon applied to granulated silkworm pupae also provided excellent kill of workers but did not exhibit delayed toxicity. In field tests, this bait provided faster control than did a chemical barrier of granular diazinon.

The design of magnetic pulse sharpening circuits for thyratron switching applications is presented. It is useful to add a saturating magnetic switch in series with the tube. Addition of the magnetic device reduces anode dissipation, hence reducing thyratron cooling requirements. The saturating magnetic switch allows the anode voltage to collapse while delaying the forward current, thus reducing the electron energy to a level below that which results in erosion. The complex interrelated issues of material selection, electrical parameters, core reset, and mechanical engineering are considered for the development of an integrated point design. Test results are presented, and life extension to >10/sup 10/ shots is discussed. >

Dichlorvos and chlorpyrifos vapor from dried residual deposits produced significant numbers of moribund workers of the western subterranean termite, Reticulitermes herperus Banks. In some cases, lethal effects were not observed until 7 h after exposure. Tenhour exposure to vapor from deposits of chlordane, chlorpyrifos, cypermethrin, or dichlorvos aged for 12 h produced significantly greater numbers of moribund workers than did the control treatment. Vapor from deposits of chlordane, chlorpyrifos, or cypermethrin aged for 12h produced more moribund insects than did 1-h-old deposits, suggesting that older deposits release more toxicant than fresh deposits. Residual deposits of chlorpyrifos or dichlorvos redeposited from their vapor phase on foil surfaces produced 83–100% moribund termites within 24 h. Redeposition of toxicant or sorption of vapor might be responsible for lethal effects. Regardless of the insecticide used, toxic amounts did not move to dry untreated soil beneath treated soil. Toxic vapor from soil treated with dichlorvos moved down simulated termite tunnels. This phenomenon was not observed for other insecticide treatments.

Communications and Power Industries, Inc (CPI) produced 81 klystrons for the Spallation Neutron Source at Oak Ridge National Laboratory. The klystrons are rated for 550 kW peak at 805 MHz. seventy units have accumulated 1,284,647 hours of filament operation and 820,429 hours of high voltage operation to date. A higher power 700 kW version has been developed and is now in production.

A variety of refugia were offered to different instars of brown recluse spiders, Loxosceles reclusa Gertsch and Mulaik, and a South American recluse spider, L. laeta (Nicolet), to determine whether they preferred certain types of refugia spaces. Variables included (1) crevice widths ranging from 3.2 to 21 mm, (2) horizontal and vertical orientations, and (3) new refugia or refugia that had silk deposited by a previous conspecific resident. An additional 30-d assay with similar-sized refugia studied each species' propensity for site fidelity or movement among refugia. L. reclusa preferred crevice widthsor = 9 mm with no correlation of body size to crevice width, whereas L. laeta preferred crevice sizesor = 6.4 mm with a marginally significant correlation between crevice width and body size. Both species preferred (1) vertical instead of horizontal-oriented refugia and (2) refugia with conspecific silk compared with previously uninhabited refugia. There was no significant difference between the species in their propensity to move among refugia in the 30-d trial; however, both species had individuals that were always found in the same refugium for the entire assay and individuals changing refugia every 2-3 d. The propensity to switch refugia was not affected by the degree of starvation for the period tested as was initially hypothesized. The possible implications of this research toward developing novel control measures for Loxosceles spiders are discussed.

Using natural venom collected from the red imported fire ant, Solenopsis invicta Buren, we determined the dose of venom necessary to kill 50% of the workers (LD50) of Argentine ants, Linepithema humile (Mayr), and several other ant species that the fire ant may encounter in California. Of the species tested, the Argentine ant was most susceptible to the venom. On a weight-adjusted basis the red imported fire ant was 330 times more resistant to the venom than the Argentine ant. In addition, the native southern fire ant, Solenopsis xyloni McCook, was significantly more susceptible to the venom than S. invicta. Formica perpilosa Wheeler was most resistant to the venom when the LD50 was not adjusted for weight, requiring a dose 684 times higher than that of the Argentine ant. When we tested synthetic venom (solenopsin A, which is the main component of S. xyloni venom) against the Argentine ant, the LD50 value was unchanged. However, both S. invicta and S. xyloni were ≈6 times more susceptible to the synthetic compound than to natural venom. Therefore, S. invicta venom is less toxic to fire ants while being just as toxic to Argentine ants as the simpler, more primitive venom of S. xyloni. Fire ant gaster flagging and venom dabbing applies enough venom to the Argentine ant to be lethal and may help explain the superior interference competition shown by the red imported fire ant.

Western subterranean termites, Reticulitermes Hesperus Banks, did not tunnel in soil with particle sizes ranging from 0.84 to 2.36 mm. Instead, they tunneled at equal rates in soils with particle sizes ranging from 0.15 mm. The latter range of soils was treated with termiticides in the study. In continuous-exposure studies in which termites were placed on soil treated at ≥ 50 ppm with termiticide, bifenthrin, cypermethrin, or permethrin had the greatest activity. Soil treated with chlordane, permethrin ( 50 ppm permethrin. Fenvalerate (< 100 ppm) and isofenphos formulations were the least active treatments. In tunneling studies, termites did not tunnel into soil treated with formulations of bifenthrin or cypermethrin, even at the lowest concentration tested. No tunneling occurred in soil treated with formulated chlordane, chlorpyrifos, fenvalerate, isofenphos, or permethrin at concentrations ≥ 50 ppm. Mortality from the tunneling activities was greatest in tubes filled with soil treated with formulated bifenthrin and chlorpyrifos. Even though termites tunneled only in the untreated soilbelow the soiltreated with chlordane, chlorpyrifos, fenvalerate, isofenphos, or permethrin formulations at concentrations ≥50 ppm, mortality and sublethal effects were observed. Insecticide probably diffused from treated areas to untreated areas in concentrations high enough to produce kill or affect behavior.

Laboratory studies were done to evaluate the repellency and efficacy of 25 insecticides against foraging workers of the Argentine ant, Iridomyrmex humilis (Mayr). The trail pheromone of I. humilis, cis-9 hexadecenal, was used to induce trailing and movement through sections of glass tubing treated with insecticides. General repellency of formulations was ranked as granular < emulsifiable concentrate < dust < wettable powder. As the repellency of the insecticide increased, mortality increased. Potential field efficacy of 25 insecticides as barrier treatments is discussed.

Four different termite control strategies consisting of two soil treatments with cypermethrin and fipronil and two bait treatments with hexaflumuron and sulfluramid were evaluated for their efficacy and potential for controlling the invasive eastern subterranean termite, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae), in Quillota and Valparaiso, Chile. Monitoring stations were installed at all sites to measure the overall termite activity next to and at distances up to 30 m away from infested structures, most being 3-5 m. Foraging activity was extremely seasonal with the maximum consumption rates occurring from January to April. Termite foraging activity was low from July to September. After treatments in January 2003, there was a significant decrease in wood consumption, percentage of active stations, and numbers of termites in traps for the first 6 mo with hexaflumuron baits. No significant change in R. flavipes foraging activity was observed on wood consumption and percentage of active stations for sulfluramid bait or cypermethrin and fipronil soils treatments. The seasonal pattern of foraging activity remained unchanged for all treatments in 2004 and 2005, except structures baited with hexaflumuron. Feeding activity at the monitors in the area surrounding the hexaflumuron baits declined to 0 after January 2004. Alate flights occurred in approximately 38% of the structures treated with cypermethrin and sulfluramid bait in 2003 and in approximately 40% of the structures treated with cypermethrin, fipronil, and sulfluramid bait in 2004. Sulfluramid baits and cypermethrin soil treatments did not have any impact within a 15-m radius of the structures. Soils treatments of fipronil and cypermethrin prevented termites access in 75% of the homes. The number of active monitoring stations only declined within 2 m of the fipronil-treated zone. Hexaflumuron exhibited a reduction in activity for at least a 15-m radius.

The potential horizontal transfer ofnonrepellent termiticides has become an important paradigm to control termites in recent years. In this study, 14C-radiolabeled fipronil was used in a series of laboratory experiments to demonstrate the extent and ability of termites to transfer lethal amounts of fipronil to unexposed nestmates. Fipronil is an active and nonrepellent termiticide against western subterranean termites, Reticulitermes hesperus Banks, on sand at relevant doses. It exhibited delayed toxicity with the lowest LD50 approximately 0.2 ng/termite expressed between day 4 and 7. Both continuous and brief exposures to fipronil-treated sand seriously impaired the termite's ability to move and respond to a dodecatrienol trail, limiting potential horizontal transfer. In tunneling studies, fipronil prevented termite tunneling at concentrations as low as 0.5 ppm and was nonrepellent even at 500 ppm. Greater than 90% mortality was recorded by day 7 with concentrations ranging from 0.5 to 500 ppm. There was a linear relationship between the time of exposure and uptake of [14C]fipronil when termites were continuously exposed to 0.5, 1.0, and 5.0 ppm for 24 h. However, uptake discontinued when the termites were immobilized. Maximum transfer of fipronil from donors to recipients occurred within the first 24 h. Fipronil was transferred by body contact and trophallaxis did not play a major role in horizontal transfer. In successive transfer studies, there was not enough fipronil on recipients for them to serve as secondary donors and kill other termites. In a linear arena study, there was an inverse relationship between the amount offipronil on dead termites and their distance from the treated zone. Maximum mortality was observed within 1.5 m from the treated zone. Results in our laboratory studies suggest that horizontal transfer was not a major factor contributing to the efficacy of fipronil in the field.

A flea larval bioassay was developed by an international team of scientists to monitor the susceptibility of fleas (Ctenocephalides felis) to imidacloprid (Advantage, Bayer HealthCare). The assay was validated using laboratory and field isolates of C. felis. Flea eggs representing different field isolates of C. felis were collected by veterinarians in the United States, United Kingdom, and Germany. Of the 972 flea isolates obtained during the 5-year study, 768 contained sufficient numbers of eggs to conduct the larval bioassay. Greater than 5% survival occurred for only six of the field isolates evaluated. Further evaluation and analysis of these isolates demonstrated that they did not differ significantly in their susceptibility to imidacloprid from the reference strains used to develop the assay. Collections of field flea isolates will continue in an attempt to detect and document any change in the susceptibility of field flea populations to imidacloprid.

The spallation neutron source (SNS) has recently completed the commissioning of its 1.0 GeV proton storage ring, which included the ring extraction kicker system. This extraction system is comprised of fourteen high-voltage Blumlein-configured pulse-forming networks switched by fourteen thyratrons. The system also includes fourteen Blumlein control racks, which provide a high-voltage source, monitoring of interlocks, and signal conditioning to the system control racks. The four-system control racks are for adjusting timing and monitoring of the charge voltages and current pulses at the kicker magnets. The kicker system is then controlled by EPICS, the accelerator's control system. The kickers were designed at Brookhaven National Laboratory as in companion papers (BNL), and built to print by Applied Power Systems, Inc., (APS), of Hicksville, NY. The hardware and software utilized and the commissioning results of the fourteen Blumlein kickers will be presented

This paper describes the types and quantities of dc and pulsed magnet power supplies required for the Spallation Neutron Source (SNS) Linear Accelerator: High-Energy Beam Transport (HEBT), Ring and the Ring-to-Target Beam Transfer (RTBT). There are over 600 magnets and more than 550 magnet power supplies. These magnet power supplies range in size from the bipolar corrector supplies rated at 35 volts, 20 amps to the main-ring dipole supply that is rated at 440 volts, 6000 amps. The Linac power supplies have a ripple/stability specification of 1000 parts per million while the ring supplies have a specification of 100 parts per million. There are also pulsed-power supplies for beam injection and beam extraction. The paper will show acceptance test results from the manufacturers as well as test results performed by the SNS magnet power supply group.