Through a recent (2003–2007) survey of ectoparasites on hoofed mammals in western North America, a literature review, and examination of archived museum specimens, we found that the exotic deer-chewing louse, Bovicola tibialis (Piaget), is a long-term, widespread resident in the region. The earliest known collection was from Salt Spring Island, Canada, in 1941. We found these lice on the typical host, that is, introduced European fallow deer (Dama dama L.), and on Asian chital (Axis axis [Erxleben]), native Columbian black-tailed deer (Odocoileus hemionus columbianus [Richardson]), and Rocky Mountain mule deer (O. h. hemionus [Rafinesque]) × black-tailed deer hybrids. Chital and the hybrid deer are new host records. All identified hosts were known to be or probably were exposed to fallow deer. Geographic records include southwestern British Columbia, Canada; Marin and Mendocino Counties, California; Deschutes, Lincoln, and Linn Counties, Oregon; Yakima and Kittitas Counties, Washington; Curry County, New Mexico; and circumstantially, at least, Kerr County, Texas. All but the Canadian and Mendocino County records are new. Bovicola tibialis displays a number of noteworthy similarities to another exotic deer-chewing louse already established in the region, that is, Damalinia (Cervicola) sp., which is associated with a severe hair-loss syndrome in black-tailed deer. We discuss longstanding problems with proper identification of B. tibialis, the probability that it occurs even more widely in the United States, and the prospects for it to cause health problems for North American deer. Additional information gathered since our active survey establishes further new distribution and host records for B. tibialis.

Climate and vegetation in Spain vary from north to south, affecting tick distribution and consequently the presence of tick-borne diseases. The aim of this study was to investigate throughout a 2-yr study the distribution of the different exophilic questing tick species present in 18 areas: eight located in central and 10 in northern Spain. The same methodology was used in both areas, sampling vegetation on a monthly basis by blanket dragging for 20- to 30-min intervals. A total of 12 species belonging to the genera Ixodes, Haemaphysalis, Rhipicephalus, Dermacentor, and Hyalomma was identified. Differences in species distribution and prevalence were dramatically different. The most frequent and abundant species in northern Spain were Ixodes ricinus (67% of adult ticks) and Haemaphysalis punctata (8%), whereas Hyalomma lusitanicum (86%) and Dermacentor marginatus (12%) were the most abundant in central Spain. There were important differences in the monthly seasonal patterns for the different tick species. These results highlight important differences in tick distribution in neighboring areas and underline the need for ongoing surveillance programs to monitor tick population dynamics and the prevalence of tick-borne pathogens.

The abiotic and biotic factors that govern the spatial distribution of Lyme disease vectors are poorly understood. This study addressed the influence of abiotic and biotic environmental variables on Ixodes pacificus Cooley & Kohls (Acari: Ixodidae) nymphs, because it is the primary vector of Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwaldt & Brenner in the far-western United States. Three metrics of Lyme disease risk were evaluated: the density of nymphs, the density of infected nymphs, and the nymphal infection prevalence. This study sampled randomly located plots in oak (Quercus spp.) woodland habitat in Sonoma County, CA. Each plot was drag-sampled for nymphal ticks and tested for B. burgdorferi infection. Path analysis was used to evaluate the direct and indirect relationship between topographic, forest structure and microclimatic variables on ticks. Significant negative correlations were found between maximum temperature in the dry season and the density of infected ticks in 2006 and tick density in 2007, but we did not find a significant relationship with nymphal infection prevalence in either year. Tick density and infected tick density had an indirect, positive correlation with elevation, mediated through temperature. This study found that in certain years but not others, temperature maxima in the dry season may constrain the density and density of infected I. pacificus nymphs. In other years, biotic or stochastic factors may play a more important role in determining tick density.

The introduction of Aedes albopictus (Skuse) in the United States has been associated with declines in abundance of resident mosquito species, presumably because of resource competition, as larvae of Ae. albopictus have been illustrated as superior competitors under certain resource conditions. We evaluated the hypothesis that varying the type and ratio of two food resources (Foxtail grass: American elm) alters the competitive outcome of Ae. albopictus and Culex pipiens (L.). We measured survivorship, development time, size, and adult longevity, and estimated the population growth index (λ′) of populations raised both alone and in equal number with the interspecific competitor, across five ratios of the two food resources. Competition was asymmetric with Ae. albopictus, the superior competitor across all resource treatments; however, the competitive advantage Ae. albopictus had over Cx. pipiens was reduced as grass became the predominant resource. With elm as the predominant resource, the population growth index (λ′) for both Ae. albopictus and Cx. pipiens was lower in intraspecific and interspecific competition treatments, respectively. The treatments also impacted adult life history, as life spans of both Ae. albopictus and Cx. pipiens varied when they emerged from larval conditions with different resource and competition treatments. We discuss the possible differences in the two species' efficiencies in exploiting the two resource types. Despite some resource conditions alleviating the competitive effects of Ae. albopictus on Cx. pipiens, competition remained asymmetric; thus, additional mechanisms are likely operating under field conditions when the two species coexist.

The kairomone octenol is known as attractive to hematophagous Diptera such as mosquitoes, tsetse flies, and midges. There is little evidence that traps baited with octenol are also effective in attracting phlebotomine sand flies. The present report evaluated octenol in modified Centers for Disease Control and Prevention (CDC) traps in two experiments: 1) modified CDC trap without light and 2) modified CDC trap with light. The traps were baited with octenol at concentrations of 0.5, 27, and 43 mg/h in Rincão locality, São Paulo, Brazil. Traps without octenol were used as controls. The sand fly Nyssomyia neivai (Pinto) (=Lutzomyia neivai) (Diptera: Psychodidae: Phlebotominae) was the prevalent species (99.9%) in both experiments. The results of the experiments showed that traps baited with octenol at 27 and 43 mg/h caught significantly more N. neivai than control and octenol at 0.5 mg/h with and without light. This is the first report that shows that octenol itself is attractive to N. neivai and associated with light traps significantly increases the catches.

When devising methods to sample Aedes aegypti (L.) eggs from naturally-occurring containers to investigate selective oviposition, failure to take into account certain aspects of Ae. aegypti behavior can bias study inferences. In Iquitos, Peru, we tested three assumptions related to designing Ae. aegypti oviposition field studies, as follows: 1) lining containers with paper as an oviposition substrate does not affect oviposition; 2) diurnal egg-laying activity peaks in the late afternoon or early evening, and there is little oviposition during midday; and 3) the gonotrophic cycle length of wild females averages from 3 to 4 d. When wild females were presented with containers lined and unlined with paper toweling, the presence of paper increased oviposition in plastic and metal containers, but had no effect in cement containers. Recording the number of eggs laid by Ae. aegypti every 2 h throughout the day delineated a bimodal diurnal oviposition pattern, with a small morning peak, decreased activity during midday, and a predominant peak in the late afternoon and evening from 16:00 to 20:00 h. Daily monitoring of captive individual F₀ females revealed that the gonotrophic cycle length was typically 3–4 d for the Iquitos population. These findings will be used to adjust field study design to 1) account for sampling eggs using paper toweling, and 2) determine the time of day and number of days over which to sample Ae. aegypti eggs. We explored how failure to consider these behaviors could potentially bias field assessments of oviposition preferences.

A species-specific multiplex polymerase chain reaction targeting the cytochrome b gene of cattle, horses, humans, and dogs was developed to determine the blood meal sources of stable flies, Stomoxys calcitrans (L.), collected from Florida equine facilities. Of 595 presumptive blood-fed stable flies analyzed, successful host amplification was obtained in 350, for a field host-detection efficiency of 58.8%. The majority of analyzed stable flies had fed on cattle (64.6%), followed by horses (24.3%), humans (9.5%), and dogs (1.6%). A survey of animal-enclosed pastures occurring within 3 km of stable fly collection sites revealed that the nearest cattle were between 0.8 and 1.5 km from the four horse farm sampling sites. Cattle-feeding frequencies were greater on farms where cattle were located at distances of 0.8 km, suggesting that between farm differences in host-feeding frequency is related to the number of and distance from a particular host type. Time course evaluations of previously laboratory-fed stable flies demonstrated that host-detection efficiency with this system was 100, 50, and 0% when flies were evaluated at 16, 24, and 48 h postblood feeding, respectively. The results of this study suggest short-term stable fly dispersal of up to 1.5 km in a 48-h time period. The implications of these findings are discussed.

The repellency of Zanthoxylum armatum seed oil (ZA-SO), alone or in combination with vanillin (VA), its six major constituents, and another four major previously known Zanthoxylum piperitum fruit oil constituents, as well as aerosol products containing 5 or 10% ZA-SO and 5% VA, was evaluated against female Aedes aegypti in laboratory and field studies. Results were then compared with those of N,N-diethyl-3-methylbenzamide (DEET) as a standard. Hand in cage laboratory tests showed that 0.2, 0.1, and 0.05 mg/cm² ZA-SO resulted in >92% protection through 30-min postexposure and was not significantly different than 0.05 mg/cm² DEET. Skin treated with linalool and limonene (from Z. armatum) provided >80% repellency to female Ae. aegypti at 10-min exposure, whereas cuminaldehyde, citronellal, geranyl acetate, and cuminyl alcohol (from Zanthoxylum piperitum) provided >90% protection during this same time period. Only cuminaldehyde and citronellal provided complete protection comparable to DEET at 10-min postexposure. After that time, repellency of all plant constituents to mosquitoes was considerably decreased (<≈65%). An increase in repellency and duration of effectiveness was produced by a binary 1:4 mixture of ZA-SO and VA (0.05:0.2 mg/cm²) that was significantly more effective than 0.05 mg/cm² DEET through 90 min. In field tests, an aerosol formulation containing 5 or 10% ZA-SO plus 5% VA gave 100% repellency at 60-min postexposure. Although these formulations were equal to the level of protection afforded by 10% DEET, repellency to the binary ZA-SO aerosol formulations at 90 min was significantly less effective than DEET. However, mixtures formulated from ZA-SO and VA merit further study as potential repellents for protection of humans and domestic animals from biting and nuisance caused by mosquitoes.

Human head lice (Pediculus humanus capitis De Geer) occur worldwide and infest millions of children and adults every year. Head lice infestations, which are known as pediculosis capitis, are psychologically stressful, physically irritating, and are one of the leading causes of K-6 school absence. The prevalence of head lice in many countries is increasing rapidly because of resistance to chemicals used in many head lice treatments. We tested the efficacy of an alternative method for controlling head lice, the LouseBuster, a custom-built medical device designed to kill head lice and their eggs using controlled, heated air. A total of 56 infested subjects was treated with the LouseBuster, and the efficacy of the treatment was evaluated by comparing the viability of lice and eggs on randomly assigned pre- and posttreatment sides of each subject's scalp. We evaluate treatment efficacy in the hands of novice versus experienced operators. We also evaluate treatment efficacy on different hair types and at different ambient humidities. Overall mortality of lice and eggs was 94.8% after treatment by experienced operators. Novice operators also achieved good results after a short training session; their results did not differ significantly from those of experienced operators. No adverse events were associated with the LouseBuster treatment. The LouseBuster is efficacious for killing head lice and their eggs. The use of heated air is appealing because it is a fast, safe, nonchemical treatment. Head lice are also unlikely to evolve resistance to desiccation, which is the apparent mode of action.

Resistance of head lice to pyrethroids induces difficult therapeutic problems. Previous studies demonstrated that this resistance was present in a French urban area, but its prevalence needed to be more precisely evaluated in terms of genotyping lice collected from more infested children over a certain period of time. We monitored the presence of the head lice kdr-like haplotype of the voltage-gated sodium channel α-subunit gene in schoolchildren seen three times on a 6-wk period. The prevalence of pediculosis was 2.39% (n = 1551). Genotyped lice (n = 167) were homozygous resistant in all but one pupil. The high frequency of the mutant haplotype (0.93) advocated for the abandonment of pyrethroid insecticides in this area and for the consideration of other treatment options.

A vertebrate bloodmeal is required by female mosquitoes of most species to obtain nutrients for egg maturation. The yellowfever mosquito, Aedes aegypti (L.), feeds predominantly on humans, despite having the capacity to use blood from other hosts for this process. Here, we report that female Ae. aegypti infected with a virulent strain of the intracellular bacterium Wolbachia pipientis (wMelPop) from Drosophila melanogaster (Meigen) have a reduced ability to use blood for egg development. Blood feeding by wMelPop-infected females on mouse, guinea pig, or chicken hosts resulted in a near complete abolishment of reproductive output associated with both a decline in the numbers of eggs oviposited as well as the hatching rate of successfully laid eggs. In contrast, the reproductive output of wMelPop-infected females fed human blood was only mildly affected in comparison to individuals fed animal blood sources. Blood-feeding assays over two reproductive cycles definitively illustrated a nutritional interaction between host blood source and egg development in wMelPop-infected Ae. aegypti. Removal of Wolbachia from mosquitoes using antibiotic treatment rescued egg development on all blood sources. Further investigation of this phenotype may provide new insights into the nutritional basis of mosquito anthropophily.

Ticks (Acari: Ixodidae) are important pests transmitting tick-borne diseases such as Crimean-Congo hemorrhagic fever (CCHF) to humans. Between 2002 and 2009, numerous CCHF cases were reported in Turkey, including Amasya province. In the current study, species diversity, seasonal abundance of ticks, and presence of CCHF virus (CCHFV) in ticks infesting humans in several districts of Amasya province were determined. In the survey, a total of 2,528 ixodid ticks were collected from humans with tick bite from April to November 2008 and identified to species. Hyalomma marginatum (18.6%), Rhipicephalus bursa (10.3%), Rhipicephalus sanguineus (5.7%), Rhipicephalus (Boophilus) annulatus (2.2%), Dermacentor marginatum (2.5%), Haemaphysalis parva (3.6%), and Ixodes ricinus (1.6%) were the most prevalent species among 26 ixodid tick species infesting humans in Amasya province. Hyalomma franchinii Tonelli & Rondelli, 1932, was a new record for the tick fauna of Turkey. The most abundant species were the members of Hyalomma and Rhipicephalus through summer and declined in fall, whereas relative abundances of Ixodes and Dermacentor ticks were always low on humans in the province. Of 25 Hyalomma tick pools tested, seven pools were CCHFV positive by reverse transcription-polymerase chain reaction. Results indicated diversity of ixodid tick species infesting humans was very high, abundance of ticks changed by season, and ticks infesting humans had potential for transmitting CCHFV.

We collected ectoparasites from 27 of 51 wild-caught, free-ranging exotic reptiles examined in Florida from 2003 to 2008. Sampled animals represented eight species, five of which yielded ectoparasites. Reported new parasite distribution records for the United States include the following: the first collection of the African tick Amblyomma latum (Koch) from a wild-caught animal [ball python, Python regius (Shaw) ] in the United States; the first collection of the lizard scale mite Hirstiella stamii (Jack) from any wild-caught animal [green iguana, Iguana iguana (L.) ] ; and the first collection of the lizard scale mite Geckobia hemidactyli (Lawrence) in the continental United States from a wild-caught tropical house gecko, Hemidactylus mabouia (Moreau de Jonnès). We also report the first collections of the Neotropical ticks Amblyomma rotundatum (Koch) and Amblyomma dissimile (Koch) from wild-caught Burmese pythons, Python molurus bivittatus (Kuhl); the first collections of A. dissimile from a wild-caught African savannah monitor, Varanus exanthematicus (Bosc); and from wild-caught green iguanas in the United States; and the first collections of the native chiggers Eutrombicula splendens (Ewing) and Eutrombicula cinnabaris (Ewing) from wild-caught Burmese pythons. These reports may only suggest the diversity of reptile ectoparasites introduced and established in Florida and the new host-parasite relationships that have developed among exotic and native ectoparasites and established exotic reptiles.

Ticks, fleas, and vector-borne pathogens were surveyed in diverse small mammals in Yosemite National Park, California, from 2005 to 2007. A total of 450 unique captures of small mammals was collected during a 3-yr period and yielded 16 species of fleas and 10 species of ticks, including known vectors of Anaplasma phagocytophilum and Borrelia burgdorferi and plague. Serology was performed for A. phagocytophilum, spotted fever group Rickettsia spp., B. burgdorferi, and Yersinia pestis. A. phagocytophilum exposure was identified in 12.1% of all wild small mammals tested, with seropositive animals in 10 species, notably Belding's ground squirrels (Spermophilus beldingi), jumping mice (Zapus princeps), and voles (Microtus sp.). Spotted fever group Rickettsia spp. exposure was detected in 13.9% of all small mammals tested, with seropositive animals in eight species. Additionally, 37.0% of rodents in five species tested were seropositive for B. burgdorferi. No individuals were seropositive for Y. pestis. No animals were polymerase chain reaction positive for any pathogen tested. These results provide baseline data for future research and prediction of emerging vector-borne disease in Yosemite National Park, as well as adding to the known ranges and host species for tick and fleas in California.

Necrophagous insects are valuable tools for postmortem interval (PMI) estimation or for determining the cause of death. Due to the increase in deaths related to drug abuse, it is crucial to know how these substances affect the development of flies that feed on corpses, to avoid errors in the PMI estimates. This study evaluated the effect of nandrolone decanoate, an anabolic androgenic steroid, on the development of immatures of Chrysomya megacephala (F.), Chrysomya putoria (Wiedemann), and Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae) when added to an artificial rearing diet. Four experimental groups were delineated: three of them were given diets containing 4.5, 22.5, or 45 mg/kg nandrolone decanoate; and a drug-free control group. Weights were recorded at 12-h intervals from larval eclosion to pupation. No statistically significant differences were observed in mean larval weights, emergence interval, or emergence rates for all groups. However, differences in the three species were observed during the larval development. Initially, C. putoria reared in the highest concentration of decanoate showed greater weight gain. However, at older ages, immatures reached lower mean weights than the control group. For C. albiceps, the highest concentration of decanoate contributed to an effective lack of weight gain during almost the entire course of larval development. Therefore, the influence of any drug on development should always be considered.

Established procedures for collecting and preserving evidence are essential for all forensic disciplines to be accepted in court and by the forensic community at large. Entomological evidence, such as Diptera larvae, are primarily preserved in ethanol, which can evaporate over time, resulting in the dehydration of specimens. In this study, methods used for rehydrating specimens were compared. The changes in larval specimens with respect to larval length and weight for three forensically important blow fly (Diptera: Calliphoridae) species in North America were quantified. Phormia regina (Meigen), Cochliomyia macellaria (F.), and Chrysomya rufifacies (Macquart) third-instar larvae were collected from various decomposing animals and preserved with three preservation methods (80% ethanol, 70% isopropyl alcohol, and hot-water kill then 80% ethanol). Preservative solutions were allowed to evaporate. Rehydration was attempted with either of the following: 80% ethanol, commercial trisodium phosphate substitute solution, or 0.5% trisodium phosphate solution. All three methods partially restored weight and length of specimens recorded before preservation. Analysis of variance results indicated that effects of preservation, rehydration treatment, and collection animal were different in each species. The interaction between preservative method and rehydration treatment had a significant effect on both P. regina and C. macellaria larval length and weight. In addition, there was a significant interaction effect of collection animal on larval C. macellaria measurements. No significant effect was observed in C. rufifacies larval length or weight among the preservatives or treatments. These methods could be used to establish a standard operating procedure for dealing with dehydrated larval specimens in forensic investigations.