We detected a novel tick-transmitted Ehrlichia in a goat following exposure to lone star ticks (Amblyomma americanum) from a park in the metropolitan area of Atlanta, GA, U.S.A. Nineteen days after infestation with field-collected adult ticks, the goat developed a fever of two days duration, which coincided with mild clinical pathologic changes and the presence of DNA from a novel Ehrlichia in peripheral blood. The goat transmitted ehrlichiae to uninfected nymphal A. americanum that fed upon the goat, and the ticks maintained the pathogen transstadially. Five months after exposure, immunosuppression of the goat resulted in transient ehrlichemia with transmission of ehrlichiae to feeding ticks. Sequencing and phylogenetic reconstructions of the 16S rRNA, gltA, map1, map2, and ribonuclease III genes suggest the agent might be a divergent strain of Ehrlichia ruminantium, the agent of heartwater, or a new, closely related species. Convalescent serum from the goat reacted with the MAP-1 protein of E. ruminantium and with whole-cell Ehrlichia chaffeensis antigen. DNA from the novel Ehrlichia was detected in 5/302 field-collected adult A. americanum from the park. Our data suggest that A. americanum is a natural vector and reservoir of this Ehrlichia and that domestic goats can be reservoirs The geographic range of the agent and its pathogenicity to humans and livestock needs to be evaluated.

Questing ticks from various districts and agro-ecological zones (AEZ) in the Tanga Region of Tanzania were studied for a two-year period between September 1999 and July 2001. Collections of both nymphal and adult ticks occurred at 29 sites using a blanket or white cloth dragging technique. The species recorded in the order of decreasing abundance were Rhipicephalus appendiculatus, Boophilus spp., and Ambylomma variegatum. Rhipicephalus appendiculatus field infestation levels varied across administrative districts and seasons, with Amani and the cool-to-dry season having lower tick counts ( = −2.09, SE = 0.71, P < 0.001 and = −1.54, SE = 0.56, P = 0.006 for Amani and cool to dry season, respectively). Based on the polymerase chain reaction technique, Theileria parva infection prevalence in adult R. appendiculatus was estimated to be 2.6%. Implications of these findings in light of the spatial and temporal distribution of ticks are discussed for the accurate diagnosis of multiple tick-borne diseases, the infected vector tick, the endemic status of T. parva in the region, and the implemention of control strategies.

Phlebotomus sergenti populations from different areas of the Mediterranean basin are known to exhibit high intraspecific variability. Previous studies of ITS2 revealed the presence of two branches that may represent sibling species. To corroborate this finding by other tools, two colonies of P. sergenti originating from Turkey and Israel, each belonging to a different ITS2 branch, were compared by three different methods: geometric morphometric analysis of wing shape, RAPD (random amplified polymorphic DNA), and cross-mating study. For geometric morphometric analysis, two-dimensional Cartesian coordinates of 16 landmarks from the wings were digitized and analyzed. Significant shape differences were found between colonies but not between sexes within each colony. RAPD results formed two distinctive clades corresponding to the origin of the colony but also showed heterogenity among members of both colonies. In cross-mating studies, viable hybrid F1 and F2 progeny were obtained when both Turkish males/Israeli females and Israeli males/Turkish females were crossed. F1 progeny was included in RAPD analysis and these hybrids formed a distinctive clade with an intermediate position between the two parental clades. No significant differences were found in egg production of crossed sand flies. The cross-mating study showed that there is no reproductive barrier between P. sergenti from different geographical areas. On the other hand, RAPD and geometric morphometric analysis revealed a significant difference between colonies and confirmed the suitability of previous ITS2 analysis for discrimination among sand fly populations. Further development of molecular markers should resolve a possible existence of sibling species within Phlebotomus sergenti.

The aim of this study was to biometrically analyze the behavioral activity of Ixodes ricinus ticks as influenced by season and trend in numbers, based on material collected during three years in the Ślęża Landscape Park within the Ślęża Massif (Lower Silesia, Poland) using a time series decomposition method. The effects of the abiotic factors of air temperature and humidity on this activity were also determined. A total of 2,745 nymphs and adults of I. ricinus was observed and collected from 2001 through 2003. It was the only collected species from the 17 representatives of the family Ixodidae recorded from Poland. The abundance of the common tick in the Ślęża Landscape Park confirms the risk of tickborne diseases in these nature areas that are under legal protection. The chance of being bitten by ticks increases in the spring and autumn when the behavioral activity of these arthropods reaches their highest levels. Predictions concerning the level of tick behavioral activity should take into account not only seasonality but also the effects of random components, which accounted for about half of the tick activity in our study. The method of time series decomposition employed in our research appears to be useful in making such prognoses. Humidity is particularly significant as it can determine the activity of I. ricinus to a large extent.

We determined changes in species composition and densities of immature stages of Anopheles arabiensis mosquitoes in relation to rice growth cycle in order to generate data for developing larval control strategies in rice ecosystems. Experimental rice paddies (6.3m × 3.15m) exposed to natural colonization of mosquitoes were sampled weekly for two rice growing cycles between February 2004 and March 2005. Overall, 21,325 Anopheles larvae were collected, of which 91.9% were 1^st and 2^nd instars and 8.1% were 3^rd and 4^th instars. An. arabiensis was the predominant species (84.1%) with other species, An. pharoensis (13.5%), An. funestus (2.1%), An. coustani (0.3%), and An. maculipalpis (0.1%) accounting for only a small proportion of the anophelines collected. Culex quinquefasciatus (65.7%) was the predominant species among the non-anopheline species. Others species collected included: C. annulioris (9.9%), C. poicilipes (7.3%), C. tigripes (7.2%), C. duttoni (0.6%), Aedes aegypti (5.3%), Ae. cumminsii (3.5%), and Ae. vittatus (0.7%). The densities of the major anopheline species were closely related to rice stage and condition of the rice field. An. arabiensis, the predominant species, was most abundant over a three-week period after transplanting. Low densities of larvae were collected during the late vegetative, reproductive, and ripening phases of rice. An increase in larval density ten days post-transplanting was found to correlate with the application of fertilizer (sulphate of ammonia). Culicine and aedine species densities were significantly higher during the post-harvesting period. Our results suggest that the transplanting stage is favorable for the growth of immature stages of An. arabiensis and provides a narrow window for targeted larval intervention in rice.

The trophic behavior and host preference of two sibling species, Anopheles minimus s.s. (= An. minimus species A) and species C, were observed during a two-year period at Pu Teuy Village, Sai Yok District, Kanchanaburi Province, western Thailand. Anopheles minimus s.s. and species C were more prevalent during the hot and wet periods of the year. Both species demonstrated exophagic and zoophilic activities. Feeding activity of An. minimus C was unique compared to An. minimus sensu lato from other localities in Thailand. Outdoor blood feeding by An. minimus C occurred throughout the night with one distinct feeding peak immediately after sunset (1800 h), whereas indoor feeding showed two small peaks at 2000 and 2400 h. The small number of An. minimus s.s collected during this study precluded a determination of peak activity patterns. A better understanding of mosquito behavior related to host and patterns of feeding activity will facilitate and improve the efficiency of vector control operations.

The response of female tabanids to natural attractants was studied in the Monjoroš Forest along the Nature Park Kopački rit in eastern Croatia. Tabanids were caught in canopy traps baited with either aged cow, horse, sheep, or pig urine and also in unbaited traps. Tabanids were collected in a significantly higher numbers in traps baited with natural attractants compared to unbaited traps. The number of females of Tabanus bromius, Tabanus maculicornis, Tabanus tergestinus, and Hybomitra bimaculata collected from canopy traps baited with cow urine and traps baited with other natural attractants differed significantly. Females of Haematopota pluvialis were also collected more frequently in canopy traps baited with aged cow urine than in those with aged horse urine, but this difference was not significant. However, the number of females of Haematopota pluvialis collected from canopy traps baited with other natural attractants (sheep and pig urine) differed significantly when compared with aged cow urine baited traps. Canopy traps baited with aged cow urine collected significantly more Tabanus sudeticus than did traps baited with aged pig urine. Finally, the aged cow urine baited canopy traps collected 51 times more tabanids than unbaited traps, while aged horse, aged sheep, and aged pig urine baited traps collected 36, 30, and 22 times as many tabanids, respectively, than unbaited traps.

The behavioral responses of three colonized strains of Culex quinquefasciatus, two from recent field collections in Thailand (Nonthaburi and Mae Sot) and one from a long-established colony from the National Institute of Health (NIH), Ministry of Public Health, Thailand, were compared during and after exposure to deltamethrin (0.02 g/m²), propoxur (0.2 g/m²), and fenitrothion (0.2 g/m²) using an excito-repellency escape chamber system. We observed striking differences in behavioral response and excito-repellency between mosquito strains and test compounds. Greater escape responses were observed in the NIH strain during direct contact with deltamethrin and fenitrothion compared with the two field populations. Deltamethrin was the most irritant, followed by fenitrothion. Escape responses with propoxur were significantly delayed but increased slightly towards the end of the 30-min exposure period, more notably in the Nonthaburi strain (P<0.05). Non-contact repellent responses were generally much weaker than irritancy, with the greatest escape response seen with NIH and Nonthaburi. Deltamethrin showed the weakest repellent response overall (< 10% escape), while propoxur again demonstrated a delayed effect (NIH and Mae Sot) before escape occurred. We conclude that irritant and repellent behavioral responses by Cx. quinquefasciatus are important components for assessing the impact of residual spraying in mosquito control programs. A better understanding of chemical properties that elicit behavioral responses in mosquitoes should be considered in formulating control strategies designed to control mosquitoes or mitigate disease transmission risk.

Biological data were compared under laboratory conditions for four local populations of the malaria vector, Anopheles sacharovi (Favre, 1903) in different ecological conditions at altitudes between 353 and 1,126 m in the Sanliurfa province of Turkey. No significant differences were found for complete development time from egg to adult among the populations and development times were not correlated with altitude. Based on cohorts of adults in each population, horizontal life tables were constructed. The average longevity was in the range of 15.19±0.69 to 21.86±1.04 days for adult females, which was longer than for adult males. No significant difference was found in life expectancy at emergence, e_x when x=1, between females and males in general (P>0.05) in all populations. The net reproductive rate, R_o, was the highest for the SND population, while the rest of the populations showed very low reproductive rates independent of altitudinal effects. Populations that produced offspring earlier in life also produced more total female offspring, since the generation time, T_c, was negatively correlated with R_o among the populations (r = −0.712, P<0.05). Important parameters to explain the population growth, the intrinsic rate of increase, r_m and birth rate, b, were found to be higher in the SND (0.13 and 0.30, respectively). Time required for the population to increase two-fold (doubling time, DT) was also significantly shorter in the SND population. Nineteen parameters in all life stages, both pre-adult and adult features of An. sacharovi, were used as physiological variables and these Operational Taxonomic Units were analyzed using Principal Component Analysis (PCA). Analyses confirmed results from the previous molecular studies that BRC and SND formed a distinct group from the other pair, PMK and GDK, along the first two principal components.

We examined the best location in a house to install MosquiTRAPs, sticky ovitraps that attract and capture Aedes aegypti females and investigated the physiological state of captured female mosquitoes. The study was performed in a twenty-block area in Mirassol, São Paulo State, Brazil, in which five blocks were randomly chosen for MosquiTRAP installation. In each block, four houses were selected for the installation of eight traps: four indoors (bedroom, living room, bathroom, and kitchen) and four outdoors in the shade (two at the front of the house and two in the backyard). These houses were visited over an eight-week period. The outdoor MosquiTRAPs captured five times more females than indoor traps and appeared to be the best places to install MosquiTRAPs. There were no significant differences among indoor sites or among outdoor sites with respect to the number of females captured. The capacity of the MosquiTRAP to capture a large number of gravid Ae. aegypti females reinforces its potential as an entomological surveillance tool in dengue control programs.

The international trade in used tires, coupled with the ability to lay non-desiccating eggs, has enabled Aedes albopictus (Skuse) (Diptera: Culicidae) to travel and establish on new continents, including North, Central, and South America, the Caribbean, Australasia, Africa, and Europe. Concerns have been raised over its potential role in the transmission of arboviruses and Dirofilaria nematodes. Following importation into northerly latitudes, photoperiodicallyinduced egg diapause enables establishment of Ae. albopictus, and a number of abiotic factors determine the subsequent seasonal activity. The United Kingdom (U.K.) imports over 5 million used tires annually, and this seems the most likely route by which Ae. albopictus would be imported. The anthropophilic and container-breeding nature of Ae. albopictus could cause an urban human biting nuisance and the potential for involvement in (human and veterinary) disease transmission cycles needs to be assessed. This paper addresses the likelihood for importation of Ae. albopictus into the U.K. and assesses, using a Geographic Information Systems (GIS)-based model, the ability for Ae. albopictus to establish, and the likely seasonal activity. It also reviews its possible role as a potential disease vector in the U.K.. The model predicts that abiotic risk factors would permit establishment of Ae. albopictus throughout large parts of lowland U.K., with at least four to five months of adult activity (May–September), being more prolonged in the urban centers around London and the southern coastal ports. Pre-emptive surveillance of possible imported Ae. albopictus, through a targeted approach, could prevent the establishment of this exotic mosquito and mitigate any subsequent human and animal health implications for the U.K., either now or in the future.

The effect of dairy pond water quality on mosquito biology was studied under laboratory conditions during 2004. Due to high turbidity and larval toxicity of raw water samples from dairy ponds with no mosquito breeding, water samples from both mosquito breeding and non-breeding ponds were filtered and diluted 5X with distilled water prior to being tested for sublethal effects on mosquito development. The diluted pond waters showed no significant deleterious effects on the overall development of Culex quiquefasciatus Say at 23.9° and 26.6° C. However, the 3^rd and 4^th instar larvae were significantly shorter and lighter in weight when reared in diluted water samples from mosquito non-breeding ponds. Similar effects were found on the developmental stages of Cx. tarsalis Coquillette. Data on water quality parameters of filtered pond waters showed higher levels of hexavalent chromium (4X), nitrites (10X), nitrates (2X), sulfates (5X), and salinity (2X) in water samples from non-breeding ponds. Based on these data, the presence of high levels of hexavalent chromium and sulfate appear to be responsible for the absence of mosquito breeding in some dairy ponds.

Flight behavior studies were carried out from December 2004 through February 2005 at two sites in Thailand to compare the movement patterns of Aedes aegypti into and out of experimental huts baited with a human host, dog host, or without a host using a mark-release-recapture study design. Studies were conducted in isolated villages of Kanchanaburi and Chiang Mai Provinces, Thailand. In the presence of a human host only 4.9% (39/800) of the Ae. aegypti females departed the hut as compared to 46.5% (372/800) when a dog was present. There was no significant difference in the numbers of Ae. aegypti exiting when comparing dog to no host. A peak in exiting behavior in the absence of any host (human or dog) was observed between 1400–1700 h. Ingress behavior was much stronger when a human host was present in the hut with the peak of entering occurring in the morning (0830-1130 h) compared to 1000-1200 h without a host. Overall, significant differences between the two host types were observed with Ae. aegypti females being more attracted to humans (p< 0.05) than dogs. There was no significant difference between numbers of Ae. aegypti entering the hut baited with a dog and the hut containing no host source. The experimental hut design used in the present study can serve as a protocol for testing the exiting and entering behavior of Ae. aegypti in response to chemical compounds.

Urban agriculture is common across Africa and contributes to the livelihoods of urban dwellers. Some crop systems create suitable mosquito breeding sites and thus might affect malaria transmission. The purpose of this study was to identify, map, and characterize potential mosquito breeding sites in agricultural land use zones in a medium-sized town of western Côte d'Ivoire and to assess risk factors for productive Anopheles breeding sites. Two surveys were carried out; one toward the end of the rainy season and the second one during the dry season. In all identified potential mosquito breeding sites, two experienced entomologists searched for the presence of Anopheles larvae and pupae with a standardized technique. Totals of 369 and 589 sites were found in the rainy and dry seasons, respectively, mainly in vegetable gardens and irrigated rice fields. Anopheles larvae were present in 50.7% and 42.4% of the sites investigated during the rainy and dry seasons, respectively. Typical Anopheles larval habitats were characterized by the presence of algae, the absence of floating vegetation, and the co-occurrence of Culex larvae. The highest Anopheles larval productivity was observed in rice paddies, agricultural trenches between vegetable patches, and irrigation wells. An indirect link could be established between the occurrence of productive Anopheles breeding sites and agricultural land use through specific man-made habitats, in particular agricultural trenches, irrigation wells, and rice paddies. Our findings have important bearings for the epidemiology and control of urban malaria in sub-Saharan Africa.

Mosquito production from drains and catch basins in the cities of Vero Beach and Key West, FL were monitored from May 2004 through August 2005. A total of 48,787 mosquitoes were captured during the study. Of these, over 99% belonged to two species, Culex nigripalpus Theobald (2,630) and Culex quinquefasciatus Say (45,946). Other species collected included Culex restuans Theobald, Culex salinarius Coquillett, Aedes aegypti (L.), Aedes albopictus (Skuse), and Uranotaenia lowii Theobald. Significantly greater numbers of Cx. nigripalpus were collected at Vero Beach than at Key West, but no significant differences in numbers of Cx. quinquefasciatus and in total numbers of mosquitoes between the two cities were evident. Rainfall, salinity, type of structure, structure setting, and presence or absence of predators or competitors influenced the numbers of mosquitoes collected and/or the frequency of positive, negative, dry, or flooded samples.

A wide range of parasites are known to cause behavioral changes in their hosts and parasitized insects are especially amenable to the study of such changes. The majority of studies addressing parasite-induced behavioral alterations have focused on parasites with complex life cycles and the adaptive nature of such changes. Behavioral changes caused by parasitoids, single-host parasites that kill their host upon emergence, have been studied less and the adaptive nature of these changes is likely to be different than those in complex life cycles. I investigated behavioral alterations in Aedes aegypti mosquito larvae infected with parasitoid nematodes (family Mermithidae). I conducted several experiments in which I tested the following hypotheses: 1) Mermithid nematodes induce behavioral changes in mosquito larvae and the changes are density dependent. 2) Different species of mermithid nematodes induce similar changes in mosquito larvae behavior. 3) Behavioral alterations vary with mermithid developmental stage. 4) Mosquito larvae infected with mermithid nematodes behave similarly to uninfected food-deprived mosquito larvae. I found that 4^th instar Ae. aegypti infected with Romanomermis culicivorax or Strelkovimermis spiculatus exhibited resting behaviors significantly more often than uninfected controls but that intensity of infection did not affect activity levels. In earlier instars, infected mosquito larvae were more active than uninfected control larvae in some behaviors associated with feeding. There was no significant difference between infected and uninfected food-deprived mosquitoes in nine of the ten behaviors observed. The decrease in activity of late instar Ae. aegypti larvae infected with mermithids may be a parasitoid adaptation that reduces the risk of predation and thus increases host and parasitoid survival. The increase in feeding activity in earlier instars as well as the similarity between uninfected food-deprived and infected Ae. aegypti behavior may indicate that these behaviors are adaptive for the parasitoid, increasing nutritional acquisition for successful parasitoid development.

Behavioral, genetic, and immune variation within a host population may lead to aggregation of parasites whereby a small proportion of hosts harbor a majority of parasites. In situations where two or more parasite species infect the same host population there is the potential for interaction among parasites that could potentially influence patterns of aggregation through either competition or facilitation. We studied the occurrence and abundance patterns of two congeneric flea species on black-tailed prairie dog (Cynomys ludovicianus) hosts to test for interactions among parasite species. We live-trapped prairie dogs on ten sites in Boulder County, CO and collected their fleas. We found a non-random, positive association between the two flea species, Oropsylla hirsuta and O. tuberculata cynomuris; hosts with high loads of one flea species had high loads of the second species. This result suggests that there is no interspecific competition among fleas on prairie dog hosts. Host weight had a weak negative relationship to flea load and host sex did not influence flea load, though there were slight differences in flea prevalence and abundance between male and female C. ludovicianus. While genetic and behavioral variation among hosts may predispose certain individuals to infection, our results indicate apparent facilitation among flea species that may result from immune suppression or other flea-mediated factors.

The roles of entomologic risk factors, including density of nymphal blacklegged ticks (Ixodes scapularis), prevalence of nymphal infection with the etiologic agent (Borrelia burgdorferi), and density of infected nymphs, in determining the risk of human Lyme disease were assessed at residences in the endemic community of South Kingstown, RI. Nymphs were sampled between May and July from the wooded edge around 51 and 47 residential properties in 2002 and 2003, respectively. Nymphs were collected from all residences sampled. Tick densities, infection rates, and densities of infected nymphs were all significantly higher around homes reporting Lyme disease histories in 2003, while only infection rates were significantly higher in 2002. However, densities of infected nymphs did not significantly predict the probability of Lyme disease at a residence (by logistic regression) in either year. There were no significant differences in entomologic risk factors between homes with state-confirmed Lyme disease histories and homes with self-reported cases (not reported to the state health department). Therefore, although entomologic risk factors tended to be higher at residences with cases of Lyme disease, entomological indices, in the absence of human behavior measures, were not useful predictors of Lyme disease at the scale of individual residences in a tick-endemic community.

Alteration of fitness components was assessed in the yellow fever mosquito, Aedes aegypti, in automobile tires and vases (ovitraps) under field conditions. Larval numbers were manipulated in both kinds of containers to compare low, high, and control (natural) densities. Densities were set from a census of a wild population, then doubling and reducing to half the mean crowding, m*. Artificially altered densities were not high or low enough to produce differences among treatments. Tires generated more vigorous larval populations and females with higher fecundity than did small containers, although the mortality was more intense.

We measured reproductive and population parameters of adult sand flies, Phlebotomus papatasi (Scopoli, 1786) (Diptera: Psychodidae), in environmental chambers maintained at temperatures of 15, 18, 20, 25, 28, and 32° C. Based on cohorts of adults at each temperature regime, horizontal life tables were constructed using established laboratory colonies initiated from specimens collected in Sanliurfa Province, southeastern Anatolia, Turkey. The fecundity and longevity of the insects were both highly variable, depending on the temperature. At 15° C, all of the cohort females died before laying eggs, so the construction of a life table for this temperature regime was not possible. Within a range of 18 to 32° C, the longevity of adult P. papatasi increased as the temperature decreased; at 15° C, the mean survival times of females and males were 19.04±6.94 days (9–35) and 17.84±7.11 days (9–33), respectively. While the highest number of eggs was found in the cohort at 28° C (44.08±7.79), this was only 3.60±1.55 in the cohort at 32° C and 2.8±0.9 in the cohort at 18° C. This result showed that extreme temperatures negatively affect the fecundity of this species. The cohort reared at 28° C exhibited the highest intrinsic rates of population increase (r_m) for P. papatasi. The r_m ranged from 0.098 at 28° C to 0.007 at 18° C. The cohort placed at 28° C was found to be significantly different (P<0.01) from the other cohorts producing the fewest progeny in terms of net reproductive rate, R₀, (15.87). The values for mean generation time (T) were estimated to vary from 36 days to 271 days depending on temperature. Principal Component Analysis (PCA) confirmed results from the previous studies that the cohort at 28° C orientated and clustered as a distinct group along the first two PCs.

Bats and their ectoparasites are associated with bacterial agents of unknown pathogenicity. We tested sera from 56 Eptesicus fuscus from Georgia against Borrelia hermsii, Orientia tsutsugamushi, Rickettsia conorii, and Rickettsia rickettsii. We detected antibodies reactive against a relapsing fever Borrelia and spotted fever group Rickettsia in 3/56 and 1/56 bats, respectively. We attempted to culture Bartonella from the blood of these bats but were unsuccessful. In addition, we fed bat ticks, Carios kelleyi, infected with Rickettsia on a specific pathogen-free guinea pig. The guinea pig had a weak seroconversion to R. rickettsii with a peak titer of 1:32 starting on day 14. Rickettsia was not detected in any of the tissue samples from the guinea pig by molecular means. Our results indicate that E. fuscus is naturally exposed to both a spotted fever group Rickettsia and a relapsing fever group Borrelia. If these agents are transmitted by bat ticks, then people living in close proximity to bat ticks might be exposed.

Field survival of Aedes aegypti females is a key parameter for estimating the dengue transmission potential of a mosquito population. The objectives of this study were to explore the dynamics of these survival rates at different times of the year in French Guiana and to analyze the results from the perspective of dengue patterns. The mosquitoes were captured, marked, released, and recaptured during four consecutive days in six houses every month, for three to 24 months, from January 1997 to December 1998. Laboratory experiments showed no effects on female survival but some effect on the survival of males. Females' daily survival in the field varied from 0.525 to 1 but was mostly between 0.8 and 0.95 during the entire year, with a mean value of 0.913. The field survival of Ae. aegypti females in French Guiana was thus in agreement with the likely transmission of dengue and the dengue endemic patterns throughout the year. On the other hand, heavy rainfalls during this time were less favorable to Ae. aegypti survival, which may explain part of the El Niño effect on dengue epidemics in French Guiana. The methods and results on Ae. aegypti survival will be implemented in a global dengue surveillance network in French Guiana.

Larval ecology is an important aspect of the population dynamics of anopheline mosquitoes (Diptera: Culicidae), the vectors of malaria. Anopheles larvae live in pools of stagnant water and adult fitness may be correlated with the nutritional conditions under which larvae develop. A study was conducted in Mbita, Western Kenya, to investigate how properties of the soil substrate of Anopheles gambiae breeding pools can influence development of this mosquito species. An. gambiae eggs from an established colony were dispensed into experimental plastic troughs containing soil samples from a range of natural Anopheles larval habitats and filtered Lake Victoria water. The duration of larval development (8–15 days), pupation rate (0–79 %), and adult body size (20.28–26.91 mm³) varied among different soil types. The total organic matter (3.61–21.25%), organic carbon (0.63–7.18%), and total nitrogen (0.06–0.58%) levels of the soils were positively correlated with pupation rate and negatively correlated with development time and adult body size.

Saliva of female flies is responsible for localized hypersensitivity reactions and life-threatening systemic hemorrhagic syndromes in humans and animals. In this study, morphology and electrophoretic protein profiles of female salivary glands of Oriental black flies in the subgenus Simulium Latreille s. str., Simulium (Simulium) nigrogilvum, S. (S.) rufibasis, S. (S.) nodosum, and subgenus Gomphostilbia Enderlein, S. (Gomphostilbia) asakoae were analyzed. The paired female salivary glands of the four simuliid species were morphologically similar and situated on either side of the esophagus. Each gland is composed of two main parts, a secretory arm and a reservoir. In each species, the size of the gland correlated with salivary gland protein contents. SDS-PAGE analysis revealed differences of electrophoretic protein profiles and specifically major protein bands of the female salivary glands in each species, suggesting that protein profiles might be useful for construction of an additional tool to distinguish these black fly species. The information obtained from this study is an initial step for further research on salivary proteins that are involved in vertebrate hemostatic response.

Forest products were tested to see if they functioned as a barrier to nymphal Ixodes scapularis. These products could potentially be used to define a border between high density and low density tick zones on residential properties in Lyme disease endemic regions of North America. Common home and garden items were also tested. Three wood products effectively acted as barriers to nymphal I. scapularis: Alaska Yellow Cedar sawdust, Alaska Yellow Cedar woodchips, and cellulose. These three products were then weathered to determine how long they remained active. Cellulose and Alaska Yellow Cedar woodchips lost their activity almost immediately (within three days); in contrast, Alaska Yellow Cedar sawdust impeded crossing by nymphal ticks for up to one month. Creating barriers at the woods-lawn interface may someday play a role in integrated campaigns to prevent Lyme disease but will not serve as a stand-alone measure to block transmission of Lyme disease spirochetes.

Field strains of the house fly (Musca domestica L. Diptera: Muscidae) were collected in April and September 2002 from cow farms (Antalya, i̇zmir) and garbage dumps (Adana, Ankara, Istanbul, Şanli̇urfa) in Turkey. The resistance levels of first to fifth generation offspring were evaluated against six insecticides (cypermethrin, cyphenothrin, deltamethrin, permethrin, resmethrin, fenitrothion). Resistance levels for pyrethroid group insecticides ranged from 23.27 (permethrin-Istanbul fall strain) to 633.09 (cypermethrin-i̇zmir spring strain) and for fenitrothion ranged from 5.78 (Istanbul fall strain) to 51.04 (Antalya spring strain). Our results showed that pyrethroid resistance was high and changed from spring to fall in relation to usage and application frequencies of these compounds at the study sites. Although fenitrothion resistance levels were determined to be lower than pyrethroids, these levels were still high and led to control failure. Flies from cow farms were more resistant than those from garbage dumps, but resistance levels for Şanli̇urfa and Adana strains were also high in relation to usage of different insecticides for agricultural purposes. Although resistance levels against different pyrethroids decreased from spring to fall, these levels still indicated the presence of a strong selective pressure on the populations.