Triatoma carcavalloi is considered a rare Chagas disease vector often collected inside domiciles in Rio Grande do Sul State. In this Brazilian state, T. carcavalloi has been collected in the same ecotope (rock piles) with two other species (T. rubrovaria and T. circummaculata), with which it also shares morphological characteristics. Previous morphological studies placed T. carcavalloi in the same species complex (“infestans complex”) and subcomplex (“rubrovaria subcomplex”) as T. rubrovaria, whereas T. circummaculata was placed in the “circummaculata complex.” The phylogeny of a group composed of 16 species of triatomines was revaluated with the inclusion of T. carcavalloi by Bayesian analysis using mtDNA sequences of subunits 12S and 16S of the ribosomal RNA, and the cytochrome oxidase I (COI) genes. The phenotypic relationship among T. carcavalloi and related triatomines was also inferred from morphometries. Phylogenetic results indicate that T. carcavalloi is a sister species of T. rubrovaria, and both were recovered as closely related to T. circummaculata. Morphometric studies confirmed the closeness among T. carcavalloi, T. rubrovaria, and T. circummaculata, prompting the placement of the latter species in the “infestans complex” and “rubrovaria subcomplex.”

Fecundity of mosquitoes can vary with many factors and can have a strong effect on population growth. This study reports the effects of body size, blood meal size, and age on the reproductive output of nulliparous Culex quinquefasciatus, a vector of arboviruses and other pathogens. Mated adult female mosquitoes from a colony were reared under standard conditions and fed on chickens at different ages post-eclosion. Blood meal size and wing length were recorded, as well as the number of eggs in the first-cycle egg raft. Each of these factors had a significant influence on fecundity considered in a simple regression context. Multiple regression analysis revealed a significant interaction effect between age and body size on fecundity. Up to 13 days of age, fecundity was positively correlated with body size, but in mosquitoes older than 13 days, this relationship was not significantly different from zero. These results are discussed in terms of the known physiology of this and other species.

Water samples from 11 belowground stormwater treatment Best Management Practices (BMPs) were evaluated for their capacity to support rapid development of the West Nile virus (WNV) mosquito vector, Culex quinquefasciatus. The observed minimum development time from egg to pupa ranged from six to over 30 days. Concentrations of potential food resources (total suspended solids and the particulate organic matter in water samples) were significantly correlated to development times. In addition, the rate of immature mosquito development was both site-dependent and variable in time, suggesting that factors favorable to rapid development were strongly influenced by watershed characteristics and seasonal changes in temperature. Measured temperatures in belowground BMPs suggest that these structures may remain amenable to WNV virus activity longer each year than sites aboveground.

Variation in egg surface morphology and morphometries of Culex quinquefasciatus mosquitoes of the Jodhpur, Bikaner, Jamnagar, and Bathinda strains were correlated with geographical distribution in different ecological regions of India. We report the geographic variation in Cx. quinquefasciatus based on 44 attributes of micropylar and conical-shaped regions of eggs, including micropylar apparatus (corolla, disc, and mound), micropylar tubercles, and the exochorionic tubercle, pores, and network in anterior, middle, and posterior regions. No remarkable differences were observed in the surface morphology of eggs of these strains except the absence of small tubercles in the anterior and middle region of the JMN strain. However, a statistical analysis indicated significant morphometric variations in 66% of the attributes of the eggs. The cluster analysis of all egg attributes showed that the JD, BKN, and BTH strains are closer to each other than the JMN strain. The positive correlation (r = 0.95) also indicated an effect of geographical distribution on morphometry of various egg attributes of these strains. The present study suggests that ecological variation may have affected the morphometric attributes of the egg of four strains of Cx. quinquefasciatus from different geographical areas.

A 15-month bionomic study of Anopheles species was conducted in two ecologically distinct villages (coastal and upland) of Sukabumi District, West Java, Indonesia from June 2006 to September 2007. Mosquitoes were captured using human-landing collections at both sites. During the study, a total of 17,100 Anopheles mosquitoes comprising 13 Anopheles species were caught: 9,151 at the coastal site and 7,949 at the upland site. Anopheles barbirostris, Anopheles maculatus, and Anopheles vagus were the predominant species caught at the coastal site, and Anopheles aconitus, Anopheles barbirostris, and An. maculatus predominated in the upland site. Overall, species were exophagic at both sites, but there was variation between species. Anopheles aconitus was endophagic at the coastal site, exophagic at the upland site, collected most often in April 2007 and had a peak landing time between 22:00 and 23:00. Anopheles sundaicus was only collected at the coastal site, exophagic, collected most often in October 2006, and had a peak landing time between 19:00 and 20:00. Potential malaria vector species such An. aconitus, An. maculatus, and An. sundaicus were present throughout the year. None of the 7,770 Anopheles tested using CSP-ELISA were positive for malaria, although the risk for malaria outbreaks in Sukabumi district remains high.

Effective management of avian malaria (Plasmodium relictum) in Hawai'i's endemic honeycreepers (Drepanidinae) requires the identification and subsequent reduction or treatment of larval habitat for the mosquito vector, Culex quinquefasciatus (Diptera: Culicidae). We conducted ground surveys, treehole surveys, and helicopter aerial surveys from 2001–2003 to identify all potential larval mosquito habitat within two 100 ha mesic-dry forest study sites in Hawai'i Volcanoes National Park, Hawai'i; 'Ainahou Ranch and Mauna Loa Strip Road. At 'Ainahou Ranch, anthropogenic sites (43%) were more likely to contain mosquitoes than naturally occurring (8%) sites. Larvae of Cx. quinquefasciatus were predominately found in anthropogenic sites while Aedes albopictus larvae occurred less frequently in both anthropogenic sites and naturally-occurring sites. Additionally, moderate-size (∼20-22,000 liters) anthropogenic potential larval habitat had >50% probability of mosquito presence compared to larger- and smaller-volume habitat (<50%). Less than 20% of trees surveyed at ' Ainahou Ranch had treeholes and few mosquito larvae were detected. Aerial surveys at 'Ainahou Ranch detected 56% (95% CI: 42–68%) of the potential larval habitat identified in ground surveys. At Mauna Loa Strip Road, Cx. quinquefasciatus larvae were only found in the rock holes of small intermittent stream drainages that made up 20% (5 of 25) of the total potential larval habitat. The volume of the potential larval habitat did not influence the probability of mosquito occurrence at Mauna Loa Strip Road. Our results suggest that Cx. quinquefasciatus abundance, and subsequently avian malaria, may be controlled by larval habitat reduction in the mesic-dry landscapes of Hawai'i where anthropogenic sources predominate.

The main objective of this study was to find the optimal dosage of deltamethrin, cyphenothrin, d-tetramethrin, and tetramethrin that would elicit repellency and irritability responses of Aedes aegypti. The F1-F3 generations of field mosquitoes collected from Pu Teuy Village, Sai-Yok District, Kanchanaburi Province, Thailand, were tested with four pyrethroids to determine the LC₂₅, LC₅₀, and LC₉₉. These concentrations were 0.010%, 0.020%, and 0.055%, respectively, for deltamethrin; 0.113%, 0.167%, and 0.353%, respectively, for cyphenothrin; 2.091%, 2.770%, and 5.114%, respectively, for d-tetramethrin; and 2.377%, 4.251%, and 10.715%, respectively, for tetramethrin. All dosages were tested in the excitorepellency system. Survival analysis was used to compare each chamber of the test. It was found that cyphenothrin had a stronger repellent effect than the other pyrethroids, while the contact irritant effect was similar among compounds tested. The LC₅₀ of each pyrethroid was found to be the optimal dose for repelling Ae. aegypti. There was no significant difference in LC₉₉ values for either non-contact or contact trials for each pyrethroid.

The Twin Bridges Training Area (TBTA) in the Republic of Korea consists of dirt roads, barren training areas, and forested hillsides adjacent to linear and broad expanses of tall grasses, herbaceous, and scrub vegetation. Of the six species of small mammals, the striped field mouse, Apodemus agrarius, was the most frequently captured (96.1%). Apodemus agrarius capture rates varied from 17.7 to 33.2% during three trapping periods. Gravid females were observed during November–December 2006 (8.4%) and March 2007 (5.1%). In 2005, the overall seroprevalence of Hantaan virus (HTNV) was high (34.4%) and lower during surveys in 2006 (14.2%) and 2007 (13.8%). Seroprevalence was directly correlated with weight increase of A. agrarius.

Anopheles albimanus Wiedemann is a vector of malaria in northern Belize. Previous studies have identified behavioral responses in this species when exposed to certain chemicals. We used a high throughput screening system to evaluate the contact irritant and spatial repellency responses exhibited by An. albimanus collected from Orange Walk, Belize, Central America. Anopheles albimanus behavior was significantly altered by a number of key public health insecticides. Significant irritant responses to alphacypermethrin, deltamethrin, permethrin, DDT, and propoxur were recorded, while spatial repellency responses were only elicited by DDT. Malathion resulted in neither a contact irritant or spatial repellency response. These results are in congruence with behavioral patterns previously observed for An. albimanus and for Aedes aegypti in the same system. This study produced baseline data on the behaviors of An. albimanus and confirms that the majority of compounds used as indoor residual sprays may induce premature exiting by An. albimanus in addition to killing the mosquito. This effect would decrease contact with humans and thus disrupt malaria transmission.

Rickettsia parkeri, a member of the spotted fever group rickettsias, was first described in 1939 and was thought to be non-pathogenic until recently, when it was found to cause a spotted fever-like illness in humans and areas of necrosis (eschars) at the sites of tick bites. Accordingly, there is currently much interest in this emerging pathogen. In this study, all published articles concerning R. parken were reviewed and analyzed for evidence of relatedness among this agent and other spotted fever group (SFG) rickettsiae which also produce similar clinical syndromes and/or eschars, including R. conorii, R. africae, and R. sibirica. A synthesis of the historical (antigenic) and recent (molecular) data supporting a phylogenetic sub-grouping of these SFG organisms is presented and comments are offered about the taxonomy of rickettsial organisms in general, and R. parken in particular.

Culicoides biting midges (Diptera: Ceratopogonidae) were trapped between 1999 and 2004 at 122 locations in mainland Greece and on most of the larger Aegean and Ionian islands, using OVI light traps, in order to determine the distribution and seasonal activity of bluetongue virus vectors and other Culicoides species. Thirty-nine Culicoides species were identified, six of which (C. furcillatus, C. impunctatus, C. paolae, C. pictipennis, C. riethi, and C. scoticus) were identified for the first time in Greece. Two of these (C. impunctatus and C. scoticus) may be of veterinary importance due to their role as vectors of bluetongue virus and related orbiviruses. In addition, C. imicola was detected for the first time in mainland Greece.

The nymph of the western black-legged tick (Ixodes pacificus) is an important bridging vector of the Lyme disease spirochete (Borrelia burgdorferi) to humans in the far-western United States. The previously unknown dispersal capabilities of this life stage were studied in relation to logs, tree trunks, and adjacent leaf-litter areas in a mixed hardwood forest using mark-release-recapture methods. In two spatially and temporally well-spaced trials involving logs, the estimated mean distances that nymphs dispersed ranged from ≈0.04 to 0.20 m/day on logs vs 0.11 to 0.72 m/day in litter. Prior to recapture in either trial and within the confines of the sampling grids, the greatest estimated dispersal distances by individual nymphs released on logs, and in litter 0.5 m or 1.5 m from logs, were 2.4, 3.0, and 3.0 m, respectively. Nymphs released on logs or litter tended to remain within the same biotopes in which they were freed while host-seeking. In two simultaneous trials involving trunks spaced close-at-hand, nymphs released at the trunk/litter interface on all four aspects collectively dispersed a mean of 0.353 m/day on trunks vs 0.175 m/day in litter. In either trial, the greatest distances that recaptured nymphs climbed trunks, or dispersed in litter in an encircling 3-m grid, were 1.55 m and 2.97 m, respectively. Nymphs ascending trunks did not exhibit a preference for any one aspect, and the B. burgdorferi-infection prevalences in nymphs that climbed trunks (3.2–4.0%) did not differ significantly from those that moved horizontally into litter (10.5–17.6%). We conclude that I. pacificus nymphs use an ambush host-seeking strategy; that they disperse slowly in all biotopes studied; that they usually continue to host-seek in or on whatever substratum they access initially; and that B. burgdorferi-infected nymphs are as likely to move horizontally as vertically when offered a choice.

Mark-release-recapture experiments with Aedes aegypti were performed using experimental huts equipped with entrance and exit traps to evaluate their movement patterns during a two-year period in Thailand. Results indicate no significant differences in the patterns of movement between the two years of observation. Movement into the huts occurred during the early morning period (06:00–11:00) with a peak at 07:00 in the summer and rainy season and 09:00 in the winter. In contrast, the exit pattern was observed during the late morning (09:00–12:00) and early afternoon (12:00–16:00), with a peak at 16:00 in the winter, 11:00 in the summer, and 14:00 in the rainy season. Multiple regression analysis indicated that movements of Ae. aegypti females into and out of the huts were impacted by humidity and temperature during the day.

We conducted studies on mosquitoes and West Nile virus (WNV) along a riparian corridor following the South Platte River and Big Thompson River in northeastern Colorado and extending from an elevation of 1,215 m in the prairie landscape of the eastern Colorado plains to 1,840 m in low montane areas at the eastern edge of the Rocky Mountains in the central part of the state. Mosquito collection during June–September 2007 in 20 sites along this riparian corridor yielded a total of 199,833 identifiable mosquitoes of 17 species. The most commonly collected mosquitoes were, in descending order: Aedes vexans, Culex tarsalis, Ae. dorsalis, Ae. trivittatus, Ae. melanimon, Cx. pipiens, and Culiseta inornata. Species richness was higher in the plains than in foothills-montane areas, and abundances of several individual species, including the WNV vectors Cx. tarsalis and Cx. pipiens and the nuisance-biter and potential secondary WNV vector Ae. vexans, decreased dramatically from the plains (1,215–1,487 m) to foothills-montane areas (1,524–1,840 m). Ae. vexans and Cx. tarsalis had a striking pattern of uniformly high abundances between 1,200–1,450 m followed by a gradual decrease in abundance above 1,450 m to reach very low numbers above 1,550 m. Culex species were commonly infected with WNV in the plains portion of the riparian corridor in 2007, with 14 of 16 sites yielding WNV-infected Cx. tarsalis and infection rates for Cx. tarsalis females exceeding 2.0 per 1,000 individuals in ten of the sites. The Vector Index for abundance of WNV-infected Cx. tarsalis females during June–September exceeded 0.5 in six plains sites along the South Platte River but was uniformly low (0–0.1) in plains, foothills and montane sites above 1,500 m along the Big Thompson River. A population genetic analysis of Cx. tarsalis revealed that all collections from the ∼190 km riparian transect in northeastern Colorado were genetically uniform but that these collections were genetically distinct from collections from Delta County on the western slope of the Continental Divide. This suggests that major waterways in the Great Plains serve as important dispersal corridors for Cx. tarsalis but that the Continental Divide is a formidable barrier to this WNV vector.

The ultrastructure of the male accessory glands of the blow fly, Chrysomya megacephala (Fabricius), was presented using light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A pair of accessory glands was separated at opposite sites. Morphometric results using LM yield evidenced no significant difference in the median of either length or width of the left and right glands. A significant increment in both length and width was seen to plateau between three to six days. SEM observation showed that the surface of the glands revealed a faint irregular groove pattern throughout, and it was occasionally penetrated by tracheoles. Each gland was a slender, elongated sac-like tubule having apical rounded ends, with a slight constriction at the sub-apical part of the gland being observed occasionally. TEM analyses of three-day-old males showed that the glands consisted of external capsular cells with a basement membrane underneath, glandular cells, and gland lumen. The capsular cell was flat and contained a nucleus with electron dense material in the nuclear envelope. The glandular cell, appearing as columnar, consisted of a vacuolated component that contained a large oval nucleus centrally or sub-basally located, with dense mitochondria, numerous rough endoplasmic reticulum, and secretory vesicles containing electron-lucent materials. In the gland lumen, the cross-section through the middle portion revealed dense secretory materials, characterized by electron-dense materials. Some sections revealed a large lumen where secretion accumulates within the delicate sac. The seven-day-old glands exhibited a remarkable change in the lumen, where the whole space contained a large amount of secretory materials, with the electron-dense materials being characterized as similar to those observed in three-day-old glands. About four prominent types of secretions were observed on the basis of difference in electron-density.

Triatoma dimidiata is the vector of Trypanosoma cruzi in the Yucatan Peninsula (YP). Earlier studies have shown that domestic and peri-domestic populations of the vector originated from the sylvan stock and that effectiveness of insecticide-spraying was affected by re-infestations of houses from the sylvan T. dimidiata population. In addition, in the YP most previously published reports have focused on domestic and peri-domestic populations and very little is known about the nocturnal behavior of the sylvan populations. The main aim of our study was to determine the nightly activity patterns of adult T. dimidiata in a selected location in the YP. Secondly, we sought to document the reproductive status and infection rate of active females. During eight sampling nights spaced from late March to late July, 2007, we collected 544 adult T. dimidiata. We found that square-cloth illuminated white traps were effective to attract the sylvan individuals and that T. dimidiata adults exhibited a unimodal activity pattern throughout the night. The accumulated mean of captured bugs also showed a non-linear distribution for females and males. Furthermore, we found that male and female catches were significantly correlated with the means of temperature and humidity recorded during the sampling period. Out of 46 dissected females, we observed that 43.5% of females had fully-formed eggs in their abdomens, and only two females (4.4%) had sperm within the spermatheca. The infection rate of T. dimidiata harboring T. cruzi was found to be 3.7%. The implications of the light attraction to bugs and potential dispersal capabilities are discussed in the paper in the context of infestation/re-infestation of rural houses by sylvan T. dimidiata flying adults.

Darwin's northern suburbs border an extensive coastal reed and upper mangrove wetland recognized as an important larval habitat for Aedes vigilax (Skuse), the northern salt marsh mosquito, an established vector for Ross River and Barmah Forest viruses and an appreciable pest species. We sought to identify the most important vegetation categories associated with Ae. vigilax breeding to maximize the efficiency of mosquito control efforts. Using a generalized linear model with negative binominal distribution and log link, this study compares larval densities, determined by focused dipping, between 13 discernable vegetation categories. The incidence rate ratios (RR) generated can be used to compare the magnitude of larval densities for each vegetation category, compared with the reference category. Aedes vigilax larval densities were almost ten times greater in artificial drainage areas (RR=9.82), followed by tide-affected reticulate (Sporobolus/Xerochloa) areas (RR=8.15), then Schoenoplectus/mangroves (RR=2.29), compared with the reference vegetation category ‘lower mangroves.’ Furthermore, larval densities were highest in May, due to tidal inundation, for drainage areas and tide-affected reticulates (RR= 12.2, 11.7, respectively) compared with March, the reference month. Thus, to maximize the efficiency of aerial salt marsh mosquito control operations in this wetland, larval control is best accomplished by concentrating on drains, Schoenoplectus/mangroves, and tide-affected reticulate areas, commencing early after the wet season. These results should apply to other areas of salt marsh mosquito breeding across northern Australia.

Adjacent to the northern suburbs of Darwin is a coastal wetland that contains important larval habitats for Aedes vigilax (Skuse), the northern salt marsh mosquito. This species is a vector for Ross River virus and Barmah Forest virus, as well as an appreciable human pest. In order to improve aerial larval control efforts, we sought to identify the most important vegetation categories and climatic/seasonal aspects associated with control operations in these wetlands. By using a generalized linear model to compare aerial control for each vegetation category, we found that Schoenoplectusl/mangrove areas require the greatest amount of control for tide-only events (30.1%), and also extensive control for tide and rain events coinciding (18.2%). Our results further indicate that tide-affected reticulate vegetation indicated by the marsh grasses Sporobolus virginicus and Xerochloa imberbis require extensive control for Ae. vigilax larvae after rain-only events (44.7%), and tide and rain events coinciding (38.0%). The analyses of vector control efforts by month indicated that September to January, with a peak in November and December, required the most control. A companion paper identifies the vegetation categories most associated with Aedes vigilax larvae population densities in the coastal wetland. To maximize the efficiency of aerial salt marsh mosquito control operations in northern Australia, aerial control efforts should concentrate on the vegetation categories with high larval densities between September and January.

Rapid detection of West Nile virus (WNV) in mosquito pools is essential for predicting epizootics and epidemics. We compare the efficiency and sensitivity of the Rapid Analyte Measurement Platform (RAMP) to reverse transcriptase polymerase chain reaction (RT-PCR) from 2005 to 2008 from field mosquito populations in Mercer County, NJ. Overall, 316 pools tested negative and 115 pools tested positive for WNV. Eighty-nine pools tested positive using RAMP and all were confirmed by RT-PCR; 26 pools were WNV-negative using RAMP but positive using RT-PCR. False-positives from RAMP were not detected in our four-year study, indicating that RAMP is a reliable tool when used to augment existing RT-PCR-based WNV surveillance programs. Local mosquito control programs using RAMP will benefit from its ease of use, quick results, and lack of false positives but should understand the sensitivity of this test when compared to RT-PCR. Used with standard methods, RAMP will enhance existing mosquito control and WNV surveillance by providing rapid results and improved mosquito management decisions.

Insect growth regulators (IGRs) are currently the fastest-growing class of insecticides, and in Turkey these products represent a new approach to pest control. In recent years, several IGRs were also registered for the control of the house fly, Musca domestica L. (Diptera: Muscidae), in Turkey. A field survey was conducted in the summers of 2006 and 2007 to evaluate resistance to some agriculturally and medically used IGRs on house flies from livestock farms and garbage dumps in the greenhouse production areas (Merkez, Kumluca, Manavgat, and Serik) of Antalya province (Southwestern Turkey). The results of larval feeding assay with technical diflubenzuron, methoprene, novaluron, pyripoxyfen, and triflumuron indicate that low levels (RF< 10-fold) of resistance to the IGRs exist in the house fly populations from Antalya province. Exceptions, however, were two populations, Guzoren and Toptas, from the Kumluca area which showed moderate resistance to diflubenzuron with 11.8-fold in 2006 and 13.2-fold in 2007, respectively. We found substantial variation in susceptibility of field-collected house fly populations from year to year and from product to product. We generally observed an increase in resistance at many localities sampled from 2006 to 2007. The implications of these results to the future use of IGRs for house fly control are discussed. It will be critically important to continue monitoring efforts so that appropriate steps can be taken if resistance levels start to increase.