Mosquitoes of 14 species belonging to 9 subgenera and 9 genera were recorded in Chorao mangroves of Goa, and 12 species belonging to 9 subgenera and 7 genera in the mangroves of Vikhroli, Maharashtra, in India. Genera recorded were Aedes, Anopheles, Armigeres, Culex, Mansonia, Ochlerotatus, Orthopodomyia, Toxorhynchites, Uranotaenia, and Verrallina. Species common to both the mangroves were Ae. albopictus, Ae. novalbopictus, An. subpictus, Cx. sitiens, Oc. wardi, Ur. atra, and Ve. lugubris. Tree holes, crab holes, and swamp pools were the common larval habitats in Chorao, but tree holes were absent in Vikhroli. Adults of Ae. albopictus, Ae. novalbopictus, Ar. subalbatus, Cx. gelidus Cx. sitiens, Ma. indiana, Ur. atra, and Ve. lugubris were found landing on humans. Aedes novalbopictus, Oc. wardi, and Or. anopheloides are new records for the state of Goa.

The pupa of Culex restuans is redescribed in detail with a chaetotaxal table and a full illustration. The chaetotaxy of the pupa of Cx. restuans is compared with that of Cx. nigripalpus, the primary vector of St. Louis encephalitis and West Nile virus in Florida.

This paper demonstrates the possibility of using geostatistics to monitor the dispersal of mosquitoes for mosquito control programs at the municipal level. The case study objective was to quantify the dispersal of floodwater mosquitoes from the natural marshland Kopački rit into the city of Osijek, Croatia, and to analyze the main factors controlling it. Fifty thousand adult Aedes vexans, Ochlerotatus sticticus, and Ochlerotatus caspius mosquitoes were marked with a powdered fluorescent pigment and released from the southern part of Kopački rit on April 28, 2004. Forty CO₂-baited Centers for Disease Control and Prevention traps were set in the area of the municipality of Osijek (171 km²) and were monitored for 10 days. A total of 582,471 mosquitoes were captured and examined in the laboratory. The mosquito counts from different sites were then interpolated using ordinary kriging and visualized dynamically to detect the dominant migrational directions. Mosquito dispersal and frequency were greatly influenced by wind speed (r  =  0.82). The marked mosquitoes were found at 12 sites located from 1 km to 11.7 km away from the release point. The recapture rate was 0.044% (54% Oc. sticticus, 32% Ae. vexans, and 14% Oc. caspius). Based on the Lincoln index, the estimated total population size for floodwater mosquitoes in the study area ranged from 875 million to 2.0 billion mosquitoes. Limitations of the approach, recommendations for the improvement of the monitoring network, and spatial predictions are further discussed.

This study of 2 wetlands in subtropical Australia, constructed to treat sewage effluent, examined the relationships between dips positive for mosquito larvae and water quality, operational status of the system, vegetation, and nontarget macroinvertebrates. One site is inland and the other is close to the coast. Larvae of disease vector mosquitoes were present at various times in the wetlands, especially in summer and autumn. The proportion of early instars (1st and 2nd) was greater than that of later ones (3rd and 4th). Dissolved oxygen was negatively, and temperature was positively, associated with the proportion of dips containing larvae. For the coastal site we noted that larvae were more common during draw-down of water for maintenance and also as the system started to come online. Vegetation associated with larvae included dense Typha orientalis and algae. Where there were several types of plants, such as at the coastal site, plant density and water depth were not significantly related to larval presence. Where there were several types of macroinvertebrates there were fewer dips positive for larvae. To provide water treatment capacity and minimal mosquito production we concluded that design should include a variety of plant types, discouraging low dissolved oxygen (for example, by aeration) and ongoing maintenance should be carried out in winter or spring, when mosquitoes are fewer than in summer.

Field experiments were conducted in east-central Alabama in 2003 and 2004 to compare the attractiveness of selected gravid-trap infusions to ovipositing female mosquitoes. Comparisons were made among infusions of the following plants: Bermuda hay, Cynodon dactylon, and 3 species of emergent aquatic plants typical of Culex larval habitats, i.e., soft rush, Juncus effusus; a common sedge, Rhynchospora corniculata; and broad-leaf cattail, Typha latifolia. Experiments were conducted at a site in Lee County, AL, with an abundance of common nuisance mosquitoes, including Culex quinquefasciatus and Aedes albopictus. Carbon dioxide–baited miniature light traps were operated concurrently with gravid traps to provide an activity index of mosquito species at the site. Gravid traps with hay infusion collected the greatest numbers of Cx. quinquefasciatus and Culex restuans females (2003). The results indicate that hay infusion is highly attractive to Cx. quinquefasciatus and is the infusion of choice for collecting females of this species in gravid traps. In the case of Ae. albopictus, infusions were not determined to be significantly different from one another in their attractiveness to gravid females. In general, females of Cx. quinquefasciatus and Cx. restuans demonstrated selectivity when choosing an oviposition site, whereas Ae. albopictus females did not. Factors associated with the oviposition biology of the latter species most likely account for their lack of preference for any single infusion type.

Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) egg development and its relation to environmental parameters is an understudied aspect of vector biology. Although several studies have illustrated the dramatic effects of temperature on egg development, egg hatching dynamics remain unclear. The objective of this study was to expose An. gambiae eggs to various temperatures for different lengths of time and determine the impact on egg development and hatching count. Batches of mosquito eggs (N  =  30 eggs/replicate) were incubated under moist conditions at temperatures of 12, 22, 27, 33, and 42°C for intervals of 1, 3, 7, and 10 days. After that, they were flooded with distilled water at 27°C, and hatching counts were observed for up to 7 days. Mosquito eggs held at 22 and 27°C had the highest overall mean hatching count. During early incubation periods, eggs held at 33°C had hatching counts comparable to 22 and 27°C, but counts decreased drastically during later incubation periods. Temperatures of 12 and 42°C reduced mosquito egg viability, because few eggs hatched in these temperature regimes. Other experiments revealed that during early embryonic development, temperature had a major effect on the developing embryo, while later in embryonic development it had no dramatic effect. Microscopic observation of the An. gambiae embryo showed that extreme low and high temperatures affected the normal development of the embryo. A regression model was developed to describe the effect of incubation temperature and incubation period on egg hatching counts, which demonstrated that the optimum temperature for egg hatching ranges from 24 to 30°C, irrespective of incubation period. The interaction between temperature and time period may have implications for dry-season survival and climate-based models of malaria risk.

During the summer of 2004, 3 field studies were performed to evaluate the Mosquito Magnet Pro^TM trap with and without 1-octen-3-ol (octenol) in enhancing collections of Aedes albopictus (Skuse). At Field Site 1, 1,501 Ae. albopictus were collected, with 89% collected with octenol. At Field Site 2, 570 Ae. albopictus were collected, with 86% collected with octenol. Aedes albopictus collections were significantly enhanced in both preliminary Field Trials 1 and 2 (P < 0.03). There was a 3-fold increase in collections of Anopheles punctipennis and an 18-fold increase in collections of Ae. vexans at Field Site 2. At Field Site 3, 5,571 were Ae. albopictus, with 75% collected with octenol. Results from the 3rd field trial indicated that Ae. albopictus (P < 0.03), Coquillettida perturbans (P < 0.01), and Ochlerotatus triseriatus (P < 0.03) were significantly more attracted to traps supplemented with octenol than to traps operating without octenol. There was a 2.4-, 6-, and 3.5-fold increase in collections of Ae. albopictus with octenol in Field Trials 1, 2, and 3, respectively.

The effectiveness of CO₂-baited Centers for Disease Control and Prevention miniature light traps elevated in the tree canopy (∼7.6 m) was compared with light traps placed at ground level (∼1.5 m) and grass-sod infused gravid traps for collecting Culex pipiens, Culex restuans, and Culex salinarius and detecting West Nile virus (WNV) activity in an operational surveillance program that encompassed 12 ecologically diverse sites in Connecticut in 2004 and 2005. More than twice as many Cx. pipiens were collected on average in light traps suspended in the tree canopy than in either light or gravid traps placed at ground level. This difference was generally restricted to those collection sites where markedly greater numbers of Cx. pipiens were collected with all trapping methods but was not associated with site-specific urbanization indices. Culex restuans was not preferentially attracted to light traps suspended in the tree canopy. No differences in the overall abundance of this species were recorded with either of the 2 trapping procedures, but both light traps were more effective than the gravid traps. Culex salinarius was significantly more attracted to ground-based light traps than traps suspended in the tree canopy, while gravid traps were ineffective at all sites regardless of the level of urbanization or any other specific land-use characteristic. CO₂-baited light traps placed in the tree canopy were generally superior to ground-based light traps for detecting WNV in Cx. pipiens. West Nile virus–infected females were collected more regularly, and the frequency of infected pools was significantly greater. Twofold higher minimum field infection rates (maximum likelihood estimation [MLE]  =  6.7 vs. 3.0 per 1,000 mosquitoes) were also recorded from canopy collections of this species, and virus was detected in canopy-collected females several weeks before it was detected in collections from light traps at ground level. We conclude that the use of CO₂-baited light traps placed in the tree canopy for targeted trapping of Cx. pipiens and subsequent detection of WNV are likely to yield better overall results than light traps placed at ground level in this region of the northeastern United States. The virus isolation data obtained from Cx. pipiens collected in gravid traps compared favorably both temporally and spatially with results from canopy trap collections. There were no significant differences in the overall frequency of WNV-infected pools or MLEs for Cx. pipiens, but fewer total WNV isolations were made from Cx. pipiens collected in the gravid traps and virus was detected more infrequently. Results reaffirmed the utility of gravid traps as effective surveillance tools for detection of WNV in Cx. pipiens in the northeastern United States. However, findings also demonstrated that CO₂-baited light traps placed in the tree canopy provided more consistent results where weekly detection of virus amplification is a critical objective. The comparative effectiveness of ground- and canopy-based light traps for detection of WNV-infected Cx. restuans and Cx. salinarius was inconclusive owing to the limited number of virus isolations that were made from these species during the 2 years of study. However, WNV virus isolations were made several weeks earlier and more frequently from Cx. restuans collected in traps placed in the canopy rather than at ground

Research programs in mosquito-borne diseases have necessitated the bloodfeeding of mosquitoes in captivity. Parafilm has been shown to be an effective membrane through which mosquitoes can access blood, and numerous feeding devices using parafilm membranes have been reported. However, these devices can be incompatible with experimental conditions, which may require small blood volumes, exact and constant blood temperatures, and inexpensive or disposable materials. We report herein on 2 methodologies that can be used to make parafilm blood bags with a support side and a feeding side made up of a thinner sheet of parafilm. Blood bags were easily and cheaply made to handle volumes as little as 150 µl or as large as 5 ml, to be disposable, and to be easily fastened to a heat source to provide constant and reproducible blood temperatures. Blood bags represent perhaps the most versatile and inexpensive approach to parafilm membrane feeding yet reported.

As part of an ongoing mosquito surveillance program, 27 sites in the greater metropolitan Albuquerque area (Bernalillo County, New Mexico) were trapped from May through September 2004. Each site was sampled for 1 night weekly, using a standard CO₂-baited Centers for Disease Control and Prevention light trap and a gravid trap. Captured mosquitoes were catalogued by location, species, and date, and selected pools were tested for West Nile virus (WNV) by reverse transcription–polymerase chain reaction. Based on previous surveillance, WNV was already established in the state of New Mexico. Surveillance during 2003, the 1st year of WNV detection in New Mexico mosquitoes, was focused on the bosque forest of the Rio Grande river valley. Surveillance during summer of 2004 was extended to additional areas around the city of Albuquerque, the state's largest population center. In addition to the standard surveillance objectives, a secondary goal was to determine whether foci of WNV activity were detectable in other habitats besides the riparian ecosystem of the Rio Grande, and in other species not previously identified as vectors. There was no demonstrable advantage to extending the traditional trapping area outside of the Rio Grande valley. Sites in the valley area had WNV-positive mosquitoes earlier in the season, and for a longer period than the added sites. In addition, riparian sites had the highest diversity of species, the largest numbers of Culex spp. captured, and the largest proportion of the WNV-positive mosquito pools from the study. Species found in other areas of the metropolitan area were also represented in the valley. Although WNV activity was detected in other areas of the city, its activity began later and ended earlier than in the river valley. We surmise that the greatest benefit to mosquito surveillance could be achieved by focusing on the river valley area.

Efficacy of tank mixtures of commercial Bacillus thuringiensis subsp. israelensis (Bti) and Bacillus sphaericus (Bs) water-dispersable granule (WDG) formulations was evaluated in septic tanks, against Culex pipiens L. (Diptera: Culicidae) larvae. VectoLex® WDG (Bs) VectoBac® WDG (Bti) were evaluated at various ratios from 488 g/ha VectoLex 250 g/ha VectoBac up to 3,000 g/ha of each. All applications and ratios delivering VectoLex WDG at a rate equal to or greater than 988 g/ha provided more than 90% control for 28 days after treatment. The lowest dose provided this level of control for at least 7 days after treatment, with greater than 80% control after 2 wk. These results suggest that a retreatment interval of 2 wk is recommended with the lowest dose and retreatment intervals of 4 or more wk are recommended with the doses equal to or higher than 988 g/ha VectoLex 250 g/ha VectoBac.

Copepods from the genus Mesocyclops are considered predators and potential biological control for mosquito larvae. Two copepod species M. meridianus and M. longisetus were found in natural developmental habitat for malaria vector Anopheles aquasalis in Paria, Venezuela. Predatory potential on 1st-stage mosquito larvae An. aquasalis was evaluated under laboratory conditions for the 2 species of copepod. Further records of both copepod life cycle and body size were taken. A 2 × 3 factorial design was used, consisting of 1:1 and 10:1 prey–predator ratios with and without interspecific interactions. Despite significant body-size differences, M. longisetus and M. meridianus reached maturity 17 days after hatching with no significant differences. Life cycle span of both copepod species are described for the first time. The 2 species showed the same predatory potential despite larval (prey) abundance variation.

In recent times, bioprospecting for plants that show bioactive properties has yielded many chemicals that can be used in controlling mosquitoes. Crude extracts of 4 terrestrial and 3 mangrove plants were assayed against 2–3 larval instars of Aedes aegypti. Among the plants tested, Cordia curassavica showed the highest levels of activity for all the extracts tested. Azadirachta indica showed the least activity, whereas the 2 cultivars of Mangifera indica showed substantial activity for the aqueous extracts. The mangrove species proved to be relatively nontoxic to Ae. aegypti larvae when compared to the terrestrial plants. The results of this study suggest that some common plants in Trinidad may be highly effective in controlling the urban vector of yellow fever and dengue fever, Ae. aegypti.

The effects of water volume, container surface area and the density of hosts and fungal zoospores on the infectivity of the oomycete fungus Leptolegnia chapmanii to Aedes aegypti were investigated in the laboratory. Late 3rd or early 4th instars from a laboratory colony were used as hosts in all assays. Fourth instars infected with L. chapmanii for 48 h (6.1 ± 0.2 × 10⁴ zoospores/larva) were used as inoculum. Mortality rates were >90% in containers with 20 or fewer larvae when exposed to 1 infected larva, but they decreased to 37% in containers with 60 larvae. Mortality rates varied from 82% to 92% when healthy 4th instars were exposed to 1 and 2 infected larvae, respectively, whereas 100% mortality was obtained with ≥3 infected larvae. Infection and mortality rates in containers with volumes that varied from 300 to 5,000 ml but that had similar water surface area (397 cm²) varied from 89 to 92%, respectively. When water volume was held constant at 250 ml in containers with variable surface areas (14.5–875 cm²), larval mortality varied from 96% to 25%, respectively. The ability of L. chapmanii to infect mosquito larvae is dose dependent and influenced by larval density and surface area.

Mosquito-borne diseases are of public health importance in war-torn northern Sri Lanka. The severity of mosquito bites and attitudes of the public toward mosquito problems were investigated using a structured questionnaire among communities in 3 administrative divisions in Jaffna District. One hundred fifty-four households were interviewed during this study. Sixty-four percent of the respondents reported that the mosquito problem was severe in their localities. Fifty-two percent stated that mosquito-biting activity was severe in the evening (1500 h–1900 h), 41% at night (after 1900 h), and 7% throughout the day. Severity of mosquito menace was found to have no association with type of house construction. Seventy-seven percent were able to name at least 1 disease transmitted by mosquitoes. Statistical analysis showed no association between education level and public awareness on mosquito-borne diseases. Nearly 88% were able to identify at least a breeding source of mosquitoes and most of them practice measures to eliminate suitable environments for mosquito breeding. Ninety-six percent used personal protective measures against mosquito bites during some seasons or throughout the year. Mosquito coils were the most commonly used personal protective method followed by bed nets. The monthly expenditure for personal protective measures varied from US$0.19 (LKR 20) to US$3.40 (LKR 350).

An efficacy study was conducted to evaluate sand granule formulations of Aquaprene^TM (1.8% and 2.8% active ingredient [AI]) and Altosid® XR-G (1.5% AI) as a preflood application against Ochlerotatus taeniorhynchus larvae in small field test plots. Aquaprene sand granules (2.8% AI) were applied at 2.5 and 5 lb/acre and the 1.8% AI formulation at 4.2 lb/acre. The 1.8% AI formulation was compared with Altosid XR-G sand granules (1.5% AI) applied at 5 lb/acre. Plots were flooded after 7 days, and 1st and 2nd instars were introduced, pupae were collected, and the plots were drained and dried for 9 days. Assessments were made 21 and 35 days posttreatment. Both Aquaprene sand granules formulations exhibited excellent control throughout the 35-day study.

Six experimental ground ultra-low volume (ULV) applications of Pyrenone® 25-5 (0.0025 lb/acre) and Aqua-Reslin® (0.007 lb/acre) were made by truck-mounted Pro-Mist® or London Fog® equipment over 1-mi² study areas in rural and residential environments of the Coachella Valley, Riverside County, California. Efficacy of replicate applications was evaluated by measuring mortality among caged sentinel mosquitoes, by evaluating changes in host-seeking abundance at replicated dry ice–baited traps positioned along intersecting east–west and north–south transects, and by differential recapture patterns of marked females released near traps in the sprayed central core and unsprayed control areas. Sentinel mortality agreed well with estimates of droplet density measured by “slide spinners” and was affected by 1) distance of cages from the truck route; 2) landscape features, such as tree lines that created wind shadows; 3) irregular landscape that disrupted the particle cloud; 4) low wind speed that failed to carry the droplet cloud through the environment; and 5) failure of the droplets to penetrate dead airspace within stands of vegetation. Despite variable sentinel mortality, Culex tarsalis relative abundance in rural landscapes within and around our study areas always declined after ULV applications. Concurrent decreases in abundance at traps within sprayed and adjoining unsprayed areas confounded our estimates of percentage of control using Mulla's formula, which compares abundance in sprayed and unsprayed areas pre- and postspray. ULV applications significantly affected recapture patterns, in that recapture rates within the spray zone usually were significantly less than in the unsprayed zone. Collectively, our data indicated that ground ULV applications measurably reduced Cx. tarsalis abundance in rural areas of the Coachella Valley but that further evaluations may be necessary to validate efficacy on Culex quinquefasciatus populations in residential communities.

A study comparing the effectiveness of barrier treatment of military tents with bifenthrin and permethrin in preventing entry of mosquitoes was conducted at Wide Bay Training Area, Queensland, Australia. Five military tents were erected at a site in bushland at Mosquito Creek, about 2 km from the coast. Two tents were sprayed with bifenthrin (Bistar 80SC, 0.1% mix, 12.5 ml/liter) and 2 with permethrin (Perigen® 500, 1.2%, 24 ml/liter). One was left untreated and served as a control. Carbon dioxide–baited traps were placed inside each tent 0, 2, 4, 6, and 8 wk after treatment, and a single trap was placed in forest 50 m from the tents. The predominant mosquito species collected was Aedes vigilax (78% of collection). Compared to the untreated control, protection against mosquitoes entering treated tents was initially 78.6% for bifenthrin-treated tents and 84.3% for permethrin. At 4 wk, protection was 68.6% for bifenthrin and 50.7% for permethrin. After 6 wk, less than 34% protection was provided by either insecticide. There was no significant difference between the protection provided by either insecticide treatment. The study showed that barrier tent treatments provide a reasonable increase in preventing the entry of mosquitoes for at least 4 wk.

Data on adulticide deposition were collected during studies optimizing aerial ultra-low volume applications and droplet size in the desert environment of the Coachella Valley, Riverside County, California. Pyrenone 25-5® and BVA Spray 13® oil were applied by a single-engine, fixed wing aircraft equipped with 2 Micronair® AU5000 atomizers. Data recorded by a portable weather station documented that weather conditions were suitable for application. Adulticide residue was collected using 24-cm-diameter filter papers positioned along 2–3 transects, with 3 positive controls held outside of the treated zone. The trace amounts of 2 major insecticidal components (pyrethrin I and II) and the synergist piperonyl butoxide (PBO) were detected from samples near the center of the spray zone by high-performance liquid chromatography (HPLC); pyrethrin deposition was highest at the center, 156 µg/m², and it was not detectable 60 m beyond the center of the transect, whereas PBO deposition was 5,000 µg/m² at the center but was not detectable beyond 150 m. Droplet diameters on spinning Teflon® slides were larger than expected for the rated output of the atomizers. For these single swath trials, the lack of swath overlap due to drift resulted in low mortality in sentinel mosquitoes. Detection of residues was limited to the centroid of droplet densities on spinning glass slides and with mortality among sentinel mosquitoes, indicating HPLC may be useful in detecting postspray residues.

Bioefficacy of PermaNet® was evaluated in both the laboratory and field against Anopheles culicifacies and An. stephensi, major malaria vectors in India. Contact bioassays were carried out after repeated washings and ring net bioassays to determine the median knockdown time of mosquitoes. Three villages were selected for the field trial: in the 1st village PermaNets were distributed, in the 2nd village untreated nets were distributed, and the 3rd village was a control. Entomological data were collected using standard procedures. The PermaNet contact bioassays showed high mortality (>80%) even after 20 washes against both the vector species. The median knockdown time of An. culicifacies and An. stephensi was 392 and 480 sec when exposed to fresh PermaNets and 472 and 986 sec when exposed to PermaNets that had been washed 20 times, respectively. PermaNets showed high efficacy in reducing the person–vector contact as evidenced by reduced person-hour density in the PermaNet village. Long-term field trials are indicated to test the impact of use of PermaNets in controlling malaria.

Uranotaenia (Pseudoficalbia) mashonaensis is recorded from the Jordan Rift Valley of northern Israel based on the collection of adults of both sexes on different occasions. This is the 1st report of this species outside of the Afrotropical region.

The occurrence of Aedes albopictus in Lebanon and Syria is reported for the first time. Larvae were found in 4 localities in Lebanon, and 1 female was captured inside a house located in a coastal locality in Syria. The potential of the species to vector arboviral disease in the region is noted.

Hurricane Katrina caused massive destruction and flooding along the Gulf Coast in August 2005. We collected mosquitoes and tested them for arboviral infection in a severely hurricane-damaged community to determine species composition and to assess the risk of a mosquito-borne epidemic disease in that community about 6 wk after the landfall of Hurricane Katrina. Light-trap collections yielded 8,215 mosquitoes representing 19 species, while limited gravid-trap collections were not productive. The most abundant mosquito species was Culex nigripalpus, which constituted 73.6% of all specimens. No arboviruses were detected in any of the mosquitoes collected in this survey, which did not support the assertion that human risk for arboviral infection was increased in the coastal community 6 wk after the hurricane.

During the past 10 years, West Nile virus (WNV) has been responsible for large and severe human outbreaks and horse epizootics through the Old and the New World. Since WNV was first isolated from field-collected mosquitoes of Culex modestus in 1964 in France, this species, which aggressively feeds on birds and mammals, is considered a putative WNV vector in Europe. We report on the first evidence on the laboratory vector competence of Cx. modestus for WNV. To assess this trait, F3 and F4 females from southern France were fed through a membrane with a strain of WNV isolated from a horse in the Camargue (Rhône River delta) in 2000. On day 14 after virus ingestion, 90% of mosquitoes displayed a disseminated infection. WNV was detected in the saliva from 2 of 5 infected mosquitoes selected for testing. These preliminary results demonstrate that Cx. modestus is capable of experimentally transmitting WNV.

A wind-sensitive vane apparatus was designed and implemented specifically to accommodate the attachment of otherwise unidirectional insecticide treatment cages used in ground ultra-low volume mosquito adulticide field tests. This cage support system is useful in keeping the potential West Nile virus and St. Louis encephalitis vector Culex quinquefasciatus caged mosquitoes oriented into the wind during field efficacy tests. Testing capacity for resistance surveillance was tripled during the 2005 season, and more reliable results were achieved as a consequence.