Abstract Background High coverage of insecticide-treated bed nets in Asembo and low Seme, two adjacent communities western Nyanza Province, Kenya; followed by expanded as the Kenya national malaria programme rolled out; provided a natural experiment for quantification changes relative abundance primary vectors this holoendemic region. Both belong to Anopheles gambiae sensu lato (s.l.) species complex, namely A. stricto (s.s.) arabiensis . Historically, former was proportionately dominant...

Recent field studies have suggested that the dynamics of West Nile virus (WNV) transmission are influenced strongly by a few key super spreader bird species function both as primary blood hosts vector mosquitoes (in particular Culex pipiens) and reservoir-competent hosts. It has been hypothesized human cases result from shift in mosquito feeding these to humans after abundance birds decreases. To test this paradigm, we performed meal analysis integrating host-feeding patterns Cx. pipiens,...

Models of the effects environmental factors on West Nile virus disease risk have yielded conflicting outcomes. The role precipitation has been especially difficult to discern from existing studies, due in part habitat and behavior characteristics specific vector species because differences temporal spatial scales published studies. We used statistical modeling techniques analyze forecast fine scale (2000 m grid) (weekly) patterns mosquito infection relative changing weather conditions urban...

The distribution and abundance of Ixodes scapularis were studied in Wisconsin, northern Illinois, portions the Upper Peninsula Michigan by inspecting small mammals for ticks collecting questing at 138 locations state parks natural areas. Environmental data gathered a local level (i.e., micro meso levels), geographic information system (GIS) was used with several digitized coverages environmental to create habitat profile each site grid map Wisconsin Illinois. Results showed that presence I....

Summary As highland regions of Africa historically have been considered free malaria, recent epidemics in these areas raised concerns that high elevation malaria transmission may be increasing. Hypotheses about the reasons for this include changes climate, land use and demographic patterns. We investigated effect change on south‐western highlands Uganda. From December 1997 to July 1998, we compared mosquito density, biting rates, sporozoite rates entomological inoculation between 8 villages...

The growth and development of Anopheles gambiae Giles larvae were studied in artificial habitats western Kenya. Larvae responded to increasing densities by extending their time emerging as smaller adults, although survival was not significantly affected. Addition nutrients the form cow dung collected near study site had no impact on larval development. Regression analysis showed that female increased 0.020 d dry mass decreased 0.74 μg with each additional larva. By fitting data pupation...

Host-feeding patterns of Culex pipiens L. collected in southwest suburban Chicago 2005 were studied using polymerase chain reaction (PCR) and DNA sequencing techniques. spp. mosquitoes, most identified to Cx. the remainder restuans by PCR, had fed on 18 avian species, commonly American robin (Turdus migratorious), house sparrow (Passer domesticus), mourning dove (Zenaida macroura). Additional blood meals derived from four mammal primarily humans raccoons (Procyon lotor). During a West Nile...

Water—filled treeholes provide an experimental setting for examining processes within ecosystem, and influences of external factors on those processes. Using a limnological, approach involving both natural tree holes laboratory microcosms the hole we identified studied interacting, biotic processes, including dynamics bacterial populations variation in concentration inorganic nutrients water, density—dependent competition food among larvae mosquito Aedes triseriatus. We characterized...

The risk of Lyme disease for humans in the eastern United States is dependent on density host-seeking Ixodes scapularis Say nymphal stage ticks infected with Borrelia burgdorferi. Although many local and regional studies have estimated using these parameters, this first large-scale study a standardized methodology. Density I. nymphs was measured by drag sampling closed canopy deciduous forest habitats 95 locations spaced among 2 degrees quadrants covering entire east 100th meridian. Sampling...

Host-feeding patterns of Culex pipiens L. collected in southwest suburban Chicago 2005 were studied using polymerase chain reaction (PCR) and DNA sequencing techniques. spp. mosquitoes, most identified to Cx. the remainder restuans by PCR, had fed on 18 avian species, commonly American robin (Turdus migratorious), house sparrow (Passer domesticus), mourning dove (Zenaida macroura). Additional blood meals derived from four mammal primarily humans raccoons (Procyon lotor). During a West Nile...

West Nile virus infection in humans urban areas of the Midwestern United States has exhibited strong spatial clustering during epidemic years. We derived landscape classes from physical and socio-economic factors hypothesized to be associated with Virus (WNV) transmission compared those human cases illness 2002 Chicago Detroit. The objectives were improve understanding exposure virus-infected mosquitoes context, assess degree which environmental found important also Five that partitioned...

Abstract Spraying of agricultural crops with insecticides can select for resistance in nontarget insects and this may compromise the use control vector‐borne diseases. The tolerance malaria vector, Anopheles arabiensis to deltamethrin was determined a field population from cotton‐growing region Northern Cameroon both prior midway through 4‐month period insecticide application cotton crop. A 1.6‐fold increase median knockdown time observed. To determine whether increased associated...

Urban habitat heterogeneity can modify interactions across species and lead to spatially fine grained differences in β-diversity patterns their associated ecosystem services. Here, we study the impacts of landscape climatic variability on: (1) richness diversity mosquitoes (Diptera: Culicidae) (2) abundance West Nile virus infection rate house mosquito, Culex pipiens, Chicago, USA. We conducted a four year long (2005–2008) 8 sites that captured gradient urban heterogeneities. found total 19...

It has been speculated that widespread and sustained use of insecticide treated bed nets (ITNs) for over 10 years in Asembo, western Kenya, may have selected changes the location (indoor versus outdoor) time (from late night to earlier evening) biting predominant species human malaria vectors (Anopheles funestus, Anopheles gambiae sensu stricto, arabiensis). Mosquitoes were collected by landing catches a six week period June July, 2011, indoors outdoors from 17 h 07 h, 75 villages Kenya....

Abstract Background Malaria vector control in Africa depends upon effective insecticides bed nets and indoor residual sprays. This study investigated the extent of insecticide resistance Anopheles gambiae s.l., s.s. arabiensis western Kenya where ownership insecticide-treated has risen steadily from late 1990s to 2010. Temporal spatial variation frequency a knock down ( kdr ) allele A. was quantified, as phenotypic among geographic populations s.l. Methods To investigate temporal frequency,...

Besides significantly reducing malaria vector densities, prolonged usage of bed nets has been linked to decline Anopheles gambiae s.s. relative arabiensis, changes in host feeding preference vectors, and behavioural shifts exophagy (outdoor biting) for the two important vectors Africa, An. s.l. funestus. In southern coastal Kenya, net use was negligible 1997-1998 when funestus were primary with arabiensis merus playing a secondary role. Since 2001, increased progressively reached high levels...

A scheme updating that of Dethier et al. (1960) (J. Econ. Entomol. 53: 134-136) for chemicals influencing insect locomotor behavior is introduced. Attractant, repellent, and arrestant retain their previous definitions. However, attractants or repellents are now recognized to operate both by kinetic tactic mechanisms. Locomotor initiator a new term stimuli activate normal levels locomotion. stimulant reserved activation abnormally high locomotion, like arising upon sublethal exposure certain...

The influence of host diversity on multi-host pathogen transmission and persistence can be confounded by the large number species biological interactions that characterize many systems. For vector-borne pathogens, composition communities has been hypothesized to affect transmission; however, specific characteristics remain largely unknown. We tested hypothesis vector use force infection (i.e., summed infectious mosquitoes resulting from feeding upon each vertebrate within a community hosts),...

Culex flavivirus (CxFV) is an insect-specific globally distributed in mosquitoes of the genus Culex. CxFV was positively associated with West Nile virus (WNV) infection a case-control study 268 mosquito pools from endemic focus WNV transmission Chicago, United States. Specifically, WNV-positive were four times more likely also to be infected than spatiotemporally matched WNV-negative pools. In addition, residential sites characterized by dense housing and impermeable surfaces nearby urban...

Historically, the malaria vectors in western Kenya have been Anopheles funestus, gambiae s.s., and arabiensis. Of these species, An. funestus populations declined most after introduction of insecticide-treated bed nets (ITNs) 1990s Asembo, collections region remained low until at least 2008. Contrary to findings during early years ITN use majority collected here 2010 2011 were funestus. Female had characteristically high Plasmodium falciparum sporozoite rates showed nearly 100%...

Long-lasting insecticide-treated mosquito nets (LLINs) are a primary malaria prevention strategy in sub-Saharan Africa. However, emergence of insecticide resistance threatens the effectiveness LLINs. Cross-sectional surveys LLINs were conducted houses seven and four villages Gem Bungoma Districts western Kenya, respectively. Condition (number area holes nets), number species mosquitoes resting inside them, insecticidal activity quantified. Mosquitoes collected allowed to lay eggs progeny...