Salt Lake City Mosquito Abatement District

Salt Lake City, UT, United States

Salt Lake City Mosquito Abatement District

Salt Lake City, UT, United States
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Muturi E.J.,University of Illinois at Urbana - Champaign | Costanzo K.,Canisius College | Kesavaraju B.,Salt Lake City Mosquito Abatement District | Alto B.W.,University of Illinois at Urbana - Champaign | Alto B.W.,University of Florida
Journal of Medical Entomology | Year: 2011

Density-dependent processes such as larval competition may be important regulatory factors among some mosquito species. The application of pesticides used for control may alter these density-dependent interactions with consequences for the number of survivors and associated sublethal and chronic effects on these individuals. We examined how intraspecific competition among larvae and low concentrations of malathion alter Aedes aegypti L. and Aedes albopictus Skuse adult life history traits and competence for arboviruses using Sindbis virus as a model system. Larvae were reared at densities of 150 and 300 larvae per container and in the absence or presence of 0.04 parts per million of malathion, before surviving females were exposed to an infectious blood meal containing 105 plaque-forming units/ml Sindbis virus. For both species, competition and the presence of malathion reduced survival to adulthood. The presence of malathion eliminated the negative effects of competition that resulted in lengthened development time and smaller-sized adults. For Ae. aegypti, but not Ae. albopictus, high competition conditions and the presence of malathion independently and not interactively led to an increase in virus dissemination from the midgut. Our results suggest that larval competition and chemical contaminants may influence disease transmission directly by altering adult mosquito fitness and indirectly by altering vector interactions with arboviruses. © 2011 Entomological Society of America.


Alto B.W.,University of Florida | Lampman R.L.,University of Illinois at Urbana - Champaign | Kesavaraju B.,Salt Lake City Mosquito Abatement District | Muturi E.J.,University of Illinois at Urbana - Champaign
Journal of Medical Entomology | Year: 2013

Competitive interactions between mosquitoes Aedes aegypti (L.) and Aedes albopictus (Skuse) may depend on environmental conditions. Pesticides may alleviate density-dependent competition for limited food, and a differential species response to sublethal concentrations may modify interspecific competition. We tested the hypothesis that exposure to malathion alters interspecific resource competition between these two species. In the absence of malathion, Ae. aegypti survivorship and per capita rate of population change were negatively affected by increasing densities of Ae. albopictus. However, the asymmetrical negative effect of Ae. albopictus on Ae. aegypti was eliminated in the presence of malathion. In addition, the presence of malathion resulted in shorter development time compared with the controls. The relative importance of pesticide-mediated coexistence in nature has not been evaluated, so its role in mediating coexistence is unclear; however, these findings underscore the potential of environmental concentrations of malathion, and perhaps other pesticides to facilitate coexistence between species. © 2013 Entomological Society of America.


Muturi E.J.,University of Illinois at Urbana - Champaign | Costanzo K.,University of Illinois at Urbana - Champaign | Kesavaraju B.,Salt Lake City Mosquito Abatement District | Lampman R.,University of Illinois at Urbana - Champaign | And 2 more authors.
Acta Tropica | Year: 2010

Mosquito larval development occurs in aquatic habitats that are directly or indirectly exposed to chemical contaminants. Little is known about how interaction of these chemicals with other biotic and abiotic stressors impact mosquito populations. We used two levels of nutrient (low and high) and four larval densities (10, 20, 30, 40) to examine the effects of low concentrations of insecticide malathion, on Culex pipiens L. mosquitoes experiencing stress from larval competition. Addition of malathion at the high nutrient condition enhanced survival with increasing larval densities, but this effect was not observed at low nutrient condition. Males exposed to malathion were significantly larger than those from control treatments while the effect of malathion on size of females varied with larval density and the level of nutrients. Larval exposure to malathion and low nutrient resulted in significantly larger females with increases in larval densities compared with other treatments. The effect of malathion on male longevity varied with larval density and amount of nutrients. At higher densities, male longevity was consistently higher in low nutrient than in high nutrient conditions and addition of malathion in high nutrient treatment increased male longevity at the highest density. These effects are most likely attributable to release from competition among survivors after mortality from malathion and density-dependent effects. We conclude that biotic conditions of the larval habitat can alter the impact of low concentrations of chemical contaminants on mosquito populations in ways that may influence the pattern of disease transmission and the outcome of vector control efforts. © 2010.


News Article | December 6, 2016
Site: www.eurekalert.org

Rising temperatures due to climate change were found to have less influence on mosquito populations than land use changes and the decay of residual DDT in the environment Mosquito populations have increased as much as ten-fold over the past five decades in New York, New Jersey, and California, according to long-term datasets from mosquito monitoring programs. The number of mosquito species in these areas increased two- to four-fold in the same period. A new study finds the main drivers of these changes were the gradual waning of DDT concentrations in the environment and increased urbanization. The findings were published December 6 in Nature Communications. The potential effects of climate change on the spread of insect-borne diseases is a major public health concern, but this study found little evidence that mosquito populations in these areas were responding to changes in temperature or precipitation. "At first glance, recent increases in mosquito populations appear to be linked to rising temperatures from climate change, but careful analyses of data over the past century show that it's actually recovery from the effects of DDT," said corresponding author Marm Kilpatrick, associate professor of ecology and evolutionary biology at UC Santa Cruz. Kilpatrick explained that the effects of climate change are expected to be seen at the edges of species' geographic ranges, as species adapted to warm climates move further north and cold-adapted species retreat from the southern parts of their ranges. So a tropical species like Aedes aegypti, which transmits Zika, dengue, and other human diseases, could expand its range northward in the United States as temperatures warm. "On the cold edge of a species' distribution, temperature matters a lot. In Washington D.C., for example, where Aedes aegypti is not common now, it might become more common if the winters get milder. Whereas in Florida, urbanization and mosquito control efforts are more likely to be the dominant drivers of mosquito populations," Kilpatrick said. Urbanization is an important factor because it changes the species composition in an area, favoring the types of mosquitoes that live near and feed on people, such as Aedes aegypti, and causing other species to decline, such as those adapted to wetlands and other natural habitats. Mosquito control programs continue to help limit mosquito populations in many areas, but currently available techniques are not nearly as effective as DDT was, Kilpatrick said. "Everyone knew DDT was an extremely effective insecticide, but I was surprised by how long-lasting its effects were. In some areas, it took 30 to 40 years for mosquito populations to recover," he said. More than a billion pounds (600 million kilograms) of DDT were used in the United States from the 1940s through the early 1970s. Its use was curtailed in the 1960s and finally banned in the United States in 1972 because of adverse environmental effects, especially on birds and other wildlife, as well as potential human health risks. Yet DDT was still detectable in soil cores as recently as 2000 in New York state, where DDT use was much higher than in New Jersey and California. In all three regions, both mosquito abundance and the number of species decreased dramatically during the period of DDT use, then steadily increased as the amount of DDT in the environment declined. In New York, the researchers found, patterns of DDT use and its concentration in the environment could explain most of the long-term trends in mosquito populations. In New Jersey and California, however, the analyses showed that urbanization was also an important factor. Average annual temperatures showed surprisingly little correlation with mosquito population trends. "Precipitation was more important than temperature, but land use was more important than either of those factors," Kilpatrick said. "The long-term impacts of land use changes on ecosystems are sometimes underappreciated." The coauthors of the paper include Ilia Rochlin and Dominick Ninivaggi at Suffolk County Vector Control in New York; Ary Faraji at the Salt Lake City Mosquito Abatement District; and Christopher Baker at UC Davis.


News Article | December 6, 2016
Site: www.rdmag.com

The rapidly growing mosquito population may be less because of climate change and more because of urbanization and the slow decay of DDT (dichlorodiphenyltrichloroethane). Marm Kilpatrick, an associate professor of ecology and evolutionary biology at the University of California Santa Cruz and corresponding author of a new study on mosquito population growth, explained what the growth is due to. “At first glance, recent increases in mosquito populations appear to be linked to rising temperatures from climate change, but careful analyses of data over the past century show that it's actually recovery from the effects of DDT,” Kilpatrick said in a statement. According to long-term datasets from mosquito monitoring programs, mosquito populations have increased as much as ten-fold and the number of mosquito species has increased two-to-four fold over the past five decades in New York, New Jersey and California. While the potential effects of climate change on the spread of insect-borne diseases is a public health concern, the study found little evidence that the mosquito populations in these areas were responding to changes in temperature or precipitation. “Precipitation was more important than temperature, but land use was more important than either of those factors,” Kilpatrick said. “The long-term impacts of land use changes on ecosystems are sometimes underappreciated.” Urbanization is said to lead to increased populations because it changes the species composition in an area, favoring the types of mosquitoes that live near and feed on people and causes other species to decline, including those adapted to wetlands and other natural habitats. Another factor in mosquito growth is the gradual waning of DDT. While mosquito control programs continue to help limit mosquito populations, they are not as effective as DDT—an organochlorine chemical used widely as an insecticide. “Everyone knew DDT was an extremely effective insecticide, but I was surprised by how long-lasting its effects were,” Kilpatrick said. “In some areas, it took 30 to 40 years for mosquito populations to recover.” Between the 1940’s and 1970’s more than a billion pounds of DDT was used in the U.S. However, it was curtailed in the 1960’s and eventually banned in 1972 because of adverse environmental effects, particularly on birds and other wildlife, as well as potential human health risks. In New York, New Jersey and California both mosquito abundance and the number of species decreased dramatically during the period where DDT was used, then increased as the amount of DDT in the environment declined. As recently as 2000 in New York DDT was still detectable in soil cores and researchers found that patterns of DDT use and its concentration in the environment could explain most of the long-term trends in mosquito populations in the Empire State. The analyses of New Jersey and California showed that urbanization was also an important factor in explaining the long-term population trends of mosquitoes. According to Kilpatrick, the effects of climate change is expected to be seen at the edges of species’ geographic ranges, as species adapted to warm climates move further north and cold-adapted species retreat from the southern part of their ranges. This means tropical species like Aedes aegypti would expand their range northward in the United States as temperatures warm and transmit diseases like Zika and dengue into a new segment of the population. “On the cold edge of a species' distribution, temperature matters a lot,” Kilpatrick said. “In Washington, D.C., for example, where Aedes aegypti is not common now, it might become more common if the winters get milder. “Whereas in Florida, urbanization and mosquito control efforts are more likely to be the dominant drivers of mosquito populations," he added. The coauthors of the paper include Ilia Rochlin and Dominick Ninivaggi at Suffolk County Vector Control in New York; Ary Faraji at the Salt Lake City Mosquito Abatement District and Christopher Baker at UC Davis. The study, which appeared in Nature Communications, can be viewed here.


Kesavaraju B.,Salt Lake City Mosquito Abatement District | Afify A.,Rutgers University | Gaugler R.,Rutgers University
Journal of Medical Entomology | Year: 2012

Malathion is an organophosphate insecticide that is used for the control of adult mosquitoes and agricultural pests. Recent studies have shown that malathion affects competition among mosquitoes in the larval stage. Individuals from laboratory colonies are often used in experiments but it is not known whether there is a difference between laboratory and field strains in their response to competition and malathion. Intraspecific larval competition in the presence of malathion (0.11 mg/liter) was compared between laboratory and field strains of Aedes albopictus (Skuse), a native of Asia that has established in the United States. There was no difference in the responses of the two strains to the presence of malathion. The fitness (finite growth rate) of the field strain decreased at the highest larval density tested but there was no difference in fitness across densities for the laboratory strain. This finding suggests that laboratory rearing could reduce sensitivity to crowding. © 2012 Entomological Society of America.


Faraji A.,Salt Lake City Mosquito Abatement District | Faraji A.,Rutgers University | Unlu I.,Rutgers University
Journal of Medical Entomology | Year: 2016

The Asian tiger mosquito, Aedes albopictus (Skuse), is a highly invasive container-inhabiting species with a global distribution. This mosquito, similar to other Stegomyia species such as Aedes aegypti (L.), is highly adapted to urban and suburban areas, and commonly oviposits in artificial containers, which are ubiquitous in these peridomestic environments. The increase in speed and amount of international travel and commerce, coupled with global climate change, have aided in the resurgence and expansion of Stegomyia species into new areas of North America. In many parts of their range, both species are implicated as significant vectors of emerging and re-emerging arboviruses such as dengue, chikungunya, and now Zika. Although rapid and major advances have been made in the field of biology, ecology, genetics, taxonomy, and virology, relatively little has changed in the field of mosquito control in recent decades. This is particularly discouraging in regards to container-inhabiting mosquitoes, because traditional integrated mosquito management (IMM) approaches have not been effective against these species. Many mosquito control programs simply do not possess the man-power or necessary financial resources needed to suppress Ae. albopictus effectively. Therefore, control of mosquito larvae, which is the foundation of IMM approaches, is exceptionally difficult over large areas. This review paper addresses larval habitats, use of geographic information systems for habitat preference detection, door-to-door control efforts, source reduction, direct application of larvicides, biological control agents, area-wide low-volume application of larvicides, hot spot treatments, autodissemination stations, public education, adult traps, attractive-toxic sugar bait methods, lethal ovitraps, barrier-residual adulticides, hand-held ultra-low-volume adulticides, area-wide adulticides applied by ground or air, and genetic control methods. The review concludes with future recommendations for practitioners, researchers, private industry, and policy makers. © 2016 Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the United States.


Kesavaraju B.,Salt Lake City Mosquito Abatement District | Leisnham P.T.,University of Maryland University College | Keane S.,University of Maryland University College | Delisi N.,Salt Lake City Mosquito Abatement District | Pozatti R.,University of Maryland University College
PLoS ONE | Year: 2014

The Asian tiger mosquito, Aedes albopictus, was first detected in North America twenty five years ago. It utilizes waterholding container habitats as immature development sites, and has rapidly spread throughout the eastern United States. Aedes albopictus has occasionally been detected in the western United States, but until recently no established populations of A. albopictus were reported. The western tree-hole mosquito, Aedes sierrensis, is the most common tree-hole mosquito throughout the western United States, and is expected to more frequently encounter A. albopictus. In this study, competition between A. albopictus from the eastern United States and A. sierrensis from the western United States was tested in order to better understand the potential for either competitive displacement of A. sierrensis by A. albopictus or competitive resistance of A. sierrensis to A. albopictus. Varying densities of each species were reared with limited resources in a response surface design. Consistent with a prior study, we found that A. albopictus was clearly a superior larval competitor than A. sierrensis. Aedes sierrensis λ′ (finite rate of increase) decreased with increasing A. albopictus density, but in contrast, A. albopictus λ′ actually increased with increasing A. sierrensis density; a result that was not reflected by individual fitness parameters. These results indicate that A. sierrensis will not be an effective barrier to A. albopictus invasion into tree-holes in the western United States. © 2014 Kesavaraju et al.


Kesavaraju B.,Salt Lake City Mosquito Abatement District | Dickson S.,Salt Lake City Mosquito Abatement District
Journal of the American Mosquito Control Association | Year: 2012

A new technique is described here to count mosquitoes using open-source software. We wanted to develop a protocol that would estimate the total number of mosquitoes from a picture using ImageJ. Adult mosquitoes from CO2-baited traps were spread on a tray and photographed. The total number of mosquitoes in a picture was estimated using various calibrations on ImageJ, and results were compared with manual counting to identify the ideal calibration. The average trap count was 1,541, and the average difference between the manual count and the best calibration was 174.11 ± 21.59, with 93% correlation. Subsequently, contents of a trap were photographed 5 different times after they were shuffled between each picture to alter the picture pattern of adult mosquitoes. The standard error among variations stayed below 50, indicating limited variation for total count between pictures of the same trap when the pictures were processed through ImageJ. These results indicate the software could be utilized efficiently to estimate total number of mosquitoes from traps. © 2012 by The American Mosquito Control Association, Inc.


Kesavaraju B.,Salt Lake City Mosquito Abatement District | Kiyoguchi D.,Salt Lake City Mosquito Abatement District | Dickson S.,Salt Lake City Mosquito Abatement District
Journal of the American Mosquito Control Association | Year: 2011

Members of the Culex pipiens complex are principal vectors for West Nile virus (WNV) in the USA. Previous studies have shown that gravid traps might be more effective than CO2-baited traps in sampling for Cx. pipiens. We compared the efficacy of gravid traps manufactured by 3 different companies: Bioquip, Clarke, and J. W. Hock. All gravid traps have a similar setup to hold the oviposition attractant but differ in the way they collect the mosquitoes. The gravid trap manufactured by J. W. Hock Company trapped significantly more Cx. pipiens than the other traps. Because CO2-baited American Biophysics Corporation (ABC) traps are most often used by mosquito abatement agencies, we compared the efficacy of the Hock gravid trap with a CO2-baited ABC trap. There was no significant difference in the number of Cx. pipiens trapped between the Hock gravid and CO2-baited ABC trap. Because gravid traps predominantly attract previously bloodfed females (thereby aiding in WNV surveillance) and are logistically easier and cheaper to set up, we argue that the Hock gravid trap might be ideal for sampling Cx. pipiens populations. © 2011 by The American Mosquito Control Association, Inc.

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