The Unmeasured ecological effect of mosquito control

Intensive mosquito control programs are likely to contribute to insect diversity loss, but these effects are both underestimated and understudied. We recommend to conduct direct biodiversity monitoring programs to understand the effects of both chemical and biological control.

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Mosquito Control Priorities in Florida—Survey Results from Florida Mosquito Control Districts

Pathogens ◽

10.3390/pathogens10080947 ◽

2021 ◽

Vol 10 (8) ◽

pp. 947

Author(s):

Rishi Kondapaneni ◽

Ashley N. Malcolm ◽

Brian M. Vazquez ◽

Eric Zeng ◽

Tse-Yu Chen ◽

...

Keyword(s):

State Government ◽

Mosquito Control ◽

Control Strategies ◽

Mosquito Species ◽

Research Priorities ◽

Current Control ◽

Control Programs ◽

Common Control ◽

Surveillance Programs ◽

Research Questions

Florida lies within a subtropical region where the climate allows diverse mosquito species including invasive species to thrive year-round. As of 2021, there are currently 66 state-approved Florida Mosquito Control Districts, which are major stakeholders for Florida public universities engaged in mosquito research. Florida is one of the few states with extensive organized mosquito control programs. The Florida State Government and Florida Mosquito Control Districts have long histories of collaboration with research institutions. During fall 2020, we carried out a survey to collect baseline data on the current control priorities from Florida Mosquito Control Districts relating to (1) priority control species, (2) common adult and larval control methods, and (3) major research questions to address that will improve their control and surveillance programs. The survey data showed that a total of 17 distinct mosquito species were considered to be priority control targets, with many of these species being understudied. The most common control approaches included truck-mounted ultra-low-volume adulticiding and biopesticide-based larviciding. The districts held interest in diverse research questions, with many prioritizing studies on basic science questions to help develop evidence-based control strategies. Our data highlight the fact that mosquito control approaches and priorities differ greatly between districts and provide an important point of comparison for other regions investing in mosquito control, particularly those with similar ecological settings, and great diversity of potential mosquito vectors, such as in Florida. Our findings highlight a need for greater alignment of research priorities between mosquito control and mosquito research. In particular, we note a need to prioritize filling knowledge gaps relating to understudied mosquito species that have been implicated in arbovirus transmission.

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Permethrin Resistance in Aedes aegypti Affects Aspects of Vectorial Capacity

Insects ◽

10.3390/insects12010071 ◽

2021 ◽

Vol 12 (1) ◽

pp. 71

Author(s):

Tse-Yu Chen ◽

Chelsea T. Smartt ◽

Dongyoung Shin

Keyword(s):

Aedes Aegypti ◽

Sodium Channel ◽

Mosquito Control ◽

Vector Competence ◽

Vectorial Capacity ◽

Parental Population ◽

Control Programs ◽

Channel Gene ◽

Sodium Channel Gene ◽

Specific Pcr

Aedes aegypti, as one of the vectors transmitting several arboviruses, is the main target in mosquito control programs. Permethrin is used to control mosquitoes and Aedes aegypti get exposed due to its overuse and are now resistant. The increasing percentage of permethrin resistant Aedes aegypti has become an important issue around the world and the potential influence on vectorial capacity needs to be studied. Here we selected a permethrin resistant (p-s) Aedes aegypti population from a wild Florida population and confirmed the resistance ratio to its parental population. We used allele-specific PCR genotyping of the V1016I and F1534C sites in the sodium channel gene to map mutations responsible for the resistance. Two important factors, survival rate and vector competence, that impact vectorial capacity were checked. Results indicated the p-s population had 20 times more resistance to permethrin based on LD50 compared to the parental population. In the genotyping study, the p-s population had more homozygous mutations in both mutant sites of the sodium channel gene. The p-s adults survived longer and had a higher dissemination rate for dengue virus than the parental population. These results suggest that highly permethrin resistant Aedes aegypti populations might affect the vectorial capacity, moreover, resistance increased the survival time and vector competence, which should be of concern in areas where permethrin is applied.

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Bacterial Toxins Active against Mosquitoes: Mode of Action and Resistance

Toxins ◽

10.3390/toxins13080523 ◽

2021 ◽

Vol 13 (8) ◽

pp. 523

Author(s):

Maria Helena Neves Lobo Silva-Filha ◽

Tatiany Patricia Romão ◽

Tatiana Maria Teodoro Rezende ◽

Karine da Silva Carvalho ◽

Heverly Suzany Gouveia de Menezes ◽

...

Keyword(s):

Mode Of Action ◽

Mosquito Control ◽

Binary Toxin ◽

Lysinibacillus Sphaericus ◽

Control Programs ◽

Resistance Selection ◽

Single Receptor ◽

Combined Use ◽

Environmentally Safe ◽

Medical Importance

Larvicides based on the bacteria Bacillus thuringiensis svar. israelensis (Bti) and Lysinibacillus sphaericus are effective and environmentally safe compounds for the control of dipteran insects of medical importance. They produce crystals that display specific and potent insecticidal activity against larvae. Bti crystals are composed of multiple protoxins: three from the three-domain Cry type family, which bind to different cell receptors in the midgut, and one cytolytic (Cyt1Aa) protoxin that can insert itself into the cell membrane and act as surrogate receptor of the Cry toxins. Together, those toxins display a complex mode of action that shows a low risk of resistance selection. L. sphaericus crystals contain one major binary toxin that display an outstanding persistence in field conditions, which is superior to Bti. However, the action of the Bin toxin based on its interaction with a single receptor is vulnerable for resistance selection in insects. In this review we present the most recent data on the mode of action and synergism of these toxins, resistance issues, and examples of their use worldwide. Data reported in recent years improved our understanding of the mechanism of action of these toxins, showed that their combined use can enhance their activity and counteract resistance, and reinforced their relevance for mosquito control programs in the future years.

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Investigating Male Aedes aegypti (Diptera: Culicidae) Attraction to Different Oviposition Containers Using Various Configurations of the Sound Gravid Aedes Trap

Journal of Medical Entomology ◽

10.1093/jme/tjz229 ◽

2019 ◽

Vol 57 (3) ◽

pp. 957-961

Author(s):

Kyran M Staunton ◽

Barukh B Rohde ◽

Michael Townsend ◽

Jianyi Liu ◽

Mark Desnoyer ◽

...

Keyword(s):

Aedes Aegypti ◽

Zika Virus ◽

Disease Transmission ◽

Urban Landscape ◽

Mosquito Control ◽

Transmission Risk ◽

Northern Australia ◽

Control Programs ◽

Male Dispersal ◽

Olfactory Attractant

Abstract Aedes aegypti (Linnaeus), the primary vectors of the arboviruses dengue virus and Zika virus, continue to expand their global distributions. In efforts to better control such species, several mosquito control programs are investigating the efficacy of rearing and releasing millions of altered male Aedes throughout landscapes to reduce populations and disease transmission risk. Unfortunately, little is known about Ae. aegypti, especially male, dispersal behaviors within urban habitats. We deployed Sound-producing Gravid Aedes Traps (SGATs) in Cairns, northern Australia, to investigate male Ae. aegypti attraction to various oviposition container configurations. The traps were arranged to include: 1) water only, 2) organically infused water, 3) infused water and L3 larvae, 4) infused water and a human-scented lure, and lastly 5) no water or olfactory attractant (dry). Our data suggest that males were more attracted to SGATs representing active larval sites than potential larval sites, but were equally attracted to dry SGATs relative to those containing water and/or infusion. Additionally, we found that female Ae. aegypti were equally attracted to wet SGATs, with or without infusion, but not dry ones. These results suggest that male Ae. aegypti within northern Australia are more attracted to active larval sites and equally attracted to dry containers as wet or infused ones. Additionally, female Ae. aegypti are unlikely to enter dry containers. Such findings contribute to our understanding of potentially attractive features for local and released Ae. aegypti throughout the northern Australian urban landscape.

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Comparison of mosquito control programs in seven urban sites in Africa, the Middle East, and the Americas

Health Policy ◽

10.1016/j.healthpol.2007.01.009 ◽

2007 ◽

Vol 83 (2-3) ◽

pp. 196-212 ◽

Cited By ~ 31

Author(s):

Daniel E. Impoinvil ◽

Sajjad Ahmad ◽

Adriana Troyo ◽

Joseph Keating ◽

Andrew K. Githeko ◽

...

Keyword(s):

Middle East ◽

Mosquito Control ◽

Control Programs ◽

Urban Sites

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Parasitism Capacity of Trichogramma pretiosum and Trichogramma acacioi (Hym.: Trichogrammatidae) on eggs of Sitotroga cerealella (Lep.: Gelechiidae)

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132008000600021 ◽

2008 ◽

Vol 51 (6) ◽

pp. 1249-1254 ◽

Cited By ~ 2

Author(s):

Dirceu Pratissoli ◽

José Cola Zanuncio ◽

Ulysses Rodrigues Vianna ◽

Josimar Souza Andrade ◽

Fernando Domingo Zinger ◽

...

Keyword(s):

Biological Control ◽

Sitotroga Cerealella ◽

Alternative Host ◽

Trichogramma Pretiosum ◽

Parasitoid Species ◽

Control Programs ◽

Total Parasitism

The objective of this work was to evaluate the parasitism capacity of Trichogramma pretiosum Riley and T. acacioi Brun, Moraes and Soares (Hymenoptera: Trichogrammatidae) in eggs of the alternative host Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) aiming to use both species in biological control programs of Nipteria panacea Tierry-Mieg (Lepidoptera: Geometridae). The parasitism rhythm and total parasitism of these parasitoid species were affected by the temperature with higher values during the first 24 h of their life. Parasitism period was longer for T. pretiosum and T. acacioi at the lowest temperature.

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Susceptibility Status of Aedes aegypti L. Against Different Classes of Insecticides in New Delhi, India to Formulate Mosquito Control Strategy in Fields

The Open Parasitology Journal ◽

10.2174/1874421401806010052 ◽

2018 ◽

Vol 6 (1) ◽

pp. 52-62 ◽

Cited By ~ 1

Author(s):

Roopa Rani Samal ◽

Sarita Kumar

Keyword(s):

Secondary Metabolites ◽

Aedes Aegypti ◽

Control Strategy ◽

Mosquito Control ◽

Current Status ◽

New Delhi ◽

Probit Regression ◽

Statistical Parameters ◽

Insecticide Susceptibility ◽

Control Programs

Background: Mosquito control is a major concern throughout the world because of rising cases of mosquito-borne diseases. The outbreak of Zika, Dengue and Chikungunya has caused grave situations raising urgent need to control Aedes aegypti. Moreover, extensive use of synthetic insecticides in mosquito control programs has resulted in high levels of insecticide resistance leading to the use of magnified concentrations, impacting human health and environment adversely. The knowledge about current status of the insecticide susceptibility against Ae. aegypti could help to devise mosquito control strategy. Objective: Present study evaluates the larvicidal potential of thirteen insecticides belonging to seven different classes; organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, avermectins and secondary metabolites; against early fourth instars of Ae. aegypti. Materials and Methods: The insecticide susceptibility was evaluated as per WHO protocol. Fatality counts were made after 24h of exposure; and the LC50, LC90 and other statistical parameters were computed by probit-regression analysis. Results: The data reveals the maximum efficacy of pyrethroids and fenitrothion, with lethal values less than 0.001 ppm. Avermectins, organochlorines and carbamates were moderately toxic, while neonicotinoid posed appreciable toxicity. In contrast, berberine, a secondary plant metabolite was found inefficient. The larvicidal efficacy of tested insecticides against Ae. aegypti was found in the decreasing order of pyrethroids > organophosphates > avermectins > organochlorines > carbamates > neonicotinoids > secondary metabolites. Conclusion: Present investigations explore various toxicants as Dengue vector control agents in order to devise a suitable control strategy for mosquito control in fields.

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Reproduction of Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) and Trissolcus sp. aff. urichi (Hymenoptera: Scelionidae) in Eggs of Nezara viridula (Hemiptera: Pentatomidae) of Different Ages

Journal of Agricultural Science ◽

10.5539/jas.v13n10p96 ◽

2021 ◽

Vol 13 (10) ◽

pp. 96

Author(s):

Eduardo Carvalho Faca ◽

Fabrício Fagundes Pereira ◽

Winnie Cezario Fernandes ◽

Ivana Fernandes da Silva ◽

Valmir Antônio Costa ◽

...

Keyword(s):

Biological Control ◽

Life Cycle ◽

Sex Ratio ◽

Cycle Length ◽

Nezara Viridula ◽

Control Programs ◽

Breeding Methodology ◽

Different Ages ◽

Laboratory Bioassays

The study of the interaction between parasitoid and host, especially the age of these organisms, is an important step towards the implementation of biological control programs. Therefore, we investigated the performance of Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) and Trissolcus sp. aff. urichi (Hymenoptera: Scelionidae) parasitizing eggs of Nezara viridula (Hemiptera: Pentatomidae), considering different ages of the parasitoids and the host. We performed four laboratory bioassays: two using females of O. submetallicus and Trissolcus sp. aff. urichi at 24, 48, 72, 96, 120, or 144 hours of age exposed to parasitism in N. viridula eggs (24 h) and two trials with N. viridula eggs at 24, 48, 72, 96, 120, or 144 hours exposed to the parasitism of O. submetallicus and Trissolcus sp. aff. urichi (24 h). We evaluated the percentage of parasitism and emergence, life cycle length, progeny, sex ratio, and the longevity of the parasitoids. The parasitism of O. submetallicus in N. viridula eggs was influenced by the age of the parasitoid, 120 hours being the minimum to obtain better parasitism. From this age on, there is interference in the longevity of the progeny. Trisolcus sp. aff. urichi, at all ages, parasitized N. viridula eggs relatively well, but with almost no emergence of the parasitized eggs. Females of O. submetallicus parasitized and developed in eggs of N. viridula of all ages. Females of Trissolcus sp. aff. urichi parasitized their host, but there was barely any emergence. These pieces of information regarding the breeding methodology contribute to the implementation of new protocols for the multiplication of these parasitoids in the laboratory, and later, their release in the field.

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Discovery of Novel Entomopathogenic Fungi for Mosquito-Borne Disease Control

Frontiers in Fungal Biology ◽

10.3389/ffunb.2021.637234 ◽

2021 ◽

Vol 2 ◽

Author(s):

Anastasia Accoti ◽

Cecilia Springer Engdahl ◽

George Dimopoulos

Keyword(s):

Entomopathogenic Fungi ◽

Mosquito Control ◽

Control Strategies ◽

Pathogenic Fungi ◽

Suitable Alternative ◽

Control Programs ◽

Wide Range ◽

Outdoor Environments ◽

Environmentally Safe ◽

Emergence Of Resistance

The increased application of chemical control programs has led to the emergence and spread of insecticide resistance in mosquitoes. Novel environmentally safe control strategies are currently needed for the control of disease vectors. The use of entomopathogenic fungi could be a suitable alternative to chemical insecticides. Currently, Beauveria spp. and Metarhizium spp. are the most widely used entomopathogenic fungi for mosquito control, but increasing the arsenal with additional fungi is necessary to mitigate the emergence of resistance. Entomopathogenic fungi are distributed in a wide range of habitats. We have performed a comprehensive screen for candidate mosquitocidal fungi from diverse outdoor environments in Maryland and Puerto Rico. An initial screening of 22 fungi involving exposure of adult Anopheles gambiae to 2-weeks-old fungal cultures identified five potent pathogenic fungi, one of which is unidentified and the remaining four belonging to the three genera Galactomyces sp., Isaria sp. and Mucor sp. These fungi were then screened against Aedes aegypti, revealing Isaria sp. as a potent mosquito killer. The entomopathogenic effects were confirmed through spore-dipping assays. We also probed further into the killing mechanisms of these fungi and investigated whether the mosquitocidal activities were the result of potential toxic fungus-produced metabolites. Preliminary assays involving the exposure of mosquitoes to sterile filtered fungal liquid cultures showed that Galactomyces sp., Isaria sp. and the unidentified isolate 1 were the strongest producers of factors showing lethality against An. gambiae. We have identified five fungi that was pathogenic for An. gambiae and one for Ae. aegypti, among these fungi, four of them (two strains of Galactomyces sp., Mucor sp., and the unidentified isolate 1) have never previously been described as lethal to insects. Further characterization of these entomopathogenic fungi and their metabolites needs to be done to confirm their potential use in biologic control against mosquitoes.

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