scholarly journals Does membrane feeding compromise the quality ofAedes aegyptimosquitoes?

2019 ◽  
Author(s):  
Perran A. Ross ◽  
Meng-Jia Lau ◽  
Ary A. Hoffmann
Keyword(s):  
Aedes Aegypti ◽  
Disease Control ◽  
Inbreeding Depression ◽  
Mass Rearing ◽  
Feeding Rates ◽  
Female Reproduction ◽  
Control Programs ◽  
Host Seeking ◽  
Membrane Feeding ◽  
Host Cues

AbstractModifiedAedes aegyptimosquitoes are being mass-reared for release in disease control programs around the world. Releases involving female mosquitoes rely on them being able to seek and feed on human hosts. To facilitate the mass-production of mosquitoes for releases, females are often provided blood through artificial membrane feeders. When reared across generations there is a risk that mosquitoes will adapt to feeding on membranes and lose their ability to feed on human hosts. To test adaptation to membrane feeding, we selected replicate populations ofAe. aegyptifor feeding on either human arms or membrane feeders for at least 8 generations. Membrane-selected populations suffered fitness costs, likely due to inbreeding depression arising from bottlenecks. Membrane-selected females had higher feeding rates on membranes than human-selected ones, suggesting adaptation to membrane feeding, but they maintained their attraction to host cues and feeding ability on humans despite a lack of selection for these traits. Host-seeking ability in small laboratory cages did not differ between populations selected on the two blood sources, but membrane-selected females were compromised in a semi-field enclosure where host-seeking was tested over a longer distance. Our findings suggest thatAe. aegyptimay adapt to feeding on blood provided artificially, but this will not substantially compromise field performance or affect experimental assessments of mosquito fitness. However, large population sizes during mass rearing with membrane feeders should be maintained to avoid bottlenecks which lead to inbreeding depression.Author summaryWith modified mosquitoes being mass-reared for release in disease control programs, there is interest in understanding factors that can affect the quality of release stocks. In the laboratory, membrane feeding devices are often used to provide blood to female mosquitoes which they need to lay eggs. Over time, mosquitoes could adapt to membrane feeding and lose their preference for (or ability to feed on) natural hosts. Adaptation could affect the performance of lab-reared mosquitoes when deployed in the field, especially if the success of disease control programs relies on female reproduction such as in gene drive orWolbachia-based approaches. We tested to see ifAedes aegyptimosquitoes, the principal vectors of dengue virus, would adapt to feeding on blood provided via membranes. We found some evidence of adaptation, with membrane-selected mosquitoes having higher feeding rates on membranes, but this didn’t affect their ability to feed on humans or their attraction to host cues. Although membrane feeding alone does not substantially affect mosquito quality, it can lead to inbreeding depression if populations pass through bottlenecks as they adapt to feeding on blood provided artificially. Our results may inform mass-rearing programs involving the release of modified female mosquitoes.

scholarly journals Efficacy of Blood Sources and Artificial Blood Feeding Methods in Rearing of Aedes aegypti (Diptera: Culicidae) for Sterile Insect Technique and Incompatible Insect Technique Approaches in Sri Lanka

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Nayana Gunathilaka ◽  
Tharaka Ranathunge ◽  
Lahiru Udayanga ◽  
Wimaladharma Abeyewickreme
Keyword(s):  
Feeding Rate ◽  
Mass Rearing ◽  
Blood Feeding ◽  
Metal Plate ◽  
Feeding Rates ◽  
Artificial Membrane ◽  
Plate Method ◽  
Membrane Feeding ◽  
Feeding Technique ◽  
One Way Anova

Introduction. Selection of the artificial membrane feeding technique and blood meal source has been recognized as key considerations in mass rearing of vectors. Methodology. Artificial membrane feeding techniques, namely, glass plate, metal plate, and Hemotek membrane feeding method, and three blood sources (human, cattle, and chicken) were evaluated based on feeding rates, fecundity, and hatching rates of Aedes aegypti. Significance in the variations among blood feeding was investigated by one-way ANOVA, cluster analysis of variance (ANOSIM), and principal coordinates (PCO) analysis. Results. Feeding rates of Ae. aegypti significantly differed among the membrane feeding techniques as suggested by one-way ANOVA (p<0.05). The metal plate method was identified as the most efficient and cost-effective feeding technique. Blood feeding rate of Ae. aegypti was higher with human blood followed by cattle and chicken blood, respectively. However, no significant difference was observed from the mosquitoes fed with cattle and human blood, in terms of fecundity, oviposition rate, and fertility as suggested by one-way ANOVA (p>0.05). Conclusions. Metal plate method could be recommended as the most effective membrane feeding technique for mass rearing of Ae. aegypti, due to its high feeding rate and cost effectiveness. Cattle blood could be recommended for mass rearing Ae. aegypti.

scholarly journals The need for practical insecticide-resistance guidelines to effectively inform mosquito-borne disease control programs

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alice Namias ◽  
Ndey Bassin Jobe ◽  
Krijn Petrus Paaijmans ◽  
Silvie Huijben
Keyword(s):  
Insecticide Resistance ◽  
Disease Control ◽  
Vector Control ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Exposure Dose ◽  
Local Conditions ◽  
Control Programs ◽  
Host Seeking ◽  
Seeking Behavior

Monitoring local mosquito populations for insecticide resistance is critical for effective vector-borne disease control. However, widely used phenotypic assays, which are designed to monitor the emergence and spread of insecticide resistance (technical resistance), do not translate well to the efficacy of vector control products to suppress mosquito numbers in the field (practical resistance). This is because standard testing conditions such as environmental conditions, exposure dose, and type of substrate differ dramatically from those experienced by mosquitoes under field conditions. In addition, field mosquitoes have considerably different physiological characteristics such as age and blood-feeding status. Beyond this, indirect impacts of insecticide resistance and/or exposure on mosquito longevity, pathogen development, host-seeking behavior, and blood-feeding success impact disease transmission. Given the limited number of active ingredients currently available and the observed discordance between resistance and disease transmission, we conclude that additional testing guidelines are needed to determine practical resistance—the efficacy of vector control tools under relevant local conditions— in order to obtain programmatic impact.

scholarly journals Toxicity of two groups of pesticides against the mosquito Aedes aegypti

2020 ◽  
Vol 13 (1) ◽  
pp. 148-155
Author(s):  
Mohammed Rashed Al Zahrani ◽  
Fatehia Nasser Gharsan ◽  
Khalid Mohammed Al-Ghamdi ◽  
Jazem Abdullah Mahyoub ◽  
Tariq Saeed Alghamdi
Keyword(s):  
Saudi Arabia ◽  
Aedes Aegypti ◽  
Disease Control ◽  
Human Health ◽  
Mosquito Control ◽  
Disease Outbreaks ◽  
Control Programs ◽  
Chemical Pesticides ◽  
Improve Disease Control

The mosquito Aedes aegypti (Linnaeus) (Diptera: Culicidae) is a vector for several pathogens that affect human health worldwide. Therefore, mosquito control is the best approach to prevent disease outbreaks. In this milieu, it is preferable to evaluate the effectiveness of chemical pesticides at regular intervals to identify the most effective ones and use them during the outbreaks of diseases and spread of pests. Here, we aimed to study the toxicity of six pesticides, which are classified under two groups, namely pyrethroids and organophosphates, against A. aegypti mosquitoes to improve disease control in Saudi Arabia. Hortak was the most effective in larval mosquito control (LC50 = 0.0031 ppm), followed by Aquapal Super 20 EW (LC50 = 0.0389 ppm), whereas Solfac was the least effective (LC50 = 0.1119 ppm). In addition, the sensitivity of the tested larvae to Safrotin and Keen 600 EC was 8.1 and 58.9 times higher than that to Resfin-5, which was the least effective, respectively. Hortak and Safrotin exhibited the highest toxicity against the larvae of A. aegypti. Our findings confirm that the tested pesticides can be used in mosquito-control programs during epidemic outbreaks and emergency.

scholarly journals An elusive endosymbiont: Does Wolbachia occur naturally in Aedes aegypti?

2019 ◽  
Author(s):  
Perran A. Ross ◽  
Ashley G. Callahan ◽  
Qiong Yang ◽  
Moshe Jasper ◽  
A. K. M. Arif ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Control ◽  
Mosquito Species ◽  
Natural Populations ◽  
Laboratory Population ◽  
Kuala Lumpur ◽  
Population Replacement ◽  
Field Surveys ◽  
Control Programs ◽  
Naturally Occurring

AbstractWolbachia are maternally-inherited endosymbiotic bacteria found within many insect species. Aedes mosquitoes experimentally infected with Wolbachia are being released into the field for Aedes-borne disease control. These Wolbachia infections induce cytoplasmic incompatibility which is used to suppress populations through incompatible matings or replace populations through the reproductive advantage provided by this mechanism. However the presence of naturally-occurring Wolbachia in target populations could interfere with both population replacement and suppression programs depending on the compatibility patterns between strains. Aedes aegypti were thought to not harbor Wolbachia naturally but several recent studies have detected Wolbachia in natural populations of this mosquito. We therefore review the evidence for natural Wolbachia infections in Ae. aegypti to date and discuss limitations of these studies. We draw on research from other mosquito species to outline the potential implications of natural Wolbachia infections in Ae. aegypti for disease control. To validate previous reports, we obtained a laboratory population of Ae. aegypti from New Mexico, USA, that harbors a natural Wolbachia infection, and we conducted field surveys in Kuala Lumpur, Malaysia where a natural Wolbachia infection has also been reported. However, we were unable to detect Wolbachia infection in both the laboratory and field populations. Because the presence of naturally-occurring Wolbachia in Ae. aegypti could have profound implications for Wolbachia-based disease control programs, it is important to continue to accurately assess the Wolbachia status of target Aedes populations.

Larvicidal Activity of Essential Oils Against Aedes aegypti (Diptera: Culicidae)

2020 ◽  
Vol 26 (33) ◽  
pp. 4092-4111
Author(s):  
Mikael A. de Souza ◽  
Larissa da Silva ◽  
Maria A. C. dos Santos ◽  
Márcia J. F. Macêdo ◽  
Luiz J. Lacerda-Neto ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Essential Oils ◽  
Larval Mortality ◽  
Analytical Techniques ◽  
Extraction Methods ◽  
Control Programs ◽  
Plant Parts ◽  
Natural Insecticides ◽  
Methods Analytical ◽  
Meta Analyses

The Aedes aegypti is responsible for the transmission of arboviruses, which compromise public health. In the search for synthetic product alternatives, essential oils (OEs) have been highlighted by many researchers as natural insecticides. This systematic review (SR) was performed according to PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and its objective was to evaluate studies addressing OEs with larvicidal properties against Ae. aegypti, through electronic database searches (Pubmed, Science Direct and Scielo), covering an overview of the plant sources OEs, which plant parts were used, the extraction methods, analytical techniques, major and/or secondary constituents with greater percentages, as well as the LC50s responsible for larval mortality. Following study analysis, plants distributed across 32 families, 90 genera and 175 species were identified. The Lamiaceae, Myrtaceae, Piperaceae, Asteraceae, Rutaceae, Euphorbiaceae and Lauraceae families obtained the highest number of species with toxic properties against larvae from this vector. Practically all plant parts were found to be used for OE extraction. Hydrodistillation and steam distillation were the main extraction methods identified, with GC-MS/GC-FID representing the main analytical techniques used to reveal their chemical composition, especially of terpene compounds. In this context, OEs are promising alternatives for the investigation of natural, ecologically correct and biodegradable insecticides with the potential to be used in Ae. aegypti control programs.

scholarly journals Cold storage and gamma irradiation of Sitotroga cerealella Olivier eggs (Lepidoptera: Gelechiidae) in relation to the success of parasitism by Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae)

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Naglaa F. Abdel-Hameid ◽  
I. R. M. Elzoghby ◽  
A. L. Mehany ◽  
W. A. A. Sayed
Keyword(s):  
Gamma Irradiation ◽  
Cold Storage ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Sitotroga Cerealella ◽  
Trichogramma Evanescens ◽  
Control Programs ◽  
Angoumois Grain Moth ◽  
Rearing Techniques ◽  
The Times

AbstractThe performance of parasitism by the egg parasitoid, Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) on eggs of Angoumois grain moth, Sitotroga cerealella Olivier (Lepidoptera: Gelechiidae) was investigated under cold storage and gamma irradiation treatments of the host eggs. Cold storage treatment could improve the parasitoid mass rearing techniques and reduced the costs of biological control programs, while gamma irradiation might be used as a supplementary support at the times of high demand. The suitability of the S. cerealella eggs, stored at – 20 °C for 0.5, 1, or 2 h. as a host for T. evanescens was evaluated. The sensitivity of S. cerealella eggs to gamma irradiation treatments and the acceptability of irradiated eggs for parasitism by T. evanescens females for the parental P and F1 generations were examined. The results revealed that parasitism was drastically reduced more than adult’s emergence and sex-ratio (% of females) after cold storage periods of S. cerealella eggs. Moreover, the parasitism percentages were relatively reduced to (97.1, 96.1, 93.03, and 92.7 %) after irradiating the S. cerealella eggs at 40, 60, 80, and 100 Gy, respectively than the control (97.3% emergence). The percentages of emergence and females’ percent were slightly decreased by gamma irradiation doses, while, equal preferred by the F1 generation of parasitoid that produced from irradiated S. cerealella eggs.

scholarly journals Permethrin Resistance in Aedes aegypti Affects Aspects of Vectorial Capacity

Insects ◽  
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.

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

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.

scholarly journals Effects of Alternative Blood Sources on Wolbachia Infected Aedes aegypti Females within and across Generations

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 140 ◽  
Author(s):  
Véronique Paris ◽  
Ellen Cottingham ◽  
Perran Ross ◽  
Jason Axford ◽  
Ary Hoffmann
Keyword(s):  
Aedes Aegypti ◽  
Human Blood ◽  
Mass Rearing ◽  
Egg Hatch ◽  
Mass Release ◽  
Deliberate Release ◽  
Blood Source ◽  
Wolbachia Density ◽  
Infected Line ◽  
Strong Adaptation

Wolbachia bacteria have been identified as a tool for reducing the transmission of arboviruses transmitted by Aedes aegypti. Research groups around the world are now mass rearing Wolbachia-infected Ae. aegypti for deliberate release. We investigated the fitness impact of a crucial element of mass rearing: the blood meal required by female Ae. aegypti to lay eggs. Although Ae. aegypti almost exclusively feed on human blood, it is often difficult to use human blood in disease-endemic settings. When females were fed on sheep or pig blood rather than human blood, egg hatch rates decreased in all three lines tested (uninfected, or infected by wMel, or wAlbB Wolbachia). This finding was particularly pronounced when fed on sheep blood, although fecundity was not affected. Some of these effects persisted after an additional generation on human blood. Attempts to keep populations on sheep and pig blood sources only partly succeeded, suggesting that strong adaptation is required to develop a stably infected line on an alternative blood source. There was a decrease in Wolbachia density when Ae. aegypti were fed on non-human blood sources. Density increased in lines kept for multiple generations on the alternate sources but was still reduced relative to lines kept on human blood. These findings suggest that sheep and pig blood will entail a cost when used for maintaining Wolbachia-infected Ae. aegypti. These costs should be taken into account when planning mass release programs.

Sign in / Sign up

Export Citation Format

Share Document