Spinosyns Delivered in Sugar Meals to Aedes aegypti and Aedes albopictus (Diptera: Culicidae): Acute Toxicity and Subacute Effects on Survival, Fecundity, and Fertility

Author(s):  
Abdullah A Alomar ◽  
Barry W Alto ◽  
Edward D Walker

Abstract Sugar is an essential source of nutrition for adult mosquitoes to acquire energy. Toxic sugar bait (TSB) provides a promising method for mosquito control by incorporating toxins into artificial sources of sugar (i.e., toxic baits) presented to wild populations. Spinosyns comprise a family of bacterial secondary metabolites with a unique mode of action against the insect nervous system, an appealing environmental safety profile, and potential for incorporation into sugar baits. This research evaluated acute and subacute effects of spinosad (spinosyns A and D) and spinetoram (spinosyns J and L) in sugar meals on survival, fecundity, and fertility of Aedes aegypti and Aedes albopictus. Acute toxicity of spinosyns doubled from 24 to 48 h of assessment, revealing a relatively slow and cumulative action of the formulated spinosyns. Median lethal concentrations at 48 h were lower for spinetoram than for spinosad, lower for Ae. albopictus than Ae. aegypti, and lower for males than females. When exposed to subacute LC50 concentrations of spinosad and spinetoram for 24 h, survival of males and females of both species was diminished compared with controls, fecundity of females was increased, but fertility as measured by hatch rate of eggs was decreased. The formulations may have increased the nutritive value of the sugar meals thereby boosting fecundity, while toxifying embryos, reducing fertility. The inclusion of subacute effects of spinosyns allows assessment of the broader consequences of TSB for adult mosquito control.

2013 ◽  
Vol 3 (3) ◽  
Author(s):  
Janno B. B. Bernadus ◽  
Victor D. Pijoh ◽  
Venny Kareth

Abstract: Dengue Hemorrhagic Fever (DHF) has become a public health problem in Indonesia because of its high prevalence and ability to spread more widely. In North Sulawesi itself Case Fatality Rate of carrying dengue is increasing from year to year. The local village Malalayang has a high potential for spreading this disease. The result of an  entomology survey on adult mosquitos showed that Aedes sp was found in 40 houses of 80 house samples. From these 40 houses we got 71 mosquito samples. From these 71 samples tested and identified, we found three species: Aedes aegypti (30 samples, 42.25%), Aedes albopictus (22 samples, 30.99%), and Culex sp (19 samples, 26.76%). Mosquito density can be seen from the indices of the resting rates, which were 0.375 for Aedes aegypti, 0.275 for Aedes albopictus, and 0.65 for Aedes sp. Key words: density, adult mosquito, Aedes sp., resting rate.   Abstrak: Demam Berdarah Dengue (DBD) merupakan penyakit yang menjadi masalah kesehatan masyarakat di Indonesia karena prevalensinya yang tinggi dan penyebarannya semakin luas. Di Sulawesi Utara, Case Fatality Rate penyakit DBD tercatat terus meningkat dari tahun ke tahun. Kelurahan Malalayang I merupakan daerah yang potensial sebagai daerah penyebaran DBD. Survei entomologi terhadap nyamuk dewasa Aedes sp pada 80 rumah  memperlihatkan bahwa 40 diantaranya terdapat 71 sampel nyamuk. Setelah diperiksa dan diidentifikasi ternyata ditemukan tiga spesies yaitu Aedes aegypti 30 sampel (42,25%), Aedes albopictus 22 sampel (30,99%) dan Culex sp 19 (26,76%). Kepadatan nyamuk  dapat dilihat  dari angka indeks  pada resting rate yaitu Aedes aegypti = 0,375 , Aedes albopictus = 0,275 dan  Aedes sp.= 0,65. Kata kunci:  kepadatan, nyamuk dewasa, Aedes sp., resting rate.


2021 ◽  
Author(s):  
Célia Lutrat ◽  
Roenick Proveti Olmo ◽  
Thierry Baldet ◽  
Jérémy Bouyer ◽  
Eric Marois

Aedes albopictus is a major vector of arboviruses. Better understanding of its sex determination is crucial for developing mosquito control tools, especially genetic sexing strains. In Aedes aegypti, Nix is the primary gene responsible for masculinization and Nix-expressing genetic females develop into fertile, albeit flightless, males. In Ae. albopictus, Nix has also been implicated in masculinization but its role remains to be further characterized. In this work, we established Ae. albopictus transgenic lines ectopically expressing Nix. Several were composed exclusively of genetic females, with transgenic individuals being phenotypic and functional males due to the expression of the Nix transgene. Their reproductive fitness was marginally impaired, while their flight performance was similar to controls. Overall, our results show that Nix is sufficient for full masculinization in Ae. albopictus. Moreover, the transgene construct contains a fluorescence marker allowing efficient automated sex sorting. Consequently, such strains constitute valuable sexing strains for genetic control.


2021 ◽  
Vol 68 (1) ◽  
pp. 92-96
Author(s):  
Dena Autry

Mosquito Control programs are utilizing cost-effective long term autocidal gravid traps because they minimize labor needs while targeting the gravid population of container-breeding mosquitoes. This field study compared the efficacy of the In2Care Mosquito Trap and the Centers for Disease Control and Prevention autocidal gravid ovitrap (CDC-AGO). The study consisted of two control and two treatment sites, and each treatment site had either 100 In2Care Mosquito Traps or 100 CDC-AGOs. Aedes aegypti populations in each site were monitored using Biogent (BG) Sentinel 2 mosquito traps and ovitraps. Analysis of pre- and post-treatment data indicated no significant difference in adult mosquito populations detected by BG traps from either the In2Care or CDC-AGO sites. However, the mean number of eggs collected by ovitraps showed significant reduction in both trap type treated areas posttreatment, compared to pre-treatment. Furthermore, the mean number of egg collections from the In2Care mosquito trap treated area was much less than the collection from the CDC-AGO trap treated area post-treatment.


2021 ◽  
Vol 15 (8) ◽  
pp. e0009438
Author(s):  
Isik Unlu ◽  
Ary Faraji ◽  
Nicholas Indelicato ◽  
James R. McNelly

Background Aedes (Stegomyia) albopictus (Skuse) impacts human outdoor activity because of its aggressive biting behavior, and as a major vector of mosquito-borne diseases, it is also of public health importance. Although most mosquito species exhibit crepuscular activity by primarily host seeking at dawn and dusk, Ae. albopictus has been traditionally characterized as a diurnal or day-biting mosquito. With the global expansion and increased involvement of Ae. albopictus in mosquito-borne diseases, it is imperative to elucidate the diel activity of this species, particularly in newly invaded areas. Methodology and principal findings Human sweep netting and carbon dioxide-baited rotator traps were used to evaluate the diel activity of Ae. albopictus in two study sites. Both trapping methods were used in New Jersey’s Mercer County, USA (temperate/urban), while only human sweep netting was used in Florida’s Volusia County, USA (subtropical/suburban). Human sweep netting was performed to determine adult mosquito activity at Sunrise, Solar Noon, Sunset, and Lunar Midnight. Because New Jersey is in a temperate area, diel activity was investigated during the early season (3–19 July), peak season (25 July-19 September), and late season (22 September- 22 October). Aedes albopictus showed the highest activity during peak and late seasons at Solar Noon (P < 0.05). At Sunrise and Sunset during the peak season, Ae. albopictus activity was similar. Lunar Midnight activity was significantly lower than Sunrise and Solar Noon (P < 0.05) but was similar to that of Sunset. In the late season, the highest activity was observed during Solar Noon while the least activity was observed during Sunrise and Lunar Midnight (P<0.05). Bottle rotator traps used in conjunction with the human sweep net technique exhibited similar results. Seasonal activity was not differentiated in Florida due to the consistent subtropical climate. The highest adult activity was observed at Sunrise using human sweep netting, but it was not significantly different from Solar Noon and Sunset. The lowest adult activity was observed at Lunar Midnight; however, it was not significantly different from Solar Noon and Sunset. These results provide evidence that the diel activity of Ae. albopictus, contrary to the common perception of its diurnal activity, is much more varied. Conclusion/Significance Involvement of Ae. albopictus in the transmission of debilitating mosquito-borne pathogens such as chikungunya, dengue, and Zika virus, coupled with its affinity to thrive in human peridomestic environments, substantiates that our findings have global implications in areas where Ae. albopictus populations established. It also highlights the importance of behavioral studies of vector species which will not only help mosquito control professionals plan the timing of their control efforts but also provides empirical evidence against conventional wisdoms that may unjustly persist within public health stewards.


2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Manuela Agudelo-Restrepo ◽  
Martha Lucia Hernández‐Quesada ◽  
Edinson Yonny Sanabria-Duran ◽  
Sandra Inés Uribe-Soto ◽  
Adriana Ortiz-Reyes ◽  
...  

Aedes aegypti and Aedes albopictus are the major vectors for the transmission of more than 30 disease-causing viruses as dengue fever, dengue hemorragic fever, zika, yellow fever and chikungunya. Vector control is one of the important strategies used in order to fight these diseases in tropical and subtropical countries. However, mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. The aim of this study was to identify larvicidal and adulticidal activity of secondary metabolites in extracts produced by bacteria isolated from different sources in Colombia. A total of 105 extracts produced from the same number of bacteria were evaluated for their activity against fourth instar larvae and adults of A. aegypti and A. albopictus using standard protocols defined for the WHO (World Health Organization) and CDC (Control Disease Centre, USA). Six extracts showed relevant activity (more than 50% of mosquito larvae were killed after 48 hours), two of them showed to be actives against larvae of Aedes aegypti and four against larvae of Aedes albopictus. None of the extracts showed activity against the mosquitoes in adult stage. The bacteria producing active extracts were identified using the biolog ® identification system as Serratia marcescens ss marcescens, Escherichia hermannii, Serratia marcescens ss marcescens, Bacillus marisflavi, Bacillus atropheus/subtilis and Pseudomonas chlororaphis subsp. aurantiaca. In conclusion, bacterial extracts are a good source for the search of new strategies in the control of mosquitoes. Further studies to determine the compound responsible for the insecticidal activity are in progress.


2019 ◽  
Vol 5 (3) ◽  
pp. 119-124
Author(s):  
Raodatul Jannah ◽  
Bambang Fajar Suryadi ◽  
Yuliadi Zamroni ◽  
Galuh Tresnani

Senggigi beach is one of tourist destinations of Lombok island-West Nusa Tenggara. In addition to its beautiful scenery, Senggigi has potential problems in the health field namely Aedes spp., mosquito, which became a dengue vector. This explorative and descriptive research, has been done in June-July 2017 and aimed to observe the bioecology of Aedes spp., mosquito in Senggigi beach. Sampling was done with purposive sampling method, by collecting larvae and adult mosquito Aedes spp., at specified sampling point. The collected samples then identified. The result of the study, two species of Aedes spp., mosquitos were found, there are Aedes aegypti and Aedes albopictus. Breeding habitat of Aedes spp. mosquitos were found in artificial containers. The highest density were 57.5 individuals/100 mL found in the boat habitat and the lowest density were 2 individuals/100 mL in the trash bin. The highest Relative Abundance Index value of Aedes aegypti were 100% in fish pond habitat and Aedes albopictus was 100% in three different habitats (used tire, sterofoam box and used bowl). The selection of Aedes albopictus habitat in clear and dirty water, near the yard of the house with dense vegetation rather than densely populated makes the distribution more widespread. Meanwhile, Aedes aegypti was only distributed in clear water habitats, near densely populated settlements.


2016 ◽  
Vol 36 (04) ◽  
pp. 177-187 ◽  
Author(s):  
K.S. Costanzo ◽  
R.A. Dahan ◽  
D. Radwan

AbstractThe Asian tiger mosquito,Aedes albopictus(Skuse) and the yellow fever mosquito,Aedes aegypti(Linnaeus) are medically important species that vector several arboviruses. Globally, populations of both species experience (and are sensitive to) photoperiodic variations. The present study aims to test if photoperiod regimes affect the population performance ofAe. albopictusandAe. aegypti. Since mosquitoes have sex-specific strategies to maximize fitness, we also tested the hypothesis thatAe. albopictusandAe. aegyptiwould exhibit differences in the male and female response (sexually dimorphic response) to various photoperiod treatments. We reared cohorts of first instar larvae to adulthood in three photoperiod treatments: short day (10 h light), control (12 h light) and long day (14 h light). We measured and compared survival to adulthood, population growth, development time of males and females, and wing length across treatments. Although we detected no effects of photoperiod on the population performance of both species, we found evidence of a sexual dimorphic response to photoperiod inAe. albopictus, but not inAe. aegypti, withAe. albopictusfemales being more sensitive to variations in photoperiod. The observed differences between sexes ofAe. albopictusare consistent with sex-specific developmental constraints. The absence of a sexually dimorphic response to photoperiod inAe. aegyptican be attributed to different strategies evolved in this species to prepare for unfavourable conditions associated with shorter day length. We discuss the ecological and medical implications of our findings.


2021 ◽  
Vol 9 ◽  
Author(s):  
Júlia López-Mercadal ◽  
André Barretto Bruno Wilke ◽  
Carlos Barceló ◽  
Miguel Angel Miranda

The Asian tiger mosquito Aedes albopictus (Skuse, 1894) is a highly invasive species widely distributed on the Spanish Mediterranean coast and the Balearic archipelago. Most studies involving this species in Spain have been focused on surveillance and control methods. However, micro-evolutionary studies for Ae. albopictus in Spain have been traditionally neglected. Morphological diversity could be the result of long-term evolutionary diversification in responses to selective pressures such as temperature, precipitation, food availability, predation, or competition that may influence flight activity, host-seeking, and blood-feeding behavior. Wing geometric morphometric have been used not only to study micro- and macro-evolution in mosquitoes but also in studies of population structuring and sexual dimorphism. Therefore, the main goal of this study was to investigate the wing shape patterns of Ae. albopictus populations to unveil sexual dimorphism that could provide information about their ecology and behavior. Mosquito eggs were collected using oviposition traps at the main campus of the University of the Balearic Islands (Palma de Mallorca, Spain) and reared under laboratory conditions. In order to study wing shape variation patterns in Ae. albopictus males and females, the left wing of each adult mosquito was removed and analyzed based on 18 landmarks. Our results indicated strong levels of sexual dimorphism between Ae. albopictus males and females. Furthermore, according to the cross-validated reclassification test, males were correctly distinguished from females with an accuracy of 84% and females from males 75%. We observed a significant sexual dimorphism in the wing shape patterns of Ae. albopictus when considering different seasonal patterns (spring vs. autumn). Our results suggested that selective pressures may affect males differently to females. Host-seeking, blood-feeding, and oviposition behavior of females may act as a major driver for wing shape sexual dimorphism. These results should be considered for the development of more effective and targeted mosquito control strategies.


2020 ◽  
Vol 57 (5) ◽  
pp. 1550-1559 ◽  
Author(s):  
Casey Parker ◽  
Daviela Ramirez ◽  
Carol Thomas ◽  
C Roxanne Connelly

Abstract Resistance to insecticides used to control mosquito vectors threatens the ability of mosquito-control organizations to protect public health. Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) are invasive species widely distributed throughout Florida and have been implicated in recent epidemics of Zika, dengue, and chikungunya viruses. Knowledge of the susceptibility status of these mosquito species to pyrethroid and organophosphate active ingredients (AIs) is needed to inform product selection and treatment decisions. The susceptibility of 37 Ae. aegypti and 42 Ae. albopictus populations from Florida was assessed in response to six pyrethroid and three organophosphate AIs using the CDC bottle bioassay method. Of all bioassays completed with a pyrethroid AI, 95% for Ae. aegypti and 30% for Ae. albopictus resulted in a resistant outcome. For organophosphate AIs, ~31% of assays conducted for both species were classified as resistant. The highest frequency of susceptibility for both species was observed in response to the organophosphate AI, naled. Lambda-cyhalothrin was the only pyrethroid to result in a susceptible status for Ae. aegypti and also had the highest frequency of susceptibility for Ae. albopictus. Resistance was detected to every AI tested for both Ae. aegypti and Ae. albopictus, but there was a pronounced trend of pyrethroid resistance in Florida populations of Ae. aegypti. The results of this work provide evidence for the need to decrease reliance on pyrethroids and to implement different methods of control of Ae. aegypti in Florida.


2020 ◽  
Vol 14 (11) ◽  
pp. e0008846
Author(s):  
Abdullah A. Alomar ◽  
Bradley H. Eastmond ◽  
Barry W. Alto

Zika virus (ZIKV) is an emerging mosquito-borne pathogen that can cause global public health threats. In the absence of effective antiviral medications, prevention measures rely largely on reducing the number of adult mosquito vectors by targeting juvenile stages. Despite the importance of juvenile mosquito control measures in reducing adult population size, a full understanding of the effects of these measures in determining mosquito phenotypic traits and in mosquito-arbovirus interactions is poorly understood. Pyriproxyfen is a juvenile hormone analog that primarily blocks adult emergence, but does not cause mortality in larvae. This mechanism has the potential to work in combination with other juvenile sources of mortality in nature such as predation to affect mosquito populations. Here, we experimentally evaluated the effects of juvenile exposure to pyriproxyfen and predatory mosquito Toxorhynchites rutilus on Aedes aegypti phenotypes including susceptibility to ZIKV infection and transmission. We discovered that combined effects of pyriproxyfen and Tx. rutilus led to higher inhibition of adult emergence in Ae. aegypti than observed in pyriproxyfen or Tx. rutilus treatments alone. Adult body size was larger in treatments containing Tx. rutilus and in treatments mimicking the daily mortality of predation compared to control or pyriproxyfen treatments. Susceptibility to infection with ZIKV in Ae. aegypti was reduced in predator treatment relative to those exposed to pyriproxyfen. Disseminated infection, transmission, and titers of ZIKV in Ae. aegypti were similar in all treatments relative to controls. Our data suggest that the combination of pyriproxyfen and Tx. rutilus can inhibit adult Ae. aegypti emergence but may confer a fitness advantage in survivors and does not inhibit their vector competence for ZIKV relative to controls. Understanding the ultimate consequences of juvenile mosquito control measures on subsequent adults’ ability to transmit pathogens is critical to fully understand their overall impacts.


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