scholarly journals Metarhizium anisopliae blastospores are highly virulent to adult Aedes aegypti, an important arbovirus vector

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Adriano Rodrigues de Paula ◽  
Leila Eid Imad Silva ◽  
Anderson Ribeiro ◽  
Gerson Adriano da Silva ◽  
Carlos Peres Silva ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Vegetable Oil ◽  
Metarhizium Anisopliae ◽  
Indirect Contact ◽  
Promising Alternative ◽  
Arbovirus Vector ◽  
Vector Management ◽  
Drying Techniques ◽  
Contact Bioassay ◽  
Highly Virulent

Abstract Background The use of entomopathogenic fungi (EPF) for the control of adult mosquitoes is a promising alternative to synthetic insecticides. Previous studies have only evaluated conidiospores against adult mosquitoes. However, blastospores, which are highly virulent against mosquito larvae and pupae, could also be effective against adults. Methods Metarhizium anisopliae (ESALQ 818 and LEF 2000) blastospores and conidia were first tested against adult Aedes aegypti by spraying insects with spore suspensions. Blastospores were then tested using an indirect contact bioassay, exposing mosquitoes to fungus-impregnated cloths. Virulence when using blastospores suspended in 20% sunflower oil was also investigated. Results Female mosquitoes sprayed with blastospores or conidia at a concentration of 108 propagules ml−1 were highly susceptible to both types of spores, resulting in 100% mortality within 7 days. However, significant differences in virulence of the isolates and propagules became apparent at 107 spores ml−1, with ESALQ 818 blastospores being more virulent than LEF 2000 blastospores. ESALQ 818 blastospores were highly virulent when mosquitoes were exposed to black cotton cloths impregnated with blastospores shortly after preparing the suspensions, but virulence declined rapidly 12 h post-application. The addition of vegetable oil to blastospores helped maintain virulence for up to 48 h. Conclusion The results showed that blastospores were more virulent to adult female Ae. aegypti than conidia when sprayed onto the insects or applied to black cloths. Vegetable oil helped maintain blastospore virulence. The results show that blastospores have potential for use in integrated vector management, although new formulations and drying techniques need to be investigated. Graphical abstract

Distribution of Aedes aegypti and Aedes albopictus in different eco zones of Thiruvananthapuram city with special reference to dengue viremia in humans

ENTOMON ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 223-230
Author(s):  
S. Sunil Kumar ◽  
D.A. Evans ◽  
K. Muthulakshmi ◽  
T. DilipKumar ◽  
R. Heera Pillai ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Dengue Shock Syndrome ◽  
Single Step ◽  
Equal Distribution ◽  
Distribution Study ◽  
Urban Zone ◽  
High Prevalence ◽  
Vector Management ◽  
Efficient Vector

Mosquito index study of three ecologically different ecozones of the Thiruvananthapuram district, Kerala showed sharp difference on the proportionate distribution of Aedes aegypti and Aedes albopictus. Human dengue viremia (HDV) was very high in those ecozones where A.aegypti density was high and HDV was low where A.albopictus was high. In a coastal zone of Thiruvananthapuram city, A. aegypti was the most abundant vector and in a hilly, arid suburban zone, A.albopictus was the abundant vector. In the urban zone both species of mosquitoes showed equal distribution. Study on the circulating serotypes in the serum of HDV by Single step single tube Multiplex PCR showed all the four serotypes viz DENV1, DENV2, DENV3 and DENV4 in patients of Thiruvananthapuram city, which indicated the possibility of Dengue Shock Syndrome, unless there is efficient vector management. Among the four dengue serotypes, Type 1 was the most abundant virus. Abundance of microhabitats in Thiruvananthapuram city, which support A. aegypti may be the reason for high prevalence of dengue fever in the urban zone.

scholarly journals Aedes aegypti (Diptera: Culicidae) Immune Responses with Different Feeding Regimes Following Infection by the Entomopathogenic Fungus Metarhizium anisopliae

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 95 ◽  
Author(s):  
Sara Cabral ◽  
Adriano de Paula ◽  
Richard Samuels ◽  
Rodrigo da Fonseca ◽  
Simone Gomes ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Immune Responses ◽  
Antimicrobial Peptides ◽  
Fungal Infection ◽  
Fat Body ◽  
Negative Regulator ◽  
Toll Pathway ◽  
Promising Alternative ◽  
Imd Pathway ◽  
Feeding Regimes

The mosquito Aedes aegypti is the most notorious vector of illness-causing viruses. The use of entomopathogenic fungi as bioinsecticides is a promising alternative for the development of novel mosquito control strategies. We investigate whether differences in immune responses could be responsible for modifications in survival rates of insects following different feeding regimes. Sucrose and blood-fed adult A. aegypti females were sprayed with M. anisopliae 1 × 106 conidia mL−1, and after 48 h, the midgut and fat body were dissected. We used RT-qPCR to monitor the expression of Cactus and REL1 (Toll pathway), IMD, REL2, and Caspar (IMD pathway), STAT and PIAS (JAK-STAT pathway), as well as the expression of antimicrobial peptides (Defensin A, Attacin and Cecropin G). REL1 and REL2 expression in both the midgut and fat body were higher in blood-fed fungus-challenged A. aegypti than in sucrose-fed counterparts. Interestingly, infection of sucrose-fed insects induced Cactus expression in the fat body, a negative regulator of the Toll pathway. The IMD gene was upregulated in the fat body in response to fungal infection after a blood meal. Additionally, we observed the induction of antimicrobial peptides in the blood-fed fungus-challenged insects. This study suggests that blood-fed A. aegypti are less susceptible to fungal infection due to the rapid induction of Toll and IMD immune pathways.

scholarly journals Evaluación de la actividad biocontroladora de Beauveria bassiana y Metarhizium anisopliae sobre larvas de Ancognatha scarabaeiodes (Coleoptera: Scarabaeidae)

2004 ◽  
Vol 5 (1) ◽  
pp. 43
Author(s):  
Any Mercedes Lucero Mafla ◽  
Luis Alberto Peña Villamil ◽  
Tito Bacca Ibarra
Keyword(s):  
Beauveria Bassiana ◽  
Metarhizium Anisopliae ◽  
Crop Yields ◽  
Integrated Management ◽  
White Grubs ◽  
Promising Alternative ◽  
Fungal Entomopathogens ◽  
Biocontrol Activity ◽  
Mortality Percentage ◽  
Lethal Doses

<p>Actualmente, en los municipios del departamento de Nariño (Colombia), en los cultivos de trigo y papa que son los principales sistemas de producción, se presentan altas infestaciones de poblaciones de chisas encontrándose hasta 350 larvas/m2, representando un factor limitante para la producción de los cultivos. Una alternativa promisoria para el manejo de esta plaga es la utilización de métodos biológicos que incluyen el uso de hongos entomopatógenos. El objetivo del presente trabajo fue el de evaluar el efecto de <em>Beauveria bassiana, Metarhizium anisopliae </em>sobre larvas de <em>Ancognatha scarabaeoides </em>en laboratorio e invernadero. Los aislamientos de hongos se obtuvieron de larvas infectadas en los municipios de Yacuanquer y Ospina. En el laboratorio, se seleccionaron 5 de 9 aislamientos de hongos: Mt1, Bb cosmo, Mt2, Bb4 y Bb10 que presentaron mortalidades superiores al 50%, éstas se evaluaron a concentraciones de 1x105 a 1x1010 esporas/ml. El porcentaje acumulado de mortalidad a los 18 días después de la inoculación fueron: del 100% para Bb cosmo, Mt1 y Mt2 en la concentración de 1x1010 esporas/ml y del 90% para Bb4 y Bb10 en la concentración de 1x109 esporas/ml, presentando concentraciones letales 90(CL90) de 1.1x1010, 7.3x109, 2.2x1010, 3.9x1010 y 4.3x1010 esporas/ml respectivamente. En invernadero se evaluaron los mismos microorganismos con sus respectivas concentraciones letales 50(CL50) y 90(CL90), encontrándose porcentajes de mortalidad del 76.00%, 67.50%, 63.50%, 59.00% y 53.50% para Mt1, Bb cosmo, Mt2, Bb4 y Bb10. Estos resultados indican la posibilidad de incluir estos biocontroladores nativos en el manejo integrado de las chisas en Nariño.</p><p> </p><p><strong>Evaluation of the biocontrol activity of <em>Beauveria bassiana, Metarhizium anisopliae</em>, on larvae of <em>Ancognatha scarabaeoides </em>(Coleoptera: Scarabaeidae).</strong></p><p>High grub populations of coleopteran, frequently attack crops of wheat and potato in the Department of Nariño, Colombia. Reports indicate that infestations levels reach more than 350 larvae/ m2, which severely reduce crop yields. Use of biological control measurements as fungal entomopathogens seems to be a promising alternative for management of this pest. The present work aimed to evaluate the effect of <em>Beauveria bassiana </em>and <em>Metarhizium anisopliae </em>on larvae of <em>Ancognatha scarabaeoides </em>both in laboratory and greenhouse conditions. Isolates of entomopathogen fungus were obtained from infected larvae in the municipalities of Yacuanquer and Ospina. A sample of 5 isolates, which previously had shown to cause mortality rates higher than 50%, was selected in the laboratory: Mt1, Bb cosmo, Mt2, Bb4 and Bb10. Isolates concentrations from 1x105 to 1x1010 spores/ml were tested. The cumulative mortality percentage (at 18 days after the inoculation) ranged from 100% with Bb cosmo, Mt1 and Mt2 at concentrations of 1x1010 spores/ml to 90% with Bb4 and Bb10 at concentrations of 1x109 spores/ml. Lethal doses 90 (LD90) of 1.1x1010, 7.3x109, 2.2x1010, 3.9x1010 and 4.3x1010 spores/ml were calculated for each isolate, respectively. An evaluation of the biocontrol activity of the isolates was carried out under greenhouse conditions. Mortality percentages obtained reached 76%, 67.5%, 63.5%, 59% and 53.5% for Mt1, Bb cosmo, Mt2, Bb4 and Bb10, respectively. These results suggest that the use of native biocontrolers is a promising alternative to be included in the integrated management for white grubs in Nariño.</p>

scholarly journals A Field Efficacy Evaluation of In2Care Mosquito Traps in Comparison with Routine Integrated Vector Management at Reducing Aedes aegypti

2021 ◽  
Vol 37 (4) ◽  
pp. 242-249
Author(s):  
Eva A. Buckner ◽  
Katie F. Williams ◽  
Samantha Ramirez ◽  
Constance Darrisaw ◽  
Juliana M. Carrillo ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Large Scale ◽  
Pathogen Transmission ◽  
Small Scale ◽  
Integrated Vector Management ◽  
Control Programs ◽  
Vector Management ◽  
Scale Field ◽  
Large Scale Field ◽  
Eggs And Larvae

ABSTRACT Aedes aegypti is the predominant vector of dengue, chikungunya, and Zika viruses. This mosquito is difficult to control with conventional methods due to its container-inhabiting behavior and resistance to insecticides. Autodissemination of pyriproxyfen (PPF), a potent larvicide, has shown promise as an additional tool to control Aedes species in small-scale field trials. However, few large-scale field evaluations have been conducted. We undertook a 6-month-long large-scale field study to compare the effectiveness and operational feasibility of using In2Care Mosquito Traps (In2Care Traps, commercially available Aedes traps with PPF and Beauveria bassiana) compared to an integrated vector management (IVM) strategy consisting of source reduction, larviciding, and adulticiding for controlling Ae. aegypti eggs, larvae, and adults. We found that while the difference between treatments was only statistically significant for eggs and larvae (P &lt; 0.05 for eggs and larvae and P &gt; 0.05 for adults), the use of In2Care Traps alone resulted in 60%, 57%, and 57% fewer eggs, larvae, and adults, respectively, collected from that site compared to the IVM site. However, In2Care Trap deployment and maintenance were more time consuming and labor intensive than the IVM strategy. Thus, using In2Care Traps alone as a control method for large areas (e.g., &gt;20 ha) may be less practical for control programs with the capacity to conduct ground and aerial larviciding and adulticiding. Based on our study results, we conclude that In2Care Traps are effective at suppressing Ae. aegypti and have the most potential for use in areas without sophisticated control programs and within IVM programs to target hotspots with high population levels and/or risk of Aedes-borne pathogen transmission.

scholarly journals Utilization of TiO2/gC3N4 nanoadditive to boost oxidative properties of vegetable oil for tribological application

Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 273-287
Author(s):  
Nisha Ranjan ◽  
Rashmi C. Shende ◽  
Muthusamy Kamaraj ◽  
Sundara Ramaprabhu
Keyword(s):  
Vegetable Oil ◽  
Friction And Wear ◽  
Oxidation Behavior ◽  
Tribological Performance ◽  
Effect Of Temperature ◽  
Wear Properties ◽  
Promising Alternative ◽  
Mineral Oils ◽  
Tribological Application ◽  
Friction And Wear Properties

AbstractThe emergence of vegetable oil as a promising alternative lubricant in the tribological application space has fueled research for making these oils as useful as mineral oils. Tribological modification of vegetable oil by the addition of TiO2/gC3N4 nanocomposite (as a nanoadditive) was studied here. The dispersion of the nanoadditive in the vegetable oil showed good oil dispersion stability without the addition of any surfactant. The tribological studies were conducted in a four-ball tester using ASTM standard D5183. In addition, the effect of temperature on tribological performance was also studied to understand the oxidation behavior of vegetable oil. The results showed a significant improvement in friction and wear properties of the optimized nano-oil. The mechanism behind the improvement in friction and wear properties is annotated in this paper.

scholarly journals Activity of additives and their effect in formulations of Metarhizium anisopliae s.l. IP 46 against Aedes aegypti adults and on post mortem conidiogenesis

Acta Tropica ◽  
2019 ◽  
Vol 193 ◽  
pp. 192-198 ◽  
Author(s):  
Juscelino Rodrigues ◽  
Priscilla Rodrigues Borges ◽  
Éverton Kort Kamp Fernandes ◽  
Christian Luz
Keyword(s):  
Aedes Aegypti ◽  
Metarhizium Anisopliae ◽  
Post Mortem

Effects of Compression Ratio on Performance and Emission of Internal Combustion Engine with Used Vegetable Oil Methyl Easter

2013 ◽  
Vol 768 ◽  
pp. 250-254
Author(s):  
N. Balakrishnan ◽  
K. Mayilsamy ◽  
N. Nedunchezhian
Keyword(s):  
Internal Combustion Engine ◽  
Vegetable Oil ◽  
Compression Ratio ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Maximum Pressure ◽  
Base Line ◽  
Promising Alternative ◽  
Performance And Emission ◽  
Used Vegetable Oil

Biomass derived vegetable oil is a promising alternative fuel for an internal combustion engine. Direct use of vegetable oil has inferior performance with higher emission due to its higher viscous in nature. This can be overcome by transesterification process with its byproduct which is called as used vegetable oil methyl ester. While blending this biodiesel with fossil diesel upto maximum of 30:70, will give the higher performance and lower emission than the fossil diesel alone. In this present study biodiesel in the form of B23 is used in a four stroke water cooled variable compression ratio engine without any modifications. The performance and emission characteristics are studied with different compression ratio and compared with a base line fossil diesel mode operation. This study reveals that the compression ratio of 18 is the optimum in the view of ignition delay, maximum pressure crank angle, exhaust gas temperature and Smoke emission.

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