Late effects of Beauveria bassiana on larval stages of Aedes aegypti Linneo‎, ‎1762‎ (Diptera: Culicidae).

I Quintero-Zapata,N Arroyo-González,E J Luna-Santillana,M S Flores-González,F L Gandarilla-Pacheco

doi:10.1590/1519-6984.237789

Abstract

Aedes aegypti is a culicide that has gained relevance over the years due to its ability to transmit various viruses that cause diseases in humans that all the years cause high mortality rates in the world population. The main problem is that Ae. aegypti has managed to establish and maintain a close relationship with humans and their habitat, which is why the search for alternatives to control vector populations becomes imperative. The objective of the present work was to study the effects of two Beauveria bassiana strains on Aedes aegypti. Third instar larvae of Ae. aegypti in 250 mL plastic containers were inoculated with the GHA and NB3 strains at different concentrations (1.5 × 104, 1.5× 105, 1.5 × 106 and 1.5 × 107 conidia/mL). The NB3 strain presented highest mortality values with 63% in the highest concentration i.e., 1.5 × 107, while for the GHA strain the highest mortality value was 30.7% at the same concentration. The results showed significant difference in mortality with respect to the strain and days post treatment (P = 0.0001), but not with respect to the conidial concentration (P = 0.634). The average mortality of larvae per day for the NB3 for different concentrations ranged from 20 to 25 larvae per day, while for the GHA daily mortality ranged from 5 to 12 larvae. In post-treatment mortality, the highest mortality was recorded in the third stage larvae for the NB3, while for GHA the highest percentage mortality was observed in individuals who managed to reach the adult state. The findings of the current research depicted the noteworthy role of B. bassiana for the management of an important vector of human disease.

Highlights

The increasing incidence and geographical distribution of arbovirosis constitutes one of the main public health problems in Americas, and in general in the entire world
Ae. aegypti eggs were obtained from the insect breeding area of the Biotechnology Institute - UANL
Papers ballots impregnated with eggs were placed in a plastic container with 4 liters of water and 0.5 g of fish food

Summary

Introduction

The increasing incidence and geographical distribution of arbovirosis constitutes one of the main public health problems in Americas, and in general in the entire world. In addition to the reappearance of dengue virus and yellow. Fever virus, new pathogenic arboviruses formerly confined to specific regions of the world, such as the chikungunya and Zika viruses, have recently caused various pandemics with significant morbidity. Mosquitoes are considered the most important vectors of human diseases, Aedes aegypti Linneo, 1762 (Diptera: Culicidae) is a culicid capable of transmitting dengue, chikungunya, Zika and mayaro fever, and of these pathologies the one with the highest incidence is dengue. In the year 2019 in America the total number of dengue cases was 2,981,769 according to reports from the Pan American Health Organization (Espinal et al, 2019; Evans et al, 2018; PAHO, 2020). Part of the solution to this problem lies in implementing strategies to prevent and control the spread of the vector of these arboviruses, there are factors that can create hurdles, including social determinants, climate change, demographic aspects, deficiencies in the epidemiological surveillance system at the laboratory level, as well as the same surveillance and control of the spread of the mosquito (México, 2014)

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