Assessment of Lethal, Sublethal, and Transgenerational Effects of Beauveria bassiana on the Demography of Aedes albopictus (Culicidae: Diptera)

Abstract

Dengue fever is one of the most rapidly spreading arthropod-borne diseases. Diurnal vectorial properties of Aedes albopictus contribute to the dispersion of the dengue viruses. Frequent and injudicious use of synthetic insecticides led to the evolution of resistant phenotypes in Ae. albopictus which necessitates the search for an alternative of current control strategies. Developing a long-lasting and environmentally safe tactic based on knowledge of ecology and population dynamics of Ae. albopictus is critical. Therefore, with a view towards biological control and ecology, the effect of entomopathogenic fungi (EPF) Beauveria bassiana on filial and first filial generations of Ae. albopictus were studied. Investigations showed 87.5% adulticidal activity leading to altered fecundity and adult longevity in a filial generation. The lethal (LC50) and sublethal (LC20) concentrations of B. bassiana were applied to filial generation (F0) to study demographic parameters in the first filial generation (F1). Results showed reduced net reproductive rates (Ro) intrinsic rate of increase (r), and mean generation time (T) compared to uninfected controls. Prolonged larval and pupal duration were observed followed by reduced longevity of male and female adults. Fecundity in the first filial generation was significantly changed with the lethal and sublethal concentrations of B. bassiana. Thus, it is concluded that B. bassiana has the potential to play a vital role in integrated mosquito management strategies.

Larvicidal, Ovicidal, Synergistic, and Repellent Activities of Sophora alopecuroides and Its Dominant Constituents Against Aedes albopictus

“…albopictus, plastic trays (capacity 250 mL, 125 cm 2 surface area) were used for the bioassay. Different concentrations (5,10,20,30, and 50 ug/mL) of extract were prepared by diluting 0.01% Tween-80 in 0.5% aqueous acetone. The plastic trays were filled with the required concentration to half of its capacity.…”

“…Larvae with a lack of movement toward the surface for oxygen intake were counted as dead. The same protocol was used but with different concentrations (20,40,60,80, and 100 ug/mL) for the dominant constituents of S. alopecuroides (Sophocarpin and Sophordine) against the third-instar larvae of Ae. albopictus…”

“…Blue bars represent the mortality of Ae. albopictus third-instar larvae after exposure to different concentrations(5,10,20,30, and 50 ug/mL) of S. alopecuroides (SACE) extract. Error bars show 95% confidence intervals (CIs).…”

“…Percentage of larval mortality of Ae. Albopictus (third-instar larvae) when Sophocarpin and Sophordine were applied at different concentrations(20,40,60, 80, and 100 ug/mL). Red bar indicates larval mortality due to Sophocarpin and blue bars represent larval mortality percentage of Sophordine.…”

Metarhizium Anisopliae Challenges Immunity and Demography of Plutella xylostella

“…Several entomopathogenic fungi have been used to control insect pests from different orders such as Diptera [ 3 , 4 ], Hemiptera [ 5 ], Coleoptera [ 6 ], Homoptera [ 7 ], and Lepidoptera [ 8 ]. The excessive and injudicious use of synthetic insecticides has resulted in pest resurgence, environment degradation, resistance development while also causing harmful effects to human health [ 9 , 10 , 11 ]. Such detrimental effects of chemical insecticides stressed the need to develop alternative control strategies.…”