Larvicidal efficiency of the mushroom Amanitamuscaria (Agaricales, Amanitaceae) against the mosquito Culexquinquefasciatus (Diptera, Culicidae)

Abstract

Introduction:We report the larvicidal activity of two formulations from Amanita muscaria against Culex quinquefasciatus, as well as the viability of the aqueous extract after storage. Methods: The larvicidal activity of aqueous extract and powder from A. muscaria, and the viability of the aqueous extract after storage, were evaluated. Results: The aqueous extract caused larval deaths, which varied from 16.4% to 88.4%. The effi ciency of the powder varied from 29.2% to 82.8%. Storage did not interfere with the larvicidal effi ciency of the aqueous extract of A. muscaria. Conclusions: These results show the potential of A. muscaria to control C. quinquefasciatus.Keywords: Bioinsecticide. Fly agaric. Filariasis vector.The mosquito Culex quinquefasciatus Say, 1823 (Diptera, Culicidae), is the main vector of the human parasitic roundworm, Wuchereria bancrofti (Cobbold, 1877) (Spirurida, Onchocercidae) on the American continent (1) . Reisen (2) reported that this mosquito can also act as a vector of arboviruses, such as West Nile and St. Louis encephalitis.This species is usually controlled by the use of synthetic chemical insecticides. The use of these products can cause problems, such as human and environmental contamination, as well as the development of resistance in insect populations (3) .Plant-based products are the most recently researched alternatives, showing great results in mosquito control (4) (5) . However, although there are few studies that investigate the use of fungi as a control measure, some fungal species have shown promising results against insects (6) (7) .Among the fungal substances known to be toxic to insects, ibotenic acid and muscimol are both found in the ectomycorrhizal fungus Amanita muscaria (Linnaeus, 1758) (Agaricales, Amanitaceae) (8) . This fungus is generally found in temperate areas, and in Brazil, has been reported from São Paulo to the southern part of the country in association with plantations of Pinus spp. or Eucalyptus spp. (9) . Although A. muscaria possesses substances that are toxic to insects, there are no studies regarding the impact of this fungal species against culicids.Thus, this work aims to report the toxicity of two formulations, an aqueous extract, and a powder, from A. muscaria against C. quinquefasciatus larvae, as well as to evaluate the ability to store the aqueous extract of this fungal species.The larvae of C. quinquefasciatus used in this study were obtained from a laboratory colony, and raised according to the methodology proposed by Gerber (10) , differing only in the diet offered to the larvae. In this investigation, the larvae were fed with minced fi sh feed.Amanita muscaria specimens were collected in July in a grove of Pinus elliottii Engelmann, 1880 ( Pinales, Pinaceae) in Capão do Leão, Brazil ( 31°48′08.7″S, 52°24′51.2″W). Basid iomata were collected when their rings were completely opened, and were subsequently put in an incubator at 45°C for 96h. After dehydration, basidiomata were milled in an electric mill with a mesh of 0.5mm.Crude ...

Larvicidal efficiency of the fungus Amanita muscaria (Agaricales, Amanitaceae) against Musca domestica (Diptera, Muscidae)

“…We observed that the larvicidal effect was dosedependent, as reported by Cárcamo et al (2016) for Culex quinquefasciatus (Diptera, Culicidae) larvae subjected to the same fungal species. However, the efficiency that we observed was lower than observed by these authors.…”

“…Nevertheless, it can only be produced in colder seasons when fresh basidiomes of A. muscaria grow in Rio Grande do Sul, Brazil (BERNARDI, E.: personal communication, 2015). On the other hand, the DPB extract can be stored up to six months without losing efficiency (CÁRCAMO et al, 2016).…”

Evaluation of Pistia stratiotes fractions as effective larvicide against Anopheles mosquitoes

“…These bioactive compounds may act as insecticides, antifeedants, moulting hormones, oviposition deterrents, repellents, juvenile hormone mimics, growth inhibitors, antimoulting hormones as well as attractants. Important also will be the identification of any toxic element or injurious fractions whose use should be actively discouraged [5]. Plant based pesticides are less toxic, delay the development of resistance because of its new structure and easily biodegradable [6][7][8].…”