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

This work reports the larvicidal action of two formulations of Amanita muscaria against Musca domestica. Two methods of extraction were tested: an aqueous extract from dried, powdered basidiomes (DPB); and an extract from fresh basidiomes liquefied in water (FLB). The mortality caused by the DPB extract varied from 14.67% to 100%. The efficiency of the FLB extract varied from 10.67% to 89.33%. The mean lethal concentration (LC50) of the DPB extract was approximately 1,931.02 ppm, whereas the LC50 for the FLB extract was about 30%. The extracted substances from these methods did not interfere with the development period of immatures and did not influence pupal weight. These results show the potential of A. muscaria extracts for controlling M. domestica

Sobrevivência e variação de peso de adultos de Periplaneta americana (Linnaeus, 1758) (Blattaria, Blattidae) submetidos a diferentes condições de estresse

http://dx.doi.org/10.5007/2175-7925.2015v28n2p103Periplaneta americana is a species of great importance to public health, since it can act as a vector of many pathogens and it reaches large populations in urban environments. This is probably due to its ability to resist starvation and desiccation. This study aimed to evaluate the effects of absence of water and food on survival and weight change among adult P. americana individuals and check whether the initial weight of individuals influences on their survival. Four groups having twenty P. americana couples were formed and subject to: I) no water or food; II) no food; III) no water; and IV) control group. Insects were isolated according to the groups, which were weighed at the beginning and end of the stress conditions. They remained under these conditions until all individuals in each test group were dead. Stress conditions caused reduction in survival time when compared to the control group. Adults with higher body mass survived longer when deprived only of food, while among those lacking water, weight had no influence on survival. Total weight loss was greater among individuals deprived of water than those deprived only of food. Periplaneta americana é uma espécie de grande importância para a saúde pública, já que pode atuar como vetor de diversos patógenos e atinge altas populações em ambientes urbanos. Isso provavelmente se deve à sua capacidade de resistir à fome e a dessecação. O objetivo deste estudo foi avaliar os efeitos da ausência de água e alimento sobre a sobrevivência e variação de peso entre adultos de P. americana e verificar se o peso inicial dos indivíduos influencia em sua sobrevivência. Quatro grupos com 20 casais de P. americana foram formados e submetidos a: I) estresse hídrico e alimentar; II) estresse alimentar; III) estresse hídrico; e IV) grupo controle. Os insetos foram individualizados conforme os grupos, os quais foram pesados no início e no fim das condições de estresse. Permaneceram sob essas condições até que todos os indivíduos de cada grupo de teste estivessem mortos. As condições de estresse causaram redução do tempo de sobrevivência quando comparados ao grupo controle. Adultos com massa corporal superior sobreviveram por mais tempo quando privados somente de alimento, enquanto que naqueles com ausência de água o peso não influenciou na sobrevivência. A perda total de peso foi maior nos indivíduos privados de água do que naqueles privados somente de alimento

Ocorrência de Aprostocetus hagenowii (Hymenoptera, Eulophidae), parasitoide de ootecas da barata americana, no Rio Grande do Sul Occurrence of Aprostocetus hagenowii (Hymenoptera, Eulophidae), parasitoid of the american cockroach oothecae at Rio Grande do Sul

Relata-se a ocorrência do parasitoide Aprostocetus hagenowii (Ratzeburg, 1952) (Hymenoptera: Eulophidae) em ooteca de Periplaneta americana Linnaeus, 1758 (Blattodea: Blattidae), no extremo Sul do Brasil. As ootecas foram coletadas no mês de dezembro de 2007, no campus da Universidade Federal de Pelotas (31°48'34"S, 52°25'42"O), Município do Capão do Leão, Rio Grande do Sul. Após a coleta, as ootecas foram acondicionadas individualmente em tubos de ensaio, sendo posteriormente mantidas em câmara climatizada a 25°C, com umidade relativa =70%, até a eclosão das ninfas ou emergência dos parasitoides. Uma das ootecas estava parasitada e apresentou 89 parasitoides (79 fêmeas e 10 machos); a referida ocorrência constitui o primeiro registro para o Sul do Brasil. O conhecimento das regiões de ocorrência dos inimigos naturais de P. americana é de grande importância para se traçar uma estratégia de controle das populações desse blatódeo.It is reported the occurrence of the parasitoid Aprostocetus hagenowii (Ratzeburg, 1952) (Hymenoptera: Eulophidae) in oothecae of Periplaneta americana Linnaeus, 1758 (Blattodea: Blattidae) at the extreme southern Brazil. The oothecae were collected in December of 2007 at the campus of the Universidade Federal de Pelotas (31°48'34"S, 52°25'42"W), city of Capão do Leão, Rio Grande do Sul. After the collection the oothecae were placed individually in glass vials maintained in acclimatized chamber at 25°C, with relative air humidity =70% until the eclosion of the nymphs or the emergence of the parasitoids. The infested ootheca presented 89 parasitoids (79 females and 10 males). The referred occurrence represents the first report to southern Brazil. Knowing the regions of occurrence of the natural enemies of P. americana is of great importance when developing a control strategy to the populations of the blatod

Short Communication Larvicidal effi ciency of the mushroom Amanita muscaria ( Agaricales, Amanitaceae) against the mosquito Culex quinquefasciatus (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 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 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) (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 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 extract was obtained from the fungal powder and added to sterile dist illed water at a concentration of 1:10 (w/v). The resulting mixture was put in a shaker (120rpm) at 50°C for 48h. Subsequently, the product was centrifuged for 10 min at 3,000rpm and the supernatant was fi ltrated using a paper fi lter. A portion of the extract was used immediately and the remainder was either stored in refrigerator (3°C ± 2°C) or freezer (-20°C) for six months. The experiment to detect larvicidal activity was performed following the standard protocol from the World Health Organization After six months of chilling or freezing, the larvicidal activity of stored extracts were evaluated against C. quinquefasciatus larvae using a fi nal concentration of 232.0ppm. For each group, fi ve replicates were created using 50ml of extract and 50 thirdinstar larvae. Two treatments served as control conditions: a negative control (water only plus larvae) and a positive control (aqueous extract that had not been stored plus larvae). The evaluation of larvicidal activity was performed as previously described. Mortality was evaluated using an analysis of variance (ANOVA) (p = 0.05), in which means were compared using Tukey's test (p = 0.05). The median lethal concentration (LC 50 ) and 90% lethal concentration (LC 90 ) of each formulation were analyzed using probit analysis. All analyses were performed using SPSS v ersion 22.0 for Windows (IBM, Armonk, NY, USA) The aqueous extract of Amanita muscaria caused signifi cant mortality in C. quinquefasciatus larvae (F = 156.11; DF = 5; p < 0.001). The mean mortalities caused by extracts varied from 16.4% to 88.4%, while in control groups, the mean mortality was approximately 3.2% The powder of Amanita muscaria caused significant mortality of C. quinquefasciatus larvae (F = 101.01; DF = 5; p < 0.001). The mean mortalities caused by the powder preparation varied from 29.2% to 82.8%, whereas, in the control group, the mean mortality was approximately 3.2% The mean lethal concentration (LC 50 ) of the aqueous extract of A. muscaria was approximately 51.46ppm and the The mortalities of C. quinquefasciatus larvae caused by different methods of storing the aqueous extract of A. muscaria did not show signifi cant differences between groups (F = 0.9; DF = 2; p = 0.43), which varied from 83% to 86.8%. The mortalities observed were signifi cantly higher than those observed 97 ACKNOWLEDGMENT

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 muscariaagainst 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 efficiency of the powder varied from 29.2% to 82.8%. Storage did not interfere with the larvicidal efficiency of the aqueous extract of A. muscaria. CONCLUSIONS These results show the potential of A. muscariato control C. quinquefasciatus

Exigências térmicas de pré-oviposição e incubação para populações de Periplaneta americanaLinnaeus, 1758 (Blattaria, Blattidae) da região Sul do Brasil

Colônias de Periplaneta americanaLinnaeus, 1758 foram estabelecidas e mantidas sob condições de laboratório, a partir de espécimes coletados na área urbana do município de Pelotas, RS, Brasil, de janeiro/1996 a dezembro/1997 para estimativa das exigências térmicas dos estágios de pré-oviposição e incubação. Tais espécimes foram alimentados com ração peletizada comercial apropriada para coelhos e água ad libitum. Trinta casais e 30 ootecas foram expostos a temperaturas entre 15 e 40ºC, com intervalos de 5°C, em câmara climatizada com umidade relativa ³80% e fotofase de 12 horas. O período de pré-oviposição de P. americana variou de 6 a 45 e de incubação de 27,7 a 102 dias, na faixa de temperatura de 20 a 35ºC. A viabilidade de ootecas variou de 43,3% a 83,3% e de ovos de 87,1 a 98,4%. A temperatura base (Tb) e a constante térmica (K) para pré-oviposição e incubação foram de 13,8°C, 160,1 GD e 13,9°C, 554,6 GD, respectivamente. A faixa de temperatura ótima para oviposição e incubação de P. americanaem condições de laboratório foi de 20 a 35ºC, com influência considerável e inversamente proporcional na duração do período de oviposição e de incubação, mas não na viabilidade dos ovos

Rhipicephalus sanguineus sensu lato(Ixodidae) in synantropic rodents in Rio Grande do Sul, Brazil

Rhipicephalus sanguineus, the brown dog tick, is responsible for maintaining and transmitting various pathogens, both in animals and human beings, and it is of great sanitary importance. This communication reports the first occurrence of Rhipicephalus sanguineus sensu lato parasitizing Rattus norvegicus in the state of Rio Grande do Sul, Brazil, and it is also the first record of this tick species parasitizing Rattus rattus in Brazil. The rodents were captured from the port area, located in the city of Pelotas, Rio Grande do Sul, Brazil. We collected 6 larvae of this tick species from 2 male R. rattus individuals, and 3 larvae from 2 female R. norvegicus individuals; parasitized specimens of both rodent species were captured from different sites within the experimental area. This record broadens the number of Rhipicephalus sanguineus sensu lato hosts in urban areas, indicating the need for continued monitoring on population density for both R. sanguineus and synanthropic rodents

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

This work reports the larvicidal action of two formulations of Amanita muscaria against Musca domestica. Two methods of extraction were tested: an aqueous extract from dried, powdered basidiomes (DPB); and an extract from fresh basidiomes liquefied in water (FLB). The mortality caused by the DPB extract varied from 14.67% to 100%. The efficiency of the FLB extract varied from 10.67% to 89.33%. The mean lethal concentration (LC50) of the DPB extract was approximately 1,931.02 ppm, whereas the LC50 for the FLB extract was about 30%. The extracted substances from these methods did not interfere with the development period of immatures and did not influence pupal weight. These results show the potential of A. muscaria extracts for controlling M. domestica.Foi relatada a ação larvicida de duas formulações de Amanita muscaria em Musca domestica. Dois métodos de extração foram testados: extrato aquoso de basidioma desidratado e triturado (BDT), e extrato de basidioma fresco liquefeito em água (BFL). A mortalidade causada pelo extrato BDT variou de 14,67% a 100%. A eficácia do extrato BFL variou de 10,67 a 89,33%. A concentração letal média (CL50) do extrato BDT foi de, aproximadamente, 1.931,02 ppm, enquanto que a CL50 do extrato BFL foi em torno de 30%. As substâncias extraídas por esses métodos de extração não interferiram no período de desenvolvimento dos imaturos e não influenciaram no peso pupal dos indivíduos. Esses resultados mostram o potencial de extratos de A. muscaria para o controle de M. domestica