Stability and Persistence of Two Formulations Containing Anticarsia gemmatalis Nuclear Polyhedrovirus (AgMNPV)

Abstract

estudadas. As formulações foram armazenadas em condições ambiente e expostas à radiação ultravioleta em condições de laboratório e à radiação solar em condições de campo. A formulação pó molhável (PM) foi preparada através da impregnação da suspensão de vírus e adjuvantes em inerte mineral (Caolin). A formulação óleo emulsionável (OE) foi preparada pela mistura da suspensão do patógeno com óleo + adjuvantes. Durante 20 meses, com intervalos de 120 dias, amostras das formulações e do vírus original eram adicionadas à dieta artificial de lagartas de quarto ínstar de Anticarsia gemmatalis (Hübner). Após 20 meses de armazenamento, a formulação OE perdeu apenas 18,3% de sua atividade original, enquanto a formulação PM teve reduzida sua eficiência para 11,7% após 12 meses. Nenhuma diferença significativa foi observada para as duas formulações quando expostas à luz ultravioleta. Ambas protegeram o vírus quando comparado ao tratamento controle. Em condições de campo a formulação OE teve melhor persistência com cerca de 60% da atividade original presente após 14 dias da aplicação. Grande parte da formulação PM foi removida das folhas pela chuva. PALAVRAS-CHAVE: Insecta, nucleopoliedrovirus, armazenamento e radiação.ABSTRACT -The stability and the persistence of two AgMNPV formulations developed by the Instituto Biológico and the Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Brazil were studied. Formulations were stored in environmental conditions and exposed to ultraviolet radiation in laboratory and to solar radiation in the field. The wettable powder formulation (WP) was prepared by impregnating viral suspensions + adjuvants on inert mineral, chiefly kaolin. The emulsifiable oil formulation (EO) was prepared by mixing the pathogen suspension with corn oil + adjuvants. At 120-day intervals for 20 months, samples of formulations and the standard treatment (crude virus) kept in a laboratory cabinet were added to artificial diet fed to 4 th -instar Anticarsia gemmatalis (Hübner) larvae. After 20 months in storage, the formulation EO lost only 18.3% of its original activity, whereas the formulation WP had its efficiency reduced to 11.7% after 12 months. No significant differences between the two formulations were observed when exposed to the ultraviolet germicidal light, and both formulations protected the virus when compared to the standard treatment. Under field conditions, the EO formulation enhanced the viral persistence, with >60% of the original activity present 14 days after the application. Most of the WP formulation was removed from leaves by the rain.

An environmentally safe and tolerant microbial insecticide utilizing Helicoverpa armigera single nucleopolyhedrovirus (HearNPV-TR)

“…The pH of the solution prior to the addition of NPV should be 5-7. Because OBs structures dissolve in alkaline substrates, it causes virulence to decrease in a short time (Batista et al 2001). Generally, cotton seed oil and corn oil were used in the oil-based baculovirus formulations (Shapiro et al 2012).…”

“…The prepared formulation initially (0. min) had a 98% mortality rate but decreased to 66% after 1 h of UV in laboratory conditions. Batista et al (2001) prepared 2 different formulations as emulsifiable oil (EO) and wettable powder (WP) of Anticarsia gemmatalis NPV. The crude virus, WP, and EO were exposed to UV in the laboratory for 5 min.…”

“…In this case, the formulation shortens the persistence of the virus and reduces its virulence. On the other hand, it has been shown that the oilbased formulations are more stable on the foliage against environmental factors, such as rain and wind, and have high shelf life due to low pH levels (Batista et al 2001).…”

Effects of several UV-protective substances on the persistence of the insecticidal activity of the Alphabaculovirus of Chrysodeixis chalcites (ChchNPV-TF1) on banana (Musa acuminata, Musaceae, Colla) under laboratory and open-field conditions

“…In this study, several substances that were previously found to have photoprotective capacity, such as green tea, moringa, cacao, kaoline, iron oxide, charcoal, bentonite, benzopurpurine and benzimidazole [21,22,25,[30][31][32][33], were tested for the first time to determine their photoprotective activity to ChchNPV-TF1, and the joint effect virus-UV protectant on Chrysodeixis chalcites survival and plant photosynthetic activity. In our first assay, natural photoprotective substances were evaluated under laboratory conditions, and then two of the substances yielding the best results were tested in the field.…”

An <i>in vitro</i> Assessment on the Efficacy of Clay-Based Formulated Cells of <i>Pseudomonas</i> Isolate UTAR EPA2 for Petrol Degradation

“…Formulation of microbial cells has long been established for applications in the agricultural (Meyer, 2003), pharmaceutical (Tanaka et al, 1993;Frokjaer and Hovgaard, 2000) and industrial (Tanaka et al, 1993) sectors. The aims of formulating viable cells are to ensure that adequate cell viability is sustained to increase the efficacy of the cells and to facilitate the delivery and handling processes (Filho et al, 2001). This can be achieved by producing granular formulations, powder or dust formulations, microcapsules, or oilemulsion formulations (Brar et al, 2006).…”