ABSTRACT
Pest control is a main concern in agriculture. Indiscriminate application of synthetic pesticides has caused negative impacts leading to the rapid development of resistance in arthropod pests. Plant secondary metabolites have been proposed as a safer alternative to conventional pesticides. Monoterpenoids have reported bioactivities against important pests; however, due to their high volatility, low water solubility and chemical instability, the application of these compounds has been limited. Nanosystems represent a potential vehicle for the broad application of monoterpenoids. In this study, an 1,8-cineole nanoemulsion was prepared by the low energy method of phase inversion, characterization of droplet size distribution and polydispersity index (PDI) was carried out by dynamic light scattering and stability was evaluated by centrifugation and Turbiscan analysis. Fumigant bioactivity was evaluated against Tetranychus urticae, Rhopalosiphum maidis and Bemisia tabaci. A nanoemulsion with oil:surfactant:water ratio of 0.5:1:8.5 had a droplet size of 14.7 nm and PDI of 0.178. Formulation was stable after centrifugation and the Turbiscan analysis showed no particle migration and a delta backscattering of ±1%. Nanoemulsion exhibited around 50% more bioactivity as a fumigant on arthropods when compared to free monoterpenoid. These results suggest that nanoformulations can provide volatile compounds of protection against volatilization, improving their bioactivity.
ABSTRACT
Abstract Introducing an Absent Quarantine Pest (AQP) can cause severe economic, social and environmental impacts, generating food insecurity. The Analytical Hierarchy Process (AHP) method is an excellent tool for prioritizing APQs, allowing countries to better prepare against these threats. This study aimed to determine which AQPs should be prioritized in Brazil. For this, 20 AQPs were selected from the Brazilian official list. The selection was based on pests intercepted by Brazil between 2015 and 2018 and by countries of the European and Mediterranean Plant Protection Organization, in the international movement of plants. It can be concluded that out of the 20 AQPs studied, 17 are the priority and that the AHP method is effective for this purpose. Other countries from different continents can use this methodology to prioritize PQAs and thus create strategic plans to prevent entry into their territories and economic, social, and environmental impacts.
Resumo A introdução de uma Praga Ausente Quarentena (PQA) pode causar graves impactos econômicos, sociais e ambientais, gerando insegurança alimentar. O método Processo de Hierarquia Anal Analytical Hierarchy Process (AHP) é uma excelente ferramenta para priorizar APQs, permitindo que os países se preparem melhor contra essas ameaças. Este estudo teve como objetivo determinar quais AQPs devem ser priorizados no Brasil. Para isso, foram selecionados 20 AQPs da lista oficial brasileira. A seleção foi baseada em pragas interceptadas pelo Brasil entre 2015 e 2018 e por países da European and Mediterranean Plant Protection Organization. Pode-se concluir que dos 20 AQPs estudados, 17 são os prioritários e que o método AHP é eficaz para este fim. Outros países de diferentes continentes podem usar essa metodologia para priorizar os PQAs e, assim, criar planos estratégicos para prevenir a entrada em seus territórios e impactos econômicos, sociais e ambientais.
ABSTRACT
In this work, we evaluated the ovicidal activity and the deleterious effects of cashew (Anacardium occidentale) nut shell oil and its fractions on the development of Musca domestica and Chrysomya megacephala, important vectors of several diseases. The insecticidal effects of this plant were also measured on the first and second instar larvae of Anticarsia gemmatalis and Spodoptera frugiperda, soy and maize pests, respectively. The fly eggs and the crop pest insect larvae were exposed to the cashew (Anacardium occidentale) nut shell liquid (CNSL) and its fractions: technical CNSL, anacardic acid, cardanol and cardol. The results show that the cardol fraction, for both species of flies, presented the lowest lethal concentration with LC50 of 80.4â mg/L for M. domestica and 90.2â mg/L for C. megacephala. For the mortality of the larvae of A. gemmatalis and S. frugiperda, the most effective fraction was anacardic acid with LC50 of 295.1â mg/L and 318.4â mg/L, respectively. In all species, the mortality rate of the commercial compounds (cypermethrin 600â mg/L and temephos 2â mg/L) was higher than that of the evaluated compounds. Despite this, the results obtained suggest their potential in field trials, once the fractions of A. occidentale presented high mortality at low lethal concentrations in laboratory conditions, with the possibility of integrated use in the control of disease vectors and agricultural pests, employing ecofriendly compounds.
Subject(s)
Anacardium/chemistry , Insecticides/chemistry , Plant Oils/chemistry , Anacardic Acids/chemistry , Anacardic Acids/isolation & purification , Anacardic Acids/toxicity , Anacardium/metabolism , Animals , Diptera/drug effects , Diptera/growth & development , Houseflies/drug effects , Insecticides/isolation & purification , Insecticides/toxicity , Larva/drug effects , Lethal Dose 50 , Nuts/chemistry , Nuts/metabolism , Ovum/drug effects , Phenols/chemistry , Phenols/isolation & purification , Phenols/toxicity , Plant Oils/metabolism , Spodoptera/drug effects , Spodoptera/growth & developmentABSTRACT
We provide detailed temporal and morphological parameters of the immature stages of Spodoptera dolichos (Fabricius) larvae fed on artificial diet under controlled conditions (25 ± 1 °C, 70 ± 10% RH, and 14 h photophase). The viability of the egg, larval, pupal, and prepupal stages was 97.5%, 97.0%, 93.1%, and 98.9%, respectively. The average duration of the egg, larval, prepupal, and pupal stages was 5.0, 23.4, 3.2, and 21.5 days, respectively. Females took longer at the larval stage than males, with 10.5% of them having seven instars. The growth rate of female larvae that developed through six and seven instars was 1.72 and 1.54, respectively. Female pupae were significantly larger, exhibiting slower development than males.
Subject(s)
Spodoptera/growth & development , Animals , Female , Larva/growth & development , Male , Pupa/growth & developmentABSTRACT
Humans, animals and plants suffer from similar types of diseases (e.g., fungal, viral etc.). These can "emerge" as new diseases by expanding their geographical range or by jumping species (from plants to plants, or from animals to humans). Emerging diseases place an additional burden on developing countries which are often struggling to manage the diseases they already have. New diseases spread through weather, insects or other vectors, or by the movement of people, animals or goods. This study examines the role of cross-border travel in the spread of diseases. A survey of travelers and of residents along the Malawi-Mozambique border found that most cross it frequently and that they rarely travel empty-handed, often taking plants and animals with them. People also cross borders seeking medical attention. Attempting to limit travel would hamper an already struggling economy, where many people make a living by producing, processing or transporting plants and animals for food. Cross border travel per se may pose slight danger for the spread of diseases, if governments can collaborate on sharing information about the status of diseases within their border.
ABSTRACT
Opuntia ficus-indica Mill. and Nopalea cochenillifera (L.) Lyons (Cactaceae) are alternative food sources for cattle in drought areas of the Northeastern Region of Brazil. Diaspis echinocacti (Bouché) is the unique pest of these Cactacea species and it was previously detected on the following native host plants: Cereus jamacaru DC., Melocactus sp., Opuntia dillenii Haw. and O. inamoena K. Schum. The new record of native hosts are Cereus gounellei (Weber) Luetzelb., C. squamosus Gërke. and the exotic C. hildemannianus K. Schum., from drought areas; Pereskia grandifolia Haw. and Epiphyllum oxypetalum Haw., native species from tropical forest used as ornamental plants. D. echinocacti has not infested O. monacantha Haw. in the field and in laboratory bioessays. The dissemination of the neonate scale insect transported on the body surface of the predators Chilocorus nigrita (Fabricius) and Zagreus bimaculosus (Mulsant) Coccinellidae: Chilocorinae) was registered for the first time.
Opuntia ficus indica Mill. e Nopalea cochenillifera (L.) Lyons (Cactaceae) representam fontes alternativas de alimento para o gado nas regiões secas do Nordeste do Brasil. Diaspis echinocacti (Bouché), único inseto-praga destas forrageiras, foi detectado inicialmente nas seguintes cactáceas nativas: Cereus jamacaru DC., Melocactus sp., Opuntia dillenii Haw. e O. inamoena K. Schum. Os novos registros de plantas-hospedeiras são: Cereus gounellei (Weber) Luetzelb., C. squamosus Gërke. (nativas) e C. hildemannianus K. Schum., exótica, todas provenientes de regiões secas; Pereskia grandifolia Haw. e Epiphyllum oxypetalum Haw., da floresta tropical e utilizadas como plantas ornamentais. D. echinocacti não foi observada em O. monacantha Haw. no campo, nem conseguiu se estabelecer em raquetes desta planta em condições de laboratório. A disseminação de ninfas neonatas da cochonilha transportadas no corpo dos predadores Chilocorus nigrita (Fabricius) e Zagreus bimaculosus (Mulsant) (Coccinellidae: Chilocorinae) foi registrada pela primeira vez.