In this research, the repellent activity of five Lamiaceae essential oils, Agastache rugosa, Elsholtzia blanda, Elsholtzia ciliata, Elsholtzia penduliflora, and Plectranthus ovatus, was evaluated against sweet potato weevil, Cylas formicarius using a two-choice test between the essential oil-treated filter paper and the control. E. blanda and A. rugosa essential oils have some sweet potato weevil attractant properties at low dose (<47.16 nl/cm2),while N,N-diethyl-3-methylbenzamide (DEET), P. ovatus, E. penduliflora, and E.ciliata essential oils have repellent properties at doses ranging from 15.72 nl/cm2 to 196.49 nl/cm2. The effect of type of essential oil and their dose were interactively associated with repellent efficacy. There was a increase in repellent efficacy as the dose increased for all essential oils. The repellent activities of P. ovatus essential oil and E. penduliflora were higher than the others, and the repellent effects of E. ciliata essential oil and DEET were more dose-dependent than others, indicating that at low dose, P. ovatus and E. penduliflora essential oils have stronger repellent efficacy, but at higher dose DEET and E. ciliata have greater effects. Our findings clearly demonstrate that P. ovatus, E. penduliflora, and E. ciliata essential oils are candidate materials for future investigation as repellent compounds against sweet potato weevil control.

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Authors perform this research to study on constructing value chain of wild pork and wild pigs in the northern region of Vietnam. Thuy, N.T (2021) presented the analysis results show that factors including: income, natural conditions, loan capital, market have a great impact on the level of people's participation. Since then, the article has suggested some solutions to improve people's participation in agricultural value chain development of wild pigs and wild pork. Thom, BT., & Huy, D.T.N (2021) stated Feeding wild pigs and managing wild pork meat quality is meaningful in Vietnam, esp. In Thai Nguyen province as pork products can offer variety of tastes due to food processing and suitable for Vietnamese tastes and can export to the world widely. Feeding wild board in different environment also affect quality of wild pork meat, for example in US, Brazil or In Vietnam. It is in the study we will make comparison to wild pork meat in China and Thailand and suggest to enhance vale chain linkage of wild pork and wild pigs to enhance exporting markets. Last but not least, better value chain linkage can be enhanced through reducing transaction costs from wild pig farming to factories and producing wild pork meat following European standards or GlobalGAP or VIETGAP.