Tham khảo tài liệu 'insecticides pest engineering part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Management of Tuta absolute Lepidoptera Gelechiidae with Insecticides on Tomatoes 349 Tutafort plant extract shows little efficacy after the first application but increases effectiveness after the second application engendering about 80 of larval mortality table . . Yet according to manufacturer Altinco 2011 the product has a preventive action and should be applied against eggs and adults. The compound acts by contact penetrating the insect cuticle and dissolves the cell membranes causing the insect dehydrate and its death Altinco 2011 . Management of resistance to prevent or delay the development of resistance to an insecticide and cross resistance to additional insecticides is necessary for increasing the chance of chemical control of T. absoluta. Thus the avoidance of resistance requires the development of pest management programs in which efforts are made to take advantages of natural enemies of pests plant resistant cultivars if available appropriate cultural and physical methods. Accordingly diversification of control tactics should be implemented with the minimum use of chemicals. Insecticides should be applied only as needed basis and only used as the last form of control. When insecticides are applied the way that they are used should be rationalized and optimized to exploit the full diversity of synthetic chemicals and natural products mostly used at rotational basis. Development of resistance in T. absoluta is an important problem in regions where the insect is established. The expanding international trade of plant material not only spread the pest but also spreads the resistance genes associated with the pest Denholm and Jespersen 1998 . It is possible that the Mediterranean populations of T. absoluta already carried gene resistance from South American counterpart populations and thus may already express high level of resistance to one or multiple insecticide. Indeed Cifuentes et al. 2011 demonstrated high genetic homogeneity of T. absoluta .
