Letalidade de Ceratitis capitata (Wiedemann) (Diptera: Tephritidade) submetida a diferentes extratos vegetais

Abstract

The search for discovering plant species and isolating their active components with insecticidal properties against insects plagues, such as fruit flies, are receiving considerable attention worldwide, as they generate minimal environmental and living impacts compared to use of chemical insecticides. Thus, this study aimed to establish Lethality of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) submitted to different plant extracts. Hydroethanolic extracts (S. terebinthifolia, M. officinalis, S. aromaticus, P. guajava, P. amboinicus, M. villosa, C. sinensis, A. heterophyllus M. citrifolia e E. uniflora) were prepared with 30% w / v fresh leaves (plant weight / 70% ethanol volume). The insecticidal evaluation of the hydroethanolic extracts was investigated in two trials, in which the effect of the extracts on the larval stage (L3) and on the pupae of C. capitata were evaluated. The experiments were performed with ten treatments (hydroethanolic vegetable extracts) in different proportions (30%, 15%, 7,50%, 3,75%, 1,87%, 0,93%, 0% - one control with ethanol and another with water). Which were conducted in a completely randomized design with four replications. Ten larvae or pupae were placed in a plastic cup and moistened in 1 mL of the portions of the extracts in the respective treatments. The evaluation was performed every 24 hours for three days for larvae; and the pupae, after being submitted to the treatments, were conditioned for eight days (pupal development) and, after that time, the evaluations were done every 24 hours for eight days. Our results show that hydroethanolic extracts of S. aromaticum, P. guajava and E. uniflora obtained the highest levels of polyphenols. However, for larval phase L3 only the leaf extracts of M. villosa, E. uniflora, P. amboinicus and S. terebinthifolia had insecticidal effect higher than 80% on the larvae of C. capitata. Whereas in the pupa phase of this insect, only the blackhead S. aromaticum and E. uniflora reduced the pupal development by more than 90%. The extracts that registered the greatest insecticidal response against the immature phases of C. capitata were S. aromaticum, E. uniflora and M. villosa. The main bioactive components were rosmarinic acid and luteolin7-O-rutinoside for M. villosa, the derivatives of glycosylated myricetin and quercetin for E. uniflora and isohamnetin, galoose digalloyl (glucogalin), isobiflorin, biflorin and kaempferol for S. aromaticum. These findings increase the number of effective extracts against C. capitata and provide new evidence on the major bioactive compounds active in this insecticidal activity.