Tecnologia alternativa no controle de Ceratitis capitata e sua implicação na qualidade de frutos de Spondias purpurea

Abstract

The red mombin fruit Spondias purpurea is a tropical fruit of vital importance to farmers in semi-arid region of Brazil, but it presents as a major factor limiting the occurrence of fruit flies Ceratitis capitata (Diptera: Tephritidae). Several papers have discussed the applicability of natural products such as essential oils, this pest control programs. However little is known about the effectiveness of this tactic in controlling C. capitata, as well as the impact of alternative technology in fruit quality. In this study we evaluated the effects of alternative substances as potential repellents and insecticides to C. capitata, and fruit quality of red mombin fruit. The experiments were performed at the Laboratory of Entomology UFPB Areia/PB. Three experiments were conducted: repellent activity (test I), insecticidal activity (test II) and physical and chemical quality of fruits (test III). For the all tests were used for red mombin fruit ripe fruit, water and disinfected with hypochlorite 0.1%, and dry in paper towels at room temperature. They were then treated with the following products: proagrim, essential oil of fennel and orange essential oil, both of the following concentrations, 0.0 (control), 1.0, 1.5, 2.0, 2.5 and 3.0% (w/v). For treatment of fruit products were diluted in water. While the second experiment, we used the same products and concentration of which was that the insecticidal activity via topical application of products on eggs, larvae of 1st, 2nd and 3rd instars and pupae. The results obtained in the first trial, no choice, revealed that the tested products significantly affected the fruit of red mombin fruit infestation by C. capitata. The effect of pesticides on fruit infestation reduction was dose-dependent. The average fertility of C. capitata (number of larvae per fruit) in fruit of red mombin fruit ranged from 1.65 (1%) to 1.025 (3%) when applied orange oil, 0.25 (1%) 0,075 (3%) for fennel oil and 2.1 (1%) to 0.95 (3%) when applied proagrim. The free-choice test results confirmed that no-choice, demonstrating the repellent action of the tested products. The preference index recorded was 0.5398 for orange oil; 0.3435 to 0.1717 and proagrim product for oil and fennel. In the trial of insecticide activity, it was found that, regardless of the product and the developmental stage of C. capitata mortality was directly related to increased concentrations. The median lethal concentrations (LC) of the product proagrim estimated for eggs of C. capitata was 1.6965% (w/v), which was 50higher than the average concentrations lethal (LC) estimated for larvae of 1st, 2nd and 3rd instar larvae of C. capitata, corresponding to 0.3409, 0.2277 and 0.1800% (w/v), respectively. While the estimated LC5050 of fennel oil to larvae of 1st, 2nd and 3rd instar were 0.5419, 0.5189, and 0.5464% (w/v), respectively. Low-dose response was found in all stages evaluated C. capitata after application of orange oil product. Regarding the effects of these products on fruit quality of red mombin fruit, it was found that no there is product-independent linear relationship between ° Brix and pH vs concentration vs concentration of fruit red mombin fruit. Products proagrim orange oil and promote greater weight losses of fruit pulp of red mombin fruit, from product oil of fennel. However, concentrations above 2.5% of fennel oil in fruits of red mombin fruit should be taken judiciously, in order to avoid compromising the physical quality, as well as reducing the degree Brix of fruit pulp of red mombin fruit.