Naymã Pinto Dias

Nível de infestação de moscas-das-frutas em faixa de fronteira, no Rio Grande do Sul

Fruit flies are considered the major pests of fruit worldwide. Tefritids and lonchaeids are major pests in this group of insects. However, little information exists regarding the potential for harm of lonchaeids. The aim of this study was to identify the infestation levels of fruit flies in the boundary zone of Rio Grande do Sul with Argentina and Uruguay. The study was conducted in 2011 and 2012 in Itaqui, Quarai, Santana do Livramento and Uruguaiana, RS. Fruits were collected from19 exotic and native plant species, and the infestation levels in pupae/kg of fruit and pupae/fruit were calculated. The highest rate of Ceratitis capitata infestation occurred in nectarine, with 72.01 pupae/kg and 2.51 pupae/fruit. Anastrepha fraterculus showed high levels in cherry, corresponding to 57.57 pupae/kg and 0.23 pupae/fruit. Lonchaeids were represented by Neosilba and Lonchaea, infesting papaya and star fruits, respectively. In the studied municipalities of Rio Grande do Sul, the following species of fruit flies occurred: C. capitata, A. fraterculus, Neosilba zadolicha and Lonchaea sp.

Rearing two fruit flies pests on artificial diet with variable pH

Fruit flies (Diptera: Tephritidae) are considered the main fruit pests worldwide. In Brazil, two species are predominant: the South American fruit fly, Anastrepha fraterculus and the Mediterranean fruit fly, Ceratitis capitata. In this study, we evaluated the effect of artificial diets with variable pH in their larval development and adult performance. The experiments were carried out in the laboratory at 25 ± 2 °C, 70 ± 10% RH and 12:12h (L:D) photoperiod. Semisolid diets with pH values of 6.0, 5.0, 4.0, 3.0, 2.0, 1.5, and 1.0, adjusted by adding hydrochloric acid were tested. Results indicated that the diet with pH 6.0 did not support larval development of both species of fruit fly. Diets with greater acidic pH values did not allow egg, larvae or pupae development and adult reproduction of A. fraterculus. For C. capitata , the pH of artificial diet exerts greater influence compared to A. fraterculus on the duration and viability of the larval stage, number of pupae, sex ratio and longevity of males.

Oviposition of Anastrepha fraterculus and Ceratitis capitata (Diptera: Tephritidae) in citrus fruits, and development in relation to maturity of orange fruits.

Abstract Fruit flies (Diptera: Tephritidae) are considered to be one of the principal groups of pests in fruit culture worldwide. The objective of this study was to investigate oviposition by Anastrepha fraterculus (Wiedemann) and Ceratitis capitata (Wiedemann) in citrus fruits and to assess the development of these species in relation to the maturity of orange fruits. The experiments were carried out under controlled temperature conditions (25 ± 2 °C), RH (70 ± 10%), and photoperiod (12:12 h L:D). Oviposition was evaluated by exposure (with and without choice) to fruits of ‘Navelina’orange [Citrus sinensis (L.) Osbeck], ‘Clemenules’ tangerine (C. reticulata Blanco), and ‘Siciliano’ lemon [C. limon (L.)] (Rutaceae). Insect development was studied on Navelina orange at 4 stages of maturity (I: 5 cm in diameter, II: 6 to 7 cm in diameter, III: skin with color change, and IV: yellow-orange skin). We evaluated oviposition by counting the number of eggs, and we assessed biological parameters of the immature and adult stages. The number of eggs deposited in orange and tangerine by both fruit fly species did not differ significantly, and oviposition did not occur in lemon. Anastrepha fraterculus preferred to oviposit in tangerine fruits, whereas C. capitata showed preference for orange fruits. Development from egg to adult by A. fraterculus and C. capitata occurred only in stage IV oranges, and required 30.9 and 31.0 d, respectively. Females of A. fraterculus and C. capitata developing in mature orange fruits produced a mean of 378.7 and 183.5 eggs, respectively.