Dietas artificiais para a criação de larvas e adultos da mosca‑das‑frutas sul‑americana

The objective of this work was to adequate artificial diets for the development of larva and adult stages of South-American fruit fly (Anastrepha fraterculus). For the larval stage, the following diets were tested: D1, original diet, with 10 g agar; D2, modified diet, with 3.6 g agar; and D3, modified diet, with dry sugarcane bagasse. For adults, four diets were tested: A, brewers’ yeast + honey (2:1); B, refined sugar + yeast extract + crude wheat germ (3:1:1); C, soybean extract + brown sugar + crude wheat germ (3:1:1); and D, brewers’ dried yeast + honey (2:1). The evaluated biological parameters were: duration of the egg-pupa period, duration and feasibility of the pupa stage, average mass of pupae, sexual ratio, and duration and feasibility of the egg-adult period. Larval stage development for D1 and D2 was similar, and indicated that the larval rearing can be managed with 1/3 agar quantity used in D1. The dry sugarcane bagasse, used in the artificial diet, negatively affected the larval development. Artificial diets with brewers’ yeast + honey and with refined sugar + yeast extract + crude wheat germ are the most adequate ones for adult rearing.O objetivo deste trabalho foi adequar as dietas artificiais para o desenvolvimento dos estágios de larva e adulto da mosca‑das‑frutas sul‑americana (Anastrepha fraterculus). Para o estágio larval, foram testadas as seguintes dietas: D1, original, com 10 g de ágar; D2, modificada, com 3,6 g de ágar; e, D3, modificada, com bagaço seco de cana‑de‑açúcar. Para os adultos, foram testadas quatro dietas: A, levedura de cerveja + mel (2:1); B, açúcar refinado + extrato de levedura + gérmen de trigo cru (3:1:1); C, extrato de soja + açúcar mascavo + gérmen de trigo cru (3:1:1); e D, levedura seca de cervejaria + mel (2:1). Avaliaram-se os parâmetros biológicos de duração do período ovo‑pupa, duração e viabilidade do estágio de pupa, massa média de pupas, razão sexual e duração e viabilidade do período ovo‑adulto. O desenvolvimento larval em D1 e D2 foi semelhante e indicou que a criação de larvas pode ser realizada com 1/3 da quantidade de ágar da utilizada em D1. A utilização do bagaço seco de cana‑de‑açúcar, na dieta artificial, afetou negativamente o desenvolvimento larval. As dietas artificiais com levedura de cerveja + mel e com açúcar refinado + extrato de levedura + gérmen de trigo cru são as mais adequadas para a criação de adultos

Does the scion or rootstock of Citrus sp. affect the feeding and biology of Diaphorina citri Kuwayama (Hemiptera: Liviidae)?

The Asian citrus psyllid (ACP) Diaphorina citri is the main vector of the bacteria associated with Huanglongbing, and can exploit more than 50 species of the family Rutaceae as hosts. The number of possible hosts is even higher if plant varieties are included. This study evaluated the influence of different combinations of scion and rootstock citrus varieties on the development and feeding of ACP. Survival rates for the egg stage were highest on the Valencia and Sicilian varieties, both grafted on Sunki mandarin, with means of 87.99 and 87.98%, respectively; and lowest (67.63%) on Hamlin 9 Rangpur lime. The lowest levels of both nymphal and total viability (egg-adult) were obtained on Hamlin, regardless of the rootstock used. The total development time (egg-adult) ranged from 17.92 to 19.33 days for the Peˆra 9 Sunki and Hamlin 9 Swingle combinations, respectively. Cluster analysis separated the hosts into two groups, the first consisting of the combinations of the Hamlin variety, and the second group formed by the other varieties. The highest food value (assessed by the area of honeydew produced) was observed for the orange scion varieties, and among these, the highest value was observed on Valencia (0.902 cm2); the smallest honeydew area was obtained on Ponkan (0.269 cm2). The rootstocks did not affect the feeding behavior of D. citri. The results of this study could aid in the development of management techniques, mainly in providing information for the installation of new citrus groves and assistance in crop-improvement research

Quality control and characterization of the testicles and ovaries of irradiated Anastrepha obliqua from Brazil

With the aim of making the application of the Sterile Insect Technique (SIT) feasible in the management of the West Indian fruit fly in Brazil, Anastrepha obliqua (Macquart) (Diptera: Tephritidae), a number of quality parameters required by the SIT were investigated in this study. The aim was to verify the influence of a range of doses of gamma radiation (40, 50, 60, 70 and 80 Gy) on the fertility of females and to evaluate several quality control parameters, such as fly emergence, sex ratio, flight ability and survival under stress, as well as the characterization of the morphology (measurement of length and width) of the ovaries and testicles of A. obliqua. Pupae with 24 h before adult emergence were irradiated at CENA/Universidade de São Paulo. The radiosterilization test showed no difference between treatments for the parameters of fly emergence, sex ratio and survival under stress. The radiation at doses above 40 Gy resulted in ovarian atrophy in females and the absence of egg production. In males, the radiation also affected testicular development. Considering the quality parameters assessed, the sterilization results obtained agreed with previous data in the literature for other A. obliqua strains, and the dose of 60 Gy could be considered as the best compromise between insect quality and full sterility for the Brazilian strain of A. obliqua evaluated

Dietas artificiais para a criação de larvas e adultos da mosca-das-frutas sul-americana.

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Large scale artificial rearing of Anastrepha sp.1 aff. fraterculus (Diptera: Tephritidae) in Brazil

Some species of the genus Anastrepha (Diptera: Tephritidae) are successfully managed by matching the sterile insect technique with parasitoid releases. Such strategies used in integrated pest management can be implemented only where insect mass-rearing programs are feasible. In this study, we show the process of domestication, rearing technology and quality control data obtained from 54 generations of Anastrepha sp.1 aff. fraterculus (Wiedemann, 1830) kept under fully artificial conditions. Eggs were collected by an artificial oviposition panel consisting of one side of the cage made of blue voile fabric externally covered with a thin layer of silicon rubber. They were then air-bubbled in water at 25 ºC for 48 h before seeding. Larvae were reared on the regular laboratory artificial diet with 66 % of agar reduction turning over a semi-liquid diet, which reduced costs and improved insect quality. The adult and larval diets were composed of local ingredients including hydrolyzed yeast. When large-scale production of this fly is contemplated, the critical stage is larval development. This system of artificial rearing for A. fraterculus sp.1 developed in Brazil, allows for the production of a large number of insects of excellent quality using local ingredients and less agar in diet composition than the original medium used for this species. By reducing the interval of egg collection, the system might be optimized in terms of insect yield and, therefore, meet the demands of A. fraterculus sp.1 with regard to integrated pest management purposes