Custos variáveis de produção de Diachasmimorpha longicaudata (Ashmead) para controle de moscas-das-frutas = Variable costs of production for Diachasmimorpha longicaudata to control the fruit flies

O controle biológico aplicado consiste em liberações em massa de predadores ou parasitoides após a criação laboratorial em larga escala. Avaliar o custo de produção do parasitoide Diachasmimorpha longicaudata para controle biológico de moscas-das-frutas irá fornecer uma ferramenta capaz de auxiliar o planejamento, controle e uma forma de apoiar as empresas quanto as suas tomadas de decisão. Este trabalho teve por objetivo identificar e analisar os custos variáveis de produção do parasitoideD. longicaudata, criado em larvas de Anastrepha fraterculus utilizando a ferramenta de Custeio Baseado em Atividade [ABC]. Foi acompanhado o processo produtivo para obter o custo variável total de produção em laboratório de pesquisa e biofábrica de inimigos naturais, localizado em Piracicaba, São Paulo. A capacidade de produção de pupas de A. fraterculus parasitadas por D. longicaudata é de um milhão por semana nesse laboratório, sendo que um milhão de pupas representa 34 L, e um mL contém aproximadamente 30 pupas. O custo variável de produção para produzir um milhão de pupas parasitadas por semana foi de R$5.919,65 ou R$0,0059 por pupa. O custo com mão de obra representa 57% do custo total, enquanto o custo com materiais representa 43%. A tomada de decisão do produtor em relação ao controle biológico utilizando D. longicaudatadependerá de estudos prévios sobre o parasitoide e cultura pretendida. = Applied biological control consists in the mass liberation of laboratory reared predators or parasitoids. Evaluating the variable cost of production of the fruit flies parasitoid Diachasmimorpha longicaudata for biological control will provide a tool to assist the planning, control and a way to support businesses as their decision-making. This study aims to identify and analyze the variable costs productionof D. longicaudata, created in larvas of Anastrepha fraterculus using the Activity-Based Costing Tool [ABC]. The total variable cost was obtained by means of monitoring the rearing in a biofactory located in Piracicaba, Sao Paulo. The pupa production capacity of A. fraterculus parasitized by D. longicaudata is a million a week in this lab being a million pupas around 34 L or 30 per mL. The total cost of production to produce one million parasitized pupa per week was R$5,919.65 or R$ 0.0059 per pupa. The cost of labor is 57% of the total cost, while the cost of materials is 43%. The producer's decision-making in relation to biological control using D. longicaudata depends on previous studies of the parasitoid and desired crop

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

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

Can stable isotope markers be used to distinguish wild and mass-reared Anastrepha fraterculus flies?

The availability of accurate techniques to discriminate between marked laboratory-reared flies and unmarked wild flies captured in monitoring traps is essential for programs that integrate the Sterile Insect Technique (SIT) to manage fruit flies. In this study, the feasibility of using a stable isotope marking technique for the South American fruit fly, Anastrepha fraterculus (Wiedemann), was assessed. Wild flies were collected from apple orchards, which are a target of a SIT project in southern Brazil. To verify if adult flies could be labelled by the stable isotopes from larval diets, larvae were reared on two different C4-based diets and fruits in laboratory. To evaluate the influence of the two most common attractants applied to capture A. fraterculus (grape juice and CeraTrapTM) and the most common preservation method in fruit fly collections (ethanol), laboratory-reared flies were immersed in McPhail traps containing the respective treatments for two periods of time. Samples were analyzed in an elemental analyzer coupled to a Continuous Flow Isotope Ratio Mass Spectrometer (CF-IRMS) at CENA/USP. The δ13C signatures of flies reared on artificial diets differed significantly from the δ13C of flies whose larvae were reared on fruits and from wild flies. In contrast, the δ15N values were less conclusive and the technique could not rely solely on them. In all cases considered, the δ13C and δ15N signatures from males did not differ from females. Despite the alterations caused by the attractants tested and ethanol, laboratory-flies could be distinguished from the wild ones based on δ13C signatures. This is the first comprehensive study to demonstrate that it is possible to distinguish wild A. fraterculus from flies reared on larval diets containing C4 sugar. The first experimentally derived trophic discrimination factors were also obtained for this species. Thus, intrinsic isotope labelling can serve as a backup to conventional dye marking

Infestation of guava by Anastrepha fraterculus (Diptera: Tephritidae): preferred ripening stages and influence of fruit peel coloration

The current study aimed to verify the preferred guava fruit ripening stage for egg laying by Anastrepha fraterculus (Diptera: Tephritidae) and to determine the influence of peel coloration of the fruits of 2 cultivars on infestation. The cultivars used were Paluma and Seculo XXI. The infestation level was evaluated in cages, considering 2 conditions: multiple-choice and nonchoice tests. The infestation levels of A. fraterculus differed between the green and the green-ripe stages in the multiple-choice test. In Paluma fruits with the nonchoice test, the infestation was highest during the ripe stage. There were no differences in infestation levels of A. fraterculus between the green and the green-ripe stages in Seculo XXI. In general, the green-ripe and the ripe stages were preferred for egg laying by A. fraterculus. In Paluma fruits there were significant correlations of infestation levels of A. fraterculus with luminosity (L) and chromaticity (C) in the nonchoice assay. In Seculo XXI fruits there was a significant correlation of infestation levels of A. fraterculus with color angle (h) in the nonchoice assay. No correlation was found between theses parameters in the multiple-choice test

Improvement of the Mass-Rearing Protocols for the South American Fruit Fly for Application of the Sterile Insect Technique

The existing rearing protocols for Anastrepha fraterculus must be reviewed to make economically viable the production of sterile flies for their area-wide application. Additionally, evidence of sexual incompatibility between a long-term mass-reared Brazilian strain and wild populations has been found. To address these issues, this study aimed to refine rearing protocols and to assess the suitability of an A. fraterculus strain for the mass production of sterile flies. A series of bioassays were carried out to evaluate incubation times for eggs in a bubbling bath and to assess the temporal variation of egg production from ovipositing cages at different adult densities. A novel larval diet containing carrageenan was also evaluated. Egg incubation times higher than 48 h in water at 25 °C showed reduced larval and pupal yields. Based on egg production and hatchability, the density of 0.3 flies/cm2 can be recommended for adult cages. The diet with carrageenan was suitable for mass production at egg-seeding densities between 1.0 and 1.5 mL of eggs/kg of diet, providing higher insect yields than a corn-based diet from Embrapa. Even after two years of being reared under the new rearing protocols, no sexual isolation was found between the bisexual strain and wild flies

Optimization of the sterilizing doses and overflooding ratios for the South American fruit fly

<div><p>The Sterile Insect Technique (SIT) is an autocidal control method that relies on inundative releases of sterilized mass-reared insects. This technology has been used in several area-wide programmes for the suppression/eradication of fruit fly populations. Choosing the optimum sterilizing dose and the sterile release density is an essential step of the SIT. Considering unsolved issues related to the application of this technique against <i>Anastrepha fraterculus</i> (Wiedemann), this study aimed to define accurately the central target dose for both sexes of this species and to verify the induction of sterility in fertile flies at different sterile:fertile ratios. The results from the regression analyses proved that the sterilization process for the <i>A</i>. <i>fraterculus</i> Brazilian-1 morphotype (the most common in southern Brazil and Argentina) could consist of irradiating pupae 72 h before adult emergence at 40 Gy, with no detrimental effects to standard quality control parameters. The ovarian development in irradiated females was characterized, demonstrating that doses equal to or higher than 25 Gy cause complete and irreversible ovarian atrophy. The laboratory and field cage tests showed that the sterility induction increased with the proportion of sterile flies, and a sterile:fertile ratio of 50:1 should be appropriate in SIT field trials. The sterile females apparently did not distract the sterile males, despite of the slightly higher reductions in pupal yield for all ratios in their absence. The data generated in this study have a great practical value and will help decision-makers in planning field trials to evaluate the efficacy of the SIT against <i>A</i>. <i>fraterculus</i> populations.</p></div

Means (±SE) of number of pupae recovered, reduction in pupal production and pupae obtained per kg of <i>papaya</i> fruit infested by <i>Anastepha fraterculus</i> at different ratios of sterile: Fertile males without sterile females in field cages.

<p>Means (±SE) of number of pupae recovered, reduction in pupal production and pupae obtained per kg of <i>papaya</i> fruit infested by <i>Anastepha fraterculus</i> at different ratios of sterile: Fertile males without sterile females in field cages.</p

Linear regression equations of Probit sterility on log dose and estimated doses at selected sterility levels for males and females of <i>Anastrepha fraterculus</i> whose pupae were irradiated at three different times (72, 48 and 24 h before adult emergence).

<p>Linear regression equations of Probit sterility on log dose and estimated doses at selected sterility levels for males and females of <i>Anastrepha fraterculus</i> whose pupae were irradiated at three different times (72, 48 and 24 h before adult emergence).</p