Efeito de duas substâncias atrativas no comportamento alimentar, limiar de discriminação e longevidade de adultos de Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae)

The fruit-fly, Ceratitis capitata (Wiedemann, 1824), is one of the most economically important pests of agriculture in Brazil, damaging many species of fruit. The carbohydrates and the acids are common substances found in the hosts of C. capitata that act by supplying energy and stimulating ovipositon, respectively, besides being phagostimulants. The aim of this work was to evaluate the influence of the attractive substances (sucrose and citric acid) in adults of a laboratory population, studying the following parameters: diet selection behavior (phagostimulation), discrimination threshold, and longevity. Males and females showed similar selective behavior for the different attractive substances. However, females presented larger discrimination thresholds than males for the two attractive substances. Both sexes had similar longevity when reared on the same diet. The results demonstrated that sucrose is preponderant in the warranty of longevity and also regulates the amount of diet ingested by the adults, unlike citric acid, that did not have influence in any of the parameters investigated.A mosca-das-frutas, Ceratitis capitata (Wiedemann, 1824), é considerada uma das pragas agrícolas economicamente mais importantes, causando danos a vários tipos de frutas. Os carboidratos e os ácidos são substâncias comuns encontradas nos hospedeiros de C. capitata e atuam fornecendo energia e estimulando a oviposição, respectivamente, além de serem fagoestimulantes. Este trabalho visou avaliar comparativamente a influência das substâncias atrativas (sacarose e ácido cítrico) em adultos de uma população criada em laboratório, verificando os seguintes parâmetros: comportamento de seleção de dietas (fagoestimulação); limiar de discriminação; e longevidade. Na comparação entre os sexos, machos e fêmeas mostraram comportamento seletivo similar em relação às diferentes substâncias atrativas, porém as fêmeas apresentaram limiar de discriminação maior que os machos para as duas substâncias atrativas. Ambos os sexos tiveram longevidade similar quando criados com a mesma dieta. Os resultados  evidenciaram que a sacarose é preponderante na garantia da longevidade e também participa como regulador na quantidade de dieta ingerida pelos adultos, ao contrário do ácido cítrico que não teve influência em nenhum dos parâmetros avaliados

Iological and behavioral aspects of two laboratory strains of ceratitis capitata (diptera: tephritidae): the influence of periodic introduction of wild flies in the colony

The healthy maintenance of insects reared under laboratory conditions requires strategies to retain the natural characteristics of their life-histories traits. Rearing strategies include artificial selection to laboratory conditions, hybridization with compatible strains, and supplying the colony with wild individuals. We compared behavioral as well as life-history aspects of two laboratory strains of Ceratitis capitata Wiedemann (Diptera, Tephritidae) that had either been reared for 15-20 years under laboratory conditions with or without introducing wild specimens (Lab-Pop and Hybrid-pop, respectively). The parameters evaluated were: performance and food ingestion of immatures, adult size and longevity, female oviposition preference and fecundity, egg viability, and mating choice. Analyses of these parameters were conducted under laboratory rearing conditions. The largest differences observed between the two strains were related to behavioral components: food ingestion rate at the larval stage and oviposition behavior. In general, Lab-Pop individuals were less selective and more adapted to the artificial diet than Hybrid-Pop individuals (diet consumption), but there were no significant differences between the two strains in terms of percentage of emergence, egg viability, adult size, fecundity, and mating choice. It is suggested that the use of hybrid strains is more appropriate than the use of strains without the incorporation of wild individuals, especially in studies that involve behavioral parameters, as hybrid strains behave very similarly to wild populations, according our previous studies

Influência de diferentes dietas em parâmetros biológicos e comportamentais de Ceratitis capitata (Diptera: Tephritidae)

The nutritional value of four artificial diets in a laboratory population of C. capitata was compared using the following biological and behavioral parameters: immature development, longevity, fecundity, feeding behavior, and sexual selection. Only two of the four diets, one containing brewer’s yeast and agar-agar and the other one containing soy flakes, oats flakes, and brewer’s yeast, yielded satisfactory results. The diet containing soy flakes, oats flakes, and brewer’s yeast was considered more cost-effective.Comparou-se o valor nutritivo de quatro dietas artificiais para uma população de C. capitata criada em laboratório. Foram avaliados os seguintes parâmetros biológicos e comportamentais: desenvolvimento dos imaturos, longevidade, fecundidade, comportamento de seleção de dietas e seleção sexual. Duas dietas, uma à base de lêvedo de cerveja e agar (dieta Levedo) e outra à base de farelo de soja, farelo de aveia e lêvedo de cerveja (dieta Farelo), obtiveram resultados satisfatórios com relação aos parâmetros testados. A dieta Farelo foi considerada mais viável do ponto de vista econômico

Comparison of diets for rearing the larvae of Mediterranean fruit fly: nutritional and economic aspects

The Mediterranean fruit fly Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) is the main pest of fruit crops worldwide due to its broad distribution, direct damages, and adaptation to different hosts. Developing diets for the rearing fruit flies is essential for integrated management of this pest. Mass rearing of parasitoids, selection of preferred hosts, and mass rearing of genetically modified C. capitata strains subsidize methods of biological control, cultural control, and the sterile insect technique (SIT), respectively, depending directly on the mass rearing of the Mediterranean fruit fly. The aim of this study was to assess the effectiveness of artificial diets for rearing C. capitata larvae considering the cost of those most appropriate diets. Nine diets containing different combinations of protein and energy sources (brewer’s yeast, yeast extract, pollen, soybean extract, oatmeal, corn meal, and wheat germ) were formulated. The parameters immature development time (hatching), pupal viability (emerged adults), size and weight of pupae, and adult size (wing length) were assessed. The experiments were conducted in the laboratory under controlled conditions of temperature (26 ± 1 °C) and relative humidity (70% ± 10%). Statistical analysis was performed by using ANOVA with the Tukey’s test for comparison of means. Diets based on oatmeal and soybean extract, both added with brewer’s yeast, yeast extract, or pollen satisfactorily meet the nutritional requirements of C. capitata. Moreover, diets enriched with brewer’s yeast or yeast extract presented the lowest costs; therefore, they could be used in a continuous mass-scale rearing of C. capitata. Diets based on corn meal and soybean extract, both associated with brewer’s yeast, yeast extract, or pollen are more economical, but they should not be used for rearing C. capitata because they decrease the percentage of hatching and extend life cycle. Diets based on wheat germ and oatmeal, both added with brewer’s yeast, yeast extract, or pollen are not adequate for rearing C. capitata

Mass-rearing of Mediterranean fruit fly using low-cost yeast products produced in Brazil

Ceratitis capitata is one of the most important pests of fruits for exportation, and Sterile Insect Technique (SIT) has been the most efficient and environmental friendly technique used to control fruit fly populations around the world. A key goal in achieving a successful SIT program is a mass rearing system producing high quality insects at low cost. Providing adults with an artificial diet containing hydrolysed protein has been the major obstacle for bio-production facilities in Brazil, because it is expensive and has to be imported. Two other commercial products, autolysed yeast (AY) and yeast extract (YE), of domestic origin and low cost, were tested as substitutes of the imported hydrolyzed protein. To compare their efficiency we observed the female fecundity, adult survival and egg viability of flies raised on diets containing one of each of the different protein products. Flies reared on the domestic yeast products had equivalent or superior performance to the flies reared on imported protein. Both AY and YE can be a possible substitute for imported hydrolyzed protein for C. capitata mass-rearing, as they are cheaper and are readily available in the national market

Avaliação da qualidade da alimentação em parâmetros biológicos de drosophila melanogaster (Diptera: Drosophilidae): comparação entre uma população de laboratório e uma população selvagem

Feeding has influence on behavior and biological parameters of any kinds of animal species. In insects, it is necessary the use of laboratory-reared populations for the study of these aspects. Drosophila melanogaster Meigen, 1830 is the best organism to be used in laboratory experiments for these studies. Although the rearing species are widely utilized, the laboratory-reared populations can be a problem for evolution, life-history and behavior studies and also for preservation and biological control programs. Literature data shows that artificial rearing causes modifications in behavior s well as in physiologic and demographic traits of the populations when they are established in laboratory. The aim of this study was to compare the influence of the food quality, estimated by protein concentration of the diet, on immature performance and adult longevity of two D. melanogaster populations: one laboratory-reared and other originally from the field. The results showed that for basic biological aspects, such as, protein requirement in the immature and adult phase, the two populations had similar results. In both populations, the ingestion of the greatest protein concentration on immature phase results, generally, in better immature performance and larger adult longevity. Some differences have been registered between these two populations. Adult emergence was greater in laboratory population and the smaller ingestion of protein in immature phase reduced the adult longevity of laboratory males, but it did not affect the longevity of field males.Os fatores alimentares influenciam a grande maioria dos comportamentos e aspectos biológicos de qualquer espécie animal. Para o estudo desses parâmetros em insetos utilizam-se, geralmente, populações criadas em laboratório. Drosophila melanogaster Meigen, 1830 é o organismo mais freqüentemente usado em experimentos de laboratório para tais estudos. Apesar de serem amplamente utilizadas, as criações de laboratório podem ser um problema para estudos de evolução, históricos de vida, comportamento e, também, para programas de conservação e controle biológico. Isto porque tem sido demonstrado que comportamentos e algumas características fisiológicas e demográficas das populações modificam-se quando essas são estabelecidas em laboratório. Neste estudo pretendeu-se comparar a influência da qualidade da alimentação, estimada pela concentração de proteína na dieta, na performance dos imaturos e longevidade dos adultos de duas populações de D. melanogaster: uma população criada em laboratório e outra população proveniente do campo. Os resultados indicaram que para aspectos biológicos básicos, como requerimento protéico na fase imatura e adulta, as duas populações tiveram resultados similares. Em ambas, a ingestão de maior concentração protéica na fase imatura, geralmente, garantiu melhores resultados na performance dos imaturos e maior longevidade dos adultos. No entanto, algumas diferenças foram registradas comparando-se as duas populações. A emergência de adultos foi maior na população de laboratório e a ingestão de menor concentração de proteína na fase imatura diminuiu a longevidade dos machos de laboratório, mas, não afetou a dos machos do campo

Machos Virgens e Acasalados de Ceratitis capitata Wiedemann (Diptera: Tephritidae) Apresentam o mesmo Sucesso de Cópula e a mesma Capacidade de Inibição de Recópula das Fêmeas?

Ceratitis capitata Wiedemann is a polyphagous species that damages fruits and affects their production and consumption. One of the techniques to manage this pest is the Sterile Insect Technique, which consists in releasing sterile males in nature to compete with wild males for mating. The success of this technique is associated with the ability of sterile male in being selected by the female and in preventing female remating with other males. This paper aims to evaluate the influence of male reproductive status in mating success and in female remating inhibition. Tests for evaluating the latency to mate and copula duration were performed to evaluate latency to mate and copula duration based on different male status. In remating inhibition tests, females mated with virgin and mated males, were exposed to other males one day after the first mating so the rate of remating could be evaluated. The results showed that males of different reproductive status had no differences in mating success and in female remating inhibition. The latency to mate and copula duration were similar for both male status as well. Our results suggest that, assuming that the sterile males have the same basic biology of no sterile males, in SIT, after released in nature, mated males can have the same success in mating and female remating inhibition as virgin males.A mosca-das-frutas, Ceratitis capitata Wiedemann é uma espécie polífaga que causa danos à fruticultura. Para seu controle, uma das técnicas utilizada é a técnica do inseto estéril (TIE), que consiste na liberação de milhares de machos estéreis no campo para competirem com os selvagens pelas fêmeas. O sucesso desta técnica está associado à habilidade do macho estéril em ser aceito pela fêmea e também em prevenir a recópula da mesma. Neste trabalho avaliou-se a influência do status reprodutivo do macho - virgem ou acasalado - no seu sucesso de cópula e na sua capacidade de inibir a recópula das fêmeas. Foram avaliados o tempo de latência e o tempo de duração da cópula de acasalamentos com os dois tipos de machos. Para verificar a capacidade de inibição de recópula, fêmeas acasaladas com machos virgens ou acasalados foram expostas a novos machos virgens um dia após o primeiro acasalamento e observadas quanto a ocorrência de recópula. Os resultados evidenciaram que machos de diferentes status reprodutivos apresentaram similaridades quanto ao sucesso de acasalamento e a capacidade de inibir a recópula das fêmeas, além de tempos similares de latência para a cópula e duração da mesma. Tais dados sugerem que, assumindo-se que os machos estéreis apresentam a mesma biologia básica de machos não estéreis, na aplicação da TIE, machos que já acasalaram uma vez no campo podem continuar a ter a mesma eficiência que os virgens quanto ao sucesso de acasalamento e a capacidade de inibição de recópula das fêmeas

The relevance of age and nutritional status on the mating competitiveness of medfly males (Diptera: Teprhitidae)

Results of previous investigations trying to ascertain which physiological factors are more important to the mating success of medfly males are controversial. In part, this controversy owes to the fact that each factor was evaluated by an independent study using different experimental designs and populations. In the present study we compare the roles of age and nutritional status (immature and adult phases) on the mating competitiveness of Ceratitis capitata (Wiedemann, 1824) males. Three parameters were used to evaluate the male mating success: calling behavior (pheromone emission), lek participation and copulation (ability to be chosen by a female). Females gave preference to the males that were given a high protein diet in the larval phase. By contrast, females did not give preference to males that had been well-nourished in the adult phase only. The other parameters evaluated followed the same pattern: young males and males that had been fed a high protein diet during their immature phase had a greater participation in leks and called more often than older males and males that had been fed a diet poor in protein during their larval phase. Therefore, we conclude that the mating success of C. capitata males is determined both by age and nourishment during the immature stage