Responses of two Anastrepha species' immature stages infesting preferential hosts to different temperature exposures.

Anastrepha fraterculus (Wiedemann) and A. obliqua (Macquart) are important pests of fruit crops. In Brazil, these species cause damage to fruit growing in the South (annual average temperature of 20.9 °C) and Northeast (average yearly temperature of 24 °C). We evaluated the effect of temperature on the viability and development time of A. fraterculus and A. obliqua immature stages in their respective preferred hosts, guava (Psidium guajava L., Myrtaceae) and mango (Mangifera indica L., Anacardiaceae). The duration of egg and pupal stages, egg to pre-pupa, and viability of egg and pupal stages under different temperatures (15, 20, 25, 30, and 35 °C) were assessed. For both species, development time decreased with increasing temperature. Viability in the evaluated stages was only observed between 15 and 30 °C. However, the species responded differently to the exposure temperatures (15 and 30 °C), especially in the pupal stage and from egg to pre-pupa. Anastrepha fraterculus showed a lower tolerance to high temperatures, especially in the pupal stage and from egg to pre-pupa, which may explain its lower importance and economic impact in warmer Brazilian regions. Anastrepha obliqua had a lower tolerance at 15 °C, indicating greater adequacy for temperatures above 20 °C, characteristic of Northeast Brazil, suggesting the capacity to spread to cooler areas with rising temperatures.

Interference of tritrophic (grape × medfly × parasitoid) interactions by mineral and biomaterial films.

Fruit fly infestation is one of the main obstacles to the exportation of fresh agricultural produce. Films of mineral particles and biomaterials have the potential to protect fruits against tephritid fruit fly infestation. The present study evaluated the effects of particle films on the tritrophic interactions of grape (Vitis vinifera L.), the fruit fly Ceratitis capitata (Wiedemann) and the parasitoid Diachasmimorpha longicaudata (Ashmead) under semi-field conditions. Grapes were biometrically characterised (i.e. colour, firmness, mass, length and diameter), treated with mineral particles, biomaterials or distilled water (control), and then used in oviposition and parasitism bioassays. In the oviposition bioassay, the treated grapes were exposed to 50 C. capitata pairs in field cages, and after 48 h, the punctures and eggs on each fruit were counted. In the parasitism bioassay, treated grapes were artificially infested with third-instar C. capitata larvae (two per fruit), exposed (2 h) to 50 D. longicaudata pairs in field cages to determine parasitism index, larval and pupal viabilities and number of flies and parasitoids emerged. Treatment with the mineral film affected fruit colour and reduced C. capitata oviposition but failed to significantly affect the parasitism capacity of D. longicaudata. The ability of the parasitoid to locate and parasitise C. capitata larvae in kaolin-coated fruits suggests that kaolin films could be used in conjunction with biological agents to control fruit flies.

Influence of Mineral Particle Films and Biomaterials on Guava Fruits and Implications for the Oviposition of Anastrepha obliqua (Macquart) (Diptera: Tephritidae).

Anastrepha obliqua (Macquart, 1835) is an important pest of tropical fruits, especially Anacardiaceae and Myrtaceae, in the Americas. The objective of this study was to evaluate the influence of mineral films and biomaterials on the coloring of guava fruits (Psidium guajava L.) and implications for the oviposition of A. obliqua. Before the bioassays, color, firmness characteristics, total soluble solids, pH, and titratable acidity were determined to characterize the maturation stage of the fruits. Pieces of guava fruit covered in aluminum foil were immersed in suspensions of mineral particles (Surround® WP kaolin; kaolins 605, 607, 608, and 611; and talc) and biomaterials (chitosan, cassava and potato starch, and guar gum) and distilled water (control). After drying, the fruits were exposed to two A. obliqua pairs for 48 h in choice and non-choice tests, and the numbers of eggs per fruit were counted. Mineral films (Surround® WP kaolin, and kaolins 605, 607, 608, and 611) and biomaterials (cassava and potato starch) interfered with the color of guava (luminosity, chroma, and hue angle), inhibiting the oviposition of A. obliqua. Talc, chitosan, and guar gum did not influence the oviposition of A. obliqua in guava.

Bioactive Male-Produced Volatiles from Anastrepha obliqua and their Role in Attraction of Conspecific Females.

The study of insect semiochemicals, especially pheromones, is of fundamental importance for the development of strategies for controlling agricultural pests. In this study, volatile compounds involved in the communication between males and females of the fruit fly, Anastrepha obliqua (Diptera: Tephritidae), for mating purposes were characterized to develop attractant formulations for females of this species. Extracts containing volatile compounds released by males of A. obliqua were obtained by the dynamic headspace technique and analyzed by gas chromatography coupled with an electroantennographic detector (GC-EAD) and gas chromatography coupled with mass spectrometry (GC-MS). Twenty-one volatile compounds were identified in the aeration extracts of males. Five of them caused EAD responses from the antennae of females: 1-heptanol, linalool, (Z)-3-nonen-1-ol, (E,Z)-3,6-nonadien-1-ol, and (Z,E)-α-farnesene. Six synthetic mixtures of these compounds, including the five-component blend and all possible four-component blends, were formulated in a biopolymer and used in behavioral bioassays conducted in the laboratory arena with conspecific virgin females. One blend of 1-heptanol, linalool, (Z)-3-nonen-1-ol, and (Z,E)-α-farnesene attracted more females than the collection of volatiles from virgin males used as control. The other mixtures were as attractive to A. obliqua females as the control treatment. This study indicates potential for use of these compounds in monitoring and control strategies for this pest.

Comparison of diets for rearing the larvae of Mediterranean fruit fly: nutritional and economic aspects / Comparação de dietas para criação de larvas da mosca-do-mediterrâneo: viabilidade nutricional e econômica

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 (brewers 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 Tukeys test for comparison of means. Diets based on oatmeal and soybean extract, both added with brewers yeast, yeast extract, or pollen satisfactorily meet the nutritional requirements of C. capitata. Moreover, diets enriched with brewers yeast or yeast extract presented the lowest costs; therefore, they could be used in a continuous mass-scale rearing of C. capitata.(AU)

A mosca-do-mediterrâneo Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) é a principal praga da fruticultura mundial pela sua ampla distribuição, danos diretos e adaptação a diversos hospedeiros. O desenvolvimento de dietas para criação de moscas-das-frutas é fundamental para o manejo integrado dessa praga. Criação massal de parasitoides, seleção de hospedeiros preferenciais e criação massal de linhagens de C. capitata geneticamente modificadas subsidiam métodos de controle biológico, cultural e a técnica do inseto estéril, respectivamente, dependendo diretamente da criação massal da mosca-do-mediterrâneo. O objetivo do trabalho foi avaliar a eficácia de dietas artificiais para criação de larvas de C. capitata, levando-se em conta o custo daquelas mais adequadas. Nove dietas contendo diferentes combinações de fontes proteicas e energéticas (levedo de cerveja, extrato de levedura, pólen, extrato de soja, aveia, fubá de milho e gérmen de trigo) foram formuladas. Os seguintes parâmetros foram avaliados: tempo de desenvolvimento dos imaturos (eclosão-emergência), viabilidade pupal (adultos emergidos), tamanho e peso das pupas e tamanho dos adultos (comprimento da asa). Os experimentos foram conduzidos em laboratório em condições controladas de temperatura (26 ± 1°C) e umidade relativa (70% ± 10%). Para a análise estatística utilizou-se ANOVA com teste Tukey para comparação das médias.(AU)

Comparison of diets for rearing the larvae of Mediterranean fruit fly: nutritional and economic aspects / Comparação de dietas para criação de larvas da mosca-do-mediterrâneo: viabilidade nutricional e econômica

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.

A mosca-do-mediterrâneo Ceratitis capitata (Wiedemann, 1824) (Diptera: Tephritidae) é a principal praga da fruticultura mundial pela sua ampla distribuição, danos diretos e adaptação a diversos hospedeiros. O desenvolvimento de dietas para criação de moscas-das-frutas é fundamental para o manejo integrado dessa praga. Criação massal de parasitoides, seleção de hospedeiros preferenciais e criação massal de linhagens de C. capitata geneticamente modificadas subsidiam métodos de controle biológico, cultural e a técnica do inseto estéril, respectivamente, dependendo diretamente da criação massal da mosca-do-mediterrâneo. O objetivo do trabalho foi avaliar a eficácia de dietas artificiais para criação de larvas de C. capitata, levando-se em conta o custo daquelas mais adequadas. Nove dietas contendo diferentes combinações de fontes proteicas e energéticas (levedo de cerveja, extrato de levedura, pólen, extrato de soja, aveia, fubá de milho e gérmen de trigo) foram formuladas. Os seguintes parâmetros foram avaliados: tempo de desenvolvimento dos imaturos (eclosão-emergência), viabilidade pupal (adultos emergidos), tamanho e peso das pupas e tamanho dos adultos (comprimento da asa). Os experimentos foram conduzidos em laboratório em condições controladas de temperatura (26 ± 1°C) e umidade relativa (70% ± 10%). Para a análise estatística utilizou-se ANOVA com teste Tukey para comparação das médias.

Adding guarana powder to medfly diets: an alternative for improving the Sterile Insect Technique

Ceratitis capitata (medfly) is a globally important horticultural pest that can be controlled using the sterile insect technique (SIT), but the success of SIT depends on the sexual performance of mass-reared males when released into the field. We added guarana (Paullinia cupana) powder (derived from an Amazonian fruit that is considered to be a stimulant with aphrodisiac effects, capable of improving human physical stamina) to the diets of adult male medflies to determine whether it increased their sexual performance. The basic diet of a protein extract + sucrose (1:3) was enriched with guarana powder (3 % on a volume basis). Experiments examining sexual competitiveness were performed using lab-reared males fed with the enriched diet vs. lab-reared males fed on the basic diet (and lab-reared females fed on the basic diet), as well as lab-reared males fed with the enriched diet vs. wild males fed on the basic diet (and wild females fed on the basic diet). The results of both experiments indicated that males maintained on diets enriched with guarana powder showed higher copulation successes than males fed only with the basic diet. Guarana powder therefore contributed to the greater mating success of lab-reared males (probably because of its stimulant properties), and may represent a new and viable option for increasing SIT effectiveness.

Adding guarana powder to medfly diets: an alternative for improving the Sterile Insect Technique

Ceratitis capitata (medfly) is a globally important horticultural pest that can be controlled using the sterile insect technique (SIT), but the success of SIT depends on the sexual performance of mass-reared males when released into the field. We added guarana (Paullinia cupana) powder (derived from an Amazonian fruit that is considered to be a stimulant with aphrodisiac effects, capable of improving human physical stamina) to the diets of adult male medflies to determine whether it increased their sexual performance. The basic diet of a protein extract + sucrose (1:3) was enriched with guarana powder (3 % on a volume basis). Experiments examining sexual competitiveness were performed using lab-reared males fed with the enriched diet vs. lab-reared males fed on the basic diet (and lab-reared females fed on the basic diet), as well as lab-reared males fed with the enriched diet vs. wild males fed on the basic diet (and wild females fed on the basic diet). The results of both experiments indicated that males maintained on diets enriched with guarana powder showed higher copulation successes than males fed only with the basic diet. Guarana powder therefore contributed to the greater mating success of lab-reared males (probably because of its stimulant properties), and may represent a new and viable option for increasing SIT effectiveness.(AU)

Aceitação e preferência de frutos para oviposição em duas populações de Ceratitis capitata (Diptera, Tephritidae)

The influence of four host fruits, orange (Citrus sinensis L.), papaya (Carica papaya L.), mango (Mangifera indica L.) and apple (Malus domestica Borkh) on oviposition behavior of Ceratitis capitata (Wiedemann, 1824) was evaluated. Experiments were carried out on two C. capitata laboratory-reared populations: one with artificial diet for 10 years with periodic introduction of wild flies and other reared with artificial diet for 20 years without wild flies introduction. In acceptance experiments two pieces of a single fruit type were exposed to a group of 10 females; after 48 hours, these were changed by two new pieces of the same fruit type, and, in the end of the fourth day, the experiments were concluded. In preference experiments, two pieces of different fruits were offered to the females. These experiments were driven under the same conditions of the acceptance ones. Acceptance and preference experiments for both populations showed the following choice hierarchy: papaya > mango > orange > apple. The acceptance experiments showed no differences in the number of eggs/female/day laid in the first 48 hours and in the last 48 hours of the experiments. The amount of eggs in the two pieces of fruits offered to the females was similar. In spite of the two populations present similar behavior in relation to host hierarchy, the number of laid eggs was different, being larger for the population reared without wild flies introduction.