RESUMO
Palpita forficifera Munroe 1959 is a lepidopteran pest native to the Neotropical region and has been causing damage to olive tree crops in Brazil and Uruguay. The use of egg parasitoids of the genus Trichogramma may be a viable and sustainable alternative to pest management. The objective of the present work was to select species and/or strains of Trichogramma as possible agents of control for P. forficifera. Selections were made from five strains of Trichogramma foersteri Takahashi (R1, R2, R3, R4, and R5) collected in olive orchards of southern Brazil and four strains of Trichogramma pretiosum Riley (AC, PR, MJU, and RVI) from laboratory rearings. The strains of T. foersteri presented the longest periods from egg to adult (≈ 11.5 days) when compared to T. pretiosum (≈ 9.5 days). However, T. foersteri provided, in general, the highest daily percentage of parasitized P. forficifera eggs and, consequently, a higher rate of parasitism (between 50 and 69%) in relation to those of T. pretiosum (variation from 7 to 20%). In addition, T. foersteri provided a higher emergence rate (above 90%), with a sex ratio close to 1.0. However, all strains of T. pretiosum were longer-lived compared to adults of T. foersteri. From the biological parameters evaluated, two distinct groups were formed between T. foersteri and T. pretiosum. In general, T. foersteri has better potential for controlling P. forficifera, demonstrating its potential for use in field multiplication and release programs for the management of the olive larvae.
Assuntos
Himenópteros , Mariposas , Olea , Vespas , Animais , Larva , Controle Biológico de Vetores , Brasil , ÓvuloRESUMO
Spotted-wing Drosophila, Drosophila suzukii (Matsumura, 1931), is an economic pest of thin-skinned fruit crops. Its control has commonly been carried out through chemical methods. However, given the need to develop safer and environmentally friendly management alternatives, the pupal endoparasitoid Trichopria anastrephae Lima stands out as a potential biological control agent. However, the lack of information on the mass rearing of this parasitoid limits its use. Thus, the objective of our study was to provide information that is useful for rearing T. anastrephae using D. suzukii as a host. The effects of pupal age, exposure time, and pupal density on the parasitism rate were examined, as was the effect of honey provision for extending adult parasitoid longevity. Exposing 15 12-h-old pupae per female for 24 h resulted in higher parasitism rates and a greater number of emerged parasitoids. Males and females of T. anastrephae fed with pure honey (100%) or honey diluted to 50% in water lived longer compared to those fed 10% honey, no food, or only water.
Assuntos
Himenópteros , Animais , Brasil , Drosophila , Feminino , Longevidade , Masculino , PupaRESUMO
The spotted-wing drosophila, Drosophila suzukii Matsumura, is considered the main insect pest of small fruit in the world. Identifying susceptible hosts is essential to develop management strategies. The aim of this study was to verify the level of D. suzukii infestation in blackberry, blueberry, strawberry, cattley guava and Surinam cherry fruits cultivated in the southern region in Brazil, and to determine the infestation index (II) per fruit. The studies were carried out during two harvests (2015/16 and 2016/17) in three areas with organic cultivation of small fruit. The highest level of D. suzukii natural infestation was observed in blackberry (40 to 65% infestation), and strawberry (approximately 30% infestation) fruits. In contrast, blueberries were less preferred (< 7% infestation). For native fruit of the region (cattley guava and Surinam cherry), it was also verified infestation of the fly, demonstrating they are hosts for multiplication in the off-season periods of the other crops. In relation to II, blackberry and Surinam cherry provided a higher average number of insects per gram of fruit (≈ 1.6 adults of D. suzukii). In contrast, blueberries and cattley guava had the lowest insect ratio per gram of fruit (≈ 0.7 adults per gram). The period between late spring to mid-autumn was considered ideal for the pest occurrence in the field. The knowledge of natural infestation levels is essential for understanding the behavior of the pest in the field, which will assist in the design of management strategies.(AU)
A drosófila-da-asa-manchada, Drosophila suzukii Matsumura, é considerada o principal inseto-praga de pequenos frutos no mundo. A identificação de hospedeiros suscetíveis é essencial para o desenvolvimento de estratégias de manejo. O objetivo deste estudo foi verificar o nível de infestação de D. suzukii em frutos de amoreira-preta, mirtileiro, morangueiro, araçazeiro e pitangueira cultivados na região no sul do Brasil e determinar os índices de infestação (II) por fruto. Os estudos foram realizados durante duas safras (2015/16 e 2016/17) em três áreas com cultivo orgânico de pequenas frutas. O maior nível de infestação natural de D. suzukii foi observado em amora-preta (40 a 65% de infestação) e morango (aproximadamente 30% de infestação). Em contraste, o mirtilo foi menos preferido (< 7% de infestação). Para as frutas nativas da região (araçá e pitanga), também ocorreu infestação da mosca, demonstrando serem hospedeiros potenciais para a multiplicação da praga nos períodos de entressafras. Em relação ao II, amoras e pitangas proporcionaram um maior número médio de insetos por grama de fruto (≈ 1,6 adultos de D. suzukii). Por outro lado, mirtilos e araçás apresentaram a menor relação de insetos emergidos por gramas de frutos (≈ 0,7 adultos por grama). O período entre final da primavera até meados do outono foi considerado ideal para a ocorrência da praga no campo. O conhecimento dos níveis de infestação natural é fundamental para o entendimento do comportamento da praga no campo, o que auxiliará no delineamento de estratégias de manejo.(AU)
Assuntos
Drosophila , Frutas/parasitologia , Estações do Ano , Brasil , Pragas da Agricultura , Vaccinium myrtillus , Morus , Fragaria , Espécies Introduzidas , EugeniaRESUMO
The spotted-wing drosophila, Drosophila suzukii Matsumura, is considered the main insect pest of small fruit in the world. Identifying susceptible hosts is essential to develop management strategies. The aim of this study was to verify the level of D. suzukii infestation in blackberry, blueberry, strawberry, cattley guava and Surinam cherry fruits cultivated in the southern region in Brazil, and to determine the infestation index (II) per fruit. The studies were carried out during two harvests (2015/16 and 2016/17) in three areas with organic cultivation of small fruit. The highest level of D. suzukii natural infestation was observed in blackberry (40 to 65% infestation), and strawberry (approximately 30% infestation) fruits. In contrast, blueberries were less preferred (< 7% infestation). For native fruit of the region (cattley guava and Surinam cherry), it was also verified infestation of the fly, demonstrating they are hosts for multiplication in the off-season periods of the other crops. In relation to II, blackberry and Surinam cherry provided a higher average number of insects per gram of fruit (≈ 1.6 adults of D. suzukii). In contrast, blueberries and cattley guava had the lowest insect ratio per gram of fruit (≈ 0.7 adults per gram). The period between late spring to mid-autumn was considered ideal for the pest occurrence in the field. The knowledge of natural infestation levels is essential for understanding the behavior of the pest in the field, which will assist in the design of management strategies.(AU)
A drosófila-da-asa-manchada, Drosophila suzukii Matsumura, é considerada o principal inseto-praga de pequenos frutos no mundo. A identificação de hospedeiros suscetíveis é essencial para o desenvolvimento de estratégias de manejo. O objetivo deste estudo foi verificar o nível de infestação de D. suzukii em frutos de amoreira-preta, mirtileiro, morangueiro, araçazeiro e pitangueira cultivados na região no sul do Brasil e determinar os índices de infestação (II) por fruto. Os estudos foram realizados durante duas safras (2015/16 e 2016/17) em três áreas com cultivo orgânico de pequenas frutas. O maior nível de infestação natural de D. suzukii foi observado em amora-preta (40 a 65% de infestação) e morango (aproximadamente 30% de infestação). Em contraste, o mirtilo foi menos preferido (< 7% de infestação). Para as frutas nativas da região (araçá e pitanga), também ocorreu infestação da mosca, demonstrando serem hospedeiros potenciais para a multiplicação da praga nos períodos de entressafras. Em relação ao II, amoras e pitangas proporcionaram um maior número médio de insetos por grama de fruto (≈ 1,6 adultos de D. suzukii). Por outro lado, mirtilos e araçás apresentaram a menor relação de insetos emergidos por gramas de frutos (≈ 0,7 adultos por grama). O período entre final da primavera até meados do outono foi considerado ideal para a ocorrência da praga no campo. O conhecimento dos níveis de infestação natural é fundamental para o entendimento do comportamento da praga no campo, o que auxiliará no delineamento de estratégias de manejo.(AU)
Assuntos
Animais , Dípteros , Drosophila , Frutas , Drosophilidae , Pragas da Agricultura , Vaccinium myrtillus , Morus , Fragaria , EugeniaRESUMO
Ants (Hymenoptera, Formicidae) are an efficient group of insects as predators of various arthropods. Based on records of the predatory ant activity, a survey was carried out on the efficiency in predation of Anastrepha fraterculus (Diptera: Tephritidae) larvae, considering the percentage of removal of larvae using the variables of soil density and moisture content and their effect on the larvae burying. For this, A. fraterculus larvae were released to the soil and observed for 10 min while burying or removed by the ants in a peach (Prunus persica, Rosaceae) orchard. Eight ant species were recorded removing 32.70% of the larvae. Solenopsis saevissima was the most efficient species, with 42.86% of larvae removal. There were no significant correlations between the predation by ants with soil density and soil moisture content. Despite this, the study pointed out that ants belong to genera Pachycondyla, Pheidole, Pogonomyrmex and Solenopsis can be predators on A. fraterculus larvae, with emphasis on the S. saevissima. These ants can contribute as important agents of conservative biological control of the population of A. fraterculus in peach orchard and their conservation becomes interesting to use of combined control methods aiming to reduce insecticides and aggressive soil management methods.
Formigas (Hymenoptera, Formicidae) são eficientes como predadores de diversos artrópodes. Baseado nos registros de atividade predatória de formigas, um levantamento da eficiência na predação de larvas de Anastrepha fraterculus (Diptera: Tephritidae) considerando a porcentagem na remoção das larvas pelas formigas frente às variáveis de densidade e teor de umidade do solo e o seu efeito sobre o tempo de enterramento das larvas, foi realizado. Larvas de A. fraterculus foram liberadas ao solo e observadas por 10 min enquanto enterravam-se ou eram removidas pelas formigas em um pomar de pessegueiro (Prunus persica, Rosaceae). Oito espécies de formigas foram registradas removendo 32.7% das larvas oferecidas. Solenopsis saevissima foi a espécie mais eficiente com 42.9% da remoção de larvas. Não ocorreram correlações significativas entre os registros de predação por formigas com a densidade e o teor de umidade do solo. Apesar disso, o estudo apontou que as formigas pertencentes aos gêneros Pachycondyla, Pheidole, Pogonomyrmex e Solenopsis podem ser predadoras de larvas de A. fraterculus, com ênfase na espécie S. saevissima, podem contribuir como importantes agentes de controle biológico conservativo da população de A. fraterculus em pomar de pessegueiro e que sua conservação torna-se interessante frente ao uso de métodos de controle combinados visando a redução de inseticidas e de métodos agressivos de manejo do solo.
Assuntos
Formigas , Controle de Pragas , DrosophilaRESUMO
Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) is a widely distributed pest of soft-skinned and stone fruits that is controlled mainly with pesticides. An alternative to the chemical control is the sterile insect technique (SIT), an ecologically friendly method of pest management that could be used against D. suzukii. The objective of the present study was to evaluate the effects of gamma radiation on reproductive sterility, ovarian morphometry, and quality parameters of D. suzukii. Full female sterility was achieved at 75 Gy, while an adequate level of male sterility (99.67%) was obtained at 200 Gy. The ovarian size showed an exponential decay in function of irradiation dose increase. There was no significant influence of irradiation dose on the quality parameters evaluated. Our data suggest that gamma radiation can be recommended to be used in an SIT program for D. suzukii.