ABSTRACT
BACKGROUND: Improving the mating competitiveness and survival of sterile males are direct means to increase the effectiveness of the sterile insect technique (SIT). Some insecticide growth regulators, such as the juvenile hormone analogue (JHA) methoprene, have been used to improve the mating competitiveness of male tephritid flies by reducing their sexual maturation period. However, the application of methoprene reduces fly resistance to stress and decreases survival. Here, we compared the effects of methoprene and pyriproxyfen (PPF), another JHA, in Anastrepha ludens males. PPF is an insect growth regulator that exhibits higher negative effects on the larval molting process than methoprene or natural juvenile hormone. Both compounds were administered at two doses (0.05% and 0.10%) via the male diet immediately after emergence. RESULTS: Our results show that both PPF and methoprene reduced male sexual maturation. However, PPF-treated males exhibited a shorter maturation period and obtained more matings at a given age than methoprene-treated males. No significant differences were observed between the two PPF doses tested (0.05% and 0.10%). Male survival was equally reduced by the two compounds. CONCLUSION: Our results demonstrate that PPF accelerated sexual development without reducing the mating propensity of sterile male flies and can be used as a suitable alternative for methoprene. © 2023 Society of Chemical Industry.
Subject(s)
Juvenile Hormones , Tephritidae , Animals , Male , Juvenile Hormones/pharmacology , Methoprene , Sexual Maturation , Sexual Behavior, Animal , DrosophilaABSTRACT
The sterile insect technique (SIT), used to control different species of tephritid fruit flies (Diptera: Tephritidae), is an important element in sustainable agriculture because of its low negative impact on the environment. In SIT, flies are mass produced and sterilized in the laboratory and then released in a target area. However, once released, laboratory flies may confront harass environments that would reduce their performance and consequently SIT efficiency. Selecting flies that resist stressful conditions may help to improve the efficiency of the SIT by releasing males that resist desiccation, for example, ensuring, thus, their survival in environments with low relative humidity. However, the selection process may affect the resistance of flies to the stress of sterilization, since some life history traits are affected. Here, we studied the effect of irradiation on Anastrepha ludens (Loew) (Diptera: Tephritidae) desiccation resistant flies (DR) compared with nonselected flies (NS). We measured the effect of gamma irradiation dose (0, 20, 40, 60, and 80 Gy) on sterility (males and females) and quality parameters (emergence, flight ability, survival, and male sexual performance) in A. ludens adults of the DR and NS (control) strains. Our results indicate that irradiation affected equally the sterility of adults of both strains. None of the quality parameters differed between strains. The only difference was that DR flies survived longer than control flies. Thus, flies that are resistant to desiccation can be used in the SIT without altering the current process of irradiation and packing.
Subject(s)
Tephritidae , Animals , Desiccation , Female , Male , Pest Control, BiologicalABSTRACT
Theobroma cacao L. es una especie originaria de América y ha estado ligada al desarrollo de diversas culturas indígenas en las regiones tropicales húmedas. Su semilla se utiliza para la elaboración de alimentos, bebidas y golosinas y su demanda se ha incrementado cuando se cultiva sin agroquímicos. La nutrición de la planta mediante biofertilizantes microbianos es una alternativa para incrementar la oferta de cacao orgánico. En este trabajo se identificó el aporte de dos microsimbiontes en el desarrollo vegetal y nutrimental del cacao en dos condiciones de suelo del Soconusco, Chiapas, México, uno de ellos tratado con bromuro de metilo y otro sin tratar. Las semillas de cacao se inocularon con Azospirillum brasilense y Glomus intraradices, solos o combinados al momento de la siembra. Se registraron variables morfológicas y fisiológicas del rendimiento y el contenido de N2, P y Ca²+ en el tejido vegetal cada 30 días durante seis meses. Los resultados indicaron una respuesta diferencial entre condiciones de suelo y microsimbiontes en la asignación de materia seca. Los órganos de la planta más modificados fueron la raíz y la lámina foliar. Las plantas inoculadas mostraron mayor concentración de N2 en suelo no tratado. G. intraradices fue más efectivo en promover la incorporación de P en suelo no tratado y de Ca²+ en ambas condiciones del suelo.
