RESUMO
Effects of copulation and male size on the oviposition behavior of the manure fly Archisepsis diversiformis (Diptera: Sepsidae). I evaluated the effect of copulation as a stimulation factor for oviposition of Archisepsis diversiformis by using two different age groups of females. In addition, I tested the effect of copulation on female longevity and progeny sex ratio, taking into account female and male size, and oocyte development in relation to female age. A delay in copulation leads to a delay in oviposition. Females of both age groups started to oviposit between four and five days after copulation. The number of eggs that were laid during the first ten days after copulation, the average number of ovipositions (number of eggs laid per day) during the females life, and the average time between ovipositions were all similar. I found further evidence for the effect of copulation on oviposition: when females copulate, they oviposited faster than virgin females. In addition, these females laid a lower number of eggs after the age of 13 days, while females of the same age (that have copulated before, when they were two or six days old) laid a higher number of eggs (an average of 75 eggs). Oocytes in virgin females became larger with age; 57 % of the variation in the number of eggs laid by females depends on females longevity. As in other studies, female size had an effect on the total number of eggs laid. However, male size significantly affected the oviposition rate (total number of eggs/female longevity). Females tended to have a higher oviposition rate after copulating with larger males. These data suggest that for this fly species, sexual selection through female choice might be occurring. Rev. Biol. Trop. 57 (Suppl. 1): 239-250. Epub 2009 November 30.
Se evaluó el efecto de la cópula como factor estimulante de la oviposición en Archisepsis diversiformis utilizando hembras de dos edades, y en la longevidad de la hembra y en la proporción sexual de la progenie, tomando en cuenta el tamaño de hembra y macho, y el desarrollo de los ovocitos en relación a la edad de la hembra. Se demostró que una demora en copular indujo una demora en oviponer. También hubo similitud en el número de huevos puestos en los diez primeros días después de la cópula, en el número promedio de posturas (grupo de huevos puestos por día) durante toda la vida de una hembra, y en el tiempo promedio transcurrido entre posturas. Otra evidencia del efecto de la cópula en la ovipostura, fue que las hembras que copularon ovipositaron más rápido que las vírgenes. Además, éstas colocaron un número muy bajo (en promedio 14) de huevos a partir de los 13 días de edad, mientras que hembras de esta misma edad (que previamente habían copulado a los dos o seis días de edad) colocaron un mayor número (en promedio 75) de huevos. Como en otros estudios, el tamaño de la hembra tuvo un efecto significativo sobre el número total de huevos puestos. Sin embargo, el tamaño del macho afectó significativamente la tasa (Nº total de huevos/duración de la vida de la hembra) de ovipostura. Estos datos sugieren la posibilidad de que la selección sexual por elección femenina actúe en hembras de esta especie de mosca.
Assuntos
Oviposição/fisiologia , Comportamento Sexual Animal , Copulação/fisiologia , Dípteros , Ligação do Par , Costa RicaRESUMO
The aim of this study is to report the first occurrence of the parasitoid Triplasta coxalis (Ashmead, 1865) (Hymenoptera: Figitidae: Eucoilinae) in pupae of Archisepsis scabra (Loew, 1861) (Diptera: Sepsidae) in cattle dung in Brazil. The experiment was carried out in Monte Alegre, MG. One obtained the pupae through the flotation method. They were individually placed in gelatin capsules until the emergence of the adult dipterous or their parasitoids. Fourty seven pupae of A. scabra were obtained, two of which yielded the parasitoid T. coxalis. The percentage of parasitism was 4.3 percent.
Objetivou-se, no presente trabalho, relatar a primeira ocorrência do parasitóide Triplasta coxalis (Ashmead, 1865) (Hymenoptera: Figitidae: Eucoilinae) como inimigo natural de Archisepsis scabra (Loew, 1861) (Diptera: Sepsidae) em fezes bovinas no Brasil. O experimento foi realizado em Monte Alegre, MG. As pupas foram separadas pelo método de flutuação e individualizadas em cápsulas de gelatina onde foram mantidas até a emergência dos dípteros e/ou dos parasitóides. Obtiveram-se 47 pupas de A. scabra, das quais emergiram dois parasitóides pertencentes à espécie T. coxalis. A porcentagem de parasitismo foi de 4,3 por cento.