<b>Effect of the age of Trichogramma exiguum and diamondback moth embryonic development on the biological characteristics of the parasitoid</b> - DOI: 10.4025/actascibiolsci.v29i2.522

Abstract

The objective of this work was to evaluate the influence of the embryonic development of eggs from the P. xylostella host on Trichogramma exiguum females of different ages. Fifty females – either just-emerged or 24, 48, 72 and 96 hours after emergence of this parasitoid were divided into five groups. Each female was offered a recipient with 30 P. xylostella eggs, which were 1-, 2- and 3-days-old. The greatest rates of parasitism were observed on eggs with 3 days of embryonic development, with exception of those 72-hours-old. Viability was not influenced by parasitoid age or host embryonic stage. Sex ratio was similar in all three embryonic host stages for T. exiguum females that were 24-, 48- and 72-hours-old. While evaluating parasitoid progeny obtained from eggs with 3, 2 and 1 days of embryonic development, it was verified that the highest values of longevity were obtained when the females used were just-emerged, or 48- and 72-hours-old, respectively. These results indicate the importance of the age of the parasitoid, as well as the host embryonic development period, in order to maintain quality of T. exiguum at laboratory conditions, in mass culture, as well as in field releases for biological pest control.