Aspectos biológicos de Coleomegilla maculata (DeGeer) (Coleoptera: Coccinellidae) alimentada com Drosophila melanogaster Meigen (Diptera: Drosophilidae)

Abstract

The biological aumentative control consists in the rearing and multiplication of biological control agents in the laboratory for releases them in cultivation areas to control the target pest. However, one of the obstacles to the rearing of these agents is the development of methodologies that allow the use of natural or alternative food that does not compromise the performance of them. The objective of the present work was to evaluate the use of Drosophila melanogaster Meigen (Diptera: Drosophilidae) larvae as an alternative prey for larvae and adults of the lady beetle Coleomegilla maculata (DeGeer) (Coleoptera: Coccinellidae), in order to improve the methodologies for the rearing of entomophages under laboratory conditions. For this, experiments were carried out comparing larvae of D. melanogaster with the aphid Lipaphis erysimi (Kaltenbach) (Hemipera: Aphididae), as natural prey of C. maculata, and thus were generated two chapters with specific objectives. The objective of chapter I was to evaluate the suitability of the alternative prey (D. melanogaster) offered to C. maculata in comparison with L. erysimi, observing the biological and reproductive parameters of this lady beetle. The experiment was conducted under controlled environmental conditions (temperature 25 ± 1 °C, humidity 60 ± 10%, photophase 12 hours) at the Integrated Center for Pest Management (CIMP), DEnF - UFRRJ, RJ and was composed of two treatments and 10 replicates, in a completely randomized design, with each replicate consisting of six individuals. The objective of chapter II was to evaluate the larval and adult food intake of C. maculata using larvae of D. melanogaster and L. erysimi aphids, in equivalent amounts, and their influence in the duration of the post-embryonic phases, and also to determine the nitrogen and carbon contents to assess the quality of the prey offered. The experiment was conducted in a controlled environment under the same conditions as before. The design was completely randomized, with ten treatments (5 different densities of each prey) and five replications, totaling 50 individuals. The prey was weighed and offered daily, as well as the leftovers from the diet offered the previous day were quantified as well. The nutritional values of the prey with determination of nitrogen and carbon were taken in the "John Day Laboratory" of Embrapa Agrobiology. It can be concluded that live larvae of D. melanogaster are suitable for the development of C. maculata.