Aspectos bioecológicos de Chrysoperla externa (Hagen, 1861) alimentada com o pulgão Rodobium porosum (Sanderson, 1900) e interação com plantas atrativas em cultivo de roseira

Abstract

Chrysoperla externa (Chrysopidae) is one of the natural enemies of the aphid Rhodobium posorum (Aphididae) in rosebush. Attractive plants can house predators and parasitoids that will control pests. The knowledge of the interactions that occur in the rosebush/aphid/attractive plant s system is important to the use of this predator in biological control programs. The objective of this research was to evaluate the bioecological aspects of C. externa in the tritrophic system, including rosebush, R. porosum aphid and the attractive plants: African marigold (Tagetes erecta L., Asteraceae), basil (Ocimum basilicum L. Lamiaceae) and marigold (Calendula officinalis L. Asteraceae), in laboratory and in greenhouse. In chapter 1, it was evaluated the development, reproduction, as well as the fertility life table of C. externa fed with the R. porosum aphid. This aphid was an adequate food for the development and reproduction of C. externa. In Chapter 2, the olfactory response of C. externa to volatiles of rosebush and attractive plants (African ma rigold, basil and marigold) was evaluated in the laboratory, in the presence or absence of the aphid and, in the greenhouse, it was evaluated the oviposition behavior of C. externa in the tritrophic system that included rosebush, aphids and attractive plants (African marigold, basil and marigold). Basil was the most attractive for C. externa (χ² = 9.2564; df = 1; P<0.05), with 74.3% of attractiveness. The presence of the rosebush did not affect the oviposition preference of C. externa. There was a higher percentage of C. externa eggs (100%) in the basil used as an attractive plant associated with the rosebush. The volatiles released by basil were attractive to C. externa, indicating that the use of plant as a component of diversification may be beneficial for the attraction and maintenance of populations of this predator. In Chapter 3, it was evaluated the effect of basil (O. basilicum) as an attractive plant and of releases of C. externa on the biological control of rosebush pest in a greenhouse, compared to the conventional (chemical) control. The greatest abundance of specimens collected was in the diversified culture (2,222 specimens). In the conventional rosebush, most of the individuals collected were of phytophagous species. In the diversified cultivation, the number of predatory insects found was higher, compared to the conventional rosebush. Basil attracted great diversity of natural enemies, causing a positive effect on pest control in the rosebush. The yield and quality of the harvested roses were not affected by the evaluated treatments. The combination of the use of basil as an attractive plant and the release of chrysopids favors the biological control of rosebush cultivation.