Resistência de genótipos de feijão a Chrysodeixis includens (Walker, 1858) (Lepidoptera: noctuidae)

Abstract

The common bean (Phaseolus vulgaris L.) has great economic importance in Brazil, and in a worldwide panorama, Brazil is recognized as one of the largest cultivators. However, during cultivation, the common bean is subject to losses, due to attacks from insect pests, like Chrysodeixis includens (=Pseudoplusia includens) (Lepidoptera: Noctuidae) (Walker), which cause damage and reduce production through feeding on leaf tissue and pods. The soybean looper is mainly controlled using synthetic insecticides, practice which may cause environmental disequilibrium and even induce resistance in insect populations. Thus, alternative and conventional compatible control methods should be studied. Plant breeding could be a viable alternative, as pest resistant cultivars could be developed, reducing the need of insecticides, also reducing the negative impacts towards the environment. Thus, the objective of this study was to evaluate common bean genotypes`, Phaseolus vulgaris L., resistance towards the soybean looper, C. includens. The soybean looper`s biology was studied with life and fertility table constructed using 14 common bean genotypes, the nonovipositon preference was studied on 15 genotypes, the non-feeding preference and free choice leave tissue consumption was studied using 23 common bean genotypes. The C. includens biological parameters, reproduction and multiplication index were all influenced in different levels by the different common bean genotypes. However, C. includens reached adulthood and produced viable descendants on every evaluated genotype. The Uirapuru genotype negatively effects the biological and reproductive aspects of C. includens, possibly serving as a viable plant breeding source. The genotype Tangará favors biological and reproductive conditions for C. includens, thus its cultivation should be with caution and constant monitoring. The genotypes Quero-Quero, Nhambu, Corujinha, Andorinha, ANFC 9, Siriri, BRS Radiante and Verdão demonstrate a higher atractivity to third instar C. includens caterpillars. But the genotypes BRS Esteio, Sabiá, Eldorado, Gralha, Tuiuiú, Verdão and Tangará were deterrent towards C. includens` oviposition. The soybean looper`s oviposition is correlated to the common bean`s leaf color intensity.