|DA SILVA OLIVEIRA, CARLOS - State University Of Mato Grosso Do Sul|
|HOFFMANN, LUCIA - Embrapa|
|TOSCANO, LUCIANA - State University Of Mato Grosso Do Sul|
|STEINER, FABIO - State University Of Mato Grosso Do Sul|
|ZOZ, TIAGO - State University Of Mato Grosso Do Sul|
Submitted to: International Journal of Tropical Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2020
Publication Date: 11/23/2020
Citation: Da Silva Oliveira, C.E., Hoffmann, L.V., Toscano, L.C., Steiner, F., Zoz, T., Witt, T.W. 2020. Resistance of cotton genotypes to silverleaf whitefly (Bemisia tabaci [gennadius] biotype B). International Journal of Tropical Insect Science. https://doi.org/10.1007/s42690-020-00373-8.
Interpretive Summary: Whiteflies are a major pest in cotton and they have caused an increase in insecticide use in the crop. This study evaluated if different cottons were preferred by whiteflies based on the hairiness of the leaves and the type of hairs on the leaves. Also, the plant defenses of cotton can delay the growth of whiteflies. Six different types of cotton with different leaf hairiness were evaluated. Cotton types with less leaf hairs were less preferred by whiteflies to lay their eggs on. Some types of cotton had plant defenses that delayed the growth of whiteflies. This information may allow for the creation of new cotton types that are not attractive to whiteflies, thus reducing the need for pesticides.
Technical Abstract: Silverleaf whitefly (Bemisia tabaci biotype B) has caused significant damage, year after year, and can be considered one of the major pests responsible for the increase in use of insecticides in cotton. This research aimed to evaluate the biology and preference for oviposition and feeding of Bemisia tabaci biotype B in wild cotton genotypes. The experiments were conducted at the Experimental Farm of the Mato Grosso do Sul State University, Cassilândia-MS, from March 24th to May 13th, 2017. The treatments were composed of the following genotypes, APGO 01 and APGO 02 (Gossypium barbadense), BRS 269 (standard cultivar/control), TEX 1116 and TEX 1964 (G. hirsutum) and G. arboreum. The infestations were carried out on plants 25 days after emergence in a no-choice test and at 42 days for the free-choice test. The number of eggs per leaf, the density of trichomes, the viability of nymphs and the duration of the juvenile phases, in days, on the youngest leaf in the upper third of the plant were evaluated. Low preference for oviposition of B. tabaci biotype B on genotypes APGO 01 and APGO 02 was observed in the no-choice test. A positive correlation was observed between the density of trichomes and the preference of oviposition. A negative effect of glandular trichomes and preference for oviposition was observed for APGO 02. Resistance by antibiosis and / or non-preference for feeding in the genotypes APGO 01, APGO 02 and G. arboreum were observed for prolonging the development of the insect in the juvenile/nymph phase.