Resumo

CERNA-CHAVEZ, E et al. Variation in susceptibility to insecticides in Bemisia tabaci biotype B fed on different hosts. Phyton (B. Aires) [online]. 2016, vol.85, n.2, pp.256-261. ISSN 1851-5657.

Bemisia tabaci (Gennaadius) biotype B is one of the most important pests due to the number of hosts and economic losses it produces. Its control is based on the application of chemicals, which has led to resistance problems. However, the host may also influence the induction of resistance to pesticides. Therefore, the present study evaluated the susceptibility of populations of B. tabaci biotype B developed indifferent hosts to three insecticides belonging to different toxicological groups. Bemisia tabaci biotype B populations were collected and reared in six different hosts (three crops and three associated weeds: Solanum lycopersicum, Solanum nigrum, Phaseolus vulgaris, Melampodium divaricatum, Cucurbita spp. and Heliotropium angiospermun) in the state of Chiapas, Mexico. By using the dipping bioassay method with nymphs five- to eight-days-old, the CL₅₀ was determined. The higher values of bifenthrin were recorded on M. divaricatum and S. nigrum with 278.74 and 177.76 ppm, respectively. For imidacloprid, S. lycopersicum and S. nigrum recorded 179.59 and 168.59 ppm, respectively. Finally for endosulfan, M. divaricatum andH. angiospermun registered values of 134.57 and 156.52 ppm, respectively. Therefore, the host affected the tolerance of Bemisia tabaci biotype B to insecticides, primarily because of the induced resistance of each of the plant species that served as hosts, providing the ability to detoxify the various pesticides by using enzymes.

Palavras-chave : Whitefly; Insecticide resistance; Host.