Biologia e tabela de vida ecológica da mosca-branca Bemisia tabaci (Gennadius) biótipo B (Hemiptera: Aleyrodidae) em meloeiro

Abstract

The whitefly, Bemisia tabaci biotype B (Hemiptera: Aleyrodidae), is considered one of the most important pest species of melon (Cucumis melo L.), in several regions of the world. Information on bioecological aspects of the whitefly in melon is extremely important for the knowledge of its population dynamics and, hence, for supporting integrated pest management program of this pest. Thus, the objectives of this study were: i) To determine the duration and survival of the immature stages of the whitefly, in a semiarid environment; and ii) To know the key mortality factors that act on the whitefly population through ecological life table, in melon. Melon plants infested with B. tabaci eggs were placed in the field to assess the biological characteristics of the immature stages, and to elaborate ecological life tables to quantify the mortality factors. The whitefly cycle had a shorter duration during in the dry period, with an average duration of the egg to adult phase of 19.4 ± 0.23 days. The survival of the whitefly was similar in the dry and rainy periods for egg stage (87.8% and 87.9%), nymphal stage (92.8% and 96.7%), and for whole developmental from egg to adult eclosion (80.6% and 84.7%). Displacement (r² = 0.93) and parasitism (r2 = 0.87) acted as key mortality factors and highly correlated to generational mortality, especially in the fourth instar. We can conclude that the dry period favored the development of B. tabaci in our studied area, immature displacement and parasitism acted as mortality factors showing potential for reducing the whitefly population under the conditions of the study.