Populational Fluctuation and Distribution of Epitrix spp. Foudras (Coleoptera: Chrysomelidae) in the Organic Tobacco Management in Santa Cruz do Sul, RS, Brazil

摘要

Among the chrysomelids, some species are considered agricultural pests, such as some representatives of style="font-family:Verdana;">Epitrix style="font-family:Verdana;"> spp. Popularly known as tobacco flea, these beetles cause damage to tobacco ( style="font-family:Verdana;">Nicotiana tabacum style="font-family:Verdana;"> L.) by feeding on the leaf surface, causing injuries, reducing productivity and the final quality of the product to be marketed. However, studies of the biology and interactions of these individuals with the environment become essential in order to develop effective and sustainable control measures. The objective of this study was to analyze the distribution and population fluctuation of style="font-family:Verdana;">Epitrix style="font-family:Verdana;"> spp., as well as to evaluate the possible influence of temperature, rainfall and adjacent vegetation on the population dynamics of this beetle in organic tobacco growing in the municipality of Santa Cruz of the South, RS. The collections were carried out weekly during the 2011/2012 harvest, using Malaise and Pit-fall traps, distributed in four points along three lines. A total of 1584 individuals belonging to the genus style="font-family:Verdana;">Epitrix style="font-family:Verdana;"> were collected, and their greatest abundance was observed in late January and early February 2012 due to climatic factors, such as rainfall and temperature, favorable to the development of specimens and the tobacco leaf harvesting reduced the availability of food and conditioned a greater movement of these individuals in the crop. The results presented here are of great importance for deciding the best methodology for controlling the smoke flea, as well as knowing the influence of abiotic factors on the behavior of these organisms in the field.