Population behavior and sex ratio of Bactericera cockerelli (Sulc) (Hemiptera:Triozaidae) on potato (Solanum tuberosum L.)

Abstract

One of the main plagues in the potato crop (Solanum tuberosum L.) is Bactericera cockerelli being a vector of the diseases zebra chip and purple top. The objective of the research was to determine the population behavior and sex ratio of B. cockerelli, its relationship with the phenological phases of the potato crop and vertical distribution. Sex ratio was related to climatic factors. Three plots (500 m²) were established and plants were sampled by strata and in each phenological phase of the crop. Adults were captured for sexing to determine the type of reproduction. All data were correlated with population and climatic data, evaluated with the Anova test and Pearson correlation. The results showed that minimum temperatures and rainfall have an effect on the populations of B. cockerelli. In the distribution of the populations in the plant by strata, it was determined that the adults did not present significant differences (p = 0.2333), they can be found in any of the three strata, while the nymphs did present significant differences by stratum, showing a preference for the middle stratum (p = 0.0182). These results will allow establishing control strategies taking into account that most of the nymphs will be located in the middle stratum and the adults in any part of the plant, as well as considering the climatic factors that mostly affect paratrioza populations. The sex ratio was 48 % females and 52 % males and the type of reproduction was sexual.