Deslocamento vertical de nematóides entomopatogênicos (Rhabditida: Heterorhabditidae) na busca por Dysmicoccus texensis (Tinsley) (Hemiptera: Pseudococcidae) em laboratório e casa-de-vegetação

Abstract

Many factors must be considered in evaluating the efficiency of an entomopathogen in the control of an insect pest. With regards to entomopathogenic nematodes, in addition to their pathogenicity and virulence, it is important to know the ability to search the host, which is directly linked with its efficiency. The objective of this study was to evaluate the vertical displacement of entomopathogenic nematodes (Heterorhabditis) to control the coffee root scale Dysmicoccus texensis (Tinsley). A test was conducted in a sand column of 5 cm depth under laboratory conditions, using a randomized design, with the strains CCA and JPM3 being applied in aqueous suspension at the top of the column in three concentrations (50, 100 and 500 IJs/insect), with evaluation of mortality after 5 days. It was also conducted an experiment in a 2x2x6 factorial design, at greenhouse conditions with a soil column of 30 cm depth, composed of six extracts of 5 cm. Two nematode strains (CCA and JPM3) and two methods of application (infected cadaver and aqueous suspension) were evaluated at different depths. There was no difference between the strains evaluated in the laboratory experiment, and both reached values of 92% mortality. In the experiment conducted at the greenhouse, it was observed that JPM3 was more efficient than CCA, at the two methods of application assessed. Regarding With application methods, aqueous suspension showed better results for both strains and JPM3 was the best treatment in almost all depths evaluated.