Fenología de agallas, tendencia poblacional y daños causados por Ophelimus migdanorum y su parasitoide Closterocerus chamaeleon en árboles de Eucalyptus globulus en dos áreas periurbanas de Bogotá con parámetros de precipitación diferentes

Abstract

The gall wasp Ophelimus migdanorum, represents a phytosanitary risk for several eucalyptus species established in Colombia. The biological development and the damage it causes could be conditioned by the climate and, in the tropical Andes, especially by precipitation. We studied gall phenology, population fluctuation, and leaf damage caused by O. migdanorum and its parasitoid C. chamaeleon over five months at two sites with contrasting rainfall in peri-urban areas of Bogotá, Colombia. Gall phenology and foliar damage estimation were evaluated on ten trees per site for six months. We evaluated gall phenology through the characterization of the size, the color of the gills, and the stage of development of the wasps, and the second, based on the affected leaf area and the density of the galls on the leaf blade. Likewise, the individuals found in five attractive traps in each site were quantified biweekly to record the population fluctuation. The effect of precipitation on wasp frequency and gall density between sites and sampling dates was compared with the Chi2 test, while the relationship with precipitation was evaluated with the Kruskal-Wallis test. Only females of the gall wasp and its parasitoid were observed during the evaluation, which showed multivoltine behavior. Six developmental stages of the galls were differentiated, each having typical coloration. The size of the galls, the frequency of the development stages, the population trend, and foliar damage were favored by drier microclimates. A general trend indicates more abundance of the parasitoid C. chamaeleon than O. migdanorum. Our study indicates that in places with more rainy microclimates, there likely be less damaging effect of O. migdanorum on E. globulus.