Poblaciones de Oligonychus psidium Estebanes y Baker (Acari: Tetranychidae) correlacionadas con aspectos fenológicos del guayabo (Psidium guajava L.)

Plant phenology influences over the insects and mites that live upon them, determining along with other factors their emergence and abundance through the productive cycle of the crop. A study was conducted from January to April on eigth plants grown at Centro Frutícola del Zulia-CORPOZULIA (CENFRUZU), Mara Co., Zulia state, Venezuela to determine the population behavior and distribution of the mite Oligonychus psidium in correlation with the phenological changes of guava plants. The following phenological aspects were monitored two times per month: % vegetative sprouting (%VSP), % blooming (%BLO), % fructification (%FRU), and % developing fruits (%DFR). Simultaneously mites were counted from young leaves, mature leaves and green fruits. Weather conditions were monitored with electronic weather stations, means per each sampling date were provided. Mean mite·plant-1 was higher on mature leaves (84) than on young leaves (46.6) and green developing fruits (3.75). Mite population peaks occurred from January to February 2008 correlated with high %DFR and low %VSP and %BLO. From March to April mite population was low, as well as the %BLO and %FRU. During the first months of the year the populations of O. psidium on mature leaves were correlated with high % DFR, as well as no rain were present during that period, which probably influenced the growth of the fruits. During the season studied the plant phenology could be used to predict the emergence of this pest on guava. La fenologia de las plantas influye sobre los insectos y acaros que viven en ellas lo cual determina, junto con otros factores, su presencia y abundancia a lo largo del ciclo productivo del cultivo. En la copa de ocho plantas de Psidium guajava L. y durante el periodo enero a abril de 2008, se determino en el huerto de guayabos del Centro Fruticola del Zulia- CORPOZULIA (CENFRUZU), municipio Mara, estado Zulia, Venezuela, el comportamiento y distribucion en la planta de las poblaciones del acaro Oligonychus psidium en correlacion con los cambios fenologicos de las plantas. Se monitorearon dos veces al mes los siguientes aspectos fenologicos: % de brotacion vegetativa (%BRO), % de floracion (%FLO), % de fructificacion (%FRU) y % de frutos verdes en crecimiento (%FVC). Se contaron simultaneamente en el laboratorio las poblaciones del acaro O. psidium en hojas jovenes, maduras y frutos verdes. Las condiciones climaticas fueron monitoreadas con estaciones electronicas, presentandose los promedios para