Spatial Analysis and Population Dynamics of Haplaxius crudus (Hemiptera: Cixiidae) in Coconut Amazon

Abstract

Haplaxius crudus is the primary vector of the phytoplasma that causes the Lethal Yellowing of Coconut, a disease that has become a barrier to the establishment of large coconut plantations in the world. The objective of this study was to determine the spatial distribution pattern and population dynamics of H. crudus adults by correlating them with the abiotic factors, such as temperature and rainfall in commercial dwarf coconut palm plantations. Collection of American palm cixiid was carried out using yellow sticky traps fixed to the abaxial part of the coconut leaves. The sampled plants were georeferenced to obtain the geographic coordinates and geostatistical analysis, besides the planialtimetric survey of the experimental plot for the preparation of the map that shows the topographic conformation of the terrain. Insects were found at the study site throughout the year, showing greater abundance in months when the average monthly temperatures and rainfall were not significant. The climatic factors showed a correlation with the total of insects, positive for the temperature, with 0.733 and negative for the precipitation with -0.606. The spatial distribution of H. crudus displayed an aggregate pattern, explained by the spherical model. The infestation focus occurred in the periphery of the plot, near a Brachiaria humidicola pasture. It was concluded that the infestation of the H. crudus showed a behavior directly related to the local climatic conditions and the aggregate spatial distribution explained by the spherical model, therefore, forming shrubs with a radius of 154 to 190 m, with areas of influence between 7.45 and 17.80 ha, which coincide with the lower part of the terrain.