CHARACTERIZATION AND MORPHOLOGICAL CLASSIFICATION OF Varroa AND ITS SPATIAL DISTRIBUTION, IN COMMERCIAL HIVES OF TABASCO STATE, MEXICO

Abstract

Background. Varroa destructor is considered the main pest of Apis mellifera, its morphological characteristics, prevalence and level of infestation are affected by geographical and ecosystem conditions and the management of the hives. Objective. Morphologically characterize and classify Varroa populations in A. mellifera hives in Tabasco. Methodology. Samples of worker bees were obtained from 29 apiaries (108 hives) belonging to the 5 subregions of the state. The location of the apiaries was georeferenced, in UTM coordinates. Subsequently, 501 Varroa specimens were extracted using the shaking and washing method, which were placed individually on slides for morphometry and digitization. With the help of a Karl Zeiss stereomicroscope, Mod. Stemi 305 Trino, with integrated digital camera Mod. Axiocam 105 color (40X), the following were measured in millimeters (mm): width of the dorsal shield or body (AED), length of the dorsal shield or body (LED), genital shield width (AEG), genital shield length (LEG), anal shield width (AEA) and anal shield length (LEA). Analysis of variance (ANOVA) and comparisons of means (Tukey; P<0.05; 95% confidence), Pearson correlation analysis (r) and multivariate analysis were performed using cluster analysis. Results. The Varroa sp populations analyzed in the state of Tabasco are classified as the V. destructor species, according to the morphometric criteria established by Anderson and Trueman (2000). Significant differences were found between the subregions in five variables, except AEA (P=0.193), likewise, significant intrasubregion differences were found in four variables, between municipalities of the same subregion (intra subregion) in four morphological variables except LED (P=0.229) and ACA (P=0.229). Implications. The identification of morphological variability at the local level can help develop more effective control strategies, adapted to the specific conditions of each region. It is necessary to continue investigating other factors that may influence the morphology of Varroa, such as beekeeping practices, host bee genetics, and climatic conditions. Conclusions. The cluster analysis indicated that morphological variability between populations is small, and that specimens from different municipalities and subregions can share similar morphometric characteristics, without following a defined spatial pattern.

Keywords

• ácaros
• apicultura
• morfometría
• varroosis.