Geographic pattern of morphological variation of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), using multivariate morphometry

Abstract

The coconut mite, Aceria guerreronis Keifer, has become one of the most important pests of coconut in the Americas and Africa and recently in Southeast Asia. Despite the great economic importance of this mite, there is a lack of information on its origin and invasion history that are important to guide the search of biological control agents as well as the adoption of quarantine procedures. This study evaluates morphometric variation among A. guerreronis populations throughout its occurrence area, relates this variation with historical sequence of records, looking for information on its biogeography. Samples of 27 populations from the Americas, Africa and Asia were analysed using Principal Component Analysis and Canonical Discriminant Analysis. Results showed significant morphometric variability of A. uerreronis throughout its distribution area, with a high variability among American populations and otherwise a high similarity among African and Asian populations. The geographic pattern of variation of mite populations observed supports the hypothesis that A. guerreronis originated in the Americas and was introduced into Africa and Asia. Some inferences related to taxonomy of Eriophyoidea mites were included.Keywords: principal component analysis, canonical discriminant analysis, exotic invasive species, Cocos nucifera, biogeography. Padrão geográfico de variação morfológica do ácaro do coqueiro, Aceria guerreronisKeifer (Acari: Eriophyidae), utilizando morfometria multivariada Despite the great economic importance of the coconut mite, there is a lack of information on basic aspects. The place of origin of the coconut mite and the sources of recent invasions are unknown. The major perspectives for management and control of A. guerreronis involve the utilisation of biological control agents and the knowledge about its origin place which are important to determine priority areas to be considered in the search for effective enemies (Moraes and Zacarias, 2002). Information on the sources of A. guerreronis invading new areas can guide adoption of quarantine measures.Studies of morphological and genetic variability among A. guerreronis populations from different countries and continents can provide some of the required information. Multivariate morphometry is a useful tool in evolutive biology to test historic phylogenetic hypotheses, to detect variation in quantitative characters and to evaluate patterns of phenetic relationship (Reis, 1988). It may also provide feedback information on expected characters variability within and between populations and contribute to the taxonomic knowledge of the studied group.The present study intended to answer two main questions: 1) Is there morphological variation of taxonomic

Morphological, molecular and cross-breeding analysis of geographic populations of coconut-mite associated predatory mites identified as Neoseiulus baraki: evidence for cryptic species?

“…Hence, we carried out a multidisciplinary approach to clarify the taxonomic status of these populations by using three methods. First, we used a morphometric approach using multivariate analysis, a method applied successfully to solve taxonomic problems in mites (Boyce et al 1990;Tixier et al 2003Tixier et al , 2004Tixier et al , 2006bTixier et al , 2008aAkimov et al 2003;Klimov et al 2004;Navia et al 2009;Vidović et al 2010;Okassa et al 2010). Second, we sequenced part of the mitochondrial cytochrome oxidase subunit I (COI), as widely used for phylogenetic studies of Phytoseiidae and Tetranychidae (Navajas et al 1996(Navajas et al , 1998Toda et al 2000;Hinomoto et al 2001Hinomoto et al , 2007Navajas and Boursot 2003;Ramadan et al 2004;Klimov et al 2004;Tixier et al 2006a, b;Yang et al 2010;Ros and Breeuwer 2010).…”

Phytophagous mites (Acari: Eriophyoidea) recorded from Svalbard, including the description of a new species

“…Thus, it is possible that some lines on the prodorsal shield of A. saxifragae may have been missed in the initial descriptions. Quantitative morphological traits can also vary in eriophyoid mites, and this variation may exist between populations separated geographically or by host association (e.g., Navia et al 2009;Shen et al 2014). Thus, the observed differences in the length of sc setae and the number of empodial rays may reflect intraspecies variation.…”

Biological Studies and Pest Management of Phytophagous Mites in South America

“…The coconut mite is an invasive mite pest that has been disseminated and established rapidly in main coconut (C. nucifera) production areas (Návia et al 2009) causing copra yield reductions, premature dropping of fruit (Moore & Howard 1996). A. guerreronis is mostly found in the meristematic region of fruit, under the perianth (Fernando et al 2003).…”