Assessing the Population Structure of Colorado Potato Beetle Populations in Croatia Using Genetic and Geometric Morphometric Tools

Abstract

The Colorado potato beetle (CPB, Leptinotarsa decemlineata Say) is one of the most successful invasive species worldwide. It has been present in Croatia since 1947, where it has caused significant damage to potato plants and developed resistance to several insecticides. Our study is the first attempt to investigate the population structure of CPBs in Croatia. SNP and GM techniques provided us with data about the population structure of the CPB population. A Bayesian model-based clustering algorithm implemented in STRUCTURE, principal component analysis (PCA), and discriminant analysis of principal components (DAPC) were used to analyze the genetic structure of CPBs. For the morphometric analysis, the hindwing shape of the same CPB individuals was examined using wing venation patterns. We detected the low genetic and phenotypic variabilities of CPB populations and the presence of a single panmictic population in the study area, well adapted to different environmental conditions, indicating high phenotypic plasticity. Due to such exceptional adaptation of the CPB population, it is necessary to implement an area-wide approach in future pest control management.

Wing Shape Variation between Terrestrial and Coastal Populations of the Invasive Box Tree Moth, Cydalima perspectalis, in Croatia

“…This unique wing quality has enabled researchers to delve into essential aspects of insect biology, such as determining population structure in cases where genetic markers may be insufficient [45,46]. Understanding population dynamics is crucial for devising effective pest control strategies [47,48].…”

“…In contrast, the elongated wings observed in coastal populations may indicate a strategy for covering greater distances during dispersal. Such elongated wings are recognized for their aerodynamic advantages and are essential to the migratory movements of insects, as seen in the case of the western corn rootworm [48]. Furthermore, Mikac et al [49] have proposed that these phenotypic differences in wing shape and size bear significant implications for the dispersal of both resistant and nonresistant insects, as wing morphology plays a pivotal role in an insect's dispersal ability [50].…”