Morphological and Molecular Characterization of Panonychus ulmi and P. citri on Apple and Citrus Orchards

Abstract

Spider mites belonging to the genus Panonychus are economically important pests causing significant damage to fruit crops through feeding injury, reduced photosynthetic activity, and decline in fruit quality. The present study focused on the morphological and molecular characterization of Panonychus ulmi and Panonychus citri populations collected from apple and citrus orchards to improve species identification and understand their genetic variability. Mite specimens were collected from infested orchards and examined using standard taxonomic methods based on morphological traits including body shape, dorsal setae arrangement, coloration, and leg chaetotaxy. Due to close morphological similarities between species, molecular characterization was conducted using mitochondrial cytochrome oxidase I (mtCOI) gene sequencing for accurate identification and phylogenetic assessment. DNA amplification and sequence analysis confirmed the occurrence of both P. ulmi and P. citri in the studied orchards, with clear genetic differentiation between species. Phylogenetic analysis revealed moderate genetic variability among populations from different host plants and geographical locations, suggesting possible host-associated adaptation and environmental influence on population structure. Morphological observations were consistent with molecular findings, supporting the reliability of integrated identification approaches for spider mite taxonomy. The combined use of morphological and molecular techniques provided comprehensive insights into species diversity and genetic relationships within Panonychus populations. The findings contribute valuable information for monitoring mite infestations and developing targeted integrated pest management strategies aimed at minimizing crop losses in apple and citrus production systems.