Genetic variability of the nematode Metaparasitylenchus hypothenemi (Tylenchida: Allantonematidae), natural parasite of the coffee berry borer (Coleoptera: Curculionidae: Scolytinae), using COI sequences

The nematode Metaparasitylenchus hypothenemi (Poinar) (Tylenchida: Allantonematidae) is a parasite of the coffee berry borer (Hypothenemus hampei), one of the most significant pests affecting coffee crops. This study aimed to analyze the genetic variation of M. hypothenemi using the mitochondrial cytochrome oxidase subunit I (COI) gene. Reproductive females of M. hypothenemi were extracted from parasitized wild coffee berry borers for DNA extraction, amplification, and sequencing. Phylogenetic analyses revealed 2 well-differentiated lineages and 6 haplotypes distributed across 18 populations along a 100 km transect. Global genetic diversity was moderate (Hd = 0.52 ± 0.06), with a dominant haplotype present in 16 populations and others being representative or geographically isolated. Populations showed high genetic differentiation and restricted gene flow. These findings confirm the utility of the COI gene for analyzing the genetic variation of M. hypothenemi and provide a molecular basis for future studies on its biology and management.