This application provides and discloses anti-parasitic, anti-pest or insecticidal nucleic acid molecules and their calmodulin target genes for the control of arthropod parasites and pests. In particular, this application provides and discloses insecticidal nucleic acid molecules that target Varroa calmodulin gene sequences. This application further provides methods and compositions for the control and treatment of parasites and pests in Apis mellifera (honey bee) hives.