The invention is to methods of gene silencing in arthropods using dsRNA. The method is include contacting the arthropod with, and/or directly feeding the arthropod, the dsRNA to the arthropods to deliver the dsRNA to arthropod tissues. It is envisaged that the methods of the invention will have use in determining the biological function of genes in arthropods. Methods of pest control of arthropods, and of protecting arthropods against parasites and predators are provided. Transgenic arthropods expressing dsRNA molecules are also provided by the present invention.