The role of dung beetles in the epidemiology of helminth parasites of animals in Egypt

Twelve species of scarabaeid and one tenebrionid beetles were captured from various semidesert or desert areas in Egypt where they were abundant around dung. They were kept in the laboratory for various periods before being dissected. Guinea-pigs, rabbits and dogs were inoculated with encysted larvae that were recovered. It was evident that 72.4 to 100% of Scarabaeus puncticollis, 80% of S. sacer, 60% of S. cornifrons, 58% of Bubas bubalus and 17.35% of Onitis alexis were harbouring encysted larvae of Spirocerca lupi in the coelomic cavity. B. bulbulus also harboured another unidentified nematode species. Aphodius lividus, A. nitidulus, A. contractus, Copris hispanus, Heliocopris gigas, H. isidis, Oniticellus pallens and Alphitobius diaperinus were all free of encysted larvae, but some carried free-living nematode larvae or suspected parasites. Puppies inoculated with larvae from S. puncticollis, S. sacer or S. cornifrons developed nodules on the aorta; each nodule contained a Spirocerca lupi larva. Inoculated guinea pigs and rabbits did not become infected. ADDITIONAL ABSTRACT: An investigation on the role of dung beetles as vectors of parasitic nematodes in mammals was carried out in semidesert and desert areas of Egypt on 12 species of scarabaeids and 1 tenebrionid. Scarabaeus puncticollis Latr., S. sacer L., S. cristatus (F) (cornifrons (Lap.)), Bubas bubalus (Ol.) and Onitis alexis Klug acted as effective intermediate hosts for Spirocerca lupi, a parasite of dogs. They carried the infective stage of the parasite as encysted larvae in their coelomic cavity. The other species of beetles tested were negative.