Please refer also to the following link for details on this group:
Scarabaeidae = Link 1
This large family is primarily phytophagous, the larvae living in soil or dung and feeding extensively on roots and decaying vegetable matter. Adults attack foliage, blossoms and fruit of many plants. However, the genus Trox has a number of species which have developed the carnivorous habit. Trox suberosus F. is a predator on locust eggs, Schistocera paranensis Burm. in Argentina (Hayward 1936). When conditions are favorable, the grubs destroy almost 100% of the eggs, and it was suggested that this predator be used for biological control. However, Denier (1936) could not get caged individuals to feed on any living stage of the locust, but only on those that were already dead and partially decomposed. The presence of large numbers of beetles at the egg beds was attributed to the presence there of many dead locusts.
Dung beetles are of importance in the natural control of certain pests, such as Diptera that breed in animal dung when the elimination of sufficient dung to preclude fly breeding is not always possible. A number of species, mainly Copris, Canthon, Aphodius, Phanaeus and Onthophagus, etc. have been imported to Hawaii, Australia and Puerto Rico to aid in control of horn fly and face fly., with establishment in many cases. However, Legner & Warkentin (1991) show data where the activity of Onthophagus gazella interfered with the breeding of staphylinid predators, and probably precluded the establishment of more effective predators in this family (see section on Medical/Veterinary pests).