BACILLUS AND SERRATIA SPECIES FOR SCARAB CONTROL

Few microorganisms are commercially available for use against white grubs (larvae of Scarabaeidae). Entomopathogenic bacteria, particularly Bacillus popilliae, have been used the longest for white grub suppression. Other bacteria, namely B. thuringiensis and Serratia spp. offer promise for future control. This paper examines two genera of bacteria (Bacillus and Serratia) from the historical and current perspective. Bacillus popilliae, the first microbial control agent registered in the United States, has a long history of use in suppressing populations of the Japanese beetle, Popillia japonica. However lack of in vitro production and the slow and sporadic nature of its activity, severely limits its utilization. B. thuringiensis, the most widely used microbial pesticide, has not been used for scarab, control However, strains with scarab activity have recently been discovered Scarab larvae have been collected in the United States with signs and symptoms similar to those characteristic of amber disease (caused by Serratia entomophila) in the New Zealand grass grub, Costelytra zealandica. A total of 147 bacteria have been obtained from the digestive tracts of larvae of the Japanese beetle and masked chafers, Cyclocephala spp., as well as from larvae and soil collected in Japan and China. Seventy five of these have been identified as Serratia spp. Most (40) of the remaining bacteria are in the genus Enterobacter. A majority of the bacteria (73) and of the Serratia (38) came from P. japonica.