BACILLUS AND SERRATIA SPECIES FOR SCARAB CONTROL

Few microorganisms are commercially available for use against white gr ubs (larvae of Scarabaeidae). Entomopathogenic bacteria, particularly Bacillus popilliae, have been used the longest for white grub suppress ion. Other bacteria, namely B. thuringiensis and Serratia spp. offer p romise for future control. This paper examines two genera of bacteria (Bacillus and Serratia) from the historical and current perspective. B acillus popilliae, the first microbial control agent registered in the United States, has a long history of use in suppressing populations o f the Japanese beetle, Popillia japonica. However lack of in vitro pro duction and the slow and sporadic nature of its activity, severely lim its 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 tho se characteristic of amber disease (caused by Serratia entomophila) in the New Zealand grass grub, Costelytra zealandica. A total of 147 bac teria have been obtained from the digestive tracts of larvae of the Ja panese beetle and masked chafers, Cyclocephala spp., as well as from l arvae and soil collected in Japan and China. Seventy five of these hav e 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.