COXIELLA POPILLIAE, N. SP., A RICKETTSIA CAUSING BLUE DISEASE OF JAPANESE BEETLE LARVAE

Blue disease, a fatal infection of larvae of the Japanese beetle, Popillia japonica, was first noted in larvae collected by P. S. Clarke at Nottingham, Pennsylvania, in October 1940. It has since been encountered in larvae from several other widely separated points. At some of these localities only a few infected larvae were found, whereas at others fairly large numbers of diseased individuals were found repeatedly in surveys of the areas. While most of the recoveries of the disease have been in Japanese beetle larvae, the disease has also been diagnosed in larvae of. two other scarabaeid species, Phyllophaga anxia and P. ephilida. This would suggest that still other insect species may be affected. The disease has been recovered in only a small proportion of the sites examined by field surveys, but in areas where the disease was found as many as 17 out of 50 larvae recovered in individual diggings were affected. Therefore, blue disease may have potentialities as an important insect control agency. This paper presents a summary of the studies that have been made to date at the Moores