Hacteria' Disease of the Squash-hug. 361 



cage four grasshoppers were brushed externally with the 

 body fluid from diseased squash-bugs, and in another 

 cage the infection material was from a pure culture of 

 the bacillus ten days old. In the course of ten days two 

 hoppers were dead in each cage, as also in the check lot. 

 With the hoppers from the inoculated cages, isolation 

 cultures, growth on gelatine, and microscopic characters 

 indicated that the bacillus was that of the squash-bug 

 disease; but the only attempt made to inoculate squash- 

 bugs from these dead grasshoppers gave very slight re- 

 sult. 



INFECTION EXPERIMENTS WITH GEUBS AND CATERPILLARS. 



No true bacterial disease of Heraiptera has previously 

 been reported, and, with few exceptions, these diseases 

 have been confined, as far as known, to lepidopterous 

 and coleopterous insects. In this connection it is to be 

 remembered that Bacillus insectorum {Micr^ococcus insec- 

 torum Burrill) of the chinch-bug was finally located as a 

 "normal" form, — one of various normal forms common 

 in the coecal appendages of the higher Hemiptera, — and 

 it consequently cannot be termed pathogenic with our 

 present knowledge of the subject. These facts make ex- 

 periments with the squash-bug bacillus on grubs of 

 beetles and on caterpillars greatly to be desired. 



White grubs, probably larvae of Lachnosterna fusca, 

 were inoculated externally both with fluids from diseased 

 insects and with fresh pure cultures; but in no case was 

 there any successful infection. Four grubs were used in 

 each experiment, and they were kept under observation 

 for about three weeks. 



Fall web-worras were also exposed to this disease by 

 touching to their bodies the fluids of diseased squash- 

 bugs, smearing the material over the food leaves, and 

 scattering bits of the diseased bugs about the cage; but 

 the disense took no effect. A few other preliminary ex- 

 periments were attempted, which are briefly summarized 

 below. 



