660 EXPERIMENT STATION" RECORD. 



pillars in 12 separate localities. By taking the average of these results it was 

 found that the total number of apparently living eggs had been decreased by 

 introduction of the artificially developed flacherie to about 14 per cent. 



The " experiments prove conclusively that flacherie has an injurious influence 

 upon the prosperity of the gipsy moth caterpillars, this influence varying 

 according to the manner and time of the appearance of the disease. There 

 was no difference noticed in the progress of the wilt which broke out naturally 

 and that of the artificially developed flacherie. The latter, however, is prob- 

 ably the more important factor, for with its help we may be able to introduce 

 the disease among caterpillars of localities in which the wilt, perhaps, would 

 not make its appearance naturally. ... In selecting the localities in which 

 the disease is to be introduced it is unimportant whether the caterpillars of the 

 gipsy moth are present in large or small numbers. . . . Wherever the naturally 

 as well as the artificially developed flacherie occurs the female caterpillars will 

 always succumb to it more readily than the male." 



Studies on the wilt disease, or *' fl.acherie " of the gipsy moth, R. W. 

 Glaseb and J. W. Chapman (Science, n. ser., S6 {1912), No. 920, pp. 219-22.',).— 

 The authors, who have been engaged for several months in the study of the 

 cause and nature of the wilt disease of gipsy moth caterpillars, have found 

 polyhedral bodies clustered about their tracheae analogous to those which have 

 been found in the silkworm and nonne {Lymantria monacha) caterpillars. 

 These bodies have a very high refractive index and resist all stains with the 

 exception of iodin, in which they take on a uniform tint. By using a high mag- 

 nification small wriggling organisms were observed in the fat cells and other 

 cells at such times as the polyhedral bodies were clustered around the tracheae. 

 " These moving organisms were stained and found to be bacteria. From this 

 time on we pursued the work along bacteriological lines and we believe have 

 been able to demonstrate the etiological connection of these bacteria with the 

 disease." They were found in great numbers in all parts of the intestine and 

 in many caterpillars appeared to be in the act of perforating its walls. " The 

 fat cells seem to be particularly liable to attack, which probably accounts for 

 the saponified nature of the fat of sick caterpillars. . . . The organism in 

 question is very small, having a diameter of only 0.51 to 0.85 fi. . . . It re- 

 sembles the pneumococcus very closely except that it is motile, progressing in 

 a gyrating manner. For this reason and because it seems to be an unde- 

 scribetl form, we have named it Gyrococcus." 



In inoculation experiments 10 caterpillars out of 12 inoculated in the proleg 

 succumbed to the disease. Two out of the 10 died in the pupal stage, while of 

 the 2 surviving 1 was still in the pupal stage at the time of writing and 1 had 

 emerged. Ten of the 12 inoculated in the dorsal vessel died and the remaining 

 2 were still pupae. All of the deaths are said to have been tyi:)ical of flacherie. 

 The 2 lots used for feeding experiments all died without a single exception. 

 In order to exclude the possibility of having inoculated an ultravisible virus 

 together with the Gyrococcus. a large number of caterpillars were prepared 

 (blood tested) for inoculation and feeding with material passed through the 

 Berkefeld filter. These all survived while those treated in the same manner 

 with the unfiltered culture all died. 



"The disease is probably sin-ead in nature by the juices of disintegrated 

 caterpillars flowing over the leaves which are later eaten by others. We have 

 found Gyrococcus in the feces, and the fact that such excretions are washed 

 over the leaves by rain seems to show that the disease may also be spread in 

 this manner. What economic value the flacherie disease may have in com- 

 bating the gipsy moth, we are not prepared at present to say. We have no 



