14 



In another exjieriment ants, which had been previously placed 

 in water milky with conidia, were allowed to run in a bottle 

 of earth. Two of these were taken out at intervals and tested 

 in the same manner as was described in the experiment just 

 preceding. Positive results were obtained for five hours and 

 sixteen minutes after placing the ants into the bottle, at which 

 time the last test was made. The authors are led to the conclu- 

 sion that ''this shows that ants may retain the spores long 

 enough to carry them some distance." Here again it would be 

 interesting to have the quantitative results and to know 

 whether the number of spores diminished gradually from the 

 first to the last test. 



There are a number of insects known to eat the pustules 

 of the chestnut blight fungus (9), but the most common of 

 these in Pennsylvania is the beetle, Leptostylus macula Say. 

 In order to determine whether this habit of eating the spores is 

 beneficial, the following tests have been reported (2 and 9) : 

 A number of the beetles were fed on pustles for five days, after 

 which their viscera were removed with sterile needles, put 

 into melted potato agar and plated out. Bacteria developed 

 in the plates but no fungous colonies were obtained. Other 

 beetles of this species were fed on ascosporic stromata for a 

 day and "caused to excrete the fecal material by a light pres- 

 sure on the abdomen with the forceps. The fecal material was 

 caught in potato agar tubes and plated out with the same 

 negative results as in the preceding experiment. These ex- 

 periments indicate that the insect may really be beneficial," 

 (2) since the spores are not passed out in the excreta to 

 germinate on other hosts. The present writers agree that this 

 beetle is beneficial in so far as it destroys the spores and 

 pustules, but the point seems to have been overlooked that a 

 beetle of this habit has excellent opportunities for collecting 

 and carrying away a large number of spores on its feet and 

 body, and that new infections may be caused as a result of the 

 rattling off of these spores. 



The writers above referred to (2) came to the general conclu- 

 sion that "insects are not important agents in the spread of 

 the blight, except in so far as they produce wounds by which 

 the spores may enter." 



