22 THE CANADIAN ENTOMOLOGIST. 



Recently we devoted an evening to the microscopic examination of 

 these egg clusters, having previously collected a number of them for this 

 purpose. In many instances it was found that the glutinous coating which 

 covers the clusters was imperfect, that a piece here and there had dis- 

 appeared, leaving the eggs bare, and in some cases patches of the exposed 

 eggs were empty. To ascertain, if possible, the cause of this, some of 

 such affected clusters were cut into, when they were found to be colonized 

 by mites. The outside gummy matter is of a sufficiently porous texture 

 to afford abundant shelter to these little friends, who had evidently eaten 

 into the eggs and devoured the young larvae, and had also consumed the 

 missing portions of the gummy covering. In the range of a single section 

 of an egg mass some eggs would be found inhabited by the larva? unin- 

 jured, while out of others would proceed several (in some cases as many 

 as five) active little mites, who, when thus disturbed, would run in and 

 out of their dwelling places, and keep up a peculiar drumming motion with 

 their tiny antenna?. We found what were probably two different forms 

 of the same species of mite, the one so small that four or five or more 

 could find ample room and to spare within a single egg-shell, and these 

 were very active and nearly transparent ; the other much larger, of a pale 

 red color, with bright red eyes, sluggish in its movements and only one in 

 each egg ; indeed, one specimen nearly filled an egg. On the outside 

 of some of the clusters were found some round pale red eggs, which we 

 presumed were the eggs of these mites. From their structure the mites 

 appeared to belong to the genus Trombidiuni. 



We have submitted examples of these insects and egg clusters to Dr. 

 H. Hagen, of Cambridge, Mass., and he has kindly and promptly 

 examined them and confirmed the correctness of the views above 

 advanced. Dr. Hagen says that he found the supposed mite eggs both empty 

 and full of the small, active, white creatures, that these active specimens 

 are doubtless the young of the larger red form, which latter is .04 inch 

 long, and he is of opinion that it belongs to Trombidiuni. He further 

 says : " In the whole European literature I have not been able to find 

 anything about Acari eating eggs, so the fact seems new and is very 

 important." 



On almost every cluster we have examined we have found more or 

 less of these mites, and if they are thus generally distributed over the 

 whole district inhabited by the moths, they must prove a most efficient 

 check to the undue multiplication of Clisiocampa. In No. 8 of our last 



