THE CANADIAN ENTOMOLOGIST. 153 



If these observers ha\e been correct in interpreting what they saw, we 

 must admit that different spet'ies of tlie group possess different food habits, 

 a point which should be admitted only on the strictest testimony, for while 

 instances do occur where certain sjjccies in a distinct grouj) differ in habits 

 from the others, it is of rare occurrence — a fact more fully appreciated 

 when we consider the intimate relations between structure, whereby groups 

 are defined, and habit, these having naturally a mutual correspondence, 

 whether we consider the habit necessitated by the structure or the struc- 

 ture a result of i)rogenitary habit. 



So far as the anatomy is concerned, it seems to me much in favor of a 

 vegetable diet. Carnivorous insects as a rule are furnished with strong 

 mouth parts, and are able to thrust them forward from the head, even if 

 their normal position is otherwise. In Thripidw the mandibles are 

 slender, styliform, and apparently weak and poorly adapted to the capture 

 of prey, and the mouth parts pass backward under the prothorax. Owing 

 to the minuteness of the insects positive observations upon their methods 

 of feeding are difficult. I have \\atched them with a lens, and noticed 

 that they thrust the mouth i)arts down upon the surface of a petal or other 

 portion of the blossom, much as a tiy does in sucking up sweets, but have 

 never been able to see them actually puncture the tissue. I have noticed 

 them in apple blossoms, however, where the petals were unopened and no 

 other insects were present, and in these blossoms 80 per cent, were injured 

 by punctures upon the styles and other parts, but particularly the styles, 

 and all the evidence pointed to the Thrips as the cause of injury. Should 

 the observations of other entomologists prove this to be a general habit, it 

 has great economic importance, and shows that insects may have a far 

 different influence than assisting in fertilization of plants, which we have 

 come to consider as one of their benefactions, for whereas much has been 

 written concerning the fertilization of plants by insects, comparatively 

 little has been written upon the prevention of fertilization which they may 

 cause. 



Although I have observed Thrips in many situations beside the blos- 

 soms of apple, cherry and plum, as well as in blossoms of catal})a, aspar- 

 agus, clover, potato, timothy grass, and a number of ornamental plants, I 

 have never found evidence of their attacking insects. At one time I found 

 a single individual near a colony of Aphis maidis, but nothing to indicate 

 that it was attacking the lice. 



The observations of Walsh and Riley must certainly be considered 



