GALL MITES. 



Sub-Family PHYTOPTIDyE. (Gall Mites.) 



This is a most abnormal and exceptional group, which has 

 puzzled and continues to puzzle entomologists more than have 

 any of the other mites, difficult as it is to determine the true 

 affinities and place of some of them. We think that this is its 

 proper place, but we speak with bated breath and becoming diffi- 

 dence. We shall presently explain the different positions that 

 have been or may be assigned to them, with the reasons for or 

 against their adoption. But we must first let the reader know 

 what the Phytopti are, and something about their peculiarities and 

 mode of life. 



Most of our readers must have noticed curious galls, excres- 

 cences or growths, upon the leaves or other parts of various plants. 

 These are produced by various kinds of insects; and the dis- 

 covery of the species of insect by which they are produced has 

 occupied the attention of entomologists ever since entomology 

 became a science. Many of themx are not difficult of determina- 

 tion, in this respect, that, if they are cut open, a single grub is 

 usually found to be inhabiting the gall which could be referred 

 to the particular family with whose larvae the tenant corresponded^ 

 these being all pretty well known ; or, to make perfectly sure, the 

 perfect insect could be bred from the gall. The larvae in such 

 galls are usually solitary ; or, when the gall contains more than one 

 individual, each individual occupies a separate cell in the gall. 

 There are some growths, however, which look like galls, and 

 some which look like dust or powder, the origin of which has 

 puzzled naturalists, because, whether shaped like a gall or not, 

 no grub was to be found; and, in its absence, they jumped 

 to the conclusion that they were cryptogamic growths or minute 

 fungi. This idea once received, botanists took them under 

 their charge and described the various kinds under the name 

 of Erineum, etc. Subsequent discoveries, however, have shown 



