142 THE CANADIAN ENTOMOLOGIST. 



viewed from above, the apical third of the abdomen appears thicker than 

 the middle segments. 



The antennae have 14 joints, those of the ^ having only 13. The 

 third joint is longer and considerable stouter than' the succeeding ones, 

 and is deeply and obliquely excavated on the outer side, a little beyond 

 the middle. Can this groove be of any use for holding the antennae of the 

 $ ? The object of the present note is to call attention to the habits of 

 the species, and to indicate where it may be looked for ; points upon 

 which little, if anything, is known, I believe. Mr. Ashmead, to whom I 

 sent a pair of these insects, wrote to me in regard to them : — " I know 

 nothing of the habits of the Ibaliincs, excepting what Giraud wrote, " II 

 est tres vraisemblable que sa larve vit parasite de quelque grande 

 Coleoptere lignivore.' " 



The fact that an entomologist so well acquainted with the Cynipidte, 

 and the Hterature treating of them, had to make this admission, induces 

 me to think that the few observations I have been fortunate enough to 

 make (incomplete as they are) will be welcome to students of these 

 insects, and may, perhaps, furnish a clue to enable other entomologists to 

 work out the full life histories of the members of this anomalous and 

 interesting sub-family. 



My first acquaintance with Ibalia juaculipennis was made in 1883, as 

 I find by the following memo, in a note-book: — "June 28th. Two 

 Hymenoptera, apparently ovipositing in maple." The note is illustrated 

 by a rough sketch of the insect, sufficient to identify it. At this time 

 my attention was given chiefly to Coleoptera, and other orders were only 

 incidentally collected, so that no special value was attached to the obser- 

 vation. The following summer a specimen was taken on 26th June, but 

 its label does not give any particulars, and no record of its capture is 

 found in my note-book. 



In 1886 I was fortunate enough to capture six specimens, of which 

 three were ^ and three % . My friend, Mr. Guignard, had taken a $ 

 upon an old maple on i6th June, but it was five days later that I found 

 my first two ^ % . They were ovipositing upon an old, badly decayed 

 maple ; and in one instance the ovipositor was deeply inserted. Upon 

 the same tree I captured another female, also ovipositing, on the 23rd 

 June ; and upon tlie same day secured my first male upon another old 



