206 THE CANADIAN ENTOMOLOGIST. 



never spinous, generally minutely and coarsely pilose, with a large head, 

 slender neck, and a transverse corneous shield on the upper surface of the 

 first thoracic segment. Always living in concealment. Chrysalis smooth 

 and uniform, rarely with a mucronate head, always enclosed in some sort 

 of a cocoon. Fam. IV. Hcsperidce. 



THE NUPTIALS OF THALESSA. 



BY W. HAGUE HARRINGTON, OTTAWA. 



For several years I have observed with much interest the oviposition 

 of our large and handsome " long-stings," but not until this summer have 

 I been able to witness their actions preparatory to this duty. Although 

 the males are frequently numerous when the females are ovipositing, the 

 sexes pay no attention to one another, and this fact led me frequently to 

 wonder at what time mating occurs. Last year I had, in company with 

 Mr. Fletcher, observed the males in strange positions, with the tip of the 

 abdomen applied to the bark, or inserted in a crevice, and had suggested 

 that they were awaiting the emergence of the female. The supposition 

 was, however, not proven, and the actions observed were still a matter of 

 conjecture, and for further observation. 



On the afternoon of the 7th June last, I visited some old maples 

 (Acer saccharinum) for the special purpose of making observations on 

 Oryssus. The trees are in different stages of disease and decay, and are 

 correspondingly infested by such borers as Dicerca divaricata, Tremex 

 cohimba, Xiphydria a/bicornis, Oryssus Say/, etc., while they attract 

 naturally numbers of our larger Pimplidas, such as T/ia/fssa, Xorides, 

 Ephiaiies and Xylononnis. Upon these trees during their season could 

 generally be found many specimens of T/ia/essa, but I had never seen one 

 emerge from its prison into the warmth and light of its adult existence. 

 Upon a tree which for years had been much bored by Tremex, etc., I, 

 upon the above date, saw several specimens of T. atrata and T. luiiator 

 ovipositing, and at some distance below them a group of males in an evi- 

 dent state of excitement. Three of these had their abdomens inserted 

 more than half way under a flake of bark. Here, I congratulated myself, 

 was an opportunity to ascertain whether a female was about to emerge. 

 With my knife I pried off the piece of bark, and beheld the head of an 



