68 



Tryphonin^e. — In this and the following sub-family the abdomen instead of 

 being compressed laterally and thus being more or less knife-shaped, is cylindrical or 

 flattened vertically, especially the basal segment, which instead of forming a 

 slender petiole, is in the majority of genera attached to the thorax by its 

 full width. In the present sub-family the ovipositor is short and not exserted. 

 There are a number of genera, of which Mesoleptus and Tryphon are the most 

 important, but without figures it would be difficult to satisfactorily describe any 

 of the species. Euceros is distinguished by its flattened antennae and Chorinseus 

 by having one or two segments of the abdomen longitudinally keeled above, as 

 in the genus Rhogas of the Braconidae. 



PiMPLiN^. — This sub-family contains many fine species, including the largest 

 and most striking of all our Hymenoptera. The structure of the abdomen is 

 generally as in the preceding sub-family, but the exserted ovipositor is usually 

 at least half the length of the abdomen, and not unfrequently is much longer 

 than the whole body of the insect. This development of the ovipositor is due to 

 the fact that the victims of those species in which it is very long are usually 

 wood-borers, dwelling in burrows in the wood or under the bark of various trees 

 and apparently secure from the attacks of the enemies of more exposed species. 

 Arotes contains several handsome species ; black, with markings of yellow or 

 white, and with the ovipositor about the length of the insect. I have found them 

 ovipositing in dead hickory, infested by Saperda discoidea, etc. Of Rhyssa there 

 are five species recorded from Canada, of which R. persuasoria is also found in 

 Europe. This is a large species, the female (with ovipositor) being 2J inches in 

 length. The general colour is black, with white markings, but the legs are 

 rufous. Provancher states that this species is an especial parasite of the large 

 pine-borers, Monohammus confusor and M. scutellatus. I have not recognized 

 the species at Ottawa yet, but have a male apparently belonging to it from Rev. 

 G. W. Taylor, of Victoria, B.C. The closely allied genus Thalessa contains the 

 giants of the Parasitica, those large species popularly known as " Long-stings." 

 Two species, atrata and lunator, are common, while three others, which may be 

 perhaps varieties, are recorded. The specific name of Thalessa atrata signifies 

 that the species is black, and this is true of the female, with the exception of the 

 head, the antennae and portions of the legs. The male, however, has the legs 

 almost entirely yellow, the thorax much varied with the same colour, and the 

 abdomen much lighter than that of the female. A large female measures fully 

 an inch and a half from the head to the tip of the abdomen, beyond which the 

 ovipositor extends five inches. The legs, wings and antennae are developed in 

 proportion, so that the motions of the insect are active and she flies strongly. The 

 size of these insects and their curious method of oviposition (egg-placing) have 

 made them objects of much interest to entomologists. Their larvae are parasites 

 (feeding externally) of the grubs of the wood boring " Horn tail " called Tremex 

 Golumha. I am sorry that space does not permit me to give a fuller account of 

 their habits, which have been very carefully worked out by Prof Riley. In T. 

 lunator, which is a somewhat smaller species and more variable in size, the thorax 

 and abdomen are largely marked with yellow. To those who wish to observe 

 these insects I may say that they can generally be found about old maples and 

 beeches in midsummer. 



The genus Ephialtes contains several fine species having the abdomen 

 tuberculate along the sides and the ovipositor as long as the insect itself. E. 

 irritator, which I have taken on dead hickory in June has the abdomen and legs 

 re^d, but other large species such as gigas and occidentalis are black, with the 

 exception of the legs. 



