66 



The subfamily Inquilin{» as its title indicates contains species which are 

 inquilines or guests in the galls of the preceding species, which in structure and 

 appearance they closely resemble. 



The truly parasitic species of tbe Cynipidse are comparatively few in 

 number. 



EVANIID.E. — The species belonging to this family are easily distinguished, as 

 the abdomen is attached to the disc or base of the metathorax, instead of to the 

 apex as in the other families. The species found in Canada belong chiefly to the 

 genus Aulacus, the members of which frequent decaying trees, in which they may 

 be found ovipositing. We have also two species of Foenus — insects with a curious 

 sickle-shaped abdomen — of which one [F. incertus) has a short ovipositor, while 

 the other {F. tarsatorius) has a very long one. They may frequently be seen 

 flying about trees, telegraph poles, etc., examining and entering insect burrows 

 and crevices, and also upon golden-rod and other flowers in autumn. They are 

 said to be parasitic upon certain bees. The species of E vania, which have curious 

 hatch ed-shaped abdomens, are said to infest cockroaches. 



Trigonalid^. — This family contains only one genus (Trigonalys) and the 

 four species therein are of rare occurrence and not as yet recorded from Canada. 

 Habits unknown to me. 



IcHNEUMONlDiE. — This family is a very extensive one and contains our largest 

 and best known parasites. It is divided into five sub-families of somewhat equal 

 size. Of the sub-family Ichneumoninse there are more than two hundred species 



credited to the typical genus Ichneumon, and 

 of these at least fifty occur in the vicinity of 

 Ottawa. These ichneumons are somewhat 

 wasp-like in form, but more slender ; our largest 

 species {I. grandis) is sometimes an inch in 

 length, but some of the smaller species are less 

 than one-third of an inch and the average size 

 is about two-thirds. The ovipositor is short 

 and retracted within the abdomen so as to be 

 rarely visible, but the females may be dis- 

 tinguished by their stouter abdomens, and 

 frequently by the antennae being rolled, while 

 those of the males are longer and straight. 

 The anterior wings have a small pentagonal cell 

 called an areolet, which occurs also in many 

 other Hymenoptera, (see wing of Cryptus, 

 Fig. 29) although the areolet is incomplete, 

 triangular, rudimentary or wanting in many 

 genera. Many of the ichneumons are entirely black (or with a few white 

 markings,) others have the abdomen red, others again are banded with black 

 and yellow, or are ferruginous with black markings. They are parasites of the 

 caterpillars of our butterflies and moths. The genus Ambly teles contains a num- 

 ber of species almost identical in appearance with those of the preceding genus 

 and of similar habits. Hoplismenus is distinguished by having pointed tubercles 

 or spines upon the metathorax. A common and well marked species is H. 

 morulus, which is a parasite of certain butterflies. The genus Trogus contains 

 a few large species of which T. exesorius, a yellow species with smoky wings, is 

 a common parasite of the caterpillars of our Black Swallow-tail butterfly, 

 Fapilio asterias. 



Ckyptin^. — Cryptus, the typical genus of this sub-family, contains species 



Fig. 29. 



