67 



very similar in shape and colouring to those of the preceding sub-family, but 

 of smaller size and having the ovipositor exserted and sometimes quite long. A 

 common species is Cryptus extrematis which I have 

 frequently bred from the cocoons of our large moth 

 Telea polyphemus. Figure 29 shows the female and 

 Figure 30 a cross-section of the moth's cocoon, indi- 

 cating how the cocoons of the parasite lie side by side 

 within it closely packed. The genus contains a great 

 many species, as does also the genus Phygadeuon, 

 the species of which differ chiefly in having the 

 ovipositor shorter. The genus Hemiteles contains small 

 species with incomplete areolet, which are said to be secondary parasites 

 parasites of parasites, while the species belonging to Pezomachus are wingless 

 and ant- like in shape and may be found upon the ground or on foliage. 



Ophionin^. — The species included in this sub-family usually have the 

 ovipositor short, and they differ from the rest of the Ichneumonidae in having 



the abdomen compressed laterally, so that it 

 becomes sickle-shaped. Some of the larger 

 forms show this in a marked degree. The 

 typical genus Ophion contains large yellow 

 insects of which some are very abundant. Our 

 largest species is Ophion macrurum (Figure 31) 

 which is a parasite of the caterpillar of the 

 large American silkworm moth {Telea poly- 

 phemus). The larva of the ophion is a large, 

 stout grub, which when full grown spins a 

 dark brown cocoon which almost fills the 

 cocoon of the moth, and from which the fly 

 emerges by cutting a circular door at one end. 

 0. bilineatum infests the White Miller moths, 

 while 0. purgatum (which has two yellow 

 specks in one of the cells of the anterior wing) is a x^arasite of the army worm. 



Thyreodon morio is a fine insect of nearly the size and shape of 0. macruruvi, 

 but of a deep black colour, with dark, smoky wings and yellow antennse. The genera 

 Exochilum and Heteropelma contain a few large species of the same general 

 appearance, while Opheltes glaucopterus might be mistaken for Ophion 

 onacrurum, except that there is an areolet in the anterior wing and that the 

 terminal segments of the abdomen are black. This fine species has been bred by 

 my friend Mr. Fletcher from the cocoons of 

 Cimhex Americana, the great Willow Sawfly.* 

 Anomalon and Campoplex contain a large 

 number of species of moderate size, with the 

 abdomen long and very thin. They are 

 parasites of caterpillars, such as the de- 

 structive Tent caterpillars, and they do good 

 service in keeping down such pests. 

 Another large genus of very beneficial species 

 is Limneria, but in this and the remaining 

 genera of the sub-family the species are mostly 

 small. Figure 32 shows Thersilochus conotra- 

 cheli a parasite of the plum weevil. In Banchus 

 with a sharp spine. 



Fig. 32. 



the scutellum is often armed 



Canadian Entomologist, Vol. XIX, p. 80. 



