THE CANADIAN ENTOMOLOGIST. 308 



permit the activity of t!;e Chalcids. From my observations on the emer- 

 gence of the Chalcids, this is from the latter part of May to the beginning 

 of October, namely, about five months. On the basis of these facts, there 

 is sufficient time for the development of about six broods during the open 

 season ; assuming that healthy cocoons are available on the emergence of 

 the adult Chalcids. The cocoons are usually so located under the turf, 

 as to be readily accessible to these small Chalcids, which, on emerging 

 from one cocoon, would soon seek a healthy host. It would seem, there- 

 fore, from the study of the parasite and from such evidence as I have been 

 able to collect concerning the history of the prevalence of its host in 

 certain localities, that this species is one of the chief factors in the natural 

 control of Z. en'c/isoun wheiever the Chalcid occurs. 



Sr^f/imary. 

 In the observations which were made on the development of the 

 Chalcid Ccdlopisthia nematicida, it was found that in the September and 

 October broods the eggs, which are laid on the host larvae inside the 

 cocoons, hatch in two to three days ; the larvae become full grown in ten 

 to twelve days, and the adults may emerge about twenty-three days after 

 the eggs were deposited. The parasite feeds externally and hibernates as 

 a mature larva inside the cocoon of the host. A number of broods of the 

 parasite occur annually. 



ON THE HABITS AND STRIDULATION OF IDIONOTUS 



BREVIPES CAUDELL, AND OTHER NOTES 



ON ORTHOPTERA. 



BY E. M. WALKER, TORONTO, ONT. 



Since recording the capture of the northern Dectician, Idionotus 

 brevipes Caudell, at Fort William, Ont. (Can. Ent , XL, p. 209), I visited 

 the same locality again in 19 10, and succeeded in finding the insect a 

 second time, on the second and eighth of August. 



I found that it is by no means confined to open grassy places, as I 

 had supposed, but occurs also in paths and old lumber roads in the 

 depths of the spruce swamps, which still cover the greater part of the flat 

 country surrounding Fort William and Port Arthur. The tree growth in 

 these swamps consists mainly of black spruce, interspersed with tamarack, 

 white cedar and balsam fir. 



With the exception of a single female, which I found squatting close 

 to the ground on a path in the swamp, all the specimens taken were males,. 



September, 1911 



