THE CANADIAN KNTOMOLOGIST. U 



HABITS OF SOME MANITOBA TIGER BEETLES 

 (CICINDELID.^). No. 2. 



BY NORMAN CRIDDLE, TREESBANK, MANITOHA. 



My last paper* dealt chiefly with these insects in the adult, or beetle 

 state. In the present more attention is paid to their habits while in the 

 earlier stages. My investigations have been conducted entirely in the 

 field, under absolutely natural conditions, and unless otherwise stated, 

 were made in the neighbourhood of Aweme, Manitoba. 



Two valuable papers on Cicindelian habits have been added to my 

 literature upon this subject, through the kindness of Prof. Shelford, of 

 Chicago University, since the lirst of these articles ap[)eared. The latter, 

 " Life Histories and Larval Habits of the Tiger Beetles (Cicindelidaa),"! 

 contains much interesting information upon the earlier stages of these 

 insects, some of which must unavoidably be duplicated here. It will be 

 noticed, however, that there is a striking difference in the life-cycle of 

 some of the species observed by Prof.. Shelford at Chicago and those 

 noted by me at Aweme, even when the same, or a closely related form, is 

 involved, the difference being a prolongation of the larval life over a second 

 winter in Manitoba. This seemed to me to be such a remarkable fact, 

 considering that there are less than 600 miles of latitude between the two 

 places, that I felt almost persuaded that some mistake had been made on 

 my part, and consequently decided to make further observations before 

 l)ublishing these notes, The result has been to leave no doubt that the 

 life-cycle of species carefully observed — C. Afanitoba, venusta, iimbaia, 

 iimbalis, and probably others — lasts for approximately three years; dura- 

 tion of larval stage, 24 to 26 months ; pupal, two to four weeks; adult, 10 

 to 12 months. This corresponds to F. Enock's account of the "Life 

 History of Cicindela campestris"Xtxzt^\v:\g that the adults nearly if not 

 always appear in August or September, constant observation having failed 

 so far to detect overwintering pupre. There is, however, considerable 

 difference in the dates at which the beetles appear, the period of 

 emergence in C. Manitoba and v enu si a ohtn lasting over a month, and 

 some of the former appear so late in the season that there is a possibility 

 of a few remaining in the pupal cavity until the following spring, though the 



■Can. Ent., Vol. XXXIX, April, 1907. 



I Linnean .Society's Journal-Zoology, Vol. XXX, Mar., 1908. 

 :I:Proc. Ent. Soc, London, 1903. 

 Jami.iry, loio 



