104 The Ottawa Naturalist. [December 



SOME HABITS OF TWO BURROWING SPIDERS 



IN MANITOBA. 



By Norman Criddle, Dom. Entomological Laboratory, 



Treesbank, Man. 



Among the various natural objects met with in the vicinity of the 

 writer's home in Manitoba, none have induced more enquiries as to 

 their origin than the numerous open holes made by the large burrowing 

 spider Lycosa missouriensis Banks. These holes are, in fact, met with 

 wherever the soil is sandy and towards winter become very conspicuous 

 on account of the ring of sand thrown around them by the digging 

 spiders. The writer has long since been interested in these creatures 

 and, more than twenty years ago, commenced some observations relat- 

 ing to their winter habits. Owing to the difficulty of securing their 

 names at that time, however, the notes were laid on one side. During 

 the summer of 1917 the old interest was revived through a visit to 

 Treesbank, of Mr. J. H. Emerton, of Boston, Mass., the following 

 notes being a result. 



Two species of burrowing spiders are involved in these studies 

 both sand-loving but partial, nevertheless, to certain local conditions 

 of soil. Lycosa missouriensis is always found close to vegetation and 

 prefers a situation where dead herbage of some sort is available for the 

 construction of a turret around the entrance to its hole. Lycosa wrightii 

 Em., on the other hand, inhabits the bare sand dunes only and con- 

 structs no turret. Hence, while these two species may be met with 

 in close proximity they seldom, if ever, invade the other's territory 

 for burrowing purposes. In life L. wrightii is at once told from 

 L. missouriensis by its black venter. 



The life-habits of these two species have already been described 

 by Mr. Emerton* and need not, therefore, be repeated here. This 

 paper, consequently, will be confined to a description of the burrowing 

 habits and such other features as have not previously been touched 

 upon. 



In summer time, the excavations of both of these spiders are 

 comparatively shallow, those of L. missourienses being about 9 inches 

 in depth, while those of L. wrightii are slightly deeper. It is not 

 unusual to 'find females, when the young are upon their backs, with 

 holes only three or four inches deep. As autumn approaches both these 

 spiders commence to either deepen their burrows or prepare new ones. 

 There is much variation in the dates when individuals begin to do so. 

 In 1917, some were at work on August 2, while others did not com- 

 mence to dig for more than a month later. There is good reason to 



*Phyche, Vol. XIX, No. 2, 1912. 



