Some Solitary Wasps of Texas, 59 



which a wad of it has just been taken. To this same spot the wasp 

 returns for successive loads, thus economizing in the expenditure 

 of saliva necessary to wet the dirt. This requires, of course, more 

 moisture, even for a single partition, than the wasp's body can well 

 hold and it becomes necessary to replenish the stock at intervals. 

 So I have noticed that after every four or five loads the wasp flies 

 away in the direction of the creek, seventy-five yards distant, pre- 

 sumably for a drink, and returns to continue her work where she 

 left off. 



Like T. rubrocinctum a day's work with texense consists of at 

 least storing and closing one cell, though two cells a day is not un- 

 usual for her. Of those individuals on which I have detailed notes 

 one stored two cells in one day and one cell the next forenoon, two 

 others each two cells in one day, one stored nine Attids, one Tho- 

 misid and three Epeireds and closed the nest all in three and one- 

 half hours; another stored and partitioned off one cell in eight 

 hours and stored and plugged up the second cell in ten hours. 

 Thus texense is more industrious than rubrocinctum, which shows 

 that a semi-tropical climate is not enervating to the wasp race at 

 least. 



The development of the young wasp is more rapid in the Texas 

 species than in the northern. The period required for the egg and 

 larval stages of texense together varies from six and one-fourth to 

 seven days and averages nearly seven days. One larva spun its 

 cocoon in five and one-half days but never reached the imago stage. 

 The length of the pupal period is a little more or less than thirty 

 days. 



T. texense captures eight to twenty-five spiders for a single cell, 

 the average being about fifteen. When a nest is composed of two 

 superposed or adjoining cells the deeper one or the one first stored 

 has invariably the greater number of spiders; the difference is 

 specially noticeable when both cells have been stored the same day. 

 The wasps seem to have a decided sense of fatigue, which is quite 

 natural. The great majority of the spiders are alive when brought 

 in ; the majority of these live to about the third day. This accords 

 with the findings of the Milwaukee students in the case of T. ru- 

 brocinctum. 



T. texense begins work early in the year and is on the crest of 

 her presperity at the time rubrocinctum, her northern cousin, is 



