Insect Studv 



429 



THE MUD-DAUBER 



Teacher's Story 



THIS little cement worker is a nervousand fidgety creature, 

 jerking her wings constantly as she walks around in the 

 sunshine; but perhaps this is not nervousness, but 

 rather to show off the rainbow iridescence of her black 

 wings; surely such a slim-waisted being as she, has a 

 right to be vain. No tight lacing ever brought about 

 such a long, slim waist as hers; it is a mere pedicel, 

 and the abdomen is a mere knob at the end of it. The 

 latter seen from the outside, would seem of little use as 

 an abdomen ; but if we watch the insect flying, we can 

 see plainly that it is used to steer with. 



In early summer, we find this black wasp at her trade as a mason. 

 She seeks the edges of pools or puddles where she works industriously, 

 leaving many little holes whence she takes mud to mix with the saliva, 

 which she secretes from her mouth to make firm her cement. This 

 cement she plasters on the under side of some roof or rafter or other pro- 

 tected place, going back and forth until she has built a suitable founda- 

 tion. She works methodically, making a tube 

 about an inch long, smooth inside but rough 

 outside, the walls about one-eighth of an inch 

 thick. She does all of the plastering with her 

 jaws, which she uses as a trowel. When the 

 tube is completed except that the end is left 

 open, she starts off in quest of spiders, and 

 very earnestly does she seek them. I have 

 seen her hunt every nook and corner of a 

 piazza for this prey. When she finds a spider, 

 she pounces upon it and stings it until it is 

 helpless, and carries it to her cement tube, 

 which is indeed a spider sarcophagus, and 

 thrusts it within. She brings more spiders 

 until her tube is nearly full ; she then lays an 

 egg within it and then makes more cement and. 

 neatly closes the door of the tube. She then 

 places another tube by the side of this, which 

 she provisions and closes in the same way; 

 and then she may make another and another 

 tube, often a half dozen, under one adobe roof. 

 The wasp in some mysterious way knows 

 how to thrust her sting into the spider's ner- 

 vous system in a peculiar way, which renders 

 her victim unable to move although it yet 

 lives. The wasp is no vegetarian like the bee, 

 and she must supply her young with wasp- 

 meat instead of bee-bread. Since it is during the summer and hot 

 weather when the young wasps are hatched and begin their growth, their 

 meat must be kept fresh for a period of two or three weeks. So these 

 paralyzed spiders do not die, although they are helpless. It is certainly 

 a practical joke with justice in it, that these ferocious creatures lie 



j 





Nests of a mud-dauber on 



the back of a picture 



frame. 



