MUD-DAUBING WASPS 123 



nest and constructively repaired, ring by ring, each injured 

 cell. This she did not do. However, we once saw a case 

 where, when the cell was broken while under construction, 

 the wasp did repair it so. Here too it was probably instinc- 

 tive work, as she was already occupied with the task of 

 ring-making. 



We have every reason to believe that Pelopoeus suffers at 

 the hands of many impostors. The appalling toll of para- 

 sites has been reported previously. We find also, in the 

 laboratory, that mice carry off mud nests or open them on 

 the spot and eat the contents. One wasp was seen dead in 

 a spider's web, and a second one was actually being devoured 

 by a spider, Theridium tepidariorum Koch. [N. Banks]. 

 The Peckhams say that this wasp goes in and out of spi- 

 ders' webs for prey, and it is surprising that it should get 

 trapped in the game. 



Pelopoeus is, sometimes at least, a flower feeder. We 

 have seen her eating at the flowers of iron-weed and a pink- 

 flowered wild pea. 



These wasps do not congregate at night, but sleep indi- 

 vidually on the flowers. 3 



Their cocoons differ from those of their near relative, 

 Chalybion caeruleum as illustrated in our previous note. 4 

 Other life history details are very interestingly told by the 

 Peckhams. 5 



Ashmead 6 writes that this wasp is distributed all over 

 North America. Blackburn and Cameron 7 find that this 

 species, introduced by man's agency to the Hawaiian Is- 

 lands, is now a common species. Cameron 8 finds, too, that 



3 Rau, Ann. Ent. Soc. Amer. 9: 227-274. 1917. 



4 Psyche 12: 62-63. 1915. 



5 Bull. Wise. Geol. & Nat. Hist. Surv. 2: 176-199. 1898. 



6 Psyche 7: 65. 1894. 



7 Mem. Manchester Lit. and Phil. Soc. 10 : 233. 1886. 



8 Proc. & Trans. Nat. Hist. Soc. Glasgow II. i : 264. 1885-86. 



