36 PHIL RAU AND NELLIE RAU 



Museum pest, Anthrenus scrophulariae L. 

 Mutillid wasp, Sphaerophthalma scaeva Blake. 

 House-renters 



Bees, Osmia cordata Robt. and 0. lignaria Say. 

 Eumenid wasp, Ancistrocerus (Stenancistrocerus) 



fulvipes Sauss. 

 Eumenid wasp, Ancistrocerus camestris Sauss. 

 Wasp, Trypoxylon clavatum Smith. 

 Wasp, Trypoxylon cocker ellae Rohwer. 

 Wasp, Pseudagenia mellipes Say. 

 Wasp, Pseudagenia adjuncta Banks. 

 Meal-worm larva, Tenebrio obscurus. 

 Small click-beetle. 



Lepidopterous pupa, Apatela, possibly radcliffei. 

 Mites and spiders. 



PARASITES 



Perhaps the most destructive of these is MelittobiaJ The 

 parasites enter the mud nests by making holes about .013-inch 

 in diameter, enter the pupal cases in the same way and lay 

 their eggs. The larvae eat the contents of the cell (usually 

 in the prepupal stage), and escape as adults, leaving the cocoon 

 empty. These adults bore holes through the neighboring walls 

 and enter other cells and the life cycle is repeated. That these 

 parasites bore into cells promiscuously is evidenced by the fact 

 that their borings are also found in empty cells. Considering 

 their large broods and the rapidity with which they develop, 

 and their ability when ready to migrate, to bore into the mud 

 cells, it is surprising that even one larva should escape them. 

 They usually attack the organism in the prepupal stage, boring 

 into the cell and then into the pupal case. They do not eat 

 the pupal case, nor do they mutilate it, but leave it intact ex- 

 cepting a few small punctures, and containing a quantity of 

 fine debris — probably their own shedding-skins. 



The Dipteron which is directly parasitic upon both 5. 

 caementarium and C. caeruleum is Argyromoeba obsoletum, Loew. 10 

 These flies are by no means rare. The larva is found in the 

 wasp's pupal cocoon; this shows that the parasite attacks the 



9 Identified by Dr. L. O. Howard. 



10 Identified by Mr. F. Knab. 



