406 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



and is bent under the thorax when the insect rolls itself up. In 

 its parasitic habits it resembles the ichneumons. On discovering the 

 nest of a potter wasp it waits until the potter (fig. 24) is absent; 

 then the little rascal, not caring to make a nest of its own, deposits 

 its egg in the potter's nest. Sometimes it is surprised in the act, and 

 the indignant potter attacks it, but it rolls itself up into a ball, rely- 

 ing upon its metallic armor for protection, and the only damage it 

 can suffer is the loss of its projecting wings. St. Fargeau observed 

 a bee, who had surprised one of these little robbers flagrante delicto, 

 bite off its four wings ; but she did not thereby save her young, for 

 as soon as she was gone the wingless Chrysis crawled into the nest 

 and deposited its eggs. It is on account of this habit that the chrys- 

 ids are called cuckoo flies. The Germans call them goldwespen 

 (gold wasps), for some of the European species 

 have a golden luster. To the writer the name 

 " jewel wasps " seems most appropriate. At 

 least two species were collected in Royal Palm 

 State Park, one belonging to the section Tet- 

 rachrysis, and the other, identified by Mr. S. A. 

 fig. 25.-SoLiTA B r w4sp, ^hwer as Chrysis parvula (pL 51, fig. 13), 

 uiiijnnus quadrisectut, belonging to the section Trichrysis. On being 



;£ € SLTTS2 sh0 ™ on " of the d *y ncsts abo ™ described, 



and hollow tubes. Mr. John Peabody Harrington of the Bureau 



of American Ethnology at once recognized its 



resemblance in form to certain vessels of earthenware used by the 



Diggueno Indians of southern California as receptacles for the ashes 



of their cremated dead. 



OTHER PARASITIC WASPS. 



Closely allied to the potter wasps, but somewhat less elegant in 

 form, are the solitary wasps of the genus Odynerus, which construct 

 cells of mud in tubular cavities and store them with small cater- 

 pillars for their own larvae to feed upon. On the island of Guam 

 a certain species of this genus was very abundant, filling with its 

 cells empty cartridge cases, rolled-up magazines or newspapers left 

 lying about, the hollow internodes of bamboos, and even gun barrels. 

 In each cell examined the writer found a small, green caterpillar, 

 which had been stupefied but not killed by the insect's sting. The 

 larvae of the Odynerus in eating their animal food are much more 

 acth^e than those of pollen-feeding insects, continuing to turn their 

 heads from side to side and living for some time after having been 

 taken from their cells. 1 One of the species collected on Paradise Key 

 was identified by Rohwer as Odynerus quadrisectus (fig. 25), a 



1 See Safford, W. E., The Useful Plants of the Island of Guam. Contr. from the 

 National Herbarium, 9 : 92. 1905. 



