Pb^YCHE. 



HABITS AND PARASITES OF A NEW CALIFORNIAN WASP. 



B\' A. DAVinSOX, M. D., I.O.S ANGELES, CAL. 



While on a visit to Wilson's Peak, 

 one of the highest mountains of the 

 Sierra range north of Los Angeles, 

 (5000 feet) I gathered some twigs of 

 Nama parryi (a half shrubby peren- 

 nial common on the mountain) in 

 which soine kind of wasp had burrowed, 

 and which contained cocoons that were 

 unfamiliar to me. The greater nimiber 

 of the cells were empt\', but from those 

 that remained there emerged si.x wasps 

 and four parasites which Mr. Wm. H. 

 Ashmead kindly examined and pro- 

 nounced to be new. 



The cocoons are half an inch long l)y 

 one-eighth of an inch wide; in shape 

 and external appearance they closely 

 resemble a finely-grained case of the 

 common caddis-fly, being covered on 

 the outer surfice with a layer of tine 

 sand, and having one end truncate 

 while the other is roiuided. The cell- 

 divisions in one specimen are composed 

 of the pith of the plant. In the other 

 the partitions consist of thin discs of 

 sand. The wasp, presumably after 

 provisioning each cell, adds a quantity 

 of sand before sealing it up and this is 

 aftcrwaids utilized by the larvae in the 

 construction of its cocoon. There are, 

 in the Los Angeles district, at least two 

 or three difterent kinds of wasps that 



utilize hollow stems and fill them with 

 grains of sand to protect the larvae, but 

 the wasp in question is peculiar in that 

 it not only uses sand in 'this manner, 

 but in addition partitions ofl" one cell 

 froTn another with it. The wasps 

 emerged from June 23 to July 1, about 

 three weeks after being collected ; what 

 the larvae had fed on could not be 

 ascertaineti, since there were no parti- 

 cles of food in any of the burrows. The 

 parasites hatchetl out in the first week 

 of July from perfect cocoons of the 

 wasp, one from each, and obviously 

 must have attacked the pupae. Ap- 

 pended is Mr. Ashniead's description of 

 both wasp and parasite. 



Odytwrns rufobasilaris Ashm., sp. n. 

 9. Length, 7 mm. Black, coarsely ru- 

 goso-piinctate, the emargi nation of e^'es, 

 upper margin of clypeus, and angles of the 

 metathorax clothed with an appressed glitter- 

 ing pubescence. Clypeus convexly elevated, 

 with a slight median sinus anteriorly. Man- 

 dibles and antennae entirelv black, the fia- 

 gelliim incrassated. Anterior angles of 

 pronotum nuicli dilated, acute. Basal ab- 

 dominal segment, except the apical margin, 

 red; the anterior margin of pronotum (inter- 

 rupted at the middle), two spots on scutellum, 

 the hind inargin of the tegnlae. a spot 

 beneath, the apical margin of the first and 

 second dorsal segments of abdomen and the 

 apical margin of the second ventral segment 



