304 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



that they could either contact the spider host on the twigs at night 

 or drop to the ground to encounter their host. 



The spiders which prevailed in this area were mostly Pardosa 

 species, including the common host species sternalis Thorell. These 

 hosts were common only in the grassy and wetter part of the meadow, 

 and were not seen venturing far onto the higher and dryer ground. 

 This is significant, since the adult parasites were likewise neither 

 encountered flying nor laying eggs much beyond the margin of the 

 wetter area. Thus, the parasite-host relationship seemed well estab- 

 lished along this line. Although no parasites from the type locality 

 were reared, several pupae were found under rocks and dead twigs 

 Ijdng on the ground in the wet area. 



The entu-e type series (914 specimens) was collected between June 

 28 and July 12, 1951, and although the author made another trip to 

 the locality on Aug. 1, 1951, no specimens could be found in the area 

 where only three weeks earlier the flies were present literaUy by the 

 thousands. This suggests that the active adult period at this altitude 

 is quite limited as compared with the sea level locality of Bolinas, 

 Calif., where adult males and females have been coUected from Apr. 6 

 to Oct. 15. On July 17, 1953, the author again visited the type 

 locality. No specimens of either sex were located, nor could any 

 trace of eggs be seen. This certainly indicates that the presence of 

 these parasites is definitely cyclic and periodic. 



Another series of specmiens was collected under interesting condi- 

 tions at Luther Pass, Calif., on July 24, 1955, by J. C. Downey and 

 the author. Both pupae and larvae were collected underneath cow 

 dung along the marshy margins of Grass Lake. The Pardosa species 

 apparently seeks a protected and somewhat dry place just prior to 

 molting, and m this meadow marsh cow dung (especially older pieces) 

 was used for this pm-pose. Most often the molting spot can be de- 

 tected by the presence of the thin protective spider web, and almost 

 all of these were found in or near the old scarab or histerid beetle 

 holes in the cow dung. These afforded considerable protection to the 

 spiders. On several occasions two or thi*ee larvae or pupae of 0. 

 adaptatus were found under a single piece of dung, and perhaps 20 

 percent of the pieces examined contained some example of the parasite. 

 Although several adult males were collected, no egg sites were located, 

 probably because it was just the beginning of the emergence period 

 in this area. 



This species was reported by Bechtel and Schlinger (1957) {Ogcodes 

 "species #2") as having been stored as prey by a crabronid wasp in 

 wSan Bernardino Co., Calif. 



