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energy source. Unfed flies were offered a blood meal, through the 

 screen lid of the holding vial (Fig. 3-1, p. 98, Chap. 3) on a human 

 forearm, a hamster or a lizard. Those that fed immediately were 

 transferred to individual oviposition vials, as previously described, 

 and held until they oviposited and/or died. Females that did not 

 accept the initial offer of a blood meal were placed in a holding cage 

 (Endris et al., 1982) with males and offered a blood meal each 

 succeeding day until they either fed or died. Those that fed were 

 retained in oviposition vials until they oviposited and/or died. Dead 

 females were removed and, if they had deposited eggs in the vials, the 

 screen lids were replaced with solid plastic lids that had been 

 perforated with a dissecting needle to permit limited gas exchange. 

 During June 1982, the field laboratory consisted of a permanent, 

 screened camping shelter. To protect the captured flies from the heat 

 of the Texas summer, their containers were kept in a polystyrene 

 cooler. By placing ice in the cooler, removing or replacing the lid 

 as necessary, the temperature within the chambers and vials could be 

 maintained at or near 27°C. During the September, 1983, trip the 

 field laboratory was in an air-conditioned motel room where the 

 temperature was maintained at 23°C. 



Preliminary identification of live, wild-caught specimens was 

 performed macroscopical ly. At death they were more reliably 

 identified by microscopic examination and comparison with appropriate 

 taxonomic keys (Young and Perkins, 1984). Field identifications were 

 later confirmed as necessary in the laboratory by Dr. D. G. Young, 

 after consulting appropriate keys and available type materials. 

 Specimens were prepared and cleared for permanent slide mounts 

 according to the technique of Young (1979). 



