242 PROCEEDINGS OF THE NATIONAL MUSEUM vol. m 



The burrow containing the single brood cell consisted of a short 

 vertical shaft which took a sharp turn, at which point the food cell 

 began. Often a plug of dung or soil was found near the opening of 

 the burrow and in addition there was some soil covering the end of 

 the brood cell. The brood cells were from 2}^ to 3)2 inches long with 

 a diameter of from three-quarters of an inch to 1 inch. One-half 

 inch from the terminal end was a cavity in which the female laved a 

 single elongately oval egg (pi, 14, fig. 2). Plate 10, figiu-e 6 is a dia- 

 gram of a typical brood burrow. In no instances were two brood 

 cells found originating from one burrow. When all the food of the 

 cell was consumed, the larva plastered the sides of the cell with its 

 feces, which became hard and made a compact cell about 2 inches 

 long. Ten of these cells were measured just at the time of pupation 

 (pi. 15, fig. 2). The inside length varied from 19 to 28 mm., the 

 greatest inside width from 11 to 14 mm. The outside dimensions 

 were more variable, ranging in length from 29 to 45 mm., and in 

 width from 16 to 20 mm. 



The complete life cycle of hlackhurnii takes one year in North 

 Carolina. While exact dates are not mentioned below, as they can 

 easily vary from place to place and from one year to the next, "early" 

 refers to the first 10 da^^s in the month, "mid" to the next 10 days, 

 and "late" to the remaining days in the month. The dates and data 

 given below were accumulated from notes made on 100 larvae. 



In mid-September newly emerged adults began appearing. Feeding 

 and perhaps mating occurred in the fall and winter with oviposition 

 occurring from mid-January tlirough early May. Incubation nor- 

 mally lasted at least 10 days, apparently taking considerably longer 

 when the eggs were laid in January and February. Fhst-stage larvae 

 were found from late March untU mid-May, the stadium usually 

 lasting between 20 and 30 days. The second stadium took about 

 20 days. The first third-stage larvae appeared in late April. By the 

 end of May aU larvae collected were third instar. Early growth of 

 the third-stage larvae was rapid. In 15 or 20 days the larvae had 

 entirely consumed their available food supply, and then remained 

 quiescent until September. 



After the larva had become quiescent, if more food was added it 

 would resume feeding but with no visible increase in size. The 

 quiescent period lasted most of June, July, and August. In early 

 September pupation occm-red. On Sept. 4, 1951, several prepupae 

 were found at Faison and pupae were taken on September 11. On 

 Sept. 12, 1951, the remaining portion of the enclosure at Kaleigh was 

 dug. In it were found 1 third instar, 4 prepupae, and 19 pupae. 

 The prepupal stage lasted from 4 to 9 days, with the pupal stage 

 lasting from 15 to 20 days. It required 3 to 4 days for the adults 



