18 U.S. NATIONAL MUSEUM BULLETIN 2 79 



defined vertical burrow. The first stadium averaged about 7 days. 

 Second stage larvae resumed feeding very soon after moulting. They 

 fed actively throughout the second stadium which averaged about 7 

 to 8 days. The moults from first to second and from second to third 

 stage larvae evidently took place in the burrow proper since no special 

 cells were found. The third stage larvae also resumed feeding very 

 soon after moulting; however, after about 7 to 8 days they ceased 

 feeding and usually burrowed slightly deeper into the soil, where they 

 constructed a smooth-walled pupal cell. The larvae either voided the 

 contents of their digestive tracts just prior to construction of the pupal 

 cell or during construction, using the voided material to help firm up 

 the walls of the cell. Shortly after construction of the pupal cell the 

 third stage larvae entered the inactive prepupal stage. This stage had 

 a duration of about 7 days, with the only movement being a wriggling 

 of the prepupae, especially when disturbed. During this period the 

 prepupae underwent a shortening and a thickening. The pupal stage 

 had a duration of about 8 to 9 days. The moult from pupa to adult 

 always occurred while the pupa rested on its venter. After ecdysis the 

 adults remained quiescent for several days before leaving the pupal cell. 

 During this quiescent period the adults underwent the normal 

 hardening and darkening processes. 



Total time from egg to adult in the laboratory varied from about 44 

 to 50 days. The larvae hatching from the first clutches of eggs appeared 

 to have greater vitality and to develop more rapidly than those hatch- 

 ing from eggs oviposited late in the reproductive cycle of the female. 



One adult T. scaler, one first instar larva, and 1 1 third instar larvae 

 were collected by J. F. Cornell from a Berlese sample collected June 

 27, 1966, about 14 miles south of Corvallis, Oreg. The sample consisted 

 of the nest material of a wood rat {Neotoma sp.) and the duff and several 

 inches of soil from beneath the nest. The stage of development and size 

 of the larvae compared quite well with the laboratory-derived life 

 history data. 



A single female of T. fascifer LeConte was collected May 18, 1963, at 

 black light in Corvallis, Oreg., by the writer. A total of 60 eggs and 

 larvae was retrieved from the container housing this specimen. This 

 species also was observed to oviposit at a depth of about 1 to 3 mm. It 

 ceased ovipositing by July 17, 1963. The total time required for the 

 development of the larvae cloosely approximated that for T. scaler. 

 The recorded time for the pupal stage was longer, averaging 1 1 days. 



The females of the genus Omorgus were observed to enter the soil 

 to a depth of about 4 to 10 inches in order to oviposit. They usually 

 deposited a clutch of four eggs, less commonly three eggs. The larvae 

 hatched after about 8 days and pupated about 22 days later. The 

 average duration of the pupal stage for three species (0. monachus, 

 0. carinatus, 0. asper) was 14 to 15 days at room temperature. 



