LARVAL TAXONOMY OF THE TROGINAE IN NORTH AMERICA 53 



Summary 



1. The adults of 12 species of Trox and of 10 species of Omorgus were 

 collected from the spring of 1963, through the spring of 1965, and the 

 larvae reared in the laboratory. 



2. Collections of adult Glaresis were made in Oregon, but all attempts 

 to rear larvae in the laboratory failed. 



3. A mixture of cow hair, deer hair, sheep's wool, rabbit hair and 

 skin, and pheasant, quail, and dove feathers and skin was found 

 sufficient for rearing the 22 species. 



4. The suberosus group, one of five groups of species within the genus 

 Trox in North America as recognized by Vaurie (1955), is given 

 generic status. The other four groups, scaber, terrestris^ luberculatus, and 

 unistriatus, are retained in the genus Trox. 



5. Seventeen morphological differences were found for separating 

 the genera Trox and Omorgus. 



6. Generic descriptions for the third stage larvae of Trox and Omorgus 

 are presented. 



7. Third stage larvae of 14 species of Trox are described; 10 of them 

 for the first time. 



8. Third stage larvae of 10 species of Omorgus are described; 8 of 

 them for the first time. 



9. Keys for separating the third stage larvae of Trox from those 

 of Omorgus and for separating the third stage larvae of each genus are 

 presented. Larvae of several closely related species were inseparable 

 and are brought out in the same couplet. 



10. The general biology of the adults and larvae is described on the 

 basis of laboratory studies and field notes. 



11. The life history of T. scaber (L.) is described as it occurred in the 

 laboratory, and notes on several other species are given. 



12. Third stage larvae of the scaber group and the terrestris group were 

 found to possess group specific characteristics. 



13. The unistriatus and tuberculatus groups could not be separated by 

 larval characters. 



14. Based on larval morphology there are species groups within the 

 genus Omorgus, 



15. The pertinent morphological structures are illustrated in 59 

 figures. 



16. The lobes of the thorax and abdomen are named according to a 

 new, simplified system, and the terms subtorma, subapotorma, and 

 fused phobal mass are coined to facilitate the description of the epi- 

 pharynx and hypopharynx. 



