172 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



Inner prongs (fig. 34, b) strongly convex posteriorly, but without tubercles 

 as described above; without fine sharp points on "teeth" on ninth 



rA. vittatus(Fabricius) 

 abdominal segment <^ ^_ subfuscus (Miiller ) 



The species placed in this group are enumerated in the key and 

 include A. vittatus (Fabricius), which is regarded by Mequignon 

 (1930, p. 95) as the genotype of Athous. 



Larvae of all species are reported to occur in decaying wood, but 

 the typical larval habitat appears to be in the soil of grassy areas in 

 and around forests. When such areas have been brought under cul- 

 tivation, the larvae have been reported as damaging domestic plants. 

 Pupation occurs in late July or during August, the adults hibernat- 

 ing in their pupal chambers. 



This group may be identified by the following combination of 

 characters : Dorsum bright yellow to yellow-brown ; caudal notch 

 small; urogomphi (fig. 34, a-c) with outer prongs much longer than 

 inner prongs ; abdominal mediotergites finely punctulate, but with- 

 out prominent transverse rugae. 



Larvae of haemorrhoidalis are reported by Henriksen (1911, p. 

 275) to attain a length of 24 mm.; the other species only 18 mm. 

 All species have ninth abdominal segment with 4 prominent "teeth" on 

 lateral margins of dorsum, and distance between caudal notch and 

 pleural area approximating one-fifth of total length of segment, ex- 

 clusive of urogomphi. Frontoclypeal area truncate posteriorly. With- 

 out small seta ventrally on basal segment of labial palpus. Up to 5 

 spinelike setae on each episternum of mesothorax and metathorax. 

 Abdominal mediotergites with impressions reaching to or almost to 

 middorsal suture on second to fifth segments, and with 5 to 8 setae 

 (not definitely paired) in posterior transverse row. 



Material used in the study of the group. — A. vittatus (Fabricius) : 

 Five larvae from Vemmetofte, Sealand (Denmark), were examined. 

 These are not known to be associated with reared material, but were 

 received fully labeled from Dr. Mathias Thomsen, Royal Veterinary 

 and Agricultural College, Copenhagen. The identification is believed 

 to be reliable. (C.N.C.) 



A. haemorrhoidalis (Fabricius) : Three larvae, from France, Eng- 

 land, and Denmark, were studied. These were not identified through 

 rearing, but the larva of this species is well known in Europe and 

 the material used is believed to be reliably named. (B.M. and 

 U.S.N.M.) 



A. subfuscus (Miiller) : Five larvae were examined. These speci- 

 mens were from Germany (2), Finland (i), and Denmark (2). As 



