222 ENTOMOLOGICAL NEWS [XXXI, '2O 



Notes on the Genus Hetaerius and Descriptions 

 of three New Species (Coleop.) 



BY J. O. MARTIN, Berkeley, California 



During the past five years I have spent such time as I have 

 been able to spare during the proper season in collecting the 

 curious ant guests belonging to the genus Hetaerius. It is a 

 rather laborious form of collecting as the ant nests in which 

 these beetles are found generally occur under stones, many 

 of which require considerable effort to overturn. Thus far 

 in my experience, I have found them only during the winter 

 months after the ground has been thoroughly wet by the 

 rains. At such times the ants bring their eggs, larvae and 

 pupae, as well as the Aphids they may possess, to the under 

 side of the rocks to absorb the heat gathered by these stones 

 on such days as the sun may be shining. Here too other 

 guests may sometimes be seen and occasionally the desired 

 Hetaerius. Once I found six specimens of Hetaerius zelus in 

 a single day, often two and more often but one represented 

 the spoils of a strenuous day's work. Far outnumbering 

 these red letter days were those in which the only reward 

 was an aching back and painfully worn finger tips. 



As to the habits of these beetles I have been able to learn 

 little, for during the excitement, due to the sudden flood of 

 sunlight the main reaction seems to be toward escape to the 

 underground galleries. Sometimes the Hetaerius may be 

 found clinging to the under side of the stone, though more 

 frequently he is jarred off by the over-turning process. He 

 then feigns death as so many of the Histeridae do, but in a 

 short time comes to life and straddles rapidly away on his 

 clumsy appearing legs toward the gallery entrance. Twice 

 I have seen an ant pick up the beetle and start under ground 

 with him, but as a rule the Hetaerius makes off under his 

 own power. 



During a recent trip to Mill Valley, Marin County, Cal- 

 ifornia, I had the good fortune to take two specimens of 

 Hetaerius which on examination turned out to be uncle- 



