INTERRELATIONS OF INSECTS 343 
Atemeles cava occurs in the nests of Formica rufa, and is much 
prized by this ant on account of the fluid which the beetle 
secretes from glandular hairs on the sides of the abdomen. 
The beetle Claviger has at the base of each elytron a tuft 
of hairs, which the ants lick persistently. This beetle is blind 
Atemeles emarginatus being fed by an ant, Myrmica scabrinodis.—After WASMANN. 
and appears to be incapable of feeding itself; for when de- 
prived of ant-assistance it dies, even though surrounded by 
food. These cases of symbiosis, or mutual benefit, are well 
authenticated. 
Visitors.—-Many myrmecophilous insects are not restricted 
to ants’ nests, but are free to enter or to leave. This is true of 
such Staphylinidz as visit formicaries simply for shelter or to 
feed upon detritus, and these visitors are treated with indif- 
ference by the ants. 
Intruders.— Not so, however, with species that are inimical 
to the interests of the ants, such as many species of Staphy- 
linidee and Histeridz, which steal food from the ants, kill 
them or devour their larve or pupz at every opportunity. 
The ants are hostile to these marauders, though the latter often 
escape through their agility or else rely upon their armor for 
protection. Quedius brevis and Myrmedoma, as Schwarz 
observes, are soft-bodied forms which remain beside the walls 
of the galleries or near the entrance of a nest and attack soli- 
tary ants; while Heterius, which mixes with the ants, is pro- 
