lO MELANDER AND BRUES. 



A number of ants, foragers from near-by nests, are always to 

 be found on the nesting-ground. These belong to harmless 

 species which do not molest the bees. When an ant and a bee 

 meet on the nest there is no encounter, each retreating good-na- 

 turedly to go her own way. The Stenammas, especially, have a 

 stridulatory note as plaintive as that of Mittilla, yet this is unno- 

 ticed by the bees ; even the watchers rest unaroused in their 

 doorways while the ants pass them by. The little red thief ant 

 is also found nesting in the midst of the bee-colony. Evidently 

 it is here to ply its vocation of tunnelling into the chambers of 

 the bees to steal from them their honey. 



The little beetle, Bceoccra concolor, seems quite at home with 

 the bees. Although it belongs to a family of fungus-beetles, it, 

 nevertheless, must have some intimate connection with the bees, 

 as it was repeatedly observed running familiarly in and out of the 

 nests. It is quite possible that it may live upon the pollen in 

 deserted nests which has become mouldy by the growth of fungus 

 hyphae. The mixture of pollen and honey is thus readily turned 

 into a mass of fungus under certain conditions. 



The woes of the Halicti are not yet at an end. Another insect 

 is as persevering in its depredations as its colleagues, and accom- 

 plishes by boldness what the others try by stealth. This is a 

 larger foe, PhilantJiiis piinctatiis by name, which audaciously 

 builds its nest in the center of the Halictus colony, and when 

 ready swoops down on a bee, stings it to death, and carries it 

 home. Not one but many bees meet this death at the sting of 

 their unsuspected neighbor, who plans her murders so that they 

 take place at the flowers where the bees are at work. 



When we consider the persistence of the Mutillas we can ap- 

 preciate the extent to which specialization in keeping the nest 

 parasite-proof has been carried by this bee. Seldom are the 

 entrances left unguarded, and never is a stranger bee granted ad- 

 mission. In this respect Halictus is far more conservative than 

 the wasp Trypoxyloii. Although mistakes in selecting their own 

 domicile from a cluster of fifty similar nests were frequently 

 made, the watchers always recognized these visitors as strangers 

 and were instantly ready to show fight. Tryfox-ylon, a wasp 

 which also guards its doorways, on the contrary, makes no ob- 



