412 WILLIAM M. MANN 



importance to the plant, is taken as evidence of myrmecophily, 

 but whether the dung is actually necessary to the growth of 

 the plant is not known. The plant has few natural enemies, 

 so its defense by the ant is not to be considered. Iridomyrmex 

 myrmecodiae lives in other places as well as in the hollows of 

 Myrmecodia. so that the plant is certainly not necessary to 

 the ant. Hydnophytum montanum is recorded as having similar 

 relations to the ants. 



Nickels (33) experimented as to the possibility of extermi- 

 nating the Argentine ant (Iridomyrmex humilis) with entirely 

 satisfactory results. Sponges, moistened with sugar syrup, con- 

 taining one-fourth to one-eighth per cent, sodium arsenate, were 

 placed in the neighborhood of the nests. This was eaten by 

 the ants, and fed to the queen and brood, slowly poisoning 

 them and shutting off the increase of the colony. 



Polimanti (34) in Naples observed large numbers of the 

 winged forms of Lasius niger attracted to large arc-lights, while 

 comparatively few came to incandescent and other less bright 

 lights. He attributes this to simple phototropism. 



Poulton (35) published some notes made by Lamborn, who had 

 noticed that the larvae of Lycaenidae in the Lagos district 

 were often attended by ants. Examination of the ant-nests in 

 the hollowed head of a plant (Castus afer) showed that each 

 contained several caterpillars and pupae. These were attended 

 and licked by the ants, but the adult butterfly was killed and 

 eaten. Lamborn observed the ant Occophylla smaragdina 

 attacking the larva of a Lycaenid. This ant has been observed 

 frequently to tend the caterpillars. The larva of a Pyralid 

 moth also lives in the nest. 



Reichensperger (36) confirms the observations of Wasmann 

 that in nests of Formica sanguined infected with the beetle 

 Lomechusa, normal queens and pseudogynes are not developed 

 at the same time. The pseudogynes which he found were inter- 

 mediate between those forms which Wasmann calls Mikro- and 

 Mesopseudogynes. The percentage of these abortive females in 

 the brood gradually increased, the slave-making raids were not 

 continued, and those pupae already taken were not cared for, 

 the result being the weakening and the final disintegration of 

 the ant colony, as. a result of the presence of Lomechusa. 



