77 



The young, when first hatched, were almost immediately attended 

 by two species of ants, specimens of which were collected, and which 

 are determined by Mr. Theodore Pergande as Camponotus pictusYorel. 

 and Formica siibsericea Say. It was noticed, however, that both species 

 of ants were not found upon the same leaf. Specimens of one species 

 would guard a colony upon one leaf, while on the next leaf on the same 

 plant a colony of the leaf -hoppers might be guarded by several speci- 

 mens of the other species of ant. 



When so guarded the leaf -hoppers clustered at first near the midrib 

 and in the vicinity of the eggs in the manner shown at fig. 27. The 

 successive stages of development are shown at figs. 28 and 27. The 

 second and third larval stages are very characteristic, and not until 

 the final larval stage is reached does the young show any resemblance 

 to the adult leaf -hopper. 



A curious and interesting observation was made upon the first Qgg 



Fig. 28. — Entilia sinuata : Successive larval stages — enlarged (original). 



mass seen, and which was verified again and again, and that is that 

 the adult female seems to brood over her eggs until they are hatched. 

 She assumes a position upon the swollen midrib parallel to the leaf 

 surface, instead of perpendicular to it, and waits patiently and almost 

 motionless for several days— in fact, until the young are hatched. The 

 ants do not bother her while she is thus brooding. As soon as the 

 young hatch out they put in an immediate appearance, and all of the 

 observations made by Mrs. Rice mentioned above have been verified. 

 Considerable hone} T dew is secreted by the larva?, and this is undoubtedly 

 the cause of the care taken by the ants. When allowed to stray the 

 leaf -hoppers will run around to the upper side of the leaf, but are soon 

 driven back by the ants and kept massed into clusters. The work of 

 the insects causes the ultimate yellowing and dropping of the leaves, 

 in which case the leaf -hoppers are carefully removed by the ants and 

 placed upon fresh leaves. The Entilia may thus be considered an 



