Doering: Lepyronia qtjadrangularis. 535 



species of plant and deposited them on a new plant of entirely dif- 

 ferent flavor, only to find that the new was accepted without hesita- 

 tion. He found that the insect could easily be transferred from the 

 bean, a plant of mild flavor, to the spicy euphorbia, and back again. 

 It also could be transferred from such pepper plants as Arum itali- 

 cum, of which it takes only a small portion of the leaf to burn the 

 lips, to the perfumed niarum and common dandelion. In order to 

 find the explanation of this Fabre carried on the following experi- 

 ments. He first discovered that when he punctured a euphorbia 

 plant with a small instrument, the milky, poisonous sap oozed forth, 

 but that when the beak of the insect was pushed in only a colorless, 

 neutral fluid was obtained. In fact, the nymph soon perished in the 

 milk of the euphorbia, because of its caustic properties. He there- 

 fore concludes that the siphon of the cicada, by a selection which 

 should be envied, selects at the bottom of the puncture the substance 

 it needs for food, which is the same in all plants, and therefore pro- 

 duces the same colorless fluid, no matter what the species of plant is 

 on which the nymph is feeding. 



Other observers have found this species feeding on additional host 

 plants. Gillette and Baker (1895) took it on Clematis ligusticifolia 

 and Carex (Gillette). Lintner (1895) found it very common in 

 groves of sugar maple, ''where numbers of them were often met with, 

 drowned in vessels of sap." Osborn (1916) took it on Imj)atiens 

 biflora. 



NATURAL ENEMIES. 



It is generally conceded that the froth or spittle is a protective 

 measure. This is undoubtedly the case, for cercopid nymphs are 

 remarkabh* free from parasites or predators. A Syrphus knabi was 

 found sucking at a spittle mass for a short while, but soon flew away 

 without causing any disturbance. At one time a nabid nymph was 

 found sucking the nymph of Clastoptera proteus. The latter was 

 found about two inches away from the nearest spittle mass, and 

 probably had just left the mass when it was captured by the nabid 

 nymph. Three adults of this same species of cercopid were found 

 in the web of a small spider. They were all dead. Gruner (1900) 

 experimented with red ants and the nymphs of Aphrophora and 

 Philcenus. If he placed the nymphs, without any spittle, near the 

 ants, the latter immediately pounced on them and began dragging 

 them away. However, when he placed grass tufts, bearing nymphs 

 in spittle masses, near them, the ants immediately covered the tufts, 



