Tree-hoppers

(Family Membracidae.)

These insects comprise some of the most grotesque species which nature has evolved. Comstock offers the apt suggestion that "Nature must have been in a joking mood when tree-hoppers were developed." The antennae are inserted in front of and between the eyes and the prothorax is prolonged so that it frequently covers the rest of the body. It is by the curious modifications of this prothorax that the strange and grotesque forms of the insects are produced. The majority of these modifications have been developed in order to bring about protective resemblance since by these modifications the insects are made to look like different plant structures. The thorn-like process on the thorax of the common little treehopper of the bitter-sweet (Enchenopa binotata) is a good example. The insects customarily rest in such position along the twig of a vine that they precisely resemble vegetable thorns. This family like so many others reaches its most remarkable development in the tropics but many strange forms occur in the United States. The species just mentioned, when enlarged, bears a fanciful resemblance to the partridge and was once the subject of a charming popular article by the late William Hamilton Gibson, entitled "A Queer Little Family on the Bitter-Sweet," published in the Harper's Monthly for August, 1893. A common form is the little hump-backed species known as Telamona monticola, which somtimes swarms upon the branches of the Virginia creeper in June. Another most interesting form is that known as Entilia sinuata, which is found upon the leaves of sun-flower and other annual plants. This species lays its eggs in the midrib of the upper leaves. The mother insect broods over her eggs until they are hatched and the young from the time of hatching until full grown are constantly attended by ants which are attracted to the sweet secretion which this insect, together with many others of the same family, just as with certain of the Jassidae, exudes from its anus.

Life History of the Buffalo Tree-Hopper

(Ceresa bubalus.)

This little insect is probably the species of the greatest economic importance of any of this group of tree-hoppers. It is popularly known by the name of the "buffalo tree-hopper." Its popular name is derived from its supposed similarity in shape to the male bison, the prothorax being greatly enlarged towards the head and projecting at the sides into two strong horns. It is common all through the United States, from Missouri northwards into Canada, and is sometimes the cause of considerable damage in orchards, particularly to young trees and nursery stock. The injury is produced by the cutting of the small limbs by the female with her saw-like ovipositor, in which process she makes large holes through the bark in which the eggs are inserted in clusters. The insect flies with a loud buzzing noise from tree to tree and is very shy. The twigs chosen for egg-laying are preferably those of two or three years growth and various kinds of trees are selected. The eggs are placed in small compound groups arranged in two nearly parallel or slightly curved slits. About a minute is required for the insertion of each egg. The wound is made in such a way as to cause a certain cessation of growth between two rows of eggs to prevent their being crushed by the rapid growth of the twig. Each female lays from one hundred to two hundred eggs. The insect hibernates in the egg condition and the young hatch in the spring. They molt three or four times before becoming fullgrown and during their life feed upon the juices of the tender twigs and leaves by inserting their beaks and pumping up the sap. The insect in its early stages is wingless and is covered on the upper side along the centre with numerous barbed projections.