ARTICULATA. 171 



tlian ten. , They are destructive to various cultivated vegetables, and some 

 feed upon the leaves of the pine. 



LopTajrus {p>l. 79, fig. 43) is remarkable for having the antenna multi- 

 articulate, those of the male being bi-pectinated, and those of the female 

 serrate. The larva of L.pini is sometimes very destructive to the pines 

 in Europe. Nematus {fig. 44) has the antenna slender and nine-articulate 

 in botli sexes. The larvte have six true and fourteen false feet. They live 

 upon leaves and change in the ground, where they form a cocoon. Cimhex 

 {figs. 45, 47) has a heavy body, and the antennie with five articulations, in 

 addition to a terminal club. The species are of rather large size, and some 

 of them are finely colored. C. americana is described by Dr. T. W. Harris 

 in his report on injurious insects. 



Fam. 2. ZTroccridm. The genus Urocerus., Geoff., 1764 {Slrex, Linn., 

 1767), of which the European 77. gigas {2)1. ^i^.,fig. 42) is a good example, 

 is the type of this family. The body is lengthened, cylindric, and the 

 abdomen united by its entire base, and furnished in the female with a borer 

 for inserting the ^^g in living trees, chiefly of the resinous kind, to which 

 the larva? are at times very destructive. 



Fam. 3. Cyn'qndcB {figs. 48-53). This is a family of small insects, the 

 larvfe of which are generally parasitic in plants, where they cause the 

 excrescences named galls. The antennjB are straight, and have from 

 thirteen to sixteen slender articulations. The female has a slender ovi- 

 positor, which is internal and spiral in a state of repose. The irritation of 

 depositing an Qg^ in the plant causes an excrescence, and the continued 

 feeding of the larva upon its internal part continues to keep up the 

 abnormal action until a gall is formed, of large size, compared with that of 

 tlie little insect which finally leaves it. 



Fam. 4. Evaniidm. In this family the posterior feet are the stoutest, and 

 the abdomen is afiixed to the metanotum. Evania has a very small abdomen, 

 and is parasitic in the Blatke. Dr. Reinhardt found a species upon the 

 U. S. ship Constitution, in various parts of the world (including Cochin 

 China and Rio), where it doubtless accompanied the Blattca which infest 

 shipping. In the American genus Pelecinus^ the abdomen of the female is 

 remarkably long and slender. 



Fam. 5. IchneumonidcG {jjI. 79, figs. 32, 33, 37-39, 45). The body of 

 these insects is narrow, the antennae rather long, of numerous articulations, 

 and vibratile. The feet are long, and adapted for running, and the ovi- 

 positor straight. These insects are abundant in species and individuals, the 

 size varies considerably, but the greater part are small, and some are 

 minute. The larvae are the chief enemies of the Lepidoptera, under the 

 skin of the larva? of which the eggs are deposited by means of the ovipositor 

 of the female Ichneu7non. The young feeds upon the internal parts of the 

 caterpillar, avoiding the vital organs, and by the time the young Iclinemnon 

 has acquired its full growth, the caterpillar is ready to die. Sometimes the 

 caterpillar changes into the pupa state, from which the parasite makes its 

 appearance. A caterpillar may contain a single larva of an Iclmeumon of 

 a large size, or fifty or more small ones. They are not confined to Lepi- 



375 



