LIBRARY

690
COLLEGE ENTOMOLOGY
sometimes accompanied by girdling the living twigs below as well as above the
eggs to kill that part of the host. The larval infest aU parts of the plant, and
certain species attack the roots, trunks, limbs, and cones and may confine their
feeding to the epidermal layers or to the heartwood. All known members of the
family are phytophagous and, while the larval feed as borers on both living and
dead plant tissues, the adults either do not feed at all or partake of living foliage
FIG. 201. PS(J/idognathus sljperbus Fries, a magnificent brilliant metallic green long-horned
beetle living in the forests of tropical South America. Male and female somewhat reduced
in size.
and bark, pollen, or fungi. The Australian Mesolita myrmecophila Lea and the
American genus Eplophorus Chevrolat are associated with ants.
The life history consumes rarely less than a year, and in many species from
2 to 4 years are required to complete a cycle. The members as a group may be
classed as forest insects and their distribution, which coincides with that of the
available hosts, includes most of the world. The family is about six.th in size in
the order and contains approximately 20,000 species. It reaches its greatest
development in the tropics where the largest and most briUiant forms occur.
It is noteworthy that the number of genera is very great whereas the number of
species in each genus is relatively small. The smallest North American speCies
is Cyrtinus pygmceus Haldeman, a brown and whitish, ant-like beetle only