LIBRARY

12 COLLEGE ENTOMOLOGY
the mature larvre and in many cases may consist of the enlarged larval cases
in which pupation takes place. The cocoons are variable in fOTtn and structure,
being generally oval, globular, or somewhat cylindrical, and may be constructed
of compactly woven strands of silk, of great masses of silk, spun like lace;
ribbed, and often ornamented. Certain cocoons are usually very tight, some
are lined with cement or varnish and are quite waterproof, while others are
spun with an opening or exit hole at one end.
Cells. - Pupation frequently occurs in the larval cells of many insects. Such
cells may be constructed of earth either below or above ground, of wood in
FIG. 7. Eggs of insects, A. lucerne flea or collembolid, Sminthurus viridia (Linn.); B, green
bug or grain aphid, Toxoptera graminum (Rondani) (after Walton, 1921); C, sucking cattle
louse, Solmopatas capillatus Enderlein, attached to a hair (after Bishopp, 1921); D, tipple
capsid, Paracalaris colon (Say). in tissues of plant (after Knight, 1915); E. the ladybird beetle,
Hyperaspis binolaia Say (after Simanton, 1916); F, Phamix billbug or weevil, SphenapJI01!.IS
phwniciensis Chittenden (after Satterthwait, 1932): G, European malaria mosquito, Anopheles
mawlipennis Meigen (after Garman, 1917); H, grasshopper egg pod in the soil and a single
egg pod (after Walton, 1916); I, ichneumon fly, Diachasma tryoni Cameron (after Pemberton
and Willard, 1918); 1, damselfly, A fehiles/es californica McLachlan removed from water plant
(after Kennedy, 1916); K, webbing clothes moth. Tinea/a biselliella Hummel (after H. C.
Severin, 1921); L, dog fiea, Cicnocepllalides canis (Curtis) (after Howard, 1909); M. pear
thrips, Tamiathrips inconsequens (Uzel), removed from tissues of plant (after Foster and Jones);
N, golden eye lacewing, Chrysopa oeu/a/a Say (after Smith, 1922); 0, housefly, Musca domesUca
Linn. (after Howard, 1917).
burrows, of wax, and of paper. Case-bearing larvre also usually pupate within
their protective coverings, which may be enlarged to afford room and are
closed to provide protection.
Adult or Imago - the final instar in the development of an insect in which
all of the external characteristics have been attained and the internal systems
fully matured. Insects in the adult form are usually referred to by such common
names as grasshoppers, crickets, mayflies, lacewings, dragonflies, lice, bugs,
beetles, weevils, flies, fleas, butterflies, moths. wasps, and bees,
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