i 86 Bugs, Cicadas, Aphids, and Scale-insects 
secrete no wax, but have the body-wall of the dorsum strongly chitinized, 
and usually very convex, so that it forms 
a' strong rigid protecting shell; finally the 
females of the third (and largest) group are 
the so-called armored scales, which in the 
adult stage are degenerate creatures without 
distinct body segmentation, without antennae, 
eyes, and legs, thus being incapable of 
locomotion; they form a flattish or convex 
dorsal scale of secreted wax and of the cast 
skins or exuviae of the body. 
In all the groups the males (Figs. 252 and 
253) are very different in appearance from the 
females, being minute fly-like creatures with 
a single pair of wings, a pair of long antennae, 
and a plump, soft, little body, usually 
terminating in a single needle-like process or 
in a pair of long waxen hairs. Males are 
not yet known for some of the species. 
Fig. 253. —The fluted or cottony 
cushion-scale, I eery a purchasi, 
winged male and wingless 
female with fluted waxen egg- 
sac ( [es ). (After Jordan and 
Kellogg, much enlarged.) 
Familiar examples of the first group are the mealy-bugs (.Dactylopius sp.) 
of greenhouses and gardens, soft-bodied scales, bearing projecting rods 
and threads of white wax of varying length, and rather prettily arranged. 
A more famous and interesting member of this group is the fluted or cottony 
cushion-scale, I eery a purchasi (Fig. 253) (so called because of the beautiful 
fluted white waxen egg-sac secreted by the female), which once threatened 
to destroy all the orange-groves of California, but was brought to bay by 
a little red and black ladybird-beetle, Vedalia cardinalis (Fig. 254), brought 
from Australia for this very purpose. In 1868 some young orange-trees 
were brought to Menlo Park (near San Francisco) from Australia. These 
trees were undoubtedly infested by the fluted scale, which is a native of 
Australia. These scale immigrants throve in the balmy California climate, 
and particularly well, probably, because they had left all their native enemies 
far behind. By 1880 they had spread to the great orange-growing districts of 
southern California, five hundred miles away, and in the next ten years 
caused enormous loss to the growers. In 1888 the entomologist Koebele, 
recommended by the government division of entomology, was sent at the 
expense of the California fruit-growers to Australia to try to find and send 
back some effective predaceous or parasitic enemy of the pest. As a result 
of this effort, a few Vedalias were sent to California, where they were zeal¬ 
ously fed and cared for, and soon, after a few generations, enough of the little 
beetles were on hand to warrant trying to colonize them in the attacked 
orange-groves. With astonishing and gratifying success the Vedalia in a 
