200 
INSECTS. 
even on the roots of several different kinds of plants. They multiply rapidly, 
and often prove as injurious as the most noxious plant-lice. The orange, 
apricot, olive, peach, fig, and other fruit trees, as well as ornamental shrubs 
like the rose, have each their own species, from which they sometimes suffer 
severely. Some years ago the orange-plantations of California were threatened 
with ruin owing to the ravages of Icerya purchasi, which had been accident¬ 
ally imported from Australia, and had spread with great rapidity. Experts 
were sent to Australia to try and discover the natural enemies of the insect 
in its native country; it was found that the scale-insect was there kept in check 
by dipterous and hymenopterous parasites, but chiefly by the larvrn of a lady¬ 
bird beetle. A number of these beetles and parasitic insects were brought to 
America, and set to prey upon the Coccidce. When they had multiplied sufficiently, 
they were distributed amongst several orange-plantations, with the result that 
many were soon almost entirely cleared of the scaly-bug. Though many species 
cochineal insect (Coccus cacti), with enlarged figures to the left of (1) the male and (2) female. 
of Coccidce have to be combated because of their injuries, there are a few which 
are cultivated on account of the useful products they yield. Among these, the 
cochineal insect ( Coccus cacti) is a native of Mexico and other parts of Central 
America, where it feeds on a species of cactus; but it has been introduced into 
Spain, Algeria, and a few other countries. The male is of a dark red colour, with 
pale wings; the female has a reddish brown colour, but her body, which shows a 
distinct segmentation until the time of laying, is covered with a white powder. 
About seventy thousand dried bodies of these insects, chiefly females, are said to be 
contained in a single pound of cochineal. Long before the introduction of cochineal 
into Europe, two native species of Coccidce had been used for similar purposes. 
The dye with which the ancients produced their deep red or crimson colours was 
obtained from Cermes vermilio, known to the Greeks as kokkos and to the 
Arabians and Persians as kermes or alkermes. Another species ( Porphyrophora 
polonica), formerly known as the scarlet grain of Poland, is found in many parts 
of Central Europe, and was at one time extensively collected for the sake of the 
red dye it afforded. The lac-insect ( Carteria lacca ) of the Oriental countries. 
