212 SCALE-INSECTS, BARK-LICE, MEALY-BUGS. 
a 
Dactylopius citri Risso. (The Common Mealy-bug). 
Everyone connected with greenhouses or conservatories is. 
familiar with the soft-bodied little bug that has a white fringe 
bordering its oval body, and which takes its name from the mealy 
deposit with which it is covered. This little pest is one of the 
worst enemies of the florist and market-gardener. Although 
barely reaching one-eighth of an inch in length, it occurs in such 
numbers as to cause injuries to plants. The eggs of the mealy- 
bug are laid in a loose nest of sticky white fibers. The female 
usually remains on the nest until by its increase in size she is 
raised away from the plant, still clinging to it with the head de- 
pressed, and the tail elevated in the air. When the eggs hatch, 
a young mealy-bug emerges, which, but for its smaller size, 
closely resembles the adult. The young females change very 
little except in size; when they are about two-thirds grown, the 
winged males appear and copulation takes place, and soon after 
this eggs are laid for the next generation. Six weeks is the time 
ordinarily required to complete the cycle of life, or from the 
time the eggs hatch till those of the next generation are 
hatched. 
The Cochineal insect (Coccus cacti), illustrated in Fig. 167, 
is closely allied to the mealy-bugs. It is a native of Mexico, but 
has been introduced in other countries where it feeds upon a 
species of cactus. The dye is simply the dried immature female, 
and is famous for brilliancy and permanency. . 
Remedies. 
Mealy-bugs are well protected by the mealy covering, and 
as they choose plants that will not stand very harsh treatment, 
they are not easily combatted. In many instances, however, as. 
on cucumbers, they may be dislodged by a strong jet of water. 
In case the plant is hardy enough not to be injured, a spray or 
dip of kerosene-emulsion, (one part of the emulsion to fron 
seven to ten parts of water), will effectually check the insects. 
If scattered and not very plentiful an alcoholic extract of pyre- 
thrum (Persian Insect powder or Buhach), applied with a smal! 
atomizer, will prove very effective. The following was used 
with great success by Mr. Reid at Cornell University: alcohol, 
