THE INJURIOUS SCALE INSECTS AND MEALY BUGS, &c. 245 
citri, Boisduval ; D. longispina, Targ.-Tozz ; and D. Walkeri, Newstead. 
This latter is the only known indigenous species, and lives upon various 
grasses, but chiefly upon Dactylus glomeratus. The adult female is more 
elongate than our common greenhouse species, and has much thicker 
waxen appendages at the margin of the body. When full fed it descends 
to the base of the plants, where it makes long curling cottony egg-sacs, in 
which it completely envelops itself. A photograph of the sacs of this 
insect is shown at fig. 107. It may be interesting to add that this insect 
Fig. 107.— Walker's Mealy Bug 
{Dactylopius Walkeri) on Dactylus glomeratus (nat. size). 
is named after Mr. Alfred Ostend Walker, F.L.S., whose excellent collec- 
tion of herbaceous plants is known to many horticulturists. 
Common Mealy Bug 
{Dactylopius citri, Boisduval = destructor, Comstock). (Fig. 108.) 
Everywhere destructive, almost omnivorous, and of world-wide dis- 
tribution. It may be recognised from its less common relative (-D. 
longispinus) by the short white marginal appendages which fringe the 
body of the female, and by certain minute structural details which can 
only be seen by the aid of the microscope. 
