Part I. ] 
Stebbing : Note on the Lac Insect. 
5 
3. Reason for Production of Scale. 
The reason for the production of these scales is probably primarily 
protective. As long as the insect keeps moving 
ti scal^e ^ produc- ^bout it is not SO completely at the mercy of pre- 
daceous foes such as birds and insects as is the 
case the moment it comes to rest and buries its proboscis in the layers 
of the twig. From this time onwards the lac scale, hke aU scale insects 
which have the same habit, becomes completely at the mercy of all its 
foes. The production of a scale or covering which gradually encloses 
the insect removes this danger. 
4. Description of the Lac Scale Insect. 
Larva. 
As has been already stated lac is a resinous incrustation produced 
. . upon the tAvigs of certain species of trees by 
the insect known as Tachardia lacca or the lac 
insect. The lac originates as an excretion, exuded by the scale from the 
anal orifice, which gradually accumulates around and encloses the 
insect beneath a shell-like covering. 
The young or larval stage and the mature female and male stages 
of the insect are described below. PI. I, fig. 1, shows a much-magnified 
collection of empty egg skins from which the larva) have escaped. 
Larva . — The newly hatched insect or larva is a minute red or orange 
coloured insect, elliptical in shape, rather 
obtuse in front and more constricted towards 
the lower extremity. There is no obvious constriction between the head 
and body in front. The head has two small marginal eyes and two short 
antennae or feelers. There are six short legs on the body which consist 
of nine segments ; on the penultimate segment there are two very long 
hairs. There are two tufts of white powdery, hair-like filaments growing 
from the sides of the thorax (the segments follovdng the head) respectively, 
in the place of wings, and a tuft of the same kind, bifurcating and 
curling outwards on each side, projecting from the anal orifice. 
The length is ^’^th of an inch. It is impossible to distinguish any 
distinction of sex at this stage of hfe. PI. I, figs. 1 o, 1 6, depict the 
side and dorsal view of the male larva enlarged and 1 e, the enlarged 
antenna, and figs. 1 c, 1 d, the same of the female insect, with 1 /, the 
enlarged antenna. 
