THE BLACKHEAD FIREWORM OF CRANBERRY. 7 
DESCRIPTION OF STAGES AND HABITS. 
THE EGG. 
The egg* of the blackhead fireworm is smooth, slightly elliptical, 
with the center partially raised and rounded. It measures approxi- 
mately 0.65 millimeter wide, or about the size of the head of a very 
small pin. When first laid it has a slight opalescent sheen and a 
light lemon-yellow color which changes to a deeper yellow in about 
two weeks. The hatched egg is more inconspicuous, being trans- 
parent and appearing much like a small drop of albumin which has 
dried on the leaf. (Fig. 1.) 
Fig. 1. — Eggs of the blackhead fireworm moth on the undersides of the cranberry leaves, 
enlarged 7.5 times : a, Winter eggs ; h, eggs in the '• black-spot " or first stage of devel- 
opment ; c, hatched eggs. 
Hibernation. 
The eggs are laid by the parent moth singly or in groups on the 
underside of the cranberry leaves; rarely, a few eggs will be found 
deposited on the upper surface of the leaves. On the badly infested 
bogs as many as 10 or 12 eggs may be found on the underside of a 
single leaf. The majority of the wintering eggs are usually deposited 
on the leaves on the lower portions of the vines, the short, low up- 
rights near the ground generally containing the greatest number 
of eggs. During picking season and the following winter, many of 
these leaves are dislodged from the vines, and it is not an uncom- 
mon thing to find them on the bog floor bearing numerous eggs. An 
infestation may easily be distributed from one part of a bog to 
