452 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
The larvae bore into cones and shoots of pine and spruce, feeding on 
the seeds and basal parts of the scales in the cone during the autumn. 
The partly grown larvae hibernate during the winter, ‘and complete 
their erowth and pupate late in the spring (Tragardh, 410). The 
moths emer ge late in July and August in New England from white- 
pine leaders infested with the white- -pine weevil (Pissodes strobi) and 
from the cambium of Douglas-fir. 
Dioryctria amatella Hulst is larger than D). absetella. 'T. KE. Snyder 
stated in correspondence that it is distributed generally throug hout the 
Gulf States, being one of the most common injurious species of the 
pitch moths, damaging both 1- and 2-year-old yellow pine cones and the 
terminals of yellow pine natural reproduction and nursery stock, and 
it is also one of the most common pitch moths found in wounds of 
coniferous trees. This insect has been found emerging from terminals 
and pine cones in June and July and from September to early in 
November. 
The Zimmerman pine moth (Dioryctria zimmermani (Grote) ) is 
gray, with a wing expanse of 1 to 114% inches. The forewing Torn 
color is gray shaded with reddish and marked transversely with zigzag 
lighter and ‘darker lines. The hind wings are pale yellowish white, the 
color deeper toward the terminal fringe. The full-grown larva is 
about 84 inch in length. The head is chestnut br own, and the body 
varies in color from a dirty white, through reddish yellow to green, 
with a series of black dots, from each of which arises a single bristle. 
This species is probably distributed over most of the United States 
wherever suitable host trees are available. It attacks many species of 
pine, including Austrian, pitch, red, Scotch, Swiss, white, yellow, and 
others. According to Brunner (69), the moths emerge in Idaho and 
Montana from early in May to the middle of September, the maxi- 
mum flight occurring during July. Britton (58) found that the moths 
emerged from late in June to early in August in Connecticut. The 
egos are deposited on the bark, often near wounds, and the newly 
hatched larvae bore into the terminals or into branches, often into 
those already infested by some other insect, such as the white-pine 
weevil. Before the larvae are half grown they may move and bore into 
another section of the tree sometimes several feet away from the first 
point of attack. The winter may be passed as larvae, in any instar, 
and also in the egg stage, as the eggs deposited late in the summer do 
not hatch until spring. Pupation takes place in the larval tunnel close 
to the surface. The moths emerge approximately 1 year after the 
egos are laid. 
Trees of all sizes may be attacked. In Massachusetts pitch-pine 
trees growing in a more or less open situation seemed to be more 
subject to attack, than those in dense stands. The tunneling of the 
tips of branches causes them to turn brown and to break off. This 
injury not only retards the growth but may spoil the shape of the 
trees. Brunner (69) found that sometimes a space a foot or more 
wide and several feet long on a tree trunk had the cambium Iterally 
honey-combed with tunnels, and on one tree he counted 27 nearly ma- 
ture larvae at work. In plantations, trees up to about 15 or 20 years of 
age occasionally are so seriously injured that the growth below the 
point of attack is greatly retarded, and the trees seldom if ever recover 
(fig. 101). 
