Pt nee 
INSECT ENEMIES OF EASTERN FORESTS 469 
Jersey, Corsican, Scotch, and loblolly pines. In New York there is one 
generation a year, and the moths emerge late in April and early in 
May. The larvae bore into the tips of the current year’s growth, trans- 
form to pupae in July, and hibernate as pupae in the burrows in the 
buds. Other authors have recorded two generations a year. Although 
little is mentioned in economic literature about this insect, it 1S possi- 
ble it may have been confused at times with R. fiustrana. It caused 
considerable injury in a 
plantation of red pine in 
1932-83 at Croton Falls, - 
ING Ye: 
The pitch twig moth 
(Petrova comstockiana 
@iterm:))) 1s reddish 
brown mottled with gray, 
and with hind wings very 
pale. The wing expanse 
is about 5% inch. The 
fully grown larva is 
about 14 inch long; pale 
brown to brownish white, 
with the head and tho- 
racic shield dark brown. 
The pupa is dark brown. 
It is recorded from Mas- 
sachusetts to Virginia, 
and west into Minnesota. 
The hard pines are its 
food plants. The moths 
issue late in May and 
June. Eggs are laid on 
the twigs, probably 
singly. On hatching the 
larva bores into a twig or 
small branch just below : 
the tip and a pitch mass FIGURE 107.— Twig of red pine opened to show 
Peter en ose ranice larva of the pitch twig moth (Petrova com- 
5 stockiana). Note pitch mass over the opening 
hole. It tunnels down- of the gallery. 
ward in the twig for 3 or 
4 inches and hibernates as a partly grown larva under the pitch mass 
(fig. 107). Feeding is resumed in the spring, and the larva matures 
and transforms to the pupal stage in the burrow in May. The pupa is 
capable of moving, so that a part of it protrudes through the pitch 
mass when the moth is toemerge. There is one generation a year. Oc- 
~casionally it is somewhat destructive, as the injured twigs and small 
branches break off, thus deforming the tree. In ornamental plantings 
it is advisable to remove the larvae from their burrows in the twigs, 
but this operation is not practical in the forest. 
Petrova albicapitana (Busck), like P. comstockiana, is a pitch twig 
borer. The full-grown larva is about 1% inch long. The head and 
thoracic shield are ight brown, the body is reddish, and tubercles are 
small and shiny. It is distributed from Quebec to Saskatchewan, 
in Canada and through the northern part of the United States from 
