fore moving to another. They also feed frequently on the tender 
bark of young twigs. Sometimes they completely defoliate a tree, 
with defoliation progressing from the top downward, before they 
reach maturity. When this happens, they may abandon the tree 
and migrate for distances of several yards in search of new foli- 
age. Full-grown larvae drop to the ground, enter the soil, and 
spin tough, reddish-brown cocoons in which they spend the 
winter. In the South there may be five generations per year; in 
the Northern States and Canada there is only one. 
The red-headed pine sawfly is one of the most widespread and 
destructive of the pine sawflies. It usually feeds on young trees, 
preferably on trees from 1 to 15 feet tall (474). In the southern 
portions of its range, it seems to prefer trees growing in shaded 
areas. In Canada, eggs are typically laid on trees in full sunlight 
and often on the leaders. Damage is most severe in young planta- 
tions and nurseries and to reproduction and ornamentals. Out- 
breaks occur frequently through the area of infestation. From 
1935 to 1953, a total of 73 were recorded throughout eastern 
United States, 36 of which were widespread (58). 
Among the more important natural control factors affecting 
the species are parasites, a polyhedrosis virus disease, and tem- 
perature extremes during the larval stage. The egg parasite, 
Closterocerus cinctipennis Ashm., and the larval parasite, Spathi- 
meigenia aurifrons Curran, are often quite effective. The Euro- 
pean parasite, Dahlbominus fuscipennis (Zett.), was liberated in 
infested stands in Tennessee, Alabama, New York, and Michigan 
in the late thirties and early forties. It has been recovered only 
in Michigan. 
A number of management practices have been suggested for 
preventing damage in plantations by the red-headed pine sawfly: 
(1) Do not plant hard pines under hardwoods or closer than 25 
feet to hardwood borders; (2) remove hardwood overstories be- 
fore the planting of pines; (8) replant pines in areas of poor 
survival; and (4) promote early closure of plantations by plant- 
ing pines with spacing not greater than 6 by 6 feet (in the North 
Central States). 
Neodriprion prattt pratti, the Virginia pine sawfly, has been 
recorded from New Jersey and Maryland to North Carolina and 
westward to Illinois. Its hosts are listed as Virginia, pitch, jack, 
shortleaf, loblolly, and red pines. Newly-hatched larvae are pale 
green, with black head capsules, and are about 3 mm. long. Full- 
grown larvae (fig. 177) are spotted or marked with longitudinal 
black stripes and are from 16 to 23 mm. long. 
Winter is spent in the egg stage, and hatching occurs in early 
spring. Newly-hatched larvae feed gregariously on previous year’s 
needles, beginning about one-half inch below the tip. Feeding in 
groups of 2 to fifteen larvae each, they consume the outer portion 
of the needle, leaving the inner vascular tissue intact. After the 
first two instars, the larvae consume entire needles, except for 
the basal portion within the sheath. They may also feed on por- 
tions of developing buds and on the tender bark of twigs. By mid- 
May they become full grown and drop to the ground. Here they 
spin cocoons in the surface litter or in the soil. Pupation occurs 
in September and the adults appear in October and November. 
44] 
