Winter is spent in the egg stage, and hatching occurs in early spring. Newly 
hatched larvae feed gregariously on the previous year’s needles, beginning about 10 
to 15 mm below the tip. Feeding in groups of 2 to 15 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 portions 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. Eggs are deposited individually 
within slits made by the female ovipositor along the flat sides of needles, usually 
before the end of November. There is one generation per year (872, 1058). 
Before the development of an outbreak in Maryland, Virginia, and North Car- 
olina during the late 1950's, this species was not considered an important pest in the 
Middle Atlantic States. Surprisingly, the outbreak occurring at that time swept over 
more than 5.6 million hectares of pine and pine-hardwood type before it subsided. 
Tree mortality was not serious although some scattered killing was reported, but 
growth loss was severe. 
White-footed mice and ants destroy large numbers of cocoons and prepupae in 
heavy infestations. The ichneumonid, Exenterus nigrifrons Rohwer, is an effective 
parasite of prepupae before they spin cocoons (/34). Dahlbominus fuscipennis 
(Zetterstedt), an introduced parasite of sawfly cocoons, has been released and 
established in infested stands in Virginia. A native polyhedrosis virus has destroyed 
up to 70 percent of sawfly larvae when applied from an airplane (790). 
Neodiprion pratti (Dyar) subsp., the sand pine sawfly, was detected in outbreaks 
in west Florida for the first time during 1977. Both Ocala and Choctawhatchee 
races of sand pine are hosts. Life stages are similar in appearance to those described 
for the Virginia pine sawfly, but the supraspiracular markings consistently blend 
into a black lateral stripe in mature, feeding larvae of the sand pine sawfly. 
Winter is spent in the egg stage and hatching occurs during February and March, 
after which larvae feed on previous year’s foliage, twig bark, buds, and strobill. 
Cocoons are spun in soil or duff during March and April, and turn dark brown. 
Adults emerge from cocoons during November and December and eggs are laid in 
shoots fully exposed to sunlight. Females typically lay two to three yellow eggs 
under the flat side and toward the apex of a needle. An average of about 30 needles 
per shoot is infested. There is only one generation per year. 
Plantations 10 years old and older have been most subject to defoliation, 
especially along stand edges and within those stands of 750 or fewer trees per 
hectare. Defoliation exceeding 90 percent per tree has resulted in subsequently 
_reduced tree growth and some tree mortality has occurred during spring droughts in 
association with infestations of cerambycid beetles. Known parasites include the 
ichneumonids, Exenterus spp. and Endasys subclavatus (Say), and a bombyliid, 
Villa sinuosa sinuosa (Wiedemann). Ice storms can cause heavy mortality in young 
larvae. 
The jack pine sawfly, NV. pratti banksianae Rohwer, occurs in Canada from New 
Brunswick to Manitoba, and in the Lake States. Jack pine is the favored host, but 
red and Scotch pines are occasionally attacked if they are growing with heavily 
infested jack pine. Full-grown larvae are yellowish green and about 22 mm long. 
The head is black and there are two longitudinal pale greenish-gray stripes running 
down the back. There is also a single row of 11 black spots on each side. 
386 
