The blackheaded pine sawfly, N. excitans Rohwer, occurs from Virginia to 
Florida and west to Arkansas and Texas. It also occurs in Central America (1/297). 
Loblolly and shortleaf pines are its preferred hosts in the United States. Slash, 
longleaf, pond, spruce, sand, and Sonderegger pines are also attacked but to a much 
lesser extent (//94). The full-grown larva is olive green and about 25 mm long (fig. 
184). Its head is glossy black, there are two longitudinal black stripes on the 
dorsum, a row of black spots on each side, and a large black spot on the last 
abdominal segment. 
F-514368 
Figure 184.—Larva of the blackheaded 
pine sawfly, Neodiprion excitans. 
Winter is spent mostly in cocoons, but occasionally in the egg state or as older 
larvae (1292). Oviposition begins in March when each female lays one egg per 
needle in individual pockets sawed just above the fascicle sheaths of needies on a 
given shoot. Newly hatched larvae are gregarious, with a circle of larvae feeding on 
a single needle. Older larvae feed in steadily decreasing numbers per needle. 
Previous year’s foliage is preferred during the growing season, but all foliage may 
be consumed when needle growth ceases during the fall. When a branch or tree is 
heavily defoliated, the larvae migrate in groups to other branches or trees. Full- 
grown larvae spin golden-brown cocoons in ground litter or topsoil, but sometimes 
remain on the tree and spin their cocoons on twigs, needles, or in bark crevices on 
the lower trunk. There are three to four generations per year in the Gulf region (564, 
SOR 94s): 
Heavy infestations typically develop during the fall in moderate to dense stands 
of sawtimber, especially when overmature trees are present. Overwintering trees 
stripped of more than 90 percent of their foliage suffer growth loss and may be 
attacked and killed by /ps engraver beetles, the black turpentine beetle, cerambycid 
393 
