The impact of the Nantucket pine tip moth on pine plantations varies
widely with tree species, host vigor, and environmental factors. Heavily
infested trees may be severely stunted or deformed but mortality is
rare. Generally, the tree grows out of the susceptible stage within a
few years. In seed orchards, the tip moth is receiving increasing
attention because of its impact on height growth and, more importantly,
because of its effect on flower and cone production. All species of pine
within the range of the tip moth except white pine and longleaf pine,
are attacked. It has been reported from all states in the eastern
hard-pine region extending across east Texas, Oklahoma, Illinois,
Indiana, Ohio, and southern New York State.
[Illustration: Nantucket pine tip moth larva on pine bud.]
The tip moths overwinter as pupae in the tips of infested trees. In the
South the adults emerge on warm days during the late winter months,
mate, and the females lay eggs in the axils between needles and stem
near the terminal bud of host trees. On hatching, larvae bore first into
the base of developing needles, and later into the new terminal growth
or buds. There are two to four generations per year in the southern part
of the tip moth’s range.
Chemical control is generally not considered practical in forest
plantations, but several pesticides have proved effective in reducing
insect damage in seed orchards.
[Illustration: Newly emerged adult tip moth on a damaged shortleaf
pine tip.]