Hosts: Ponderosa pine, piñon
Pine sawfly larval appearance varies by species and by larval
instar, but most are green or yellowish green in color with black,
tan or orange head capsules. Larvae are found in either spring-summer
or fall-winter feeding gregariously on older foliage, consuming
only the outer needle tissue while leaving the central ribs intact.
The central ribs later turn yellow brown and break off. Later instar
larvae feed singly and consume most of the needle. Eggs are laid
in slits cut in the edge of living pine needles. A papery cocoon
covers pupae. Adults are broad waist wasps. Infested trees have
sparse foliage and thin crowns.
Eight species of sawflies infest pines in the Southwest, five
of those are found on ponderosa pine. Different species have different
preferences for the size of host attacked, and
location on the host where they feed. Pine sawflies in the Southwest
typically attack open-grown trees or areas where pine is growing
at a low density. The same trees are frequently defoliated year
after year. In general, defoliation causes slower growth. Repeated
defoliation can result in top-kill and tree mortality.
Similar Insects and Diseases: See pandora
moth and pine butterfly.
Note: The taxonomy of this group has recently
changed. The Neodiprion fulviceps Complex, described in
Furniss and Carolin, has been split into N. fulviceps and
a new species N. autumnalis. The life cycle information
described for N. fulviceps in Furniss and Carolin is now
considered that for N. autumnalis.