New Pest Response Guidelines - aphis - US Department of Agriculture

Survey Procedures
What To Look For
Refer to the specific seasons below for details on what to monitor and look for
during relevant phases of the Dendrolimus moth life cycle. Because local
climate conditions may alter the calendar months corresponding to the stages
of the life cycle of Dendrolimus moths, the following seasonally specific
recommendations will provide guidance on appropriate search techniques.
Early spring and late fall: This is the most effective time of the year to look for
migrating larva. At the end of the overwintering period and early in the spring,
the larva starts moving up to the tree canopy. Larva ready to overwinter will
start moving down from the tree canopy to the forest undercover or soil late in
the fall before the winter starts. Migrating larvae can be monitored by putting
glue bands around trees during this time period (Figure 4-2 on page 4-8 to
Figure 4-3 on page 4-9). Normally, these larvae are of the IV to VI instars and
because of their size, they should be relatively easy to see.
Summer: Preferred time to monitor adult populations using pheromone or light
traps. Adult moths are more active at night and are difficult to spot during the
day because they camouflage with the bark of pine trees and remain inactive.
During the day, look for adult moths on the bark of trees and the presence of
egg clusters on branches and needles. The larvae are actively feeding during
this period particularly during dusk and dawn and therefore, monitoring for
defoliation and larvae presence is recommended.
Late spring and early summer: Late instar larvae pupate at the end of the
spring. Cocoons are visible during this time and can be spotted with binoculars
or with the naked eye on tip of branches, logs or on the tree canopy. Look for
presence of cocoons.
Winter: Larvae overwinter in the leaf litter during the winter. Look for
overwintering larvae by sampling between the forest litter and soil and in a 2 m
perimeter around the trees. As much as 85% of larvae have been found
12/2012-01 Dendrolimus Pine Moths 4-7