New Pest Response Guidelines - aphis - US Department of Agriculture

Control Procedures
Insect Growth Regulators
Aerial sprays of diflubenzuron during an outbreak resulted in a 90% mortality
rate in a 790 ha section of the Piska Primaeval Forest, while aerial sprays of
teflubenzuron over 2101 ha in the Bydgoska Primaeval Forest in Poland
resulted in 90-96% mortality (Adomas, 1997, 2003). Diflubenzuron is a
molting inhibitor which has been shown to have reliable efficiency against
Dendrolimus superans (Miao et al., 1989). If a colloidal suspension is used, it
is even more efficient, as the solution holds together against rain and is
effective for about 20-30 days. This suspension was shown to be quite
effective against D. spectabilis and D. tabulaeformis (Miao and Zhang, 1986).
Biopesticides
Bacillus thuringiensis
Bacillus thuringiensis is a Lepidoptera-specific microbial that, when ingested,
disrupts the midgut membranes. Certain strains have shown some efficacy
against Dendrolimus spp., notably Bacillus thuringiensis var. kurstaki (Btk)
has shown mortality rates comparable (97%) to using pyrethroid formulations.
This mortality rate was observed, however, 23 days after spraying (Sierpinska,
1998). Some Bt strains are specific for SSM, such as strain L-93 (Zhao et al.,
1998a; Zhao et al., 1998b) or strain BtMP-342 (Shukui et al., 1996).
Apply as a full-coverage spray when larvae are present. Repeat at 10 to 14 day
intervals while larvae are active. Effectiveness of aerial delivery is enhanced if
done by helicopter, since the downdraft turns the needle surfaces for better
exposure.
Azadirachtin
Azadirachtin is the key insecticidal ingredient found in neem tree (Azadirachta
indica) oil. It is structurally similar to ecdysones, insect hormones that control
metamorphosis. After ingestion, insects stop feeding; however, death may not
occur for several days. Azadirachtin has been shown to be effective on
Dendrolimus larvae and pupae (Malinowski et al., 1998; Dobrowolski, 2002).
Timing of applications
Apply an insecticide immediately upon discovery of a Dendrolimus moth
detection. Apply insecticides in the late afternoon, evening or at night to
coincide with the nocturnal habits of adults.
Consider delaying applications if weather reports indicate greater than 50%
chance of precipitation within 48 hours after application. If rain reduces the
effectiveness of an application, retreat the area immediately, or as soon as the
label permits.
12/2012-01 Dendrolimus Pine Moths 6-7