170
Carl E. Crisp
phenoxybenzyl alcohol-[s]), decamethrin, NRDC-156 (d,cis-dibromochrysanthemic acid + 3-cyanophenoxybenzyl alcohol-[s]), NRDC-I60 (± cis analog
of cypermethrin), bioethanomethrin, and cypermethrin. NRDC-168S, the completely resolved isomer of cypermethrin, is 3590 times more potent than DDT
(Robertson, 1978b; Robertson et al., 1976, 1977).
Juvenile hormones are alternative agents to the use of insecticides (Lyon,
1976), but the R&D process has not been completed for any of the major
budworms. Seven juvenile hormone analogs were evaluated against the last instar
of western spruce budworm (Robertson and Kimball, 1979a,b). Results of tests
to determine lethal contact effectiveness showed that ZR-1622 (ethyl[2e4e]-10methoxy-3,7,1l-trimethyl-2,4-dodecadienoate) is the most effective, but is not
likely to attain the commercial availability of methoprene. The lethal contact
effectiveness of methoprene is about twice that of malathion, carbaryl, DDT,
or acephate, while the lethal effectiveness by feeding is substantially greater than
the feeding activities of conventional insecticides (e.g., permethrin, mexacarbate,
and acephate). Since methophrene affects reproductive biology, it may be more
effective than carbaryl. Juvenile hormones have two major disadvantages which
limit their usefulness for forest protection: they break down rapidly when exposed
to sunlight (Quistad et al., 1975), and they function primarily at the end of the
last larval instar-after most of the damage to trees by feeding has occurred
(Granett, 1978).
The most important defoliator in Canada and Maine is spruce budworm.
Contact toxicity tests conducted by Nigam (1978), Randall and Nigam (1966),
and Robertson et al. (1978b) show that the most toxic insecticides to budworm
larvae are cypermethrin, permethrin, fenvalerate, azamethophos, pyrethrins,
mexacarbate, and fenitrothion.
Tests against the Douglas fir tussock moth were similar to those against the
budworms (Lyon et al., 1970; Page and Lyon, 1973; Robertson and Lyon,
1973c). Pyretbroids again headed the list of most toxic compounds (e.g., bioethanomethrin, cis-resmethrin and trans-resmethrin were very toxic to these larvae).
Southern pine beetle is another major forest pest. Topical toxicity to adults
by insecticides shows that the following are toxic: permethrin, chlorpyrifosmethyl, stirofos, chlorpyrifos, naled, and fenitrothion (Hastings and Jones, 1976).
The halogenated pyretbroids have physical-chemical characteristics that would
seem to make them ideal candidates for thin film applications to the main trunk
of trees for protection against pine beetles. Western pine beetle adults were killed
by decamethrin, permethrin, chlorpyrifos-methyl, carbofuran, and chlorpyrifos
(Robertson and Gillette, 1978). Lyon (1971) evaluated the contact toxicity of
insecticides to the adult California five-spined ips (Ips paraconfusus Lanier) and
reported that the most toxic insecticides were landrin, endosulfan, lindane, malathion, and phorate.
Pine butterfly (Neophasia menapia Felder and Felder) is generally found
Carl E. Crisp
phenoxybenzyl alcohol-[s]), decamethrin, NRDC-156 (d,cis-dibromochrysanthemic acid + 3-cyanophenoxybenzyl alcohol-[s]), NRDC-I60 (± cis analog
of cypermethrin), bioethanomethrin, and cypermethrin. NRDC-168S, the completely resolved isomer of cypermethrin, is 3590 times more potent than DDT
(Robertson, 1978b; Robertson et al., 1976, 1977).
Juvenile hormones are alternative agents to the use of insecticides (Lyon,
1976), but the R&D process has not been completed for any of the major
budworms. Seven juvenile hormone analogs were evaluated against the last instar
of western spruce budworm (Robertson and Kimball, 1979a,b). Results of tests
to determine lethal contact effectiveness showed that ZR-1622 (ethyl[2e4e]-10methoxy-3,7,1l-trimethyl-2,4-dodecadienoate) is the most effective, but is not
likely to attain the commercial availability of methoprene. The lethal contact
effectiveness of methoprene is about twice that of malathion, carbaryl, DDT,
or acephate, while the lethal effectiveness by feeding is substantially greater than
the feeding activities of conventional insecticides (e.g., permethrin, mexacarbate,
and acephate). Since methophrene affects reproductive biology, it may be more
effective than carbaryl. Juvenile hormones have two major disadvantages which
limit their usefulness for forest protection: they break down rapidly when exposed
to sunlight (Quistad et al., 1975), and they function primarily at the end of the
last larval instar-after most of the damage to trees by feeding has occurred
(Granett, 1978).
The most important defoliator in Canada and Maine is spruce budworm.
Contact toxicity tests conducted by Nigam (1978), Randall and Nigam (1966),
and Robertson et al. (1978b) show that the most toxic insecticides to budworm
larvae are cypermethrin, permethrin, fenvalerate, azamethophos, pyrethrins,
mexacarbate, and fenitrothion.
Tests against the Douglas fir tussock moth were similar to those against the
budworms (Lyon et al., 1970; Page and Lyon, 1973; Robertson and Lyon,
1973c). Pyretbroids again headed the list of most toxic compounds (e.g., bioethanomethrin, cis-resmethrin and trans-resmethrin were very toxic to these larvae).
Southern pine beetle is another major forest pest. Topical toxicity to adults
by insecticides shows that the following are toxic: permethrin, chlorpyrifosmethyl, stirofos, chlorpyrifos, naled, and fenitrothion (Hastings and Jones, 1976).
The halogenated pyretbroids have physical-chemical characteristics that would
seem to make them ideal candidates for thin film applications to the main trunk
of trees for protection against pine beetles. Western pine beetle adults were killed
by decamethrin, permethrin, chlorpyrifos-methyl, carbofuran, and chlorpyrifos
(Robertson and Gillette, 1978). Lyon (1971) evaluated the contact toxicity of
insecticides to the adult California five-spined ips (Ips paraconfusus Lanier) and
reported that the most toxic insecticides were landrin, endosulfan, lindane, malathion, and phorate.
Pine butterfly (Neophasia menapia Felder and Felder) is generally found