by Art Jones
During this summer Saskatchewan Environment will use aerial spraying to treat approximately 30,000 hectares of forestland in the Deschambault Lake and Amisk Lake areas for spruce budworm. The biological pesticide, Bacillus thuringiensis var. kurstaki (Btk), which is a naturally occurring soil bacterium and kills certain types of caterpillars, will be used.
Btk has been safely used around the world for nearly 40 years. It is not harmful to other insects such as bees, or fish, birds or wildlife and poses no human health hazard. Btk does not build up in the environment and if the target insect, the budworm, does not eat it, Btk will only survive for a few days after application.
Spruce budworm is a natural part of our forest ecosystem but high populations can pose a threat to valuable timber resources," says Saskatchewan Environment Entomologist, Rory McIntosh, "The objective of our budworm management program is to protect these resources by managing heavy infestations in selected areas while allowing the insect to play its natural
role in the ecosystem in most areas."
Spruce budworm larvae are small, only 18 to 24 millimetres long. They are greenish-brown with two rows of whitish spots along the back. However, the impact they have on the forests can be enormous.
In late June or July, the adult moth lays clusters of eggs on the needles of balsam fir, white spruce and black spruce. The eggs hatch in 10 days. The larvae find a protected spot on the tree and soon begin to spin a shelter of silk where they will spend the winter. In May, the larvae emerge and feed on old needles, unopened buds or male flowers eventually making their way into the growing shoots. They pupate in June and the cycle begins again.
"One of the reasons for concern is the budworm's messy eating habits," says Environment's McIntosh "They use their silk webbing to tie two or three shoots together to form a feeding tube. Then they bite needles off at the base. The needles dry out, leaving masses of silk and dried red-brown needles hanging from the trees. Repeated defoliation during a heavy infestation of budworms can eventually kill a tree or make it so weak it dies."
Dead trees along with the masses of dry needles and silk increases the risk of severe wildfires. If damage continues over the next few years, the risk of fires spreading to nearby commercial forests, communities and tourist operations increases.
"Fire is a natural process of regeneration in our boreal forest', says Environment's McIntosh. "However, the build-up of fuel caused by the budworm and the greater chance of wild fire means that we have to use other tools to reduce this hazard. For example, carefully planned logging allows us to reduce the fire hazard while still making use of the damaged trees."
The Provincial Spruce Budworm Management Program has been operating since 1992. Results of the program are monitored and reported. Ongoing surveys reveal that defoliation in areas treated with the biological pesticide, Btk has been reduced by as much as 60% when compared to areas that have not been sprayed.
For more information contact:
Rory McIntosh
Provincial Entomologist
Saskatchewan Environment
(306) 953-3617
rmcintosh@serm.gov.sk.ca
Or
Art Jones
Communications Consultant
Saskatchewan Environment
(306) 787-5796
(306) 536-8452 (cell)
ajones@serm.gov.sk.ca
During this summer Saskatchewan Environment will use aerial spraying to treat approximately 30,000 hectares of forestland in the Deschambault Lake and Amisk Lake areas for spruce budworm. The biological pesticide, Bacillus thuringiensis var. kurstaki (Btk), which is a naturally occurring soil bacterium and kills certain types of caterpillars, will be used.
Btk has been safely used around the world for nearly 40 years. It is not harmful to other insects such as bees, or fish, birds or wildlife and poses no human health hazard. Btk does not build up in the environment and if the target insect, the budworm, does not eat it, Btk will only survive for a few days after application.
Spruce budworm is a natural part of our forest ecosystem but high populations can pose a threat to valuable timber resources," says Saskatchewan Environment Entomologist, Rory McIntosh, "The objective of our budworm management program is to protect these resources by managing heavy infestations in selected areas while allowing the insect to play its natural
role in the ecosystem in most areas."
Spruce budworm larvae are small, only 18 to 24 millimetres long. They are greenish-brown with two rows of whitish spots along the back. However, the impact they have on the forests can be enormous.
In late June or July, the adult moth lays clusters of eggs on the needles of balsam fir, white spruce and black spruce. The eggs hatch in 10 days. The larvae find a protected spot on the tree and soon begin to spin a shelter of silk where they will spend the winter. In May, the larvae emerge and feed on old needles, unopened buds or male flowers eventually making their way into the growing shoots. They pupate in June and the cycle begins again.
"One of the reasons for concern is the budworm's messy eating habits," says Environment's McIntosh "They use their silk webbing to tie two or three shoots together to form a feeding tube. Then they bite needles off at the base. The needles dry out, leaving masses of silk and dried red-brown needles hanging from the trees. Repeated defoliation during a heavy infestation of budworms can eventually kill a tree or make it so weak it dies."
Dead trees along with the masses of dry needles and silk increases the risk of severe wildfires. If damage continues over the next few years, the risk of fires spreading to nearby commercial forests, communities and tourist operations increases.
"Fire is a natural process of regeneration in our boreal forest', says Environment's McIntosh. "However, the build-up of fuel caused by the budworm and the greater chance of wild fire means that we have to use other tools to reduce this hazard. For example, carefully planned logging allows us to reduce the fire hazard while still making use of the damaged trees."
The Provincial Spruce Budworm Management Program has been operating since 1992. Results of the program are monitored and reported. Ongoing surveys reveal that defoliation in areas treated with the biological pesticide, Btk has been reduced by as much as 60% when compared to areas that have not been sprayed.
For more information contact:
Rory McIntosh
Provincial Entomologist
Saskatchewan Environment
(306) 953-3617
rmcintosh@serm.gov.sk.ca
Or
Art Jones
Communications Consultant
Saskatchewan Environment
(306) 787-5796
(306) 536-8452 (cell)
ajones@serm.gov.sk.ca
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