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Insect and Disease Control

Mission Statement:"Insect and Disease Control identifies, interprets and evaluates forest insect and disease conditions and their potential impact on the Province's forest ecosystem, as well as recommending, developing, implementing and evaluating preventative or control actions."

• 2011 Insect Control Program
• History of Forest Insect Control in Newfoundland
• Did You Know?
• Controlling Hemlock Looper
• Controlling Balsam Fir Sawfly
• Controlling Spruce Budworm

History of Forest Insect Control in Newfoundland

The first aerial insect control operations to take place in this Province occurred in the late 1960's to control the Hemlock Looper. Over the past 30 years, a majority of Newfoundland's mature Balsam Fir stands were also seriously damaged by infestations of Spruce Budworm as well as Hemlock Looper . The first extensive outbreak of Spruce Budworm, which began in the early 1970s, was initially not considered a major threat and the Province reacted by mounting a salvage program. However, road building and salvaging damaged stands could not keep up with the increasing impact from the budworm. Aerial control programs were successfully carried out between 1977 and 1985, and in 1992 against the Spruce Budworm, and between 1985 to 1990 against the Hemlock Looper. These efforts combined with weather and natural agents contributed to the collapse of this major outbreak.

In 1980, government established a Royal Commission on Forest Protection and Management whose mandate included a review of all aspects of Spruce Budworm infestation and possible control measures. A key recommendation of the Commission stated that control action be undertaken to protect the forest. Since then, the forest protection program in Newfoundland and Labrador has consisted of a combination of both aerial spray programs on the basis of necessity for pest control, combined with a broader range of management techniques. Forest management plans have been modified to incorporate the requirements of the insect control strategy, which is aimed at keeping as much of the existing canopy alive as possible until natural control factors lead to the eventual collapse of the insect infestation. The forest protection programs have contributed to the development of forest management plans outlining harvesting schedules which lessen susceptible mature and over mature trees, and utilize those that can be salvaged.

In the early 1990's Hemlock Looper infestations began in southern Newfoundland, and expanded into central and western parts of theIsland. It is at this time that control measures were initiated. The main insects of concern at present are the Balsam Fir Sawfly, Yellowheaded Spruce Sawfly and the Hemlock Looper. In sufficient numbers, these insects can cause severe defoliation of the needles of semi-mature, mature and mature Balsam Fir trees in a relatively short period. In fact, tree mortality can occur in one or two years of severe defoliation. The main controlling factors are weather and a naturally occurring disease, which is also influenced by weather. Other natural factors such as parasites and predators do contribute to population reduction, but cannot prevent defoliation during an outbreak.

The main insect infestations currently being managed in this Province are located in Western Newfoundland, on the Northern Peninsula and in Central Newfoundland. The Balsam Fir Sawfly is actively destroying forest in Western Newfoundland while the Yellowheaded Spruce Sawfly is damaging spruce plantations in Central Newfoundland and in limited areas on the Northern Peninsula. The Hemlock Looper is also active throughout the province as it feeds on mature balsam fir forests. In recent years its numbers have increased along the south coast of Labrador, the Northern Peninsula, Main River area and along the Baie Verte Peninsula.

To combat the Balsam Fir Sawfly a naturally occurring virus extracted from the population and reproduced in the laboratory is aerial applied over infested areas. As the virus takes a long period to become effective, the results of the program are often not known until the following season. Unfortunately, no foliage protection is given in the year of virus application as the insect continues to feed. In the case of Hemlock Looper and Spruce Budworm, the use of another naturally occurring product, this time a biological insecticide called Btk is aerially applied over infested areas. This bacterium occurs in the soil and has been used extensively by the agriculture industry to combat caterpillar type insects. Unfortunately, for it to work it must be ingested by the insect, so timing of the application is critical. Normally it is applied to the forest mid summer when the insects are feeding the most. Fortunately, it curbs their normally insatiable appetite thus giving foliage protection within the same year.

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Did You Know?

• The Newfoundland Forest Service is actively involved in planning for effective forest management. An important part of this plan focuses on an Integrated Pest Management approach of which Forest Protection is an integral component.
• The Newfoundland Forest Service has employed the use of spray programs where and when required since the 1960's to protect the forests of our Province.
• The Government of Newfoundland and Labrador has an excellent safety record with respect to the application of insecticides used to protect our forests; there has never been a citation issued against Government for violation of rules or regulations established for any insect control program it has undertaken.
• In the 1970's, failure to actively pursue a Forest Protection Program against an outbreak of the spruce budworm resulted in the loss of up to 50 million cubic metres of Balsam Fir and Black Spruce. This equates to about a 25 year wood supply for the entire forest industry.
• Isolating and controlling insect infestations now through implementing an effective Forest Insect Management Program will help to ensure a healthy forest ecosystem for the future. It will also help to avoid a potential insect infestation crisis situation in the future such as that faced in the 1970's with the Spruce Budworm.

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Controlling Hemlock Looper

• For the past several years Btk, has been applied using fixed wing aircraft to combat outbreaks of hemlock looper populations.
• The majority of operational control activity has taken place place on the Northern Peninsula, along the south coast of Labrador and in other areas in Western Newfoundland.
• B.t.k. has been used in Canada for over a quarter century. It has been used to protect forests in Newfoundland since 1977. B.t.k. is most commonly used to control defoliating caterpillar pests. In over 25 years of use no significant environmental impacts have been observed.

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Controlling Balsam Fir Sawfly

• Newfoundland Forest Service officials have been worked in conjunction with the Canadian Forest Service to carry out a balsam fir sawfly program in Western Newfoundland using a naturally occurring balsam fir sawfly virus.
• The infestation which originated near the community of Gallants has progressed westerly through the Bay of Islands, through Goose Arm and now into the Bonne Bay area of the province.
• The insect generally feeds on young stands of balsam fir and appears to prefer conditions associated with stands that have been pre-commercially thinned.
• It feeds on the older needles and leaves current years foliage intact; creating tress with “tuffs” of needles on the tips of branches. While it is a major defoliator it rarely kills the tree. Rather it greatly reduces the tree’s ability to put on growth; often requiring 7-10 years before the tree can recover.

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Controlling Spruce Budworm

• A Spruce Budworm infestation has existed in south – central Labrador for the past several years.
• The insect generally feeds on balsam fir trees destroying most or all of the new foliage and, sometimes, all the buds and shoots. Damaged needles turn reddish brown, giving the trees a scorched appearance. After several years of infestation, the trees may have dead tops or have died.
• B.t.k. has been applied using fixed wing aircraft to control the outbreak of Spruce Budworm.

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