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Forest Biosecurity and Risk Management Lecture Notes Week 8 and 9 Forest Pest Control • Interest has come about due to: – increased awareness of the destructive capacities of pests; – the heavy toll they take on supplies of commercial and recreational timber; – environmental concerns; – effects on threatened and endangered species; and – availability of new, specific pesticides. • With adequate knowledge of pest identification and biology, combined with good forestry management practices, it may be possible to prevent or at least reduce losses due to pests • Trees in a vigorous condition are much better able to withstand damage by pests than trees already under stress. Cont’d • Pest management should be a part of an overall forest management plan. • The need for pest control treatments can often be minimized through wise, long-term forestry practices. • The pest control method(s) chosen will depend upon the kind and amount of control necessary, balanced with costs and benefits within legal, environmental and other constraints. Cont’d • The most important principle of pest control is to use a control method only when necessary to prevent unacceptable levels of damage. • Even though a pest is present, it may not be necessary to control it. • It may cost more to control the pest than to cover damage or losses. Cont’d • Before making management decisions, managers should evaluate potential pest impacts within the context of the ecosystem in which the organism occurs, as well as the population dynamics of the organism. • Will the impact of an organism increase, decrease or maintain its level of damage over time? • What part(s) of the tree does the pest affect? • How many trees are or will potentially be affected? • What will be the long-term impact of these organisms? • Does the organism cause permanent or only temporary damage? Before choosing a control method(s): • Correctly identify the organism to ensure it is a pest. • Monitor the pest populations and determine the likelihood of economic damage. • Review available control methods. • Know and follow local, state and federal regulations that apply. • Evaluate the benefits and risks of each available treatment method or combination of methods. • Determine whether there are any threatened or endangered species in the area to be treated. • Choose the method(s) that are effective yet will cause the least harm to you, others and the environment. • Correctly carry out the control practice(s) and keep accurate records. Cont’d • Insects such as the southern pine beetle damage the cambium layer and introduce fungi that almost always cause tree death. • In contrast, many foliage feeding insects cause one- time defoliation from which the tree can recover. • Most trees can withstand complete one-time defoliation without significant long-term impact on tree health. • However, an organism that has the potential to cause multiple defoliations (such as the gypsy moth) can have a much more detrimental impact on tree and forest health. CONCEPTS OF INTEGRATED PEST MANAGEMENT (IPM) • IPM is the maintenance of destructive agents, including insects, at tolerable levels by the planned use of a variety of preventative, suppressive, or regulatory tactics and strategies that are ecologically and economically efficient and socially acceptable IPM ISSUES • IPM addresses issues which foresters recognize • Fundamental relationships exist between destructive agents and forest residents. Management – Forest insects & diseases are integral components of forest ecosystems – Activities of these agents can have major effects on forest stand growth and productivity – Destructive agents can be disruptive to forest management objectives and schedules Part 3; FOREST HEALTH SURVEILLANCE • Systematic surveys of forests, particularly high value tree crops, and surveys around country points of entry for detection of damaging (or potentially damaging) tree pests and diseases. What Does It Involve • (1) detect changes in population or distribution of known key pests. • (2) detect incursions of exotic pests of quarantine significance. • (3) detect outbreaks of indigenous species not previously known as pests. • Principle is that early detection of a pest problem allows more scope for its management Forest Health Surveillance cont... • Forest Health Surveillance (FHS) or detection monitoring provides a ‘snapshot’ of the health of the forests – it includes both extensive surveys and fixed-plot monitoring. • Data build up to a reference baseline. • Problems detected in broad-scale. surveillance then investigated by protection specialists to delineate extent, identify causes and recommend action. Why do we need forest health surveillance? • To effectively protect, manage and use forest resources, the health or condition of these forests must be known. • Forest areas, particularly native forests, are vast • Many forests are remote and infrequently visited so a serious problem could pass unnoticed for a long time. • If you don’t look, you don’t know what you’ve got. A good example is the finding of the mahogany shoot borer in Vanuatu where it was not known to occur . FHS is practiced at various levels of sophistication • Simplest form – “eyes in the forest” – but efficacy of detection by ‘routine’ forest workers is very low. • Next level – assigning certain staff (non- specialist) working in a particular forest area to look for disorders in that forest and liaise with specialists. • Top level – teams of highly trained professionals conduct systematised surveillance of forests using a range of methodologies. FHS is practiced at various levels of sophistication • Essential to have good back-up team or surveillance is pointless and it is in this area of technical back-up that many developing countries have problems. • Few entomologist, pathologists and taxonomists in tropics, the number of species is vast and taxonomy of many groups is poorly known. • Good curation important in tropics but can be financially daunting. Part 4; Problem Diagnostics • To help you identify pests, diseases and weeds, nutrient disorders, and other problems. What do we find in the field? In most cases we find problems that we will probably know already, and how to address them. Sometimes however we will find something that looks new or is quite different from what we know. In those cases we need to know what to do, and how we can diagnose the problem We then need to find out as much as we can about the problem, so that we can have it identified. We need to know: - the kind of pest (insect, weed, disease – the more detail the description the better (e.g.. scale insect; annual weed) - The host or host plants - The location (including the country) Information required • What? (Symptoms – overview and close-up) • Where? (location) • When? (date) • Who? (person who found it) Observations Attachments • A close-up picture of the pest or disease symptoms and, if it concerns a pest in the field: • A picture of the damage symptoms on the plant • A picture of the damaged plant • A view of the plantation or farm with the affected crop Example 1 • Dear Pest Netters, • A scale insect is reaching high population densities on ‘Te non’ (Morinda citrifolia) in Kiribati, and we believe that it is causing serious damage to the plants. Example 2 • The attached red/brown colored scale has reached very high densities on a number of coconut palms in Nauru and infests leaves, petioles and fruits. It has been present for several years at least, but does not seem to spread rapidly. Although we haven’t done intensive surveys, there are no indications on the presence of any parasitoids. Picture Example. IPM Approach IDENTIFY the pest DEFINE the area(s) where control of the pest is desired ASSESS the level of infestation and the potential economic (environmental) losses SURVEY for types and abundance of natural enemies CONSIDER the options for control, if necessary APPLY the appropriate control measures References • Biosecurity Promulgation (2008). Published by the Authority of the Fiji Government. Dated 19th December). • Lal.S; & Tuvou. L. (2003)Country Report – Fiji, Department of Forestry, Pacific Forest Health Workshop, Suva. • FAO. 2009. Global Review of forest pests and diseases, Food and Agriculture organisation, Forestry Department, Rome Italy.
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