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Forest Biosecurity and Risk Management


									Forest Biosecurity and Risk

   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.
• 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

• 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.
• 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.
• 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
• 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
• Does the organism cause permanent or only
  temporary damage?
    Before choosing a control method(s):
•     Correctly identify the organism to ensure it is a
•     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
•     Correctly carry out the control practice(s) and keep
      accurate records.
• 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
• 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
• Fundamental relationships exist between
  destructive agents and forest residents.
  – 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
• 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
• 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
• 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
 FHS is practiced at various levels of
• 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

 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
 We then need to find out as much as we can
  about the problem, so that we can have it
 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
• Where? (location)
• When? (date)
• Who? (person who found it)
• A close-up picture of the pest or disease
  symptoms and, if it concerns a pest in the
• A picture of the damage symptoms on the
• 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
 ASSESS the level of infestation and the potential
  economic (environmental) losses
 SURVEY for types and abundance of natural
 CONSIDER the options for control, if necessary
 APPLY the appropriate control measures
• 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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