Control of Rice Insect Pests - PowerPoint PPT Presentation

About This Presentation
Title:

Control of Rice Insect Pests

Description:

Control of Rice Insect Pests. G.C. Jahn & Islam Zahirul. Integrated Pest ... Community-wide ... rate ( = fecundity) of many phloem-feeding insects (e.g. ... – PowerPoint PPT presentation

Number of Views:4445
Avg rating:3.0/5.0
Slides: 64
Provided by: gary135
Category:
Tags: control | insect | pests | phloem | rice

less

Transcript and Presenter's Notes

Title: Control of Rice Insect Pests


1
Control of Rice Insect Pests
  • G.C. Jahn Islam Zahirul

Integrated Pest Management Training Course
2
LECTURE CONTENT
  • Introduction
  • Basics of Cultural Control
  • Single Field Cultural Control Practices
  • Community-wide Cultural Control Practices
  • Examples of Cultural Options Against Specific
    Insect Pests

3
What is CULTURAL CONTROL?
Introduction
  • The modification of management practices so that
    the environment is less favorable for pest
  • invasion
  • reproduction
  • survival
  • immigration

4
Ecological Pest Management
Introduction
  • Cultural control is referred to as Ecological
    Pest Management (EPM) by some authors (e.g.
    Speight et al. 1999)
  • This is because cultural control is a way of
    changing the ecological factors that affect pest
    numbers.

5
Is there a difference between EPM and Cultural
Control?
Introduction
  • In practice, they are the same.
  • In theory, they are different ways of looking at
    crop protection, i.e. . . .
  • EPM looks for intervention points to manipulate
    the ecosystem
  • Cultural control looks at each aspect of crop
    management and how it affects pests.
  • For our purposes the terms can be used
    inter-changeably.

6
Aims of EPM
Introduction
  • In EPM the crop is managed to
  • Improve resistance of the crop to pests, by
    optimizing plant health
  • Enhance the proliferation and efficiency of
    natural enemies

7
Aims of Cultural Control
Introduction
  • To achieve reductions in pest numbers through
    crop management.
  • Increase yield.
  • Improve grain and crop quality.
  • Improve seed viability (germination rates).
  • Decrease cost of pest management.
  • Reduce the negative impact of pest management on
    the environment and health by reducing reliance
    on pesticides.

8
Basics of Cultural Control
Basics
  • Advantages vs. Disadvantages
  • Types of cultural control
  • Primary
  • Secondary
  • Examples of Cultural Control Practices
  • Adoption scale

9
Advantages vs. Disadvantages of Cultural Control
Basics
  • Advantages
  • Inexpensive
  • Slow development of resistance (compared to
    chemical control)
  • Low environmental impact
  • Compatible with other pest management
  • Disadvantages
  • May suppress some pests, but increase others
  • May require community-wide adoption
  • Generally slower than pesticides for controlling
    outbreaks.

10
Types of Cultural Control
Basics
  • Primary Cultural Control
  • those practices adopted specifically to control
    insect pests.
  • Secondary Cultural Control
  • those practices adopted for general crop health,
    but which also prevent pest build up.

11
Examples of Primary Cultural Control
Basics
  • Draining a rice field to control caseworm.
  • Transplanting older seedling to prevent whorl
    maggot damage
  • Increasing the seeding rate to compensate for
    feeding by ants or birds
  • Adjusting the timing of planting or land
    preparation to avoid certain pests (e.g. chafer
    beetle, stem borer, rice root weevil)

12
Examples of Secondary Cultural Control
Basics
  • Maintaining water in the field to prevent mole
    crickets, ants and other soil pests.
  • Land preparation e.g. plowing to prepare the
    soil for planting while at the same time turning
    over stubble that harbors stem borers.
  • Weeding
  • Fertilization splitting nitrogen applications
    to avoid build up of certain pests (e.g. brown
    planthoppers, gall midge)

13
Examples of CULTURAL CONTROL PRACTICES
Basics
  • Rotations, intercropping, mixed cropping,
    barrier, trap crops
  • Tillage
  • Mulches
  • HPR
  • Phytosanitation
  • Water management
  • Fertilizer management

14
Adoption Scale
Basics
  • Some cultural practices offer direct benefits to
    the farmer if carried out at the farm level.
    However, some others require community-wide
    action to be effective.
  • Single field cultural practices
  • e.g. transplanting vs direct seeding for weed
    control
  • Community-wide cultural practices
  • e.g. crop rotation to break pest life cycle

15
Single Field Cultural Control Practices
Single Field Cultural Control Practices
  • Overview
  • Planting methods
  • Seedling age
  • Clipping
  • Plant Density
  • Crop cover using Azolla
  • Water management
  • Fertilizer management

16
Overview of Single Field Cultural Control
Practices
Single Field Cultural Control Practices
  • Works well when for pests that can be excluded
    from the field e.g. flooding eliminates dryland
    pests such as root aphids.
  • Works for avoiding pests in time.
  • Does not work well for reducing overall pest
    populations of species that readily move between
    fields such as adult rats or flying insects.

17
Planting Methods
Single Field Cultural Control Practices
  • Transplanting into flooded fields suppresses dry
    land adapted pests such as white grubs, root
    aphids, termites, mole cricket, ants, and others.
  • Seed beds are easier to protect from pests, than
    entire fields, due to small area.
  • Delayed transplanting is may help avoid certain
    insects (e.g. stem borer) or diseases.

18
Seedling Age
Single Field Cultural Control Practices
  • Transplanting older seedlings
  • Reduces seedling time in the field.
  • Reduces population buildup of pests that prefer
    the vegetative stage.
  • Reduces damage from caseworms and whorl maggots
  • Avoid one generation of stem borers, leafhoppers,
    and brown planthoppers.

19
Plant Density
Single Field Cultural Control Practices
  • The effect of plant density on insect pest
    abundance is varied and complex.
  • Dense plantings change crop growth, development,
    and microclimate, which in turn has an effect on
    pests and their natural enemies.
  • Sparse planting encourages weeds and indirectly
    has an effect on insect abundance.

20
Clipping
Single Field Cultural Control Practices
  • Clipping the tops of bundled tall seedlings
    prevents lodging and removes stem borer and hispa
    eggs, if present.
  • Not commonly used with modern rice varieties.
  • During the wet season, removal of the top third
    of a standing crop at the vegetative stage can
    remove leaf folders and stem borer egg masses,
    hispa eggs and grubs, and thrips.

21
Crop Cover - Azolla
Single Field Cultural Control Practices
  • Covering the paddy water surface with Azolla
    (water fern) reduces incidence of whorl maggot.
  • Azolla cover also assists predators move from
    hill to hill in search of prey (e.g.
    planthoppers).

22
What is Azolla?
Single Field Cultural Control Practices
A. nilotica
  • Azolla is an aquatic fern (pteridophyte), that
    floats on the water surface of flooded rice
    fields, small ponds, and canals.
  • 1-5 cm, except for A. nilotica of Africa which
    reaches 15 cm.
  • Multiplies vegetatively and sexually.
  • Seven Azolla species are recognized
  • Distributed widely from temperate to tropical
    regions.

23
Uses of Azolla
Single Field Cultural Control Practices
  • Symbiotic nitrogen fixation, thus high N content
  • Used for green manure in wetland rice in China,
    Vietnam, and Philippines
  • Weed suppression in rice

24
Water Management
Single Field Cultural Control Practices
  • Draining field 1-2 days suppresses
  • Whorl maggots,
  • root feeding midges,
  • water weevils,
  • caseworms
  • Alternate draining and flooding for 5-7 days
    helps control black bugs, planthoppers, gall
    midge, hispa, and stem borers

25
Fertilizer Management
Single Field Cultural Control Practices
  • IPNM Integrated Pest Nutrient Management
    Managing soil nutrients and pests in a
    complementary fashion, i.e.
  • pest management has a neutral or positive effect
    on soil quality
  • soil nutrient management has a neutral or
    positive effect on pest levels

26
Why do we need Integrated Pest and Nutrient
Management (IPNM)?
Single Field Cultural Control Practices
  • Some nutrient management causes pest outbreaks
  • Some pest management techniques degrade the soil
  • IPNM could reduce pest problems and enhance soil
    fertility

27
IPNM FOR A CHANGING RICE ECOSYSTEM
Single Field Cultural Control Practices
  • New cultivars GMOs
  • Increased amounts of fertilizer being used
  • Interactions poorly understood, therefore the
    potential for disaster (e.g. outbreaks) - note
    pesticides
  • Current pest problems related to fertilizer use
    may be exacerbated

28
EXAMPLES PEST MANAGEMENT THAT REDUCES SOIL
QUALITY
Single Field Cultural Control Practices
  • Burning straw to control insects and diseases
  • Plowing fallow land to hinder weeds and the
    insect pests they harbor
  • Draining fields

29
EXAMPLES PEST MANAGEMENT THAT IMPROVES SOIL
QUALITY
Single Field Cultural Control Practices
  • Flooding fields to prevent infestations of thrips
    mole crickets or weeds
  • Crop rotation with a legume
  • Using fish and ducks to help regulate pests

30
EXAMPLES OF PEST PROBLEMS CAUSED BY FERTILIZER
Single Field Cultural Control Practices
  • Nitrogen (N) applications tend to increase
    populations of
  • weeds
  • sheath blight
  • leafhoppers
  • gall midge
  • N applications lead to heavier stem borer larvae,
    which presumably cause more damage
  • High N levels associated with pest outbreaks

31
EXAMPLES OF USING FERTILIZER TO HELP MANAGE PESTS
Single Field Cultural Control Practices
  • N applications decrease thrips populations
  • Phosphorous (P) improves tolerance for root pests
  • Potassium (K) tends to suppress pests
  • Silicon increases resistance to blast, bacterial
    blight, planthoppers and stem borers
  • Zinc reduces stem borer damage

32
FERTILIZER APPLICATIONS CAN
Single Field Cultural Control Practices
  • Raise pest levels
  • Lower pest levels
  • Raise the levels of some pests and lower the
    levels of others
  • Have no effect on pest levels
  • Depending on several factors. . .

33
FACTORS TO CONSIDER
Single Field Cultural Control Practices
  • Fertilizer
  • Composition
  • Timing
  • Amount
  • Cultivar
  • Hybrid
  • New plant type
  • Transgenic
  • Duration

34
How would Nitrogen effect . . .
Single Field Cultural Control Practices
  • Nn Nt B D I - E
  • Birth rate?
  • Mortality?
  • Immigration
  • Emigration?

35
FERTILIZER AND BIRTH RATE
Single Field Cultural Control Practices
  • N increases birth rate ( fecundity) of many
    phloem-feeding insects (e.g. planthoppers and
    leafhoppers insects)

More babies!
36
FERTILIZER AND DEATH RATE
Single Field Cultural Control Practices
  • N tends to lower insect death rate ( mortality)
  • N increases insect tolerance to stress, therefore
    lowers mortality
  • Some parasitoids concentrate attacks on insect
    hosts that feed on the leaves with the highest N
    content

37
FERTILIZER AND IMMIGRATION
Single Field Cultural Control Practices
  • Rice treated with high N attracts more pests

38
FERTILIZER AND EMIGRATION
Single Field Cultural Control Practices
  • N tends to soften plant tissue, making
    penetration of the plant easier.
  • Therefore insects should tend to stay in a field
    with high N.
  • . . .which should reduce emigration.

Comfortable animals tend to stay at home
39
WHAT IS KNOWN? Nitrogen insects
Single Field Cultural Control Practices
  • Increase insect tolerance to stress
  • Greater insect fecundity (e.g. sucking insects)
  • Increases insect feeding rate
  • More abundant, e.g. brown planthopper
  • Less abundant, e.g. thrips and whorl maggot
  • Rice attracts more pest
  • Promotes recovery from pest damage

40
THE KNOWN Weeds Pathogens
Single Field Cultural Control Practices
  • Sheath blight - increased severity with increased
    N
  • Blast - use silica to increase resistance
  • Low density of Echinochloa can out-compete rice
    at high N

41
THE KNOWN Balance is important!
Single Field Cultural Control Practices
  • Studies in India, China, Indonesia, the
    Philippines, and Vietnam have found lower pest
    incidence in fields with site-specific nutrient
    management, compared to farmers practice
  • Why?
  • Farmers tend to apply unbalanced fertilizer
    regimes

42
THE KNOWN N effects
Single Field Cultural Control Practices
  • N increases number of eggs produced by some
    insects, (i.e. increase birth rate)
  • High N can attract ovipositing insects (i.e.
    increase immigration).
  • N augments plant growth rate, therefore softer
    tissues and easier penetration (reduces
    emigration).

43
THE KNOWN P effects
Single Field Cultural Control Practices
  • P (Phosphorus) improves root development,
    therefore greater tolerance to root pests (e.g.
    root weevil)

44
THE KNOWN Potassium (K) Effects
Single Field Cultural Control Practices
  • Lowers plant sugar
  • Lowers amino acids
  • Promotes thicker cell walls
  • Increases silica uptake
  • Therefore suppresses many pests

45
APPLICATIONS of IPNM knowledge to date
Single Field Cultural Control Practices
  • Avoid fast pest build up by splitting
    applications of N, with a basal application for
    slow release.
  • Plow straw into soil to increase silica uptake
    and reduce stem borer
  • Apply N to promote recovery following a pest
    attack

46
THE UNKNOWN
Single Field Cultural Control Practices
  • Quantifying the balance between pest yield
    increases when fertilizer is used
  • Multiple effects Fertilizer combinations on
    different soil types, with multiple pests on
    different cultivars

47
THE UNKNOWN
Single Field Cultural Control Practices
  • How will pests respond to fertilizer on new
    cultivars?
  • How do natural enemies respond to fertilizer
    applications? (How do fertilizers effect the rate
    of death of pests?)
  • How do grain sucking insects respond to
    fertilizer applications and does this effect
    grain quality?

48
OBJECTIVES OF IPNM RESEARCH
Single Field Cultural Control Practices
  • Understand processes involved in how fertilizers
    effect crop losses due to pests on different
  • cultivars
  • soil types
  • Predict the consequences of intensified rice
    production on crop losses due to pests.

49
DESIRED OUTPUTS
Single Field Cultural Control Practices
  • Identify situations where outbreaks are likely to
    occur
  • Predict effectiveness of pest control strategies
    and soil nutrient management under different
    circumstances
  • Integrate pest and nutrient management strategies

50
Community-wide Cultural Control Overview
Community-wide cultural control
  • Eliminating or drastically reducing a pest
    population by removing its habitat.
  • Preserving a high diversity of natural enemies by
    maintaining habitats.
  • Can use indicator species for diversity of
    natural enemies (e.g. dragonflies in rice).
  • Rely on taxonomy and phylogenetics to define
    biodiversity (Douglas and Brunner 2002, May 1990)

51
Indicator species
Community-wide cultural control
  • Indicator species species whose presence,
    theoretically, indicate a certain level of
    species richness in a habitat (MacNally and
    Fleishman 2002, Noss 1990)
  • Why use indicator species?
  • Complete species inventory is expensive
  • Species inventory is time consuming
  • Less expertise required

52
Community-wide Cultural Control Practices
Community-wide cultural control
  • Examples
  • Crop rotation
  • Crop area
  • Rice cropping frequency
  • Plant maturity
  • Planting time
  • Synchronous planting / flowering

53
Community-wide Cultural Control Practices --
continued
Community-wide cultural control
  • Trap crops
  • Flooding stubble
  • Tillage
  • Weed control
  • Harvest methods
  • Straw and stubble destruction
  • Ratooning

54
EPM for rice caseworm
Examples of EPM for specific insect pests
Rice caseworm - Nymphula depunctalis (Guenee),
Pyralidae, Lepidoptera.
  • Ÿ  Rice fields with wider hill spacing (30 x 20
    cm) usually suffers less damage from caseworm.
  • Ÿ  Early planting may escape the peak caseworm
    moth activity period.
  • Ÿ  Draining of fields for 5-7 days kills caseworm
    larvae.
  • Ÿ  Use of older seedlings reduces the duration of
    the susceptible stage of the crop.
  • Nitrogen fertilizer use at optimal dosages and
    split applications reduce the rice caseworms
    abundance.

55
EPM for rice whorl maggot
Examples of EPM for specific insect pests
Rice whorl maggot - Hydrellia philippina Ferino,
Ephyridae, Diptera.
  • Ÿ  Adult flies are more attracted to standing
    water. Therefore, by draining the water at 3-4
    days intervals during the first 30 days after
    transplanting, egg lying is reduced.
  • Ÿ  Covering the water surface with Azolla and
    Salvinia molesta prevents rice whorl maggot
    infestation.
  • Ÿ  Direct-seeded rice is not as attractive to
    adults as a transplanted rice crop is.
  • Ÿ  Fields with higher plant density suffers less
    damage.
  • Close planting decreases oviposition and
    subsequent damage.

56
Rice bug EPM
Slender rice bug - Leptocorisa acuta (Thunberg),
Alydidae, Hemiptera
Examples of EPM for specific insect pests
  • Ÿ   Simultaneous crop maturity in all fields in
    an area dilutes rice bug damage.
  • Ÿ   Staggered planting should be avoided.
  • Ÿ   Rice maturing late in a few fields may suffer
    severe damage because of the rice bug
    concentration.
  • Rice bugs are capable of surviving on other
    vegetation during the off-season. Control of bugs
    on other vegetation, especially in the
    off-season, can be beneficial.

57
Summary
  • Nn Nt B D I E
  • Cultural control aims to increase
  • mortality
  • emigration
  • Cultural control aims to decrease
  • natality fecundity
  • immigration

58
CONCLUSIONS
  • Cultural control is a prophylactic method of
    control, i.e. used for preventing pest problems.
  • Cultural control is rarely use as a tactical
    means of control
  • Cultural control should be considered the first
    defense, around which other control options are
    built.

59
ACKNOWLEDGEMENTS
  • T. W. Mew
  • K. L. Heong
  • A. Barrion
  • L. Almazan
  • Elsa Rubia Sanchez

60
References
  • CABI (CAB International) 2001. Crop Protection
    Compendium (2001 edition) CD or on-line
    version. United Kingdom.
  •  Dent, D. 1995. Integrated Pest Management.
    Chapman Hall, London, 356 pp.
  •  Dent, D. 2000. Integrated Pest Management (2nd
    Ed.) CABI Publishing, Wallingford, 410 pp.

61
References - continued
  • Douglas MR and Brunner PC. 2002. Biodiversity of
    Central Alpine Coregonus (Salmoniformes) impact
    of one-hundred years of management. Ecological
    Applications 12(1)154-172.
  • IRRI and UQ. 2002. RiceIPM (version 1) -
    International Rice Research Institute
    (Philippines) and The University of Queensland
    (Australia), CD.
  •  Litsinger JA., 1994. Cultural, mechanical, and
    physical control of rice insects. Pp. 549-584 In
    EA Heinrichs (ed.) Biology and Management of Rice
    Insects. International Rice Research Institute,
    Philippines, 779p.
  •  

62
References - continued
  • MacNally R and Fleishman E. 2002. Using
    indicator species to model species richness
    model development and predictions. Ecological
    Applications 12(1)79-92.
  • May, RM. 1990. Taxonomy as destiny. Nature
    347129-130.
  • Noss, RF. 1990. Indicators for monitoring
    biodiversity a hiearchical approach.
    Conservation Biology 4355-364.

63
References - continued
  • Reissig WH, Heinrichs EA, Litsinger JA, Moody K,
    Fiedler L, Mew TW and Barrion AT. 1986.
    Illustrated guide to integrated pest management
    in rice in tropical Asia. International Rice
    Research institute, Philippines, 411p.
  • Takahashi, F. 1964. Reproduction curve with two
    equilibrium points a consideration in
    fluctuation of insect populations. Research in
    population Ecology 628-38.
Write a Comment
User Comments (0)
About PowerShow.com