AGRICULTURAL INSECT PESTS

1. AGRICULTURAL INSECT PESTS • WHAT IS PEST? • any organism judged as a threat to human beings or to their interests

2. Do human actually create insect pests? • 1) manipulation of the environment (monoculture) • 2)transport across natural barrier • 3)Insecticide use • 4)Economic expectations of a crop (aesthetics value= consumer expectations)

3. WHAT CAUSES PEST OUTBREAK? • environmental change • Changes in climate, habitat, or community structure (caused either by natural phenomena or human intervention) may provide an insect population with a reproductive opportunity that could change its status from endemic to epidemic within just a few generations. • introduction from abroad • Expansion of international travel and trade continues to bring new opportunities for spread of insect pests from one part of the world to another.

4. WHAT CAUSES PEST OUTBREAK? • destruction of natural enemies • Pest populations often reach outbreak proportions if their native parasites and predators are suppressed or eradicated.  • Beneficial insects are often unintended victims of insecticides used to control pest outbreaks.  Destruction of these non-target populations may result in outbreaks of new pest species that were previously held in check by predation or parasitism. 

5. WHAT CAUSES PEST OUTBREAK? • development of resistance • When insect populations are exposed to selective pressures, whether natural or artificial, they change and adapt. • Resistance may be biochemical (e.g. an enzyme that degrades or detoxifies an insecticide), physiological (e.g. the ability to withstand greater environmental stress), or behavioral (e.g. the ability to avoid a poison or adapt to a new host plant).

6. WHAT CAUSES PEST OUTBREAK? • higher quality standards • Higher living standard of consumers make them intolerant with low quality of commodity (eg vegetables and fruits). As a result, producers are forced to apply more stringent pest control just so they will have a marketable commodity.

7. IPM Integrated Insect Pest Managementan effective and environmentally sensitive approach to pest management that relies on a combination of available pest control methods, used to manage pest damage by the most economical means, and with the least possible hazard to people, property, and the environment.

8. METHODS OF CONTROL • 1) HOST PLANT RESISTANT • 2)BIOLOGICAL CONTROL • 3) CULTURAL CONTROL • 4) GENETIC CONTROL • 5) MECHANICAL CONTROL • 6) INSECTICIDE

9. (1) HOST PLANT RESISTANT • There are three approaches that plant breeders use to develop resistant cultivars: • (1) Antibiosis.   Plants produce a wide variety of defensive compounds (allelochemicals) that protect them from herbivores.   These compounds may reduce growth, inhibit reproduction, alter physiology, delay maturation, or induce various physical or behavioral abnormalities in herbivores.  

10. (2) Antixenosis.   A physical or chemical property of a plant can make it so unpalatable that it is largely protected from herbivore attack.   This type of resistance is often known as nonpreference.   It may involve the presence of feeding repellents (or the absence of feeding attractants), or it may involve physical traits such as hairs, waxes, or a thick, tough epidermis that do not provide the pest with a desirable feeding substrate.  

11. (3)Tolerance.   Some plant genotypes are simply able to "tolerate" injurious insects better than others.   Tolerant cultivars may be exposed to the same pest populations as susceptible ones, but they do not suffer as much injury.  

12. (2) BIOCONTROL • the use of an organism to control other organsim • the use of the natural enemies to control insect pest population • i)parasitoid • ii)predator • iii)microbes

13. Parasitoid & predators • PREDATORS: • mainly spiders, ants, predatory beetles, lacewing, mantids • for vertebrate: birds, bats, small mammals, fish, duck etc • PARASITOIDS: • Primarily Hymenoptera & Diptera • eg; Trichogrammasp., Goryphusbunoh, Apanteles sp.

14. Two types of parasitoid: 1) KOINOBIONT • parasitoid allows its host to continue to feed and/or develop after oviposition, such that its larvae feed on an active host that is only killed at a later stage. 2) IDIOBIONT • parasitoid paralyzes and/or arrests the development of a host at oviposition, providing its larvae with an immobilized static resource on which to feed.

15. Parasitoid & predators • Approaches(Kaedah): • i) Conservation • ii)Import/introduce • Augmentation: release large number of natural enemies

16. Parasitoid & predators • ADVANTAGES: • i)introduced natural enemies suitable, so permanent • ii)not harmful to human • iii) to develop less expensive • iv)low potential to resistance to occur

17. Parasitoid & predators • Disadvantages: • i)inconsistent result: if the pest population is low, they might migrate to new places • ii)incompatible with pesticides • iii)low profit, less investment from private sector

18. Microbes • i)Bacteria • widely use; Bacillus thuringiensis, produce toxin, insect makan, lumpuh dan mati • specific, fewer problem hitting the nontarget insects

19. Microbes • ii)Fungi • more 750 species as entomopathogens • Metarhizium anisopliae ,Beauveria • fungi can penetrate cuticle so can be use for hemipteran and homopteran pests • need high humidity to germinate • now technology, can germinate semi-arid environment

20. Microbes • iii) viruses • need to be ingested • 6 main group of insect viruses, 3 safe to human (remember the 3 safe to human!!!!!!) • i) nuclear polyhedrosis virus (NPV) • isolated from lepidotera, Hymenopt., Dipt., Orthopt. • 125 type NPV isolated • potential biopesticide

21. Microbes • ii)granulosis virus (GV) • 50 type • most from Lepidoptera • iii) cytoplasmic polyhedrosis virus (CPV) • 200 types • less efficient because not host specific • can take longer time to kill & unstable compare to NPV • eg: NPV from Spodoptera exigua in vegetables, grapes, cotton

22. Microbes • iv)Nematodes • 40 products w/wide • Families: • i) Steinernematidae (daratan) • ii) Heterohabditidae (daratan) • iii) Mermithidae (akuatik) • Detect host by responding to chemical & physical cues

23. (3) CULTURAL CONTROL (IMPORTANT) • modifications of a pest's environment or habitat • i)crop rotation • ii)intercropping • Iii) sanitation

24. CROP ROTATION • Rotating the field to a different type of crop can break this cycle by starving pests that cannot adapt to a different host plant. • Effective against pest species that has narrow host range & limited range of dispersal • Make sure rotate with non-host crops plant • No time for colonization

25. INTERCROPPING • Planting 2 or more crops in alternating portions • Slow the spread of pest • Encourage natural enemies • Improve soil fertility • Plant flowering crops or wild vegetation to provide nectar for natural enemies

26. SANITATION • After harvest where do pests go? • i)alternative crops • Ii)crop debris • Iii)dormant in the soil • destroy animal waste and crops residue • Eg: remove and destroy fruits drops (small scale area) • Tilling or plowing a field may disrupt a pest's life cycle by causing mechanical injury, by increasing exposure to lethal cold temperatures, by intensifying predation, or by burying the pests deep beneath the soil surface.

27. 4)MECHANICAL CONTROL • The use of hands-on techniques as well as simple equipment, devices, and natural ingredients that provide a protective barrier between plants and insects. • 1)handpicking • effective with foliage-feeding insects • 2) Traps and Attractants • Sticky trap with lure such as metyhleugenol for f/fly

28. 3)Water Pressure Sprays forceful stream of water will sometimes dislodge insects such as aphids and spider mites 4)Insecticidal Soaps Control aphis and mites

29. 5)GENETIC CONTROLSIT(sterile insect technique) • Works best when pest population is low • Usually male (sterilized by gamma ray) • sterile males compete with the wild males for female insects. • female x sterile male = no offspring, thus population is reduced. • Eg: control of screwworm fly (in cattle)

30. 6)INSECTICIDE use of chemical substances to kill or disrupt the life cycle of an insect pest (conventional insecticide) There are less toxic compounds that disrupt insect development or modify behavior

31. 1) CHEMOSTERILANT(IMPORTANT) chemical control of reproduction chemical substances that are known to cause reproductive sterility in insects.  Some of these compounds inhibit ovarian growth and development, while others appear to induce fundamental changes in the chemical structure of nucleic acids (DNA and RNA). These changes (mutations) prevent cell division or obstruct normal embryonic development. These compounds are applied directly to the insect or incorporated into food that serves as a bait.

32. 2)SEMIOCHEMICAL Chemical control of insect behavior They serve as attractants or repellents, they may stimulate or inhibit feeding, they may provoke flight or inhibit it, or they may simply elicit behavior patterns at inappropriate times. Eg: Sex phemromones(ATTRACTANT) Eg: The neem tree, Azadirachtaindica (Meliaceae) is a promising new source of feeding REPELLANT that may be developed for use on selected non-crop plants

33. 3)INSECT GROWTH REGULATOR (IGR) • Chemical control of development • The enzymes and hormones that regulate developmental processes within an insect's body • 1)Chitin inhibitors. •   These chemicals (e.g., diflubenzuron and teflubenzuron) inhibit the molting process • 2) Molting Hormone Analogues • Ecdysteroids (found in some plants) stimulate the molting process by mimicking the action of molting hormone

34. 3) Anti-juvenile Hormones (prococene) • Destroy corpora allata so no JH being produced • In immature insects, causes premature development of adult • In adult, precocenes can cause sterility because the presence of juvenile hormone is necessary for normal production of eggs and sperm

35. 4) CONVENTIONAL INSECTICIDE • Three ways insecticide works: • i) SYSTEMIC INSECTICIDE • The insecticide is introduced into the soil where it is absorbed by plant roots. It then moves up through the plant to external areas (leaves, twigs, fruits, branches), where it lays on the plant surface area and is poisonous to any insects that come chewing on the plant.

36. ii)contact insecticide must directly hit the insect iii)ingested insecticide Insect consume the insecticide Insecticide can enter human body also in 3 ways: eating/drinking, inhaling and through skin

37. TYPES OF INSECTICIDES • INORGANIC (does not contain carbon) and ORGANIC (contain carbon) • COMMON TYPE OF ORGANIC INSECTICIDES: • 1)Organochlorine (OC) –works by attacking the nerve cells of insects • EG: DDT, Lindane and Chlrodane

38. 2) Organophosphates (OP) – These types of insecticides are a combination of an organic molecule and phosphates. They attack insect’s nerve. act primarily by inhibiting (merencat) enzyme acetylcholinesterase (AChE), thereby allowing acetylcholine to accumulate at synapses

39. 3)Carbamates – These insecticides work in the same way as organophosphates but do not remain in the area for nearly as long, making them a better choice for the earth. Bendiocarbamate is a common type.

40. 4) Pyrethrum – Found in nature, a product of the tropical chrysanthemum, this insecticidal chemical is very effective, even in small doses 5)Pyrethroids – A synthetic version of the natural insecticide pyrethrum, it mimics pyrethrum; significantly less toxic than other compounds. Pyrethroids are most often used in residential applications.