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Als 3153 Class 15
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- 2. Phylum Arthropoda (jointed appendages,exoskeleton, etc.) • Class Insecta (most numerous and diverse group of organisms) • Class Arachnida • Class Crustacea • Etc. (centipedes, millipedes, etc.) Spiders – often beneficial as predators Mites – some plant pests, some predators
- 3. Insects vs Arachnids(Mites, Spiders)
- 4. Insect Life Cycles •1. Simple metamorphosis • 2. Complete metamorphosis • 3. Some exceptions • #1 and #2 apply to most agricultural pests
- 5. Simple Metamorphosis Egg Nymphs Adult – hasfull-size wings, functional reproductive system
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- 7. Simple Metamorphosis Egg Nymphs Adult – hasfull-size wings, functional reproductive system Usually 4-6 instars, resemble adults, smaller size Same food and environment for nymphs and adults
- 8. Complete Metamorphosis Egg Pupa Larva –several instars, important feeding stage Adult – very different from larva Corn Earworm
- 9. Complete Metamorphosis • Lifestages are important because ecology, food habits, and management of different stages can be different • Example: butterflies and moths • Larva – feeds as damaging caterpillar • Adult – beneficial as plant pollinator
- 10. Survey of insects– Major groups (orders) of ag pests or beneficial predators and parasites • Beneficial insects: • Predators, parasites • Pollinators • Recyclers of OM
- 11. Survey of insects– Major groups (orders) of ag pests or beneficials • Dragonflies • Orthoptera and relatives (mantids, roaches) • Thrips • True bugs (Hemiptera) • Piercing-sucking insects (Homoptera) • Beetles • Nerve-winged insects (Neuroptera) • Butterflies and moths • Bees, wasps, and ants • Flies • Etc.
- 12. Survey of Insects •Dragonflies --- beneficial predators of flying insects • Praying mantids --- beneficial predators • Roaches --- recycling in some ag systems • Grasshoppers, Crickets --- can be serious ag pests
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- 15. Thrips • Almost microscopicin size, fringed wings • Beneficial pollination in flowers • Most are plant pests • Some carry plant viruses
- 16. Virus Vectors • Vector= carrier of virus • Viruses in plants • Transmitted by insects, etc. • Vector feeds on infected plant acquires virus feeds and passes virus to other plants
- 17. True Bugs • Squash bug •Note typical appearance
- 18. True Bugs • Piercing-suckingmouthparts • Some important pests, e.g., stink bugs • Some predators
- 19. Piercing-Sucking Insects • Piercing-suckingmouthparts to feed on plants • Formerly Homoptera, often included with true bugs • Many important plant pests • Some transmit viruses • Aphids, cicadas, whiteflies, scale insects, leafhoppers, etc…
- 20. Green Peach Aphid •Very abundant as plant pests
- 21. Whitefly Adult • Commonunderneath leaves
- 22. Sooty Mold -Silverleaf • Important sign of whiteflies, etc…
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- 24. Beetles • Very manyspecies • Many pests – weevils, larvae of some types are grubs or wireworms • Many beneficials – Lady beetles, ground beetles, tiger beetles
- 25. Nerve-Winged Insects (Neuroptera) •Brown Lacewing
- 26. Lacewing Larva EatingWhiteflies • Beneficial predators
- 27. Butterflies and Moths •Pests – many kinds of caterpillars • Beneficial as pollinators
- 28. Bees, Wasps, Ants •Beneficial as pollinators • Many are important as predators and parasites • Many different kinds of wasps, most nearly microscopic • Parasitoids – microscopic wasps, lay eggs in body of pest (e.g., caterpillar), or even in egg
- 29. Flies • Many differentkinds, difficult to distinguish – different flies do different things: • Important pests of livestock • Beneficial as pollinators • Beneficial as predators • Some are parasitoids • Some are plant pests (leaf miners)
- 30. Leafminers • Larvae ofsome flies, some moths
- 31. Many Important Pestsof Livestock • Flies, Lice, Fleas, etc…
- 32. Important Insect Relatives •Mites -- some beneficial predators • Mites – some livestock pests • Mites – some plant pests • Spiders – Very important as predators (much underrated) in agroecosystems
- 33. Mite Damage onLeaf
- 34. Spider Mites • Notecharacteristic webbing
- 35. Management of InsectPests
- 36. Insecticides and Acaricides •+++ effective, detailed knowledge of pest biology not needed • +++ reliable, fast-acting • +++ quick response to emergency situations • - - - non target effects • - - - $ and energy costs • - - - high expectations
- 37. Biological Control • Controlby living organism or natural product of living organism • Hyperparasitism Caterpillar Tachinid fly Parasitoid Wasp
- 38. Biological Control -- TwoApproaches • Introduced = add control agents to ecosystem (many good examples with introduced pests) • Introduced: classical (new agent) vs augmentation (agent already present) • Natural = favor increase of naturally occurring control agents (manipulate environment, cropping systems)
- 39. Biological Control Many possibleorganisms: • Predators (often not specific) • Parasites • Diseases (parasites) Fungi Bacteria Viruses Parasitoids (often highly specific) Entomopathogenic nematodes
- 40. Host Plant Resistance •Interfere with host finding, feeding, pest nutrition, timing of life cycles, etc… • Hairs on leaves, sticky, etc. • Alkaloids in plants deter insects • Crop cultivars/genotypes selected for resistance to pests
- 41. What is BiologicalControl and What Is Not ???
- 42. What is BiologicalControl? • Predators • Parasites • Diseases
- 43. What is BiologicalControl? • Predators • Parasites • Diseases • Bacterial disease of insects caused by Bacillus thuringiensis (BT)
- 44. What is BiologicalControl? • Bacterial disease of insects caused by Bacillus thuringiensis (BT) • Allow bacteria to produce spores with toxin in lab, isolate BT toxin, and spray it on pests
- 45. What is BiologicalControl? • Bacterial disease of insects caused by Bacillus thuringiensis (BT) • Allow bacteria to produce spores with toxin in lab, isolate BT toxin, and spray it on pests • Transgenic plants that produce BT toxin (Bt corn, Bt cotton)
- 46. What is BiologicalControl? • Resistant plants as biological control agents • Plants with alkaloids • Pyrethrum = natural plant alkaloid
- 47. What is BiologicalControl? • Resistant plants as biological control agents • Plants with alkaloids • Pyrethrum = natural plant alkaloid • Isolate pyrethrum from plants and use it
- 48. What is BiologicalControl? • Resistant plants as biological control agents • Plants with alkaloids • Pyrethrum = natural plant alkaloid • Isolate pyrethrum from plants and use it • Make synthetic pyrethrum • Pyrethroid = pyrethrum analog, similar chem structure
- 49. Environmental Heterogeneity • Cropgenetics (uniform genotypes vs mix) • Vegetation diversity vs pest dispersal • Vegetation diversity as reservoir for natural enemies
- 50. Plant Health • +++Healthy plant can withstand some insect damage • - - - High N can increase insect growth and reproduction
- 51. Attractants and Repellents •Attractant, e.g., pheromone (sex or aggregation) useful for: • Sampling and monitoring (important use for quarantine detection, regional monitoring) • Attracting insects to traps • Confusing normal life processes and patterns
- 52. Cultural Practices • CropRotation • Weed control of virus hosts • Sanitation and cleanup of crop residues (affected overwintering of boll weevil) • Timing of planting dates (winter wheat, Hessian fly) • Others (sterile males, etc.)
- 53. For most effectiveinsect management, usually need to know biology and habits of individual insect pests
- 54. References • Text: Ch10, pp. 201-208; Ch.11, pp. 219-222. • Metcalf C.L., W.P. Flint, and R.L. Metcalf. 1962. Destructive and Useful Insects. McGraw-Hill, NY. • Metcalf, R.L., and W.H. Luckmann. 1994. Introduction to Insect Pest Management. John Wiley & Sons, NY. • Images from UF Dept. Entomology & Nematology – Featured Creatures: • http://creatures.ifas.ufl.edu