Insects and Nematodes

1. Insects and Nematodes

2. Objectives: • Describe the biology of insects • Classify insects • Classify nematodes and describe their biology • Explain scouting and threshold in insect management • Describe methods of insect and nematode management

3. 3 major body segments: • Head- eyes, antennae, and mouthparts • Thorax- wings and 3 pairs of legs • Abdomen- contains organs for digestion, reproduction, and excretion

4. Mouthparts: • Chewing- bites off, chews, and swallows plant parts • Sucking- pierces outer layer of plants parts and draws sap from it

5. Reproduction: • Metamorphosis- stages of development where insects go from egg to adult, there are 2 types: • Incomplete- 3 stages: egg, nymph, adult • Complete- 4 stages: egg, larvae, pupa, adult Incomplete

6. Insect Classification • Scientific classification- phyla are further divide into classes; classes are further divided into orders and then families, genus, and species • Insects are in the arthropoda phylum • Nematodes are in the Nematoda phylum

7. Insect Classification • Beneficial insect- one that is of value for the role it fills in the environment • Harmful insect- one that causes damage to plants, animals or property

8. Insect Classification • Mouthparts Classification- control measures must be selected based upon the way an insect feeds • Reproduction classification- determined by the type of metamorphosis they go through which also determines control method • Feeding location classification- one of the 3 types must be identified in order to effectively choose a control method

9. Insect Classification • External feeders- chew or suck form the exterior of the plant • Internal feeders- chewing type that bore into the plant and go inside to feed • Subterranean- species in the soil that attack plant roots.

10. Nematode Classification and Biology: • Nematodes- damage plants by piercing and sucking juice or tunneling inside plant roots and secreting a substance that injures the roots. The injury allows fungi and bacteria to enter the roots which can cause disease. • 2 types root knot (attacks the roots) and foliar (attacks the leaves or stem)

11. Methods of Insect and Nematode Management: • Scouting- visually inspecting for the presence of insect pests and damage • Threshold- density of the pest population that will justify using pest management measures, there are 2 types of thresholds: • Economic- the balance of cost with returns • Aesthetic- deals with the appearance of plants such as turf

12. Selecting Management Methods: • Quarantine- isolation or exclusion of a pest problem • Cultural management- preventing insect and nematode problems by the practices used in growing the plants such as: • Crop rotation • Residue management • Trap crops • Using resistant varieties • Sanitation

13. Biological Management: • Releasing beneficial insects • Disrupting reproduction • Using bacteria and fungi

14. Chemical Use: • Pesticides: • Insecticides- used to kill insects, classified by entry • Contact- absorbed through skin or exterior • Stomach- must be ingested • Respiratory- must be inhaled • Systemic- taken up by the plant and passed on to pest through ingestion of plant • Formulation- the way pesticide is prepared • Active Ingredient- percent poison material in an insecticide • Nematocides- used to kill nematodes

15. Genetic Engineering: • Used to genetically modify or alter an organism by adding or subtracting qualities through the changing of the genetic code • Transgenic- plants altered by genetic engineering

16. Summary: • Plants can be damaged by nematodes and insect pests, the control of these pests improves the quality and amount of plant production. All known factors should be considered when planning a method of control. • Some insects are beneficial others are harmful. Knowing the biology of insects affects the control method choice. Insects have 3 parts head, thorax, and abdomen.

17. Summary: • Insects feed in two primary ways, chewing and sucking. • Some feed on the exterior of plants, some feed on the inside, while others feed below the soil. • Damage by insects often occurs at different stages of their development. Insects have either complete or incomplete metamorphosis. • The larvae stage often causes the most damage to plants.

18. Summary: • Nematodes live in the soil and attack plant roots like the cyst nematode or live above the soil and attack plant leaves and stems. • There are various control methods used to combat insects and nematodes. • Scouting helps determine the threshold of insect impact thus establishing grounds for the application of a control method such as: • quarantine, cultural control, biological control, chemical control, and genetic engineering.