INSECTS AND NEMATODES

1) Describe the biology of insects

2) Classify insects

3) Classify nematodes and describe their biology

4) Explain scouting and threshold in insect management

5) Describe methods of insect and nematode management

OBJECTIVES:

Head- eyes, antennae, and mouthparts

Thorax- wings and 3 pairs of legs

Abdomen- contains organs for digestion, reproduction, and excretion

3 MAJOR BODY SEGMENTS:

Chewing- bites off, chews, and swallows plant parts

Sucking- pierces outer layer of plants parts and draws sap from it

MOUTHPARTS:

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

REPRODUCTION:

Incomplete

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

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

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

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.

INSECT CLASSIFICATION

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)

NEMATODE CLASSIFICATION AND BIOLOGY:

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

METHODS OF INSECT AND NEMATODE MANAGEMENT:

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

SELECTING MANAGEMENT METHODS:

Releasing beneficial insects

Disrupting reproduction

Using bacteria and fungi

BIOLOGICAL MANAGEMENT:

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

CHEMICAL USE:

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

GENETIC ENGINEERING:

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 .

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.

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.

SUMMARY: