2InsecticidesIdentify common insect pests and select an effective control method for each.Describe the six ways in which insects are killed by insecticides.List the names and characteristics of the three major groups of insecticides.Compare the six ways in which insecticides are applied.Explain the relationship between the life cycle of insects and timing of application.
3What is an insect?Insectsmall animal with three defined body regions and three pairs of legs!HEAD, THORAX, and ABDOMEN!
46 Common Orders! Orthoptera- includes the grasshopper and locust Hemiptera - includes the true bugs such as leaf hoppers and plant bugsLepidoptera – moths and butterfliesHomoptera- aphidsThysanoptera- thripsColeoptera- which is the largest group of the insect orders, including beetles
5Insect grouping! How are insects grouped? They are grouped by the way they feed on plants. So they are grouped by their mouth parts.
6Mouth Parts There are six different mouth parts Sponging Rasping- suckingSiphoningChewing-lappingChewingPiercing- sucking
7How Insecticides KillChemicals must kill insects while doing little or no damage to the plant.Stomach poisonsWork against insects that eat parts of the plant.Sprayed or dusted on the plantAs insect eats the plant, it is poisoned through the stomach.Insects that chew food (caterpillars, grasshoppers, beetles) are controlled by stomach poisons.Example--Rotenone
8How Insecticides KillContact Poisonskill insects when they are hit by or come in contact with the poison.Any type of insect can be controlled this way.Kill by upsetting the insect’s nervous system or breathing system.Example--malathion
9How Insecticides KillSystemic poisonsenter the plant sap and move throughout the entire plant.When insect eats parts of plants or suck plant juice, chemical is swallowed.Effective with insects with chewing or sucking mouthparts.Effective with insects that hide under leaves or underground.Food crops—allow time for chemical to break down.Example--Orthene
10How Insecticides KillFumigantscontact poisons applied in gaseous form.Gases or fumes kill the insect after entering system through breathing pores.Insect must absorb the poison for this insecticide to be effective.Used to control soil-borne insects that damage roots.ExampleTAME
11How Insecticides KillRepellantsdo not kill insects, but drive them away before they attack the plant.Examplealuminum foil (repels flying insects)
12How Insecticides KillAttractants and Phermoneswork in the opposite way from repellants.They lure insects to their death.Page 171
13Chemical Makeup of Insecticides Three groups!Inorganic CompoundsOrganic CompoundsSynthetic Organic Compounds
14Inorganic CompoundsMineral origina mineral is used as the basis for the poisonUsually work in the form of a stomach poison.Example—Sulfur
15Organic Compounds Derived from plants Work in form of stomach or contact poisonsExample—rotenone and pyrethrum
16Synthetic Organic Compounds Recent origin (last years)Produced in the laboratoryMany are also toxic to humans.Three GroupsChlorinated HydrocarbonsOrganophosphatesCarbamates
17Synthetic Organic Compounds Chlorinated HydrocarbonsLong RESIDUAL Control (continue to kill long after application)ExampleDDT (not used in US)
18Synthetic Organic Compounds OrganophosphatesContains chemicals most toxic to warm-blooded animalsAbsorbed rapidly through the skinParathionone drop in the eye can kill a human being.ExampleMalathion (relatively safe)
19Synthetic Organic Compounds Carbamatessafest insecticides on the marketBreak down rapidly (2-7 days) and leave no residue to contaminate the environmentDo not build up in the bodies of warm-blooded animalsExample—Sevin