Insect Pests and Management

1. Insect Pests and Management OBJECTIVE: Identifying and scouting for common insect pests encountered in the garden and methods of control.

2. Specialists vs. Generalists • Specialists - insects that attack a small range of plants or within a single plant family. • Cucumber beetles - cucurbitaceae • Tomato hornworm – solanaceae • Generalists - insects that attack a wide range of plants or many plant families. • Grasshopper • Aphid • Japanese beetle Grasshopper Aphids

3. What do we have for dinner, dear? Oh, Don’t worry dear! We have a lot to choose from. They don’t call us the generalists for nothing.

4. Insects that “Suck!” • Small, soft-bodied insects with slender mouth parts, which suck out plant juices. • Aphids - attack stems and leaves • Spider Mites - attack leaves • Thrips - attack leaves, flowers, fruit, and other insects • White Flies - attack beans, solanaceae, and fruit Spider Mites Thrips

5. Insects that Suck. Aphids Spider mites

6. Insects that Chew • Those insects that chew and digest vegetative and reproductive plant parts. • Cucumber beetle - attack entire cucurbit plants • Corn borer - bore into ears of corn • Tomato hornworm - attack tomato leaves and fruit • Japanese beetle - attack anything and everything • Colorado potato beetle - attack leaves of potato and eggplant

7. Insects that Chew a c d • Colorado Potato • Beetle • b. Flea beetle • c. Cabbage worm • d. Corn borer • e. Japanese beetle b e.

8. Scouting for insects: damaged plants? • If insects are eating your plants, they leave a distinct trace behind • Aphid - sticky, honeydew, and crispy leaves • Spider Mites - stippled leaves and webs • Thrips - patchy scars on leaves • Leaf miners - subsurface discolored leaf trails • Caterpillars - chewed leaf margins and fruit

9. Scouting for insects: eggs, larvae, nymphs, or adults? • Another way to scout for insects is to observe whether or not they are present in some form. • Eggs • Larvae • Nymphs • Adults • Insects leave “frass” behind too!

10. Controls: Beneficial Insects • Many insects either parasitize or feed on insects that eat your plants. • Parasitic Wasps - attracted to flower pollen and lay their eggs on or within many herbivore eggs and larvae • Convergent Lady Beetles - feed on herbivore eggs and larvae, as well as aphids • Predaceous Mites - feed on pest mites • Green Lacewings - feed on aphids, thrips, and mites • Assassin Bugs - attack almost any insect • Bigeyed Bugs - attracked to flower nectar and feed on small insects and their eggs • Soldier Beetles - feed on aphids

11. Controls: Beneficial Insects Big eyed bug Assasin bug Lady bird Green lacewing Soldier beetle

12. Controls: Cultural • The environment provided will impact the degree to which pests are a problem. • OM • Soil Moisture • Crop Residues • Fertility • Crop Rotation - avoid specific pest colonization • Resistant Cultivars - prevent excessive damage • Soil Sterilization - reduced soil inhabiting pests • Pest Barriers - prevent pest access to plants • Companion Planting - lure pests away from crops Varying these levels will determine population numbers of different insects.

13. Controls: Natural Compounds • Organic pesticides are derived from naturally occurring substances and control specific groups of insects. • Bacillus thuringiensis (Bt) - lepidopteran larvae • Diatomaceous earth - leaf chewing insects • Pyrethrum - cucumber beetles, squash bugs, mealy bugs, moth larvae Pretty me! Dalmation chrysanthemums used for production of pyrethrum

14. Controls: Natural Compounds • Rotenone - beetles, thrips, loopers • Insecticidal Soap - white flies, mites, “suckers” • Neem – Most insects, also a broad spectrum fungicide • Pepper Wax - aphids, leaf hoppers, flea beetles

15. Controls: Synthetic Compounds • Many insecticides are synthetically derived and can control a wide spectrum of insects - dependent on dosage. • Most synthetic insecticides are recommended by crop rather than by insect due to their full spectrum effectiveness. • Issues include: hazard, toxicity, restricted use • Sevin - controls many insects at various stages; toxic to honey bees • Pounce - several worms and beetles • Lorsban - aphids, worms, maggots • Malithion – controls most insects

16. Controls: Synthetic Compounds • Systemic insecticides – • Put in soil or on plant and remain in tissues so any insect that tries to eat the plant will die. Obviously, can’t be used on food crops.