Integrated Pest Management

Transcription

1 Integrated Pest Management Science and Language Arts Brief Description: This lesson will focus all of the information the students have learned about pests in the other insect lessons in a decision-making activity. Students will make their own decisions on pest control given a set of circumstances and an opportunity to research the alternatives. Objectives: Students will be able to: 1. Identify five major categories of pests. 2. Explain integrated pest management. 3. Discuss alternative pest control techniques. 4. Use the Internet to obtain information about pests and pest control. Life Skills: 1. Acquiring, Analyzing and Using Information 2. Understanding Systems 3. Working with Groups 4. Decision Making Time: Two, 45 minute sessions, plus time for internet research Materials: Copies of Blast That Pest! information sheets for each student and Pest Problems activity cards Insect identification guides (Extensions) Cardboard Vaseline String Paper clips (one per student) 6 cloves garlic 1 medium onion 1 Tbsp cayenne pepper 1 tsp liquid soap 1 gallon of water Fine mesh strainer 3 or 4 spray bottles Weed identification guides Pens or pencils Preparation: Make double-sided copies of Blast That Pest! information sheets for each student. Make a copy of and cut out Pest Problems activity cards. Gather supplies for insect trap and organic pesticide if the extensions of the lesson will be used.

2 Background: There are thousands of pests that are harmful to humans, compete with humans for consumption of food, damage animals that humans are raising, annoy humans, or destroy the aesthetics of a human environment. Pests carry and transmit serious diseases to human populations. For many reasons pest need to be controlled. This lesson will focus on insects, but the broad concepts can be applied to all pest management. Harmful insects: The Mediterranean Fruit Fly (Ceratitis capitata) - commonly called the Medfly, it is one of the most destructive insect pests in the world and the worst pest of citrus fruit. Medflies attack over 250 fruits, nuts, and vegetables: apple, avocado, eggplant, fig, guava, mango, pear, peach, pepper, persimmon, tomato, and many others. Countries with established Medfly populations have average crop losses of 25%-50%. These are foreign pests to the continental United States and they must be eradicated whenever found in the U.S. If the Medfly is not eradicated, it could devastate agriculture by destroying crops and therefore increasing food prices. These pests are controlled by using integrated pest management techniques. Some methods include trapping, quarantine of infested areas, pesticide usage and fruit removal from surrounding sites where Medflies have been found. The Silverleaf Whitefly (Bemisia argentifolii) - This species feeds and reproduces on most types of vegetables, broadleaf row crops, weeds, and many ornamentals including poinsettia. The immature whitefly injects salivary secretions into the plant which produces a silvering of squash leaves, irregular ripening of tomato fruit, and blanching of broccoli stems and poinsettia leaves. This species is found in the Southern United States as well as in Jamaica and the Dominican Republic where it occurs on tomatoes and is responsible for the transmission of Tomato Yellow Leaf Curl Virus (TYLCV). Aphids - The greenbug and yellow sugarcane aphid are major pests to pangolagrass. It is most threatening in central and southern Florida. The greenbug is easily controlled by natural enemies. Armyworms (Fall, Southern, Striped and others) - These are caterpillars or worms and are the immature stages of grayish-brown moths. They get their name because they often move in large numbers from one area to another in search of food. Females lay their eggs on the lower leaves of grasses and the larvae begin to feed as soon as they hatch. They are easiest to control when the worms are still small. It is difficult to control the almost mature larvae.

3 Beneficial Insects: It is estimated that less than one percent of all insects are harmful to humans. The other 99% are either beneficial or are kept under control by natural predators, diseases, or other forms of competition. We are just learning effective ways to use these insects to our advantage to control the pest insects. Dragonflies - These insects reduce the population of mosquitoes and other aquatic flies. Lady beetles - There are 5,000 species of Ladybug beetles worldwide and are one of the most beneficial insects in Florida. Adults and larvae feed on aphids, mites, and immature scale insects. Earwigs - These prey upon insects such as chinch bugs, small mole crickets, and other insects on the soil surface. Damsel bugs - These insects feed on aphids and caterpillars. Integrated Pest Management (IPM): IPM uses a combination of chemical, cultural, genetic, biological, and physical methods in a way that minimizes economic and health risks, as well as the effect on non-target organisms and the environment. IPM promotes minimized pesticide use by the protection of commodities with environmentally and economically sound practices. Growers who use IPM detect pests early and make treatment decisions in a methodological way, paying special attention to site selection, soil fertility, resistant varieties, economic thresholds, and careful record keeping. Maintaining accurate records is important to measure the effectiveness of the IPM strategies. An IPM program will constantly evolve as new control strategies, monitoring techniques and threshold information become available. IPM Methods: Biological Control - This method uses the natural enemies of pests against them. Biological control agents include native, as well as introduced, parasites and predators. An example is how the citrus leafminer (CLM) was controlled in Florida in The CLM population rapidly exploded within only three months after arriving in Florida. Insecticides seemed to have little effect after repeated applications. Native parasites and predators, as well as an introduced parasitic wasp from Australia, have effectively controlled the CLM population.

4 Cultural - This method uses management techniques to control pests. An example is how farmers dealt with the multi-million dollar epidemic of potato virus Y in Minnesota. Researchers discovered that aphids could only spread the virus by immediately moving from an infected plant to a healthy one. Farmers, therefore, grew other plants around their potato fields in order to give the aphids a place to drop the virus before they reached the potatoes. The spread of the disease was reduced by half. Chemical - The use of chemical pesticides is a part of IPM as an option of last resort. IPM does not prohibit chemical use nor does organic pest control (it simply limits chemicals to naturally occurring chemicals). In Integrated Pest Management the use of chemicals is the last option when all else fails or if other options are not available. For example, predatory or biological controls are not available to control all pests, or are not as effective as the marketplace demands. In IPM when pesticides are used it is in a very selective, targeted manner directed at a limited number of pests. Introduction: 1. Ask the students: *Can someone describe to me what a ladybug looks like? (This should be easy for most students.) 2. Now think about this cute little red and black beetle. Ask the students: *Does it have a purpose? Is it an important insect to us as humans? (Allow students time to think about this and give their opinions.) *The ladybug is in fact a very important insect to humans; does anyone know why? (The ladybug was brought to California from Australia in 188,7 to eat a flat looking insect called the cottony-cushion scale that was rapidly destroying California s orange groves. The ladybug saved California s citrus fruit industry and has since proved to be one of the most beneficial insects in the United States, dining on many other plant pests.) 3. Explain that although the ladybug is a beneficial insect, not all insects are beneficial to us as humans. Insect species which interfere with human activities like agriculture, outdoor sports and recreation are considered pests. Today, we are going to explore the different kinds of pests in our area and learn ways to control them through integrated pest management (IPM).

5 Activity: 1. Instruct students to review and brainstorm to come up with a list of other living things, besides insects, that are considered pests. 2. List the five major kinds of pests on the chalkboard. (insects, diseases, weeds, rodents and other animals, nematodes [round worms]) 3. Allow students one minute to list as many ways to control pests as possible, and give examples of each. Discuss their answers. 4. Have students discuss the positive and negative effects of using pesticides. Select a volunteer to make two columns, one labeled positive and the other negative, on the board and record the students' responses. Possible answers: Positive kills insects that damage crops, houses and other structures kills insects that carry diseases helps farmers produce more and better crops Negative may end up in many unwanted places such as the soil, lakes and streams can harm people, animals and the environment insects develop resistance 5. Explain to students that due to the negative effects of pesticides other pest control methods, such as IPM (Integrated Pest Management), were developed. They will take a more in-depth look at IPM now. 6. Give a copy of the Blast That Pest! information sheets to each student. 7. Read and discuss the information sheet aloud with students. 8. Divide students into four groups and give each group one of the following Pest Problems. A. Home gardener with an insect problem. B. Golf course manager with a weed problem. C. Tomato grower with a rodent problem. D. Vegetable grower with a bacterial rot problem 9. Have groups research information on the Internet, discuss a strategy to solve their pest situation using IPM controls and give examples of each. 10. Have groups present their strategies and solutions to the class.

6 11. Discuss the information and activity by asking the students these questions: *What is integrated pest management? (A pest management strategy that uses biological, cultural, genetic, mechanical and chemical methods to control pests.) *How does a grower determine when to act on a pest problem? (When the amount of plant damage is no longer tolerable.) *What are some IPM controls that a gardener can use to reduce pests? (Cultural - wash tools after working on the garden to prevent the spread of diseases to other areas. Biological - grow plants that attract beneficial insects so they will prey on garden pests. Mechanical - mulch to prevent weed growth. Genetic - plant disease resistant varieties. Chemical - spray an insecticide.) *Who benefits from IPM use? (Pesticide users, fish and wildlife, the environment, society) *What role does the environment play in managing pests? (An environment that provides an organism with everything it needs to reproduce and spread will yield large numbers of that organism. An environment that provides that organism with competition and predators will have a lower number of that organism. Producing an environment that is unattractive to pests helps reduce the number of pests in your area.) Extensions or Alternatives: 1. Instruct students to make an inventory of all pesticides at their school or home, with adult supervision. List the pest controlled, active ingredient and toxicity (or poison) level of each pesticide. Discuss what was found and alternative methods that could be used instead of, or in combination with, the chemicals. 2. Pass out cardboard, Vaseline, string and paper clips. Instruct students to use their pencil to make holes around the edges of their cardboard. They may then unfold the paper clip and use it to help them thread the string through the cardboard. Next, students should coat the cardboard with Vaseline. Students should place their insect traps around a garden or landscaped area. Have students collect and identify the insects and determine if they are pests. You may want to do experiments by using different colored cardboard or paper (i.e. flies are attracted to yellow)

7 3. Instruct students to make an organic pesticide to control chewing insects. Have them do the following: Combine 6 cloves crushed garlic, 1 minced onion, 1 tablespoon cayenne pepper, 1 teaspoon dish washing soap, and 1 gallon of water. Mix ingredients and let sit for 15 minutes. Strain into a spray bottle and mist the plants. (NOTE: This is not guaranteed to work!) 4. Allow students to collect weeds from a garden or school yard and identify, label and press the weeds. They should include common name, date, scientific name, where it was found, and collectors name. Evaluation Options: 1. Assign a group evaluation based on cooperation, creativity and the information the group presents.