LESSON THREE

Title: Principles of IPM: Pest Identification

Learning Objective: To learn the importance of pest identification in a IPM program and methods of pest identification.

Materials: Presentation board (chalk board or flip chart) or slide projector, chalk or pen, pest life cycle hand outs, pest identification guides (computer with knowledge master, guide books and pest ID keys), pest examples to be identified (insects and weeds) and lesson fact sheet

Time Needed: 2 hours

Power Point Presentation: Lesson 2 (computer file: lesson2.ppt)

Opening: A example which illustrate (jokingly) the need to correctly ID pests: Suppose you walk into a store as it first opens in the morning. You get inside and realize things are missing from many of the shelves. The place has just been robbed. Before you can leave, the owner arrives with the police. You are unaware a silent alarm has been going off the whole time you have been in the store. They arrest you and take you to jail for burglary, just because you happened to be at the wrong place at the right time. Not a pleasant situation. Now this happens all the time to insects in field. They happen to land on a pest damaged plant at about the same time a grower is checking this plant, to determine what is causing the damage. The grower sees the insect, decides, since no other insects are around, that this insect has done the damage. The grower then prepares a pest control plan to kill this insect. Now they may be successful in killing this insect, but will they be successful in stopping the damage to their plants. Probably not. The story illustrates why proper pest identification is important.

Procedure:

 

A. Importance of Correct Identification of Pests

1. To determine if the pest is a key pest

a. Key pests: not always most numerous pest, but one that will

cause the most significant damage

2. ID can include placing the pest in a certain group and/or exact ID

3. ID must be done rather quickly, to determine the extent of the problem. 4. Incorrect identification can result in control actions which are

ineffective

5. Must ID the pest correctly before a control method is determined

Example: Incorrect identification of a pest may result in a search for parasites and predators in countries other than the native home of the pest. An example of this occurred for the beet leafhopper. It was mis-identified and searches were conducted in South America. It was later determined to be poorly identified and incorrectly classified. It’s native home was actually in the Mediterranean. Searches were then done their and a natural enemy was found. It may have been nice to travel to South America, but it was a waste of time and effort (Watson et al, 1976)

B. Importance of life cycles of pests.

1. Discussion of pest life cycles

a. Where and how they spend their life cycles

i. insects: egg, larva, pupa, and adult

ii. weeds: vegetative and reproductive

iii. diseases: infection, development of the disease, transfer of the disease

2. Importance of determining where a pest is in it’s life cycle

a. For timing of treatment activities.

i. must find the weak link in the life cycle

ii. direct deliberate control practices during weak links in the life cycle

iii. mis-timed control could be a wasted effort if pest is at it’s least

vulnerable stage of development

b. For evaluation of damage potential

i. determine if pest is at a stage of potential danger to the crop

 

C. Importance of Correctly Identifying the Damage Done by the Pest

1. Determine if the damage is fresh

2. Determine if the pest is still present

3. Determine if the damage is definitely pest related and not due to other

factors

4. Determine if the damage will lower the value of the crop

Activity

Participants are presented with insect and weed samples from Hawaii and, using a variety of methods, correctly identify these pests. The methods they will use should include those typically available to growers (guide books, pest keys and knowledge master web site information). This activity can be can be completed individually or in groups.

Resources

Watson, T.F., L. Moore, and G. W. Ware. 1976. Practical Insect Pest Management. W. H. Freeman and Co., San Fransisco. 196 pp.