Invertebrate and Vertebrate Pests

Subject : 

Biology

Topic :

Invertebrate and Vertebrate Pests

Term :

Second Term

Week:

Week 4

Class :

SSS 2

Previous lesson : 

The pupils have the previous knowledge of

PESTS AND DISEASES OF CROPS

that was taught in the last lesson

Behavioural objectives :

At the end of the lesson, the pupils should be able to

• classify pests
• mention invertebrates and vertebrate crop pest
• explain the life cycles of pests

Instructional Materials :

• Poster
• Wall Chart
• News paper
• Online Video
• Pictures

Methods of Teaching :

• Class Discussion
• Group Dialogue
• Asking Questions
• Explanation
• Role Modelling
• Role Delegation

Reference Materials :

• Scheme of Work
• Online Information
• Textbooks
• Workbooks
• 9 Year Basic Education Curriculum
• Workbooks

Content :

Classification of Pests

Classification based on the various parts of a crop plant they attack:

1. Stem borers: these are usually larvae of certain moths that bore into the stems of maize and feed on it. This result in the weakening and breaking of the stem.
2. Root feeders: these are insect larvae or adults found in the soil. They burrow into the ground and feed on yam tubers.
3. Leaf feeders: snails, beetles, grasshoppers eat up leaves of crops.
4. Younger shoot feeders: aphids, mealy bugs and scale bugs often pierce and suck out juices from younger shoots. Many sucking pests additionally transmit disease-causing organisms to the vegetation e.g. Cassava leaf mosaic virus is transmitted by white flies. Such pests are often known as vectors.
5. Fruits and seed feeders: these are moths, fruit flies, cotton strainers and some beetles eat their way into fruits and seeds causing great damage.

Damaged Crops in North Korea

A North Korean farmer assesses the damage done to his corn crop by poor growing conditions. In the mid-1990s severe flooding followed by droughts devastated the country’s agricultural output and led to serious food shortages. By the late 1990s North Korea was experiencing widespread famine.

Other invertebrate and vertebrate pests include:

1. Insects like flies, aphids
2. Mites and ticks.
3. Snails
4. Flatworms
5. Tapeworms
6. Protozoa
7. Birds
8. Rodents

Aphids on a Cabbage Plant

Aphids are small insects found throughout temperate regions of the world. They parasitize a variety of wild and commercially important plants by sucking out plant fluids. Because aphids exude a sweet, sticky fluid that can be used by certain species of ants, herds of aphids are often found guarded and tended by ants.

Life Cycles of Pests

Most insect pests have the following stages in their life cycle i.e. egg, larva, pupa, adult.

The adult pests usually feed on leaves and fruit of crops. Larva chews the bark of stems and feed on the phloem thereby damaging the crop. Insect pests go through either complete or incomplete life cycles but the larval and adult stages have been seen as causing most serious damages to crops.

Some examples of insect pest life cycles:

1. Yam beetle (undergoes complete metamorphosis), The adult feed on yam tubers in the ground.
2. Cotton Stainer (undergoes incomplete metamorphosis), the adults attack and damage cotton toll.

Presentation

The topic is presented step by step

Step 1:

The class teacher revises the previous topics

Step 2.

He introduces the new topic

Step 3:

The class teacher allows the pupils to give their own examples and he corrects them when the needs arise

Conclusion

The class teacher wraps up or conclude the lesson by giving out short note to summarize the topic that he or she has just taught.

The class teacher also goes round to make sure that the notes are well copied or well written by the pupils.

He or she does the necessary corrections when and where  the needs arise.

EVALUATION

1. What is meant by life cycle?
2. Clarify the 2 varieties of life cycles.
3. Draw the life cycle of a named pest.
4. Briefly describe how pests have an effect on root tubers.
5. Explain the term Pests. What make them so necessary to man?
6. In what methods do Pests have an effect on the standard and amount of agricultural livestock produce?
7. Point out 5 pests and describe the methods they assault or attack crops and their impact on crops.
8. In what approach has mono-cultural observe in business agriculture contributed to the emergence of pests as a manufacturing issue?