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Sunday, May 15, 2011

First Step To Understand Insecticides Mode of Action

 (The above photo does not belong to Carron Lee. It is an extract from internet)

Have you ever seen people doing fogging as shown in the photo? And how about this???

(The above photo does not belong to Carron Lee. It is an extract photo from internet)

Those are the photos showing pest controller carried out fogging treatment (Photo1) at external compound and misting treatment (Photo 2) at the internal compound. Besides that, there are a few more treatments such as residual spraying, gelling treatment and etc.

(The above photo does not belong to Carron Lee. It is an extract from internet. The photo showed a pest controller carrying out residual spraying activity. Targeted pests will be cockroaches and ants)

(The above photo does not belong to Carron Lee. It is an extract from internet. The photo showed a pest controller carrying out gelling treatment. Targeted pests: Cockroaches)

What do the photos tell us? It just tell us the way or type of treatments which available in the market. Treatment is just a method in passing the chemicals to the targeted pests? However, have we ever thought deeply how does the chemical react in the insect's body? By understand on this mechanism, it will not just help you to know more but it helps you to understand more on how to do a proper chemical rotation. 

In order for us to understand insecticides mode of action, the very basic step that we need to understand is the insect's nervous system. Nervous system is a system which act in transmitting information throughout the body. Similar with human, nervous system in insect will tell them what do they see, what do they feel and how shall they react.

Scenario: You touch a hot kettle. You know it's hot. You know you need to remove your hand immediately and it will store in your memory that you shall not touch for the second time! This whole process is done by your nervous system.

The nervous system has 2 components. 1) Peripheral nervous system and 2) Central nervous system (CNS) Take a look at the below picture.


(The above diagram does not belong to Carron Lee. It is an extract from internet)

Based on the above diagram, it is clearly understand that CNS includes Brain and Spinal Cord. Peripheral nervous system includes Peripheral nerve. Peripheral Nervous System is to TRANSMIT INGOING AND OUTGOING signals throughout our body and Central Nervous System (CNS) is to INTEPRET the signals.

(The above diagram does not belong to Carron Lee. It is an extract from internet)

The above diagram is a neuron. Neuron is a single nerve cell and this neuron will connect with other neurons and muscle fibers; as shown in the diagram below.


(The above diagram does not belong to Carron Lee. It is an extract from internet)

Gap between neurons or between neuron and muscle fiber is called synapse. Shown in diagram as below. (If you starts to get confuse, ignore all the wordings shown in the diagram except the key words that I am mentioning now)

(The above diagram does not belong to Carron Lee. It is an extract from internet)

Incoming signals (Touching on hot kettle) are transformed by the neuron into an electrical charge and these charge particals are called ions. These ions will move through channels at the neurons. There are 4 MAIN CHANNELS which allow DIFFERENT IONS to be moved along the neurons.

1) Calcium Channels
2) Chloride Channels
3) Potassium Channels
4) Sodium Channels

Different channels will have different opening and closing gate. These channels understanding is important in insecticides mode of action explanation which will be explained in the next blogpost.

When the electrical charge (ions) reaches the end of the neuron, neurotransmitter will be formed. (Please refer to the above diagram for a better understanding). Neurotransmitter will cross the synapse and bind with receptor on the receiving end of the next neuron. Signal will be converted back to electrical charge (ions) at the next neuron and signal will be transmitted along the neuron. After neurotransmitter transmitting message across the synapse, neurotransmitter will be back to its originating neuron, at a resting stage, wait for the next signal to be transmitted. This process will be passing from 1 neuron to another until it reaches CNS. Impluses from CNS will have the same process passing back to the Peripheral Nervous System. This explains the whole process of our nervous system on the above scenario. Touching the hot kettle!

I will explain to you more on the mode of action in the next blogpost.







2 comments:

  1. This is interesting. We shall wait for the mode of action!

    ReplyDelete