 Hi, in the last three classes we discussed on various aspects of ecological pest management methods. Today we will have another set of ecological methods of pest suppression wherein through physical intervention we can reduce the pest population significantly. The meaning of physical intervention is using a device or a material or a source for reducing the pest population. I have listed here some of the devices that can be used. In simple you know if you use hot water or hot air treatment for sugarcane sets before planting because all these sugarcane sets carry a lot of scale population. By treating with hot water treatment or hot air treatment these scales can be reduced or killed significantly. Similarly, the same hot water treatment to plant stored in storages. It may be a potato tuber or it may be roots or it may be corns which contain lot of a bulb flies and nematodes when exposed to hot water they will be killed significantly. Similarly, another device which is most commonly used is light trap. Light trap it involves two things. One is the use of light. Majority of the insects attract towards the light sources. The light source may be from different agencies. For example, if you use a fluorescent it gives some sort of light, UV rays it attract lot of insect population. Mercury bulb also attracts lot of insect population. And little higher black tube light trap also attract much higher population of insects. So the any light which emits UV light has the capacity to attract insects considerably. And the another term in light trap is trap. We can design various types of traps to collect the insects. The design of the trap and the placement of these traps and the height in which that we have to keep and the time in which we have to keep all improves the efficiency of light trapping. For example, I have here in a orchard a simple light trap having a mercury bulb and as the light source for physical intervention and placing a water tub with water in it and putting some kerosene or insecticide solution into that tray so that whatever insects which are attracted to this light will fall into this water and because of kerosene or because of the insecticide the insects which are attracted will be killed. Then another important thing for the insect behavior is insects are also attracted to some sort of color. Particularly the yellow color the majority of the soft bodied insects are attracted to this yellow color. This behavioral phenomena can be used to our advantage that means in managing the best population in a given ecosystem. I have here in this photograph you know in the cotton air ecosystem particularly in the early stage of cotton group we have some yellow sticky traps. These traps can be of any design not necessarily it is round or it is flat or it is square any design suitable to you you can plan it paste it with the yellow color and then smear it with any greasy substance simple castor oil can be used as a sticky material and the adults remember the adults of serpentine leaf miner which is an important invaded pest both male and female are attracted to this yellow color and they will be trapped and we can reduce the population considerably using this behavioral phenomena. Similarly cotton white flag this is another important pest as all of we know it caused major economic damage in North India during this year is also attracted to a yellow color. A simple trap may be the insecticide container itself after its use can be pasted with the yellow color and to this we can smear some greasy material again castor oil can be one of the cheapest greasy material can be smeared and then placed in the field the placement is most important you know it should be placed above the crop canopy so that the yellow color is visible to the adult white flies. However here again both male and female are attracted to this yellow color and they come and sit on this trap because of the greasy material they will be trapped there and they will be killed. So this is one of the simple device to trap insects and then reduce the population under given ecosystem. Then we have another important physical device that is flame throwers which can also be simply called as bonafires or setting up of a fire in the open field. Some insects have got the habit of emerging out from the diapause stage immediately after early showers in the beginning of the season for example we see this behavior in case of red hairy caterpillar root grapes and then some chaffers which are hiding in the soil. So this behavior can be used to our advantage setting up of bonafires in the mid of the field using the last season crop residues is one of the simple way of using this device for trapping the insects and then killing the insects on a large area basis and then one of the other important thing is bird purchase. We know there are many entomophagus birds which mainly feed on insects and survive on them only. For example we use some purchase, purchase in the sense they may be live purchase or dead wood trees. Live purchase may be some sort of sorghum seeds or maize seeds which can be mixed with the main crop may be redgram or cotton at the time of sowing because these sorghum or maize they have the habit of growing much faster and they are taller also than the main crop that is redgram or cotton they provide the resting space for the bird or else even I have a photograph here the dead wood branches of the tree can be placed in the field. You can see large number of birds coming and resting on this. The one that you are seeing in this photograph is a black drongo. This is a very efficient predator on insects. Insects which cannot be controlled at the later in stars may be third to fifth in star can be easily noticed by these birds and they prey on these things come and rest on these purchase and then eat. One of the behavioral phenomena is these birds you know cannot devour or consume when they are in flight. That is why we see large number of these birds resting on the electric fence or on the trees in our fields. They need a resting spot to sit and then devour the cot praise. So that is why we need to provide a perch in the field so that the efficacy or the efficiency of these bird predators can be improved. Then the last two important things sunlight. Sunlight itself can serve as an important physical intervention or a device in killing some of these stored insects. Lot of our stored products harbor egg population, larval population, grub population and they can be exposed to hot sunlight more than 38 degree centigrade for few hours maybe 4 to 5 hours usually kills all these stages at one stroke. Similarly the opposite way that is the use of cold as a device for example lot of our mangoes containing fruit fly, lot of our potatoes containing potato tuber worm mouth and some of the nematodes, some of the diseases are also there in these stored products. They can be stored in cold situation for example for about 12 degree centigrade for about 4 hours can knock down all these populations inhabiting in these sources of food permanently. So that is how all these techniques of physical intervention can be used in reducing the pest population which can fit very well in the IPM concept. Thank you.