 Hello friends. In our last class, we have studied how best you can use pheromones in pest management. So, now let us discuss the other modifying chemicals which are used in the insect pest management programs. Such one is insect growth regulators. These are synthetic compounds which are actually processing the activities of juvenile and molting hormone of insects which are very important in insect maturation and development. They are called insect growth regulators. These are also called as J-H mimics, J-H analogs and also juveniles. So, these insect growth regulators, they retard the development of pest species, particularly inducing its sterility and also ultimately death of the insects. These are mainly effective on immature insects. So, this phenomenon was actually met accidentally. When Dr. William, he was working with one insect that is a pyrochorus bug, when he was raring, he come across the mortality of the pyrochorus bug. So, he afterwards understood that particular chemical is involved in the mortality of these insects. So, when he traced out this paper towel which was actually made out of this balsam fir tree which is available in America, contains this J-H hormone. Actually, that killed the insect and thereby the different insect growth regulators and other juveniles came into the market. So, these insect growth regulators, they affect in different way. So, they act as anti-morphic chemicals and mainly they act on larvae, even they act on eggs and ultimately they inhibit the embryos and also a J-H chain. So, the insect growth regulators, they even inhibit the synthesis of this chitin. You know chitin is one of the important constant of the insect which is, which gives protection to the insects many ways. So, thereby it acts on the chitin synthase enzyme and most of the insect growth regulators, they act on this cuticle, especially this chitin regulator and thereby it is going to rupture the insect and forms the, thereby it is going to produce malformation effect on the insect and insect it is going to die because it is not going to reach the further stage. There are many insect growth regulators which are actually available in the market and among them mythoprene is first to release as insect growth regulators which is very effective against homopterans and also dipterans and followed by kinoprene, hydroprene, pyruproxafine and diflobengeron. So, these are the chemicals which are actually available in other countries only the diflobengeron which is available in India for the management of various insect pest. The other insect growth regulators which are available in India, they are Luffenoron which is very effective against leptopteran pest and to some extent they are also effective against colapteran groups of insects. Then buprophazine another insect growth regulators which is very effective against sucking insect pest and also some of the hemipterans which are actually involved in the damage in rice ecosystem. So, among them is one is PPS. So, it is very effective against this PPS pest. And another insect growth regulator which is commercial available that is Nauleuron and it is also very effective against this leptopteran group of insect and to some extent white fly. These insect growth regulators they have their own advantage and these can be fit well in integrated pest management programs since their requirement is very small. Hence, we are going to load the environment with less pesticides and they are somewhat specific and hence the non-target enemies are spared and they are their mode of action is more than one that is they even affect eggs, larvae and to some extent pupa also. Hence, the resistant development to other insecticides or other conventional insecticides can be avoided and these are very eco friendly because of bio degradation is very forced in the nature. At the same times, these insect growth regulators they have some disadvantages. Since they are actually effective against only narrow group of insecticides, so most of the insects cannot be controlled with these insect growth regulators and since they are effective at larval stage and if you are going to apply at a later stage of the larvae they may continue feed on the applied surfaces. Since their mode of action is slow, the damage may be continued in the field, so like other insects the chances of resistance in these growth regulators is not ruled out. They are somewhat unstable in the ecosystem. There are some naturally occurring insect growth regulators. They are somewhat unstable, but the commercially available insect growth regulators they are somewhat stable. Hence, they are producing very good effect on the insects. The cost of these insect growth regulators comparatively high than conventional insecticides. So, other method which is natural method of modifying the insect behavior that is push and pull or stimulus deterrent diversion. Already we have discussed more about this. Only thing is here volatile chemicals they are produced by the plant. They are utilized for the benefit of the insect pest management. There are many attractants, repellents and also deterrents. They are also involved in the pest management programs. So, what is attractant? Attractant is one chemical which actually brings oriented movement in insects towards the source of the food. They are also called food lures. There are various attractants which are commercially available for the management of different insect pests. Among one is that is for management of housefly. We have sugar and molasses. Likewise, melon fruit fly management, we have this culure. Then another fruit fly that is oriental fruit fly for this management, we have this methylvisional. It is much used in the management of this fruit fly. Similar to attractants, we have antifidants. Here antifidant means the surface area will be avoided by the insect from feeding. So, insect can sit on the surface that is a treated surface, but it cannot feed. So, the first chemical to release that is zinc salt of dimethyl diethiocormamic acid which was used against many rodentates for the management of the one which actually feeds on the bark of trees. There are various deterrents, I mean antifidants. They are available from different sources like botanical source, then even the from chemical source and also some of the attractants, I mean antifidants. They are also belong to some other groups like argon tins, then also triagens which are available in the market for the management of different insect pests. We have few repellents. So, these repellents actually cause insects to orient their movement away from the source. In case of attractants, there it actually causes towards the source, but here it actually repels. So, even this repellents can be working as this feeding deterrent. So after few hours of treatment of these repellents, they are going to act as feeding deterrents. How means? When you spray these repellents on a particular surface, for few hours the insect may not sit, but it would be repelled. But after few hours when it lasts the efficacy, so insects can sit on the treated surface, but it cannot feed. So, in that way repellent they are also working as this feeding deterrent. So, there are many repellents which are available from different chemicals. So, among one is this benzyl benzoate which is used for management of mites. Likewise other chemicals which are generally used for the pest management, they do act as repellents for the management of insect pests. So, another botanical product which is much used in the screw warm flies management that is pint or oil. Likewise the commonly used this pentachlorophenol for the management of termites. So, these attractants, repellents and feeding deterrents, they have their own advantages. Since they are used at low toxicity, they are safe to humans, plants and also other domestic animals. So, since they are applied on the desired plants and other insects are spared like natural enemies and chances of resistant development it is low. At the same time they are possessing some disadvantages. So, we cannot completely cover the entire surface area. So, hence the repeated application is required and if you do not apply in another area, there are chances of movement of these insects from treated place to the another untreated place. So, that is why we need to apply these programs in area wide basis. Thank you.