 Friends, in a previous class, we have studied the various chemicals which are involved in the changing the behavior of the insects for pest management. Among them, we have two main groups, that is, chemicals which are used for the intra-communication and another one is the chemicals which are used for inter-communication mechanism. So, here we have allelocemicals. These are the chemicals which are used for the inter-specific communication and they are going to change the insect behavior and also ecology. Here we have few categories, one is alumon, so here the releaser is going to benefit by releasing the chemical, not receiver, but in case of kyromon, receiver is going to benefit. In case of synomon, both the species, that is, releaser and also receiver, they are going to benefit. In case of another category of allelocemical, that is, anemone, wherein these chemicals, they are produced by non-living substances, only receiver is going to benefit. Now, let us see what exactly the pheromones which are actually used for intra-specific communication. These pheromones, they are the chemicals or mixtures of chemicals, they are released to the exterior environment by a species and it is going to bring out the changes in the another organism of the same species. Let us see what are the pheromones actually which are used for intra-specific communication. Based on their function, you can divide these pheromones into sex pheromones, aggregation pheromones, alarm pheromones, trail pheromones and also host marking pheromones. Among these pheromones, sex pheromones, they are well utilized in the integrated pest management, wherein it is much studied in leopteran groups of chemicals, I mean insects because they are somewhat simpler, but in other cases it is not well studied because of their complex nature. These pheromones, they are more complex and they are associated with the some physiological process like sexual maturity, environmental stimuli that is photoperiod and also light intensity. These are quite volatile and they are going to bring specific stimuli in related species or in same species and they are going to cause much response in the other species in longer distance. What is the main difference between sex pheromones and the chemicals which are produced by the host plant? So, these host plant chemicals, they are mostly volatile and they are not specific and they are going to attract both species of insects and at the same time other species whereas the sex pheromones, they are going to attract only particular species or same species and their volatility, it is variable from low to high. In case of pheromones, we have aggregation pheromones, so these aggregation pheromones, they are produced by a set of or group of insects, these insects, they are going to aggregate for their food sites or for reproductive habitats or even for hibernation purposes. These aggregation pheromones, they are much understood in case of bark beetles and they are going to attract the par places. Then what are the alarm pheromones? So, as the name indicates, these alarm pheromones are they are going to create some defensive mechanism and also some avoidance mechanism. So, these mechanism was much studied in case of some social insects like ants and bees and also in some of the aphid species and the function of this alarm pheromones is to raise alert in the same species and thereby they are going to raise some defense and also avoidance mechanism in the other species of the same organism. So, you have seen the when bee attacks some individual, so they are going to release some alarm pheromones, thereby the other species, I mean same honey bee, they are going to follow the victim for further attack. Next, what are the trail pheromones? So as the name indicates, these trail pheromones, they are going to mark the way, so as you seen in case of ants, so they are going to move in one direction in one line, thereby they are going to mark the where the food is available, thereby the other insects of same group they are going to follow the food source. And next in case of other insects like bees, it is very helpful in case of foraging, likewise it was much studied in bumblebees also and the little bit study is also done in case of host marking pheromones, so here is one example of fruit fly, wherein it is going to ovipoist some fruits, thereby it is another fruits, they can avoid the same host from ovipoistion and they can ovipoist in other host plants and can avoid the intercomputation between the two insects. Till now we have studied the some of the sex pheromones, some of the pheromones which are useful in pest management programs, but much of the study was done in sex pheromones, which are much used in the pest management programs, how best one can exploit these pheromones in the pest management programs. So now we have more than 2000 pheromones which are actually identified and isolated, only in few insects these have been applied for pest management program. These pheromones they are exploited in three ways, that is one for monitoring, for mass trapping and also for mating disruption technique. So these pheromones can be installed in the fields for the monitoring of insect species, so hence they are quite specific, only in some of the lepidopteran species it is much studied and also exploited for the monitoring purpose. Here is one example wherein you can put these pheromone traps in cotton fields, also in paddy fields for monitoring purpose. So based on these monitoring as well you can detect the pest and know the pest density and as well you can assess the natural animals present in that ecosystem, as well you can assess the pest phenology and also these pheromones can be effectively used in the mating disruption technique and this technique how far it is useful can be, can also be assessed through this monitoring. By using these pheromone traps as well you can assess the insect resistance which is occurring in particular species and based on your monitoring results as well you can use this monitoring data for decision making in the IPM programs. These pheromone traps or in general pheromones have been also utilized in mass trapping of the some of the insect species wherein these can be controlled in two ways one is attract and kill and another one is attract and infect or lure and infect. So by using these pheromone traps as well you can attract the insects thereby you can destroy the attracted species. So here is one example it is much studied in case of fruit fly use methyl usanol for attraction of the species and also by blending with melaton as well you can trap these fruit flies thereby you are going to destroy the many number of these fruit fly species. The another example is a pink bowl worm wherein by putting the traps that is 12 traps per acre as well you can trap number of adults so that you can reduce the population in a location. The another one is attract and infect wherein these pheromones can be blended with other entomopathic agents like nematodes, bacteria, fungi and viruses and as well you can disseminate this disease in other species of insects. So by studying the effectiveness of the pheromone traps their utilization in mass trapping of important piece. So scientists have recommended these pheromone traps for utilization in pest management program in various crops. So in crops like rice so for the management of yellow stem burrow as well you can use 5 traps per hectare and also in case of leaf marine in ground nut as well you can use 25 traps per hectare so that one can trap the adults and destroy the or reduce the pest population in a location. So another way how pheromones can be utilized in pest management means through mating disruption. So it is one technique thereby you are going to create some confusion among the same species. So these synthesized pheromones by utilizing as well you can permit the whole environment thereby it could not able to identify the same species for its mating thereby it is going to die without mating. This phenomena was much utilized in the some of the species for pest management so it was well studied and well utilized in case of paddy stem burrow and also in case of pink bull worm wherein by putting some 200 pbw ropel per hectare as well you can reduce the population of this pink bull worm. So the role of these pheromones it is well utilized and still much work has to be done in this direction for better utilization of these pheromones in the pest management program. In our next class we will study the other insects which are used for pest management program through insect modifying technique. Thank you.