Dr Mofakhar Hossain Senior Research Scientist- Invertebrate Sciences talks about Carpophilus Beetle to Stonefruit producers at the 2017 Stonefruit research Roadshow.
Dr Mofakhar Hossain on Carpophilus Beetle Download PDF in new window (Note: this document does not meet WCAG 2.0 accessibility guidelines)
Control of Carpophilus Beetles using mass trapping devices and pheromone attractants.
So today I'm talking about on control of Carpophulis beetle, especially on a stonefruit. But I want to cover actually, you can see from the title of my talk, is that this is started from the basic science to the development of the green method. The reason I have this title here is that the Stonefruit industry actually supported me more than fifteen years and I'm grateful to them for their support. And in that we are actually were able to make this system, using initially from the rotten fruit, and then we moved to the system, which is very user friendly, and then we using the chemistry of the fruit and also that trap which is in that picture here. As I also want to make sure to the audience that, you know, why we should care about this beetle. Carpophulis is one of the major pest in stone fruit, cherries, strawberries, and also in recent years, we also saw the problem in Almond industry, also in Australia.
Carpopulis can damage in fruit and can also carry brown rot, and the damage actually is on the food obviously is a direct one and the brown rot one can be also indirect one as it takes a little bit of time to show the symptoms. And due to the size and nature of these insects, this beetle is not very easily visible. And that's why it's very difficult to predict. And chemical control immediately before the harvest is also difficult and due to the URL constraints, in addition to that, it's also not a moment momentarily friendly to use the chemicals just before the harvest. And at this attract and kill system with issuing the traps here, we developed by funding from the stone fruit industry, is now commercially available. So and at this days, I know there's some stonefruit grower are using and hopefully we can make this system even better in the near future. So as I mentioned previously, also, this is our traps. And if you see the component of the traps we actually use, this trap is there, which is no more mainly the insect to entering this traps and then they are kild here. We also use the pheramone which is showing the other pheromone buttons. This is the right one there. And also we use the food attractant which is in this container and this pheromone button, this pheromone and this food attractandant work together synergistically and then they bring the beetle close to the traps and then entering the traps, and that's why they are killed.
Now you can see here also we use also some insecticide strip to kill them. This is not absolutely necessary. Once thess beetles are inside the trap, they will not be able to come out. However, you know, sometimes what happened is that just before servicing the trap, maybe a significant number of beetles enter immediately before servicing. And then if we have this, not this insecticide strip in the trap, probably once we open this trap, the beetle might escape, which we dont want. Or another hand again, this insecticide strip is mainly using to kill the insects faster.
Some important facts actually about the traps, and this is very, very important for us also to understand. And also there are some tips also there. As I mentioned, obvious previously already, Pheromone and the food attractant have synergistic effects and Pheromone and food attractant works almost 75 times better than if we use either one individually. So our whole target is obviously to maximise the system and kill as many beetle as possible. and then a pheromone sceptre should be stored in the freezer and the food attractant should be stored in the fridge for the maximum benefit. As I actually was told by couple of people or a couple of growers that sometimes they don't take care of this one properly. And that's very, very important for us to understand that if we don't store them in the freezer, for example, the pheromones button and also the food attractant in the fridge, then we lose the benefit. The reason is they're becoming kind of water and nothing else as we are losing that chemical very quickly, with room temperature. And then what are you using in the system is nothing other than water. And also the traps needs to be placed, also way before the fruit ripening. You remember we are actually using the insect pheromone and the food attractant as soon as the fruit started to ripe. Our system actually compete with the natural system and synthetic system and natural system cannot be competitive with each other. The reason is the natural system is more powerful than the synthetic system. So that means that trap placement is very, very important. Our recommendation generally is about six to eight weeks before the fruit ripening. That's our general recommendation.
And now there is an important part also of how we service out traps. It is very important that we completely replace the food attractant each week. The reason is after a week, whatever leftover in this container is, is only water. If we actually add this food attractant with this leftover thing that we are diluting our food attractant. And adding pheromone septa every two weeks, as remember, don't throw out the old one. The reason is the old Pheromone button is still good. So that means adding one is going to improve the system. It's not going to interfere with anything. So the third part is that we need to also take special care to keep the traps as clean as possible. Why? Sometime, you know the spider actually making the webs in the entry point. And if the spider webs generally the beetles tried to enter and then they cannot enter and then they go back. More importantly, if we actually don't clean it properly, sometimes there are some dead beetles sitting in the traps and some other insects or some other thing can be in the traps also. So what actually happening is that this rotting smell can interfere with our system. You don't want actually to use your trap when you are buying and spending that much money, not the full strength. So that's why the cleaning is very important also.
And another important part is that, remember to service this trap the same day of the week. Why? The reason is several example, you know, if we are doing Monday and then instead on Monday, you are doing on Tuesday. What we are doing is that we actually are not using our maximum strength. The reason is maybe Monday was a good day for Beetle to fly and enter the traps, whereas our food attractant or pheromone was not maximum strength. And then you have to lost opportunity to attract and kill a maximum number of beetles specifically on Monday. And remember, whenever you see that high number of beetle in the traps, every week, it might not be the action of the full week, as the beetle are very sensitive and they are flying, and certain circumstances are actually governed by the weather conditions and mobile conditions. So that's why, if it is a nice day, almost 70 to 80 percent beetle of the whole week, you know, beetle number, might be entering the trap on one day. That's why it's very, very important to service that trap on the day of the week, which you started initiating. Now this is, I'm using it as an example actually here, this is the one we used in their property. And that property has a high number of beetle. You can see here on that one, we started this trapping in October, 24th of October and gradually it started to increase the number. This is why we use the cumulative number. Remember, this is actually the number of beetle we got and killed in per hectare block per trap. So that means in one trap by end of the season, which is in the end of January, you can see here 240 thousand beetle killed in one trap. You know. So you can see high, a huge number of beetle actually killed. But more importantly is showing that when you are reaching, say, for example, early January or end of the December, you can see that the number did not increase anymore. So we actually kind of, that actually our hope that we want to kill maximum number of beetle before fruit started to ripen. And in this case, the fruit ripening was early January to middle of January, so variable from year to year.
So in this property, I will be showing the result in our fruit damage assessment, we actually were very successful to kill so many beetle before fruit harvest. And then the grower actually have a good result from this killing. So that's actually important again, I want to emphasize again that trap placing as early as possible at this six to eight weeks before fruit harvest is important. We want to clean up maximum number of beetle before fruit started to ripen. So this is actually a schematic diagram showing sometime I know the cost is a limiting factor for the growers and how many traps they can buy and they can use it. And that's why people what they do is sometimes they want to treat only the block, which is we call it their susceptible varieties. Remember, remember, stonefruit industry growing so many different varieties. Not all varieties are susceptible to beetles. Especially, for example, in northern Victoria I know that (?) variety, Tatura ? varierty is very susceptible. I understand the economics, but what is going to happen from all this as we found that in this example here, like block 2 and block 4, for example, is the susceptible varieties, while the surrounding blocks are not susceptible. But I would show you the next graph of what happened. What is happening is that is this block 2 and block 4 is only maturing, which is around mid-January. One of the sounding blocks actually is blocks that are late maturing one. As soon as this susceptible varieties started to ripe, if we don't kill the beetle in the surrounding blocks, they all migrate. And you can see here the area which is showing, just referring for this area here. We actually saw significant, significant higher number of damage in this area compared to the other block. The reason is lots of beetle actually probably migrated from this area to that area. So that's why it's important to use in a wider area. That's all I'm saying. If I show you the next slide, it might make sense. You can see here what this slide is showing, that top one is target block. And so you can see here the pattern is similar. You know, this is the target block and this is a sounding block. Although in these blocks the fruit is not susceptible and growers generally don't see the damage in this varieties, but still, if we have so many beetle, and you can see here the number is almost similar. Say, you know, this target block and this block. If we don't kill this beetle, we can see how many beetle were killed in that in the surrounding blocks, which is non-susceptible varieties. And then when fruit is ripening in the middle of January and then harvesting it on end of January, what is going to happen? All these beetles which are killed in the surrounding blocks will have significant impact on this susceptible varieties. That's all about it. And obviously this is a variety, the target block was (?) variety and other variety was mixed.
Now, one thing also important for us, we are dealing this issue and cost is the limiting factor. And our recommendation was initially, I think still is the recommendation is 3 per Hectare. However, if we are smart enough to use effectively these traps, as I mentioned, there are a couple of things I mentioned to you. If we can use as good as possible and if we are successful killing, we can actually reduce the number of beetle per, in the blocks very quickly. In this example, what I'm saying is that the top graph is showing, which is 05/06 season, in the same block is 06/07. You can see here. So if the number is very, very high, then we recommend to use three per traps, sorry 3 traps per hectare and then if we can reduce the number within a year in this situation here at the same block, you can see here that the number was this one out and that's gone down. And if we can reduce this to medium to low level, we can use one trap per Hectare. So that's actually a significant improvement from 3 to 1. However, what is important for us to understand, if the population is held up to the low level, medium to low level, there is a limit to how much we can do. This system is not designed to clean up everything and as you understand that not many system can do it. We want to use this trap for our economic benefit to keep the number of beetle as low as possible so that we don't see any damage in the fruit. This is actually a numbers game.
So that means during the harvest time, if we have millions of beetle in the trap, you will see a significant number of damage in the fruit. But if you have very low number of beetle, which is showing here in this situation, in that medium of low level of population in the blocks. So beetle is still there, but maybe not a hundred beetle, but millions of fruit is not going to have any economic impact on our fruit or no fruit damage is visible.
Now, what happened is that in the end of the day, if we use a system, we want to see the end product. In this situation, we want to see no damage on our fruit. That's why we actually did, when you were running the experiment, we did a comparative study. We actually had a block where we call control block. That means we did not use any attract and kill system, whereas we have that attractant in another block where we use that attract and kill system. Remember here, the grower actually, while using the killing system in the block, while they have significant problem. I mean, alternatively, you can say that that treated block always had very high number of beetle and the history of fruit damage. While in the control block we had the lower. We can not control it and we don't have money to pay, so that the grower decided that the block actually while they were not using that attract and kill system. Why? Historically, very low dam is almost zero damage and that's what we treat as a control block. So you can see here from this graph in the control blocks that some some some, you know, as this is actually we did it, you know, according to the trap number. So you can see here that some areas is significantly high number more than 23 percent damage, but overall damage was about eleven percent. Where as, this is the control block information. Where as the treated block, while we treated with 3 or 2 or 1, depending on the population, attract and kill system, we had practically zero damage. So that actually makes sense economically also. If you can save 11 percent fruit by using this trapping system, you actually, you know, kind of getting money out of getting money back from using this system. So that actually was very effective.
Now, I'm going to summarise it on what we discussed so far. We actually now we have system, attract and kill system which attracted and killed both sexes of the beetles, and this is an advantage. Why? I'm saying this is an advantage? Many of you have, you know, known, especially some mating disruption product which is using my food to controlling some say Oriental fruit moth etc etc, or some other insects also. Matings disruption is a product actually work on opposite sexes. In that case, this what happens that this population is high, there is an accidental mating and then we have some problem. While it is in this cases we actually kill both males and females, and remember here, the fruit damage is is actually done by both males and females also. So that's why it's important for us to take care of both sexes, and this system also user friendly and is also commercially available. And also another thing also I showed you in couple of you know, and I also discussed it using wide area is more sustainable and cost effective. I also showed that if you use in a small area and then that can be are also invasion from the neighbouring block. And also treating bigger area, you can also reduce the number of traps using per unit block or per hectare block. And as I mentioned also previously, wider the treatment always is useful even to reduce the population significantly down so that instead of using higher number of traps per unit block or per hectare block, you can use less number of traps. So once number actually is reaching to the medium to low level, obviously we are economy to use only one per Ha, one trap per Hectare.
And in the end of the day, as I also showed, that if we use those attract and kill systems smartly, what I am saying smartly, as I said, that it is not that, you know, pesticide you just to fill the tank and go and spray, it needs to be used, you know, like smartly. The reason is that pheromone and food attractant has to be taken care of properly so that when you are using it is maximum strength. And second part is that, as I said, that cleaning this trap, you know, time to time is very important so that we actually facilitate insects to enter there. And then also some dead insects is not interfering with our attractant, with our food, smell and etc, etc. So and by doing that way we can actually reduce significant amount of fruit damage, and that's why we can be earning more money. So and another important part is that also we found also that if we can manage this beetle smartly, so it also improve, it might also help brown rot management. So what I say might help. Obviously, you know that this beetle actually is a very good carrier of Brown Rot. and due to their behaviour, the way they'll land on fruit and the way they actually hide, so, for example, if they're reach, they're landing on a piece of fruit, whatever they're lending, they will try to go and hide as quick as possible, close to the same area, where they actually have a microclimate, that means the brown rot germination is actually increasing. The rate of increase is higher and then they can actually do higher damage. And secondly, also, more rain events and such as that can have more brown rot. So that means if we can manage this beetle population smartly or better, we can have significant impact, also have less brown rot damage.