Curculio infected all plums and apples - Ask Extension
I sprayed dormant oil, neem oil, spinosad and kaolin clay. 100% of plums and apples were infected with curculio. I removed all the fruit. Did I not sp...
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Curculio infected all plums and apples #870692
Asked May 30, 2024, 7:06 AM EDT
I sprayed dormant oil, neem oil, spinosad and kaolin clay. 100% of plums and apples were infected with curculio. I removed all the fruit. Did I not spray enough kaolin clay?
Oakland County Michigan
Expert Response
Hello,
Unfortunately, despite your efforts, you experienced a 100% infection! Plum curculio (Conotrachelus nenuphar) can indeed be a challenging pest to manage.
Let’s explore some factors that might have contributed to the infection:
Weather Trends: Weather conditions play a significant role in plum curculio's emergence and mating activity. If the weather was conducive to their activity, it could have led to higher infestations.
Non-Chemical Management Options: While you used several sprays, there are non-chemical management options that can complement your efforts. These include proper monitoring techniques and sanitation practices. For instance, removing fallen fruits promptly can help reduce the population.
Kaolin Clay: Kaolin clay (a natural mineral) is often used as a protective barrier against pests. However, its effectiveness depends on thorough coverage. Make sure you apply it evenly to all parts of the tree, including the undersides of leaves and fruit surfaces.
Timing: Proper timing of sprays is crucial. Plum curculio adults emerge after petal fall, so focus on applying treatments during this period. When targeted to control other pests, Rimon can also sterilize plum curculio eggs, preventing live larvae.
Remember that integrated pest management (IPM) involves a holistic approach, combining various strategies.
More information is at these links:
https://www.canr.msu.edu/news/plum_curculio_management_in_stone_and_pome_fruits
https://www.canr.msu.edu/ipm/diseases/plum_curculio
https://extension.usu.edu/planthealth/research/plum-curculio.pdf
I hope this helps!
Unfortunately, despite your efforts, you experienced a 100% infection! Plum curculio (Conotrachelus nenuphar) can indeed be a challenging pest to manage.
Let’s explore some factors that might have contributed to the infection:
Weather Trends: Weather conditions play a significant role in plum curculio's emergence and mating activity. If the weather was conducive to their activity, it could have led to higher infestations.
Non-Chemical Management Options: While you used several sprays, there are non-chemical management options that can complement your efforts. These include proper monitoring techniques and sanitation practices. For instance, removing fallen fruits promptly can help reduce the population.
Kaolin Clay: Kaolin clay (a natural mineral) is often used as a protective barrier against pests. However, its effectiveness depends on thorough coverage. Make sure you apply it evenly to all parts of the tree, including the undersides of leaves and fruit surfaces.
Timing: Proper timing of sprays is crucial. Plum curculio adults emerge after petal fall, so focus on applying treatments during this period. When targeted to control other pests, Rimon can also sterilize plum curculio eggs, preventing live larvae.
Remember that integrated pest management (IPM) involves a holistic approach, combining various strategies.
More information is at these links:
https://www.canr.msu.edu/news/plum_curculio_management_in_stone_and_pome_fruits
https://www.canr.msu.edu/ipm/diseases/plum_curculio
https://extension.usu.edu/planthealth/research/plum-curculio.pdf
I hope this helps!
Hello Again,
Additional information at this link:
https://fff.hort.purdue.edu/article/tips-for-managing-plum-curculio-in-tree-fruit/
I hope this helps, too!
Additional information at this link:
https://fff.hort.purdue.edu/article/tips-for-managing-plum-curculio-in-tree-fruit/
I hope this helps, too!
Maybe I forgot to mention that I am an organic farmer. I do not see any mention of organic insecticides, everything is toxic poison you’ve referred me to. Also, I need a detail of how to calculate degree days noted in your Purdue website where they quoted Michigan State University. I did not understand that at all. It looks like I need to calculate degree days to time the spray of my kaolin clay insecticide. Thank you.
Hello Again,
There are three items I wanted to mention and ask:
For organic growers, Surround WP can reduce plum curculio injury to fruit if applied to attain a heavy coating on the tree canopy; this kaolin clay product works as a plum curculio repellent. Building up and maintaining several coats of clay on fruit as the fruit continues to grow is key to the successful use of this product.
If you go to this website:
https://gddtracker.msu.edu/
You can use it to look up degree days in your Zip Code. It will calculate the Degree Days for you. From the Tabular Data Charts
Are you a commercial grower? If you are, we can refer you to the commercial grower group.
I hope this helps!
There are three items I wanted to mention and ask:
For organic growers, Surround WP can reduce plum curculio injury to fruit if applied to attain a heavy coating on the tree canopy; this kaolin clay product works as a plum curculio repellent. Building up and maintaining several coats of clay on fruit as the fruit continues to grow is key to the successful use of this product.
If you go to this website:
https://gddtracker.msu.edu/
You can use it to look up degree days in your Zip Code. It will calculate the Degree Days for you. From the Tabular Data Charts
Are you a commercial grower? If you are, we can refer you to the commercial grower group.
I hope this helps!
Hi, I think my problem was hesitating to spray because I didn’t know what I was doing. It took me eight months to decide to spray… And I did not approach each individual tree at the correct time with enough kaolin clay. I will execute a better plan next year. This year, I am wondering if I should remove the arborist wood chips underneath every fruit tree, do they harbor curculio over the winter? Should I pursue parasitic -insect nematodes? I am not a commercial grower, just a new small farmer in my third year and not doing well at all with fruit trees.
Hello Again,
Wood Chips and Curculio: While wood chips themselves don’t harbor plum curculio, proper placement and management are crucial. Avoid creating conditions that favor pests and maintain good orchard hygiene.
Arborist Wood Chips:
Using wood chips as mulch around fruit trees can have benefits, but there are some considerations to keep in mind.
Placement: It’s essential to place the wood chips correctly. Avoid piling them up against the tree trunk, as this can lead to crown diseases. Instead, spread the chips from a couple of inches away from the trunk out to the canopy edge or a little farther.
Moisture Retention: Wood chips help retain soil moisture, which can be advantageous for fruit trees. They keep the soil underneath moist for longer, allowing you to water the tree less frequently than if it weren’t mulched1.
Aesthetic Choice: If you’re using a dripline for irrigation, it can stay under the mulch or above it. The decision is primarily aesthetic and up to you.
If you are considering using biological control agents, there are naturally occurring predatory and parasitic insects, fungi, and insect-parasitic nematodes that attack plum curculio. These biological control agents can be thought of more as a long-term, sustainable approach to reducing plum curculio populations and associated damage. So, in other words, these are not agents that will reduce populations quickly, so you will want to plan ahead and allow time for these organisms to do their work! More recently, the success of insect-parasitic nematodes against plum curculio has received more attention. These nematodes only attack insects (not plants!), and when applied to the soil at the base of trees in the orchard, insect-parasitic nematodes are available in high densities to attack plum curculio larvae as they leave dropped fruit and enter the soil to pupate. By reducing the number of larvae and pupae surviving each season, there will be fewer adults that overwinter, and therefore fewer adults to emerge the following spring! There are several factors that impact the success of biological control agents, so these strategies may not work equally well for everyone, but they can be a valuable complement to chemical control strategies. This information is from a Purdue University article at this link:
https://fff.hort.purdue.edu/article/tips-for-managing-plum-curculio-in-tree-fruit/
I hope this helps!
Wood Chips and Curculio: While wood chips themselves don’t harbor plum curculio, proper placement and management are crucial. Avoid creating conditions that favor pests and maintain good orchard hygiene.
Arborist Wood Chips:
Using wood chips as mulch around fruit trees can have benefits, but there are some considerations to keep in mind.
Placement: It’s essential to place the wood chips correctly. Avoid piling them up against the tree trunk, as this can lead to crown diseases. Instead, spread the chips from a couple of inches away from the trunk out to the canopy edge or a little farther.
Moisture Retention: Wood chips help retain soil moisture, which can be advantageous for fruit trees. They keep the soil underneath moist for longer, allowing you to water the tree less frequently than if it weren’t mulched1.
Aesthetic Choice: If you’re using a dripline for irrigation, it can stay under the mulch or above it. The decision is primarily aesthetic and up to you.
If you are considering using biological control agents, there are naturally occurring predatory and parasitic insects, fungi, and insect-parasitic nematodes that attack plum curculio. These biological control agents can be thought of more as a long-term, sustainable approach to reducing plum curculio populations and associated damage. So, in other words, these are not agents that will reduce populations quickly, so you will want to plan ahead and allow time for these organisms to do their work! More recently, the success of insect-parasitic nematodes against plum curculio has received more attention. These nematodes only attack insects (not plants!), and when applied to the soil at the base of trees in the orchard, insect-parasitic nematodes are available in high densities to attack plum curculio larvae as they leave dropped fruit and enter the soil to pupate. By reducing the number of larvae and pupae surviving each season, there will be fewer adults that overwinter, and therefore fewer adults to emerge the following spring! There are several factors that impact the success of biological control agents, so these strategies may not work equally well for everyone, but they can be a valuable complement to chemical control strategies. This information is from a Purdue University article at this link:
https://fff.hort.purdue.edu/article/tips-for-managing-plum-curculio-in-tree-fruit/
I hope this helps!
