This thread will consist of questions asked during our webinars! Please do get involved and answer any questions you believe you have the answer to. We also encourage you to ask any questions of your own and get involved that way 
Webinar Discussions
- Thread starter skye @ bofin
- Start date
05/10/23 SLIMERS - the benefits of beetles
An incredibly insightful webinar with @kelly_jowett looking at the hyenas of the soil - carabid beetles! Join the slug circle to get involved and stay updated along our journey investigating the relationship between slugs and beetles with @bofinfarmers
Questions asked during the webinar:
Do all pesticides affect the beetles or just insecticides?
Is the ID app available for us to use yet?
Is there any evidence that ferric phosphate affects these beetles?
Let us know your thoughts down below in response to these questions. If you would like to watch a recording or find out the key points from the webinar, comment below and we can send you a link!
An incredibly insightful webinar with @kelly_jowett looking at the hyenas of the soil - carabid beetles! Join the slug circle to get involved and stay updated along our journey investigating the relationship between slugs and beetles with @bofinfarmers
Questions asked during the webinar:
Do all pesticides affect the beetles or just insecticides?
Is the ID app available for us to use yet?
Is there any evidence that ferric phosphate affects these beetles?
Let us know your thoughts down below in response to these questions. If you would like to watch a recording or find out the key points from the webinar, comment below and we can send you a link!
To receive a recording of the webinar, please email [email protected]. This way we will be able to send you a link with a passcode to view. Thanks.
- Location
- Kent
Yes, very good, and there was also some discussion regarding independent work that will have been done on every pesticide in order to gain approval regarding their effect on the environment , including beneficial insects. It was noted that this data is very hard to get hold of, but perhaps it should be freely available to all...or would this open a can of worms?05/10/23 SLIMERS - the benefits of beetles
An incredibly insightful webinar with @kelly_jowett looking at the hyenas of the soil - carabid beetles! Join the slug circle to get involved and stay updated along our journey investigating the relationship between slugs and beetles with @bofinfarmers
Questions asked during the webinar:
Do all pesticides affect the beetles or just insecticides?
Is the ID app available for us to use yet?
Is there any evidence that ferric phosphate affects these beetles?
Let us know your thoughts down below in response to these questions. If you would like to watch a recording or find out the key points from the webinar, comment below and we can send you a link!
Hi everyone, this is Dr Kelly Jowett.
Sincere thanks to those farmers, particularly Becci, who were interested in beetles - for prompting my involvement in the SLIMERS project!
I'm really looking forward to seeing your progress as it goes along, I'm always up for trying to ID beetles from photos, but really want to hear your experiences and opinions on the monitoring and beetles in general.
Questions from earlier:
ID app is being piloted, but currently does not have an automatic identifier - we need more photos to train the ID algorithm!
As regards pesticides, this below is what I found after a question from BASE farmers at an event - but if Keith can let me know how to access less openly accessible research, I'd be happy to report back to the slug circle more comprehensively!
There’s a lot of research out there- but much of it is quite specific, and it’s hard to compare with use in real life situations.
Broadly, though insecticides can wipe out populations in the field, carabids are great at bouncing back, so the immediate effects are given as localised and short term, and new carabids can recolonise sprayed areas. For example- “two-dimensional distribution of arthropods following an application of dimethoate have revealed that re-invasion across a 16ha field may occur within one month”. Which is why it is important to have refuge areas close to crops, and buffer applications.
There was one mention (in the few papers I read in detail) of long term sub lethal effects- in reducing size, particularly in females in treated vs olive groves untreated with dimethoate. (as well as immediate toxicity). This demonstrates the long term consequences it is hard to study- behavioural differences that make them susceptible to predation, and breeding reduction in population terms going onwards.
It’s been hard for me to look up particular chemicals as the literature is confusing with different names! (if anyone knows any good sources for overview of chemicals farmers use and their active ingredients I would be grateful if you could let me know). The only mention I could find of less lethal chemicals specifically was this “. Carabids were killed by soil treated with thionazin within dosage rates normally required for satisfactory control of nematode or insect pests of crops, i.e., 2·24–8·96 kg/ha, but menazon was virtually non-toxic.” But that is from 1972 so may be well out of date!
So grouping them by type: effects vary by the type, application, and timing:
One study of soil-applied thionazin showed that “thionazin considerably reduced numbers of Carabids for up to eight weeks after application”, with lower catches six months later when treated soils were rotavated after lifting of the potato crop; the authors thought it could be due to thionazin residues leaching into deeper layers of the soil. They found that smaller species, which were most active at the time of application in the soil surface layers, were most affected. Other soil level treatments found the same with species effects on soil active carabids.
In contrast, foliar sprays most affect bigger carabids, that may be hit by the actual spray filtering through vegetation. Other studies echoed the activity period of beetles, finding effects on only populations of spring active species, with spring application for example.
I didn't think they'd be too bad with neonics, but some reading on the research showed me that even though carabids only indirectly consume it, by eating pests, this still has an effect on predators. A study found: in the lab, slugs unaffected by the dose still transmitted the toxin to carabids, impairing or killing 60%; and in the field "thiamethoxam‐based seed treatments depressed arthropod predators, thereby relaxing predation of slugs and reducing soya bean yield by 5%. other studies have found that even low doses as used in the field can affect their walking, general activity, food consumption rate, and thermoregulation. These effects can last for at least several days, and obviously impact their ability to avoid pests and generally survive. One direct effect may be on seed predators- one study said the larvae of seed eaters Harpalus sp. may be particularly susceptible, being lower in both bt and neonic seed treatment trials. These effects may be short term: eg- “thionazin considerably reduced numbers of Carabids for up to eight weeks after application”. But effects have not really been studied long term, and authors do say that existing studies lack the power to rule out persistent effects.
But good news is that reduction in pesticide use can have measurable effects quite quickly e.g “The estimated total dry mass of carabids increased by 25% when the pesticides were reduced to one fourth of the normal application rates.”
Sincere thanks to those farmers, particularly Becci, who were interested in beetles - for prompting my involvement in the SLIMERS project!
I'm really looking forward to seeing your progress as it goes along, I'm always up for trying to ID beetles from photos, but really want to hear your experiences and opinions on the monitoring and beetles in general.
Questions from earlier:
ID app is being piloted, but currently does not have an automatic identifier - we need more photos to train the ID algorithm!
As regards pesticides, this below is what I found after a question from BASE farmers at an event - but if Keith can let me know how to access less openly accessible research, I'd be happy to report back to the slug circle more comprehensively!
There’s a lot of research out there- but much of it is quite specific, and it’s hard to compare with use in real life situations.
Broadly, though insecticides can wipe out populations in the field, carabids are great at bouncing back, so the immediate effects are given as localised and short term, and new carabids can recolonise sprayed areas. For example- “two-dimensional distribution of arthropods following an application of dimethoate have revealed that re-invasion across a 16ha field may occur within one month”. Which is why it is important to have refuge areas close to crops, and buffer applications.
There was one mention (in the few papers I read in detail) of long term sub lethal effects- in reducing size, particularly in females in treated vs olive groves untreated with dimethoate. (as well as immediate toxicity). This demonstrates the long term consequences it is hard to study- behavioural differences that make them susceptible to predation, and breeding reduction in population terms going onwards.
It’s been hard for me to look up particular chemicals as the literature is confusing with different names! (if anyone knows any good sources for overview of chemicals farmers use and their active ingredients I would be grateful if you could let me know). The only mention I could find of less lethal chemicals specifically was this “. Carabids were killed by soil treated with thionazin within dosage rates normally required for satisfactory control of nematode or insect pests of crops, i.e., 2·24–8·96 kg/ha, but menazon was virtually non-toxic.” But that is from 1972 so may be well out of date!
So grouping them by type: effects vary by the type, application, and timing:
One study of soil-applied thionazin showed that “thionazin considerably reduced numbers of Carabids for up to eight weeks after application”, with lower catches six months later when treated soils were rotavated after lifting of the potato crop; the authors thought it could be due to thionazin residues leaching into deeper layers of the soil. They found that smaller species, which were most active at the time of application in the soil surface layers, were most affected. Other soil level treatments found the same with species effects on soil active carabids.
In contrast, foliar sprays most affect bigger carabids, that may be hit by the actual spray filtering through vegetation. Other studies echoed the activity period of beetles, finding effects on only populations of spring active species, with spring application for example.
I didn't think they'd be too bad with neonics, but some reading on the research showed me that even though carabids only indirectly consume it, by eating pests, this still has an effect on predators. A study found: in the lab, slugs unaffected by the dose still transmitted the toxin to carabids, impairing or killing 60%; and in the field "thiamethoxam‐based seed treatments depressed arthropod predators, thereby relaxing predation of slugs and reducing soya bean yield by 5%. other studies have found that even low doses as used in the field can affect their walking, general activity, food consumption rate, and thermoregulation. These effects can last for at least several days, and obviously impact their ability to avoid pests and generally survive. One direct effect may be on seed predators- one study said the larvae of seed eaters Harpalus sp. may be particularly susceptible, being lower in both bt and neonic seed treatment trials. These effects may be short term: eg- “thionazin considerably reduced numbers of Carabids for up to eight weeks after application”. But effects have not really been studied long term, and authors do say that existing studies lack the power to rule out persistent effects.
But good news is that reduction in pesticide use can have measurable effects quite quickly e.g “The estimated total dry mass of carabids increased by 25% when the pesticides were reduced to one fourth of the normal application rates.”
Sharing knowledge is key to progression because knowledge has value. We will provide as many resources as part of The Slug Circle as possible. I know that @Tewoll and @Seralt (Dr. Kelly Jowett and Dr. Keith Walters) are also interested in sharing resources with you. It is by sharing these resources and involving farmers, like yourself, that we will progress with research aiming to better the future for farmers. A good example of this is the need for beetle pictures obtained through beetle monitoring in order to train the ID algorithm as suggested by Kelly above! We look forward to working with everyone within this project
As Skye says, we'll do our best to publish info with the resource area here where we can. The work referred to by @Seralt during the webinar I think relates to data that pesticide manufacturers submit as part of pesticide approval. I think the point made was that an insecticide doesn't get approved if it's found to be damaging to beneficials. Companies aren't required to publish the actual approval information, although many do for transparency. However, the information @Tewoll has given above suggests the effect of insecticide is far more nuanced than what's required for pesticide approval.
On my farm, we're trying to move away from applying insecticides to cereals in the autumn, for this very reason - I think you do far more damage to the beneficial population than the potential for BYDV damage by not spraying. Don't have any evidence of that, though. It may be that data captured during this SLIMERS trial will provide some insight...
Hi Clive, really you should have registered for the webinar - that way you would automatically receive a link to the video. But you can join the Slug Circle here http://bofin.org.uk/join-the-slug-circle/
- Location
- Kent
I havent appiled foliar insecticdes to cereals for 14 years and only a couple of times to osr. The last time I applied it to osr for turnip sawfly we saw an immediate problem with slugs that we hadn't had before - no proof I'm afraid, just anecdotal
10/01/2024 - Slug-Spotting - training the SLIMERS AI
A super interesting webinar to introduce farmer-led field trials that will use special hand-held rigs to improve a robot's ability to detect slugs. This included presentations by slug-expert Kerry from CHAP and Ray King from Small Robot Company.
Thank you to all those that attended. If you have any other questions or comments to make regarding the webinar, get involved and let us know down below. If you did not manage to join us live for the webinar, don't worry - we have inserted down below for you:
A super interesting webinar to introduce farmer-led field trials that will use special hand-held rigs to improve a robot's ability to detect slugs. This included presentations by slug-expert Kerry from CHAP and Ray King from Small Robot Company.
Thank you to all those that attended. If you have any other questions or comments to make regarding the webinar, get involved and let us know down below. If you did not manage to join us live for the webinar, don't worry - we have inserted down below for you: