Message Board - Natural Turf: What pest is this that is making my grass die?
20 Sep 2008 by Mark P Last edited 20 Sep 2008
Any help appreciated. Have suspected some type of grub on my lawn all this year, as it has had a tendency to go brown in places (see picture) and then you can pick turf off with hand. Have done leatherjacket test in past a few times (sheet overnight, etc) and nothing was there. However, noticed turf dying again and investigated to find these grubs (see picture). Any idea what they are - do not look like leather jackets from pictures I've seen and have wondered if they are chafer? It has a brown head and it sort of light brown (cream?) with bits of black in? What is best way to get rid of them? Am hoping now my lawn will eventually look lush and green once and for all when I get rid of these little bu****s !! Thanks for help..
20 Sep 2008 by Mark P
Here is a picture of lawn in places
20 Sep 2008 by Christopher Proudfoot
Not sure what it is - chafers at a guess - but I suspect Greengardener.co.uk will have the answer. I used their nemtodes to get rid of ants and they work a treat.
Good luck,
Christopher
20 Sep 2008 by juls
Mark P
They look like Chafer grubs to me. Follow this link, you will find some good pictures and ways to deal with them.
http://www.lawnmaster.co.uk/YourLawnProblems.aspx
Juls
20 Sep 2008 by Pitchcare Peter
http://www.pitchcare.com/magazine/article/2189
20 Sep 2008 by Mark P Last edited 20 Sep 2008
Thanks guys - thought they might be - but nice to get second opinion, although they don't seem to have any legs on them (yet) and they seemed to look a bit different to those seem from pictures on the internet, hence my need to require clarification from you experts !
As for removing them, don't really want to use nematodes as success seems a bit hit and miss (so I've read). Merit Turf seems to get good reviews but is very expensive (Have approx 3/4 acre lawn), but will have to buy it, if needed. Have a scotts evergreen rotary spreader, but you need to get down to 3g per m2 to apply this product and that spreader's application rate won't go down that low.
Is there any cheap (i.e. less than £100) spreaders that will do that application rate that anyone knows of?
21 Sep 2008 by widdywoo
Mark - I was going to make the point about legs. Chafers legs are usually their identifying mark.
How big are these grubs? Could you post a pic with a coin or something similar next to one, to give us an idea of scale? We once had a problem with leaf weevil grubs, but I think they are smaller than chafers.
"I'm cheap, and nought but fashion; fling me away."
21 Sep 2008 by Mark P Last edited 21 Sep 2008
Hope this picture is a little clearer. I've measured them and they are just under 20mm at full stretch and 2-3 mm width. Have had a real close look at one of them. If you look very closely there are 3 x 2 very small hair like legs at the front of them of less than a mm (see grub on the left in picture which is sideways on), but they are certainly not as long or pronounced as the chafer grub pictures I have seen this weekend from the internet.
22 Sep 2008 by Mark P
Can anyone advise, as would really like to try to get rid of them this week? Should I treat as chafer grubs and use merit turf, or a general insecticide such as Cyren?
22 Sep 2008 by Eddy21 Last edited 22 Sep 2008
Hi Mark
I have used chlorpyrifos before in the past when I worked in the UK with really good results. It is a broad spectrum insecticide and is the main active ingredient in Cyren and Crossfire. Its a product that requires plenty of water and is pretty potent stuff.
It is very important that you are fully trained to use pesticides before you even think about an application of such a product.
I would also check that this product is still on the market in the UK for use in turf situations. The only reason I say this is because we have no insecticides available anymore for use in turf here in France, so its always best to double check.
Hope this helps
Dave in Paris
Learning is there for every man
22 Sep 2008 by davtar01
It wont work on chafers!
only merit!
23 Sep 2008 by Eddy21 Last edited 23 Sep 2008
Davtar01,
After just reading the product label for both Cyren, Merit and Crossfire you are probably right there, and I stand corrected if Chaffers are the problem here.
Mark, please find attached a good picture of a European Chaffer grub for referance.
Cheers Dave
Learning is there for every man
23 Sep 2008 by ajames31
out of curiosity, could anybody tell me why crossfire 480 wouldn't have an effect on Chaffers?
i know it is marketed for Frit fly and Leather jacket control to be applied from November onwards and will stay in the upper profile of the soil, at this time the Chaffers are probably lower down over-wintering, but why wouldn't it effect Chaffers if applied in late spring early summer when the beetle has recently laid its eggs and the grub is in a larval stage? Surely the 3 modes of action it uses would have an equal effect on Chaffer grubs?
There is clearly a structured reason for this or we would all be using it!!
As above, curiosity and personal development is my only reason for asking.
24 Sep 2008 by Mark P
Well, I sent the pictures of the grubs to a couple of experts I found on the internet. Still no wiser - one said they were baby chafers, the other said they were swift moth larvae???
27 Sep 2008 by andy dixon
Hate to tell you this guys (and not sure) but i think you`re all wrong. Difficult to tell from the picture but i think it`s a juvenile cutworm. I`ve seen a far greater incidence of them in the last couple of years (probably due to the damp summers we`ve been having. They`re hard to identify as there are so many sub-species (i think). I`m no expert on them so don`t take it as gospel. Someone mentioned to me that Bio-Provado (an easily available pesticide mainly used for vine-weevil) had been approved for use on these critters on sports-turf. I know in one case i looked at on a bowling green it appeared as a fuel spillage until i pulled one of them out of the soil, just beneath surface level. They are so-named as they literally eat through the roots just below the surface
28 Sep 2008 by Steve63
does this help Mark?
Regards
Steve
Don't talk to me about Contractors Wonka, I am one myself......
28 Sep 2008 by ajames31
here is a picture of a cut worm.
The first picture mark p posted looks fairly similar to a cutworm but the second picture posted with the penny as scale tells me they are chaffers as the colour of them are the off white/yellowish with a brown head, cut worms tend to be a musky-green (more catterpillar like appearence).
If i were a betting man (which I am) I'd go with Chaffer grub.
As we know there currently is only one treatment for these critters... merit turf. I've used merit earlier this year and have had mixed results, I'm certainly not convinced by this product.
Word has it though that one company are very confident of having a sprayable product on the market within 12 months (but we heard that for years before the release of merit). I have however seen first hand a small trail of this product and i can tell you that so far so good! Lets just hope they get the licence for the open market.
28 Sep 2008 by Mark P
Thanks for the pictures and help - I honestly don't think they are a cutworm as they look different to the pictures, the body is not as compartmentalised and colour is different. They certainly look more like chafers, although they don't have the characteristic legs or greyish rears (yet).
Have heard they might be Swift Moth Larvae? Does anyone know anything about those?
Anyhow, I am now going to apply merit turf as the general consensus on here tends to favour them being chafers. After nearly having a heart attack at the price of it, am hoping for the best !
Hope you are right, ajames31, about a new product coming out for chafers and being sprayable as well would be good.
28 Sep 2008 by ajames31
mark p, I wouldn't apply merit now, you should apply mid may to mid June when the grass is growing well, this is also when the eggs are likely to be laid and all of that years batch of chaffers , which are easily killed are in the same place, this time of year the grubs are a lot bigger and are heading south for the winter, any damage or discolouration you have now will not improve with the application of merit, best bet is to leave it for now and save your merit for next year, the damaged grass may re-root on it's own or may need returfing!
It would be financial suicide to apply now!
29 Sep 2008 by Mark P
ajames31, didn't do it yesterday as planned, so will follow your advice and wait. Will definitely have to reseed in places. Would you suggest doing this now or next spring?
29 Sep 2008 by ajames31
I would give it a bash now mark, with the temperatures still up a little and a bit of rain due over the uk in the next week the it should be fine as long as the seed pokes it head out before growing really slows down, you might just have to do a little seeding again in the spring but it wouldn't be as much as it would have been!
Good luck
29 Sep 2008 by ajames31
Thought I'd share a few pictures of what chaffer grub infestation can lead to, these pictures are of secondary damage cause by rooks/crows, badgers and foxes
29 Sep 2008 by ajames31
and another one
29 Sep 2008 by ajames31
and one last one, this might make you feel a bit better about your damage mark!!!
29 Sep 2008 by Weedy Last edited 29 Sep 2008
I think you will find them to be Wire Worms. Wireworms are larvae of the Click Beetle (Agriotes species) and about four different species are described as pests in turf culture.
The larvae are brown, hard-shelled worms with three pairs of thoracic legs. They grow to about 2.5cm long. The adult beetles are about 2.5cm long with flattened, dark brown bodies, often with darker markings.
Severe symptoms rarely occur in established turf, even though large numbers of feeding larvae may be present. The main problem arises in newly established turf, where damage can be caused for 3 to 4 years after the area has been cultivated. The larvae feed on roots and shoots; on living and dead material and at different levels within the soil. Symptoms include wilting of leaves and irregular patches of turf that turn brown and die.The fact that wireworms take so long to mature means that they can cause widespread damage over a long period of time.
If they are a Beetle, control with Merit. Chlorpyrifos will contol flies like Leatherjackets - this comment answers a previous query too. The active of Merit stops the larvae from feeding, the Chlorpyrifos disrupts the nervous system.
Hope this helps solve the problem. Weedy
29 Sep 2008 by Eddy21
Hi Ajames,
Very interesting pictures you have posted and im sure Mark now feels a hell of a lot better. Just out of interest, im keen to know if that is a course in the UK?
Regards
Dave in Paris
Learning is there for every man
29 Sep 2008 by Mark P
Thanks for the pictures ajames. Got to agree, my lawn does not look as bad as that ! This weekend, like you suggested, will try to reseed the bare areas.
30 Sep 2008 by ajames31
hi dave, yeah, those pictures are from the uk, Oxfordshire to narrow it a little, I took them as recent as yesterday morning, is there any particular reason you ask?
Alex in oxfordshire
30 Sep 2008 by Eddy21
Hi Alex,
Thanks for your reply. There wasnt really any particular reason for asking, I suppose it was just out of interest really. The first picture you posted is a pretty large area of damage, is the damage just a couple of nights activity, or has that been a problem area for a while, that has just got worse over time?
Like I say this is just out of interest, over here in France Wildboar are a problem on some courses and can cause massive problems when they go searching for grubs and can cause huge amounts of damage. The only way to keep these beasts off courses is by using electric fences around the perimeters of courses.
A bit off the subject I know, but hopefully someone might find this interesting info.
Dave
Learning is there for every man
30 Sep 2008 by ajames31
Dave,
The damage in the pictures was caused over two nights, its one of many areas across our site, its not the worst area but thankfully we dont seem to be suffering as bad as the last couple of years - well, every year since gamma col was taken of the market.
We're situated on a sandy loam (around 85% sand) which makes it perfect for the grubs to thrive in.
The damage will start around the first week of August and carry on into the first couple of frosts.
The areas move around the courses year in year out as it all depends on which way the wind was blowing when the beetles hatched! Thats the main problem with using merit as a treatment, because its so expensive we can't treat the whole site so we only treat the areas the grubs were last year, which is not necessarliy where they will be that year! We've got a few guns at work that would be greatful of wild boar roaming the courses, they make a better meal than rook pie!!!
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