Sawfly in brassicas

[neilo]

I've got a few small sawfly caterpillars appeared on the leaves of my maincrop turnips yesterday. I've never seen them before there were masses of them, and obviously more are to hatch yet. I have Hallmark in the store ready to spray, but no point before they've all hatched.

Does anyone know how long they will take to hatch, or should I just spray now and follow up with another dose at the end of the week? Little damage yet, but I know they can devastate the crop very quickly.

 

[Al R]

Neighbour had swedes for human consumption up around 4” last Saturday, Monday morning they looked like this

I have a lot of stubble turnips around there small field and mine are untouched

 

[serf]

Neighbour had swedes for human consumption up around 4” last Saturday, Monday morning they looked like this View attachment 979903

I have a lot of stubble turnips around there small field and mine are untouched

Ffs there's always something on the attack !
Recon neilo best get the chem on now and see what happens and do again if needed !

 

[ajcc]

Spray asap. Hopefully residue on leaves will kill anything eating it for a week or two. The blighters hatch in big clusters at base of leaves and grow at phenomenal rate to size of Al R above.
Seem Hellish bad this year have sprayed twice against them, last week and about a month or more earlier.
Fortunately don’t seem to like fodderbeet but have mangoldfly instead on them, first time really seen them, little maggots inside the beet leaf. Also kale largely unaffected by sawfly so far......
But you need to keep walking these foddercrops this time of year, twice a week at least. Anyone who doesn’t enjoy dailydog exercising must be fed up with the chore of cropwalking vigilante.

 

[An Gof]

I've got a few small sawfly caterpillars appeared on the leaves of my maincrop turnips yesterday. I've never seen them before there were masses of them, and obviously more are to hatch yet. I have Hallmark in the store ready to spray, but no point before they've all hatched.

Does anyone know how long they will take to hatch, or should I just spray now and follow up with another dose at the end of the week? Little damage yet, but I know they can devastate the crop very quickly.

Don’t wait spray ASAP or you will have nothing. Repeat as required.

 

[DRC]

Had those for the first time ever on stubble turnips last year. Spray ASAP

 

[neilo]

I’d never had to deal with them before last year either, and only on one 5ac field then.

Just finished nuking them now. Thanks all, that was my gut feeling too, but I know there will still be eggs hatching.

 

[Jerry]

I’d never had to deal with them before last year either, and only on one 5ac field then.

Just finished nuking them now. Thanks all, that was my gut feeling too, but I know there will still be eggs hatching.

View attachment 979946

At least it’s a cheap spay. Just a shame it hits beneficials too.

 

[Derrick Hughes]

I've sprayed mine

 

[serf]

Just a shame it hits beneficials too.

Catch 22!

 

[neilo]

At least it’s a cheap spay. Just a same it hits beneficials too.

I use Hallmark as it’s supposed to be kinder on beneficials than some, but dearer and (I think) less effective than cypermethrin products.
Still only about £2/ac for the Chem though.

 

[serf]

I use Hallmark as it’s supposed to be kinder on beneficials than some, but dearer and (I think) less effective than cypermethrin products.
Still only about £2/ac for the Chem though.

What rate does that go on at ?

 

[neilo]

I used Cythrin last year and could see them falling off the leaves within minutes.
Hallmark doesn’t seem to be working as quickly ….

 

[neilo]

What rate does that go on at ?

50ml/ha

 

[Kevtherev]

Spray now and again if needed
Bloody things

 

[Jerry]

I never understand why cabbage whites are not an issue with my summer sown forage crops yet my purple sprouting and sprouts plants in the garden get hammered.

And yet never see a sawfky larvae in the garden??

 

[Kevtherev]

Seem to move in cycles some years worse than others.
I also think that with brassica crops becoming more popular on livestock farms these pests increase in number.
I’ve seen flea beetle strip a field of swedes in a matter of days.

 

[serf]

According to this they would be second hatch now

https://ahdb.org.uk/knowledge-library/turnip-sawfly-biology-and-impact-on-vegetable-brassicas-and-oilseed-rape

 

[Kevtherev]

According to this they would be second hatch now

https://ahdb.org.uk/knowledge-library/turnip-sawfly-biology-and-impact-on-vegetable-brassicas-and-oilseed-rape

Were second hatch @neilo has given them a radox shower

 

[Al R]

Were second hatch @neilo has given them a radox shower

Must be head and shoulders the way it burns the eyes