Author Topic: Mystery of the missing blackfly on my broad beans  (Read 2477 times)

pudding

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Mystery of the missing blackfly on my broad beans
« on: July 10, 2021, 09:52:17 »
No blackfly AT ALL on my broad beans this year. I always have blackfly. I do not use chemicals or sprays at all, and rely on pinching out the tops - which I have not done this year.... I almost miss the little pests (not). Lovely crop of beans. Same places as usual within the plot. Planted indoors to avoid the depredations of the local rabbit population (bigger this year than ever) and planted out over four or five weeks in early May in (home) compost strips between cardboard paths.

No change in nearby sycamore hedge which has always been blamed for the infestations. I would like to know why so I can ensure it happens again for next year! Also no cabbage whites seen flying around after expensively covering all brassicas with veggie mesh on supports. All very odd.

Only other change is not mowing nearby grass since early May except for paths eg to greenhouse. Is this somehow trapping the pests? Diverting their attention?

Any ideas welcome - as I say, I want to ensure this is not the last time this happens!

Allotments 4 All

Mystery of the missing blackfly on my broad beans
« on: July 10, 2021, 09:52:17 »

InfraDig

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Re: Mystery of the missing blackfly on my broad beans
« Reply #1 on: July 10, 2021, 11:57:22 »
At a guess, they are all in my garden!

ed dibbles

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Re: Mystery of the missing blackfly on my broad beans
« Reply #2 on: July 10, 2021, 17:32:15 »
No blackfly here either but a large number of ladybirds. Are they connected? maybe, mabe not.

No shortage of slugs though, the wet weather has seen to that :happy7:

JanG

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Re: Mystery of the missing blackfly on my broad beans
« Reply #3 on: July 11, 2021, 06:05:43 »
And hardly any blackfly on my plot either. Perhaps more predators around this year.  I’m inclined to connect it with the odd weather we’ve had so far this season.
Also the same with cabbage whites. Only seen a couple of strays whereas they’re usually rife by now.

I’m not sure that there’s anything we can do to repeat this another year. ☹️

And yes, the slugs. The ups and downs of these things ……

gray1720

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Re: Mystery of the missing blackfly on my broad beans
« Reply #4 on: July 11, 2021, 19:46:12 »
Yes, I fear the weather has had a lot to do with it - I've had a few plants with blackfly but most have avoided the little effers and I've had my best crop of broadies in years. Mind you, said fly are just settling in on my globe artichoke...
My garden is smaller than your Rome, but my pilum is harder than your sternum!

Tee Gee

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Re: Mystery of the missing blackfly on my broad beans
« Reply #5 on: July 11, 2021, 20:34:19 »
Quote
Yes, I fear the weather has had a lot to do with it

I agree! I broached on this earlier in the season when I discussed the weather’s effect on pollinators,I guess the same could be affecting pests such as black fly.

In fact I am now thinking the weather is affecting both indigenous plants and wildlife due to it being so variable and out of kilter.

Further to that, I think it is affecting plants as well. I base this on how differently many of my plants are reacting this year.

For example I planted 5 Cucumber plants in a bed, one died shortly after planting. Two are stunted and are around 6” high and bearing a few male flowers. Two grew in what. I would consider to be an ‘expected manner’ They are around four foot high but I have noticed this morning that one of these is starting to wilt and looks quite poorly, the fifth is producing both male & female flowers.

I have a couple of onions that have bolted and showing a flower head, before showing  signs of swelling at their base.

My flower beds are suffering in parts too with some plants wilting, and others flowering prolifically and others growing foliage at the expense of flowers.

Basically I would say that my garden is out of kilter and. I am getting to thinking that my plants, insect life, and me will have to be going back to the drawing board if we are to compete with the changes in the weather .

Obelixx

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Re: Mystery of the missing blackfly on my broad beans
« Reply #6 on: July 11, 2021, 21:35:49 »
I sow my broad beans in early December so they can get ahead before any drought such as we had in spring last year.   This year, perversely, April was very cold and dry.   However, the broad beans did OK, had black fly in May bit not badly and were all picked and eaten or frozen by mid June.

PSB did fine over winter as did the pointy cabbages.  Spring plantings of red and Savoy cabbage are doing well under insect netting along with broccoli, sprouts, Swiss chard and pick and come again salads.   Garlic, as discussed elsewhere, has been odd and I have yet to see how the shallots will do but leeks are growing OK.

Tomatoes and chillies have had a slow start after such a cold spring.  I have had no success sowing spring onions and beetroot and quite a few ornamentals have failed, even easy ones like nasturtiums which I grow as sacrificial plants.   I have no idea if that's temperatures or dodgy compost.

It has been our best spring/early summer yet for soft fruits such as red and black currants, purple gooseberries, strawberries, raspberries etc. but it is unusually cool and damp.





Obxx - Vendée France

Beersmith

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Re: Mystery of the missing blackfly on my broad beans
« Reply #7 on: July 11, 2021, 22:31:54 »
Every season is different. I didn't see any for ages.  But a few started to appear about two weeks back and now they are increasing very rapidly.  Plenty of ladybirds and ladybird larvae seem to be around.

Get busy please ladies!!
Not mad, just out to mulch!

pudding

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Re: Mystery of the missing blackfly on my broad beans
« Reply #8 on: July 13, 2021, 08:05:53 »
Thank you for your interesting responses. I am not the only one finding things a bit odd in the veg plot then! Weather is probably the reason, as most said. My husband's aunt used to keep a diary of the weather each day (still got it somewhere) and I feel the urge to do the same - to what end I am not entirely sure...

No sign of ladybirds or their larvae - though the beans are so thick and lustrous they may be hiding. About 40 plants are now finished and coming up and into the compost this week. The rest won't be long. They have taken a long time which I put down to the weather, and like Obelixx said, autumn sowing might be an idea for the future - now I have bought covers against the jackdaws, squirrels and rabbits, it might be a goer. My leeks are waiting for the space.

Slugs as ever. I can go out at night when it is quiet and hear them chomping all around me. Also woodlice in the strawberries. Blackbirds in the blackcurrant bush but I usually let them have a few anyway, to complement the redcurrants which they have stripped completely. I like to see them though. I like to see the rabbits, and the butterflies, but my plot is a series of defences against them all.

saddad

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Re: Mystery of the missing blackfly on my broad beans
« Reply #9 on: July 13, 2021, 14:53:18 »
There's quite an interesting little article in the current "Grow Organic" (HDRA) Mag about the distribution of pests like Blackfly and cabbage whites.

Vinlander

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Re: Mystery of the missing blackfly on my broad beans
« Reply #10 on: July 14, 2021, 12:18:54 »
I got normal blackfly numbers on my broad beans, at the normal time (ie. after they are more than 50% tall) , and the ladybirds arrived a few weeks ago so most of the fly have been polished off now - nothing unusual there either. The beans were sown in November. I count this as a lucky escape.

My indicator for a bad year is when the blackfly move onto the baby beans in a line down the crease - it didn't happen this year, so it's a middling infestation - that means I don't need to wipe the beans or my hands when picking.

I think the ladybirds are the key players here (especially the larvae - because they stay put - though the ladybirds seem better against ants - presumably they can't be mobbed) - I normally try to sow in both October & November (white seed) and also March (green seed) and I almost always find one sowing gets a light infestation (when the ladybirds arrive soon after the blackfly), and one gets a medium (when they are a bit late) and one gets it heavy when they are very late - but it's impossible to predict which sowing will get timely or late ladybirds, and that's why I do at least these 3 sowings, sometimes February too.

Since I am in Outer London I'm not sure why I've bothered with the white-seed beans - I will be trying the better-flavoured green-seeded types for all 3 (or 4) sowings next year.

Has anyone in the SE had any experience of how well green (or pink) seeded types cope with an autumn sowing?

Cheers.

PS. If there's "green" in the name they will be the better kind. "Crimson flower" broad beans are also green-seeded, but unfortunately the breeding for appearance has had its almost inevitable effect of knocking out the flavour - the baby went out with the bathwater.
With a microholding you always get too much or bugger-all. (I'm fed up calling it an allotment garden - it just encourages the tidy-police).

The simple/complex split is more & more important: Simple fertilisers Poor, complex ones Good. Simple (old) poisons predictable, others (new) the opposite.

gray1720

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Re: Mystery of the missing blackfly on my broad beans
« Reply #11 on: July 14, 2021, 14:45:10 »
My plots are on quite an exposed site on the edge of Oxford and I've found that if I start my broadies in the autumn out there, they just get blown away, frozen off, washed away, or one of any number of winter malaises. If I start them in pots at home in the autumn, they tend to get too tall while I wait for vaguely sensible weather to plant them out, and get blown horizontal as soon as I do so. This year I started them in late Jan, I think, and have the best crop I've had in years, from Aquadulce Claudia, Karmazyn (red beans) and Dreadnought, without them succumbing to anything.

Dunno how helpful that is as I don't know what your plot is like, but I've tried. I'm good at trying, my missus says I am always trying!
My garden is smaller than your Rome, but my pilum is harder than your sternum!

Tee Gee

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Re: Mystery of the missing blackfly on my broad beans
« Reply #12 on: July 14, 2021, 17:03:28 »
I used a method that worked for me, and I was rarely affected.

The method  was quite simple; I counted the number of flower trusses there were and when they got to 5 sets I removed the tip of each plant. Through trial and error I discovered that this worked, e.g. when I  allowed six trusses (or more) to flower  I invariably got an infestation, but with five or less trusses; at worst I usually only got a few or none at all!

So I guess the moral is; getting fewer is much better than getting none!

 

anything