Curc firing blanks in cold?

I have been surveying and thinning today. I have a lot more curc damage than usual, I think they started earlier due to the weather somehow. But, I don’t see any trails in the apples/pears/plums when I shave off slices around the wound. Having done this for years I know that by now the worms should be starting on their treks by now but they aren’t. Maybe the cold has affected the egg hatch? The damage is from several weeks ago. It could be the eggs are still viable but not hatched, but given how mature the apples are based on past years, it seems like they are just not hatching at all - ? Nothing I sprayed is affecting this, some apples I missed completely (no Surround on them at all) and they also have no trails.

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The fruit may have crushed the larvae as it does frequently with pears. If the larvae did not grow at their normal rate they would not stand a chance.

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I would figure there would be a tiny track first, I sliced very thinly and was not finding anything. Well there were a few where I found that telltale black pinpoint in a cross-section which means the worm was moving, so there were a few where they barely got moving and in those cases I think you are right about the crushing. And maybe even the eggs were getting crushed, they are inserted under the fruit. The curc cuts the crescent precisely to decrease the crushing pressure on the egg, but there is probably a time limit past which it doesn’t help.

In any case its very odd not to have found a single curc track in any fruit all spring. The codling moths are also having troubles, their tracks are staying just below the surface, almost popping out again. It makes it easy to spot when thinning.

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Scott - what do you think, is curc activity tied more to weather and temperature or to availability of vulnerable fruitlets? This year has had things out of synch.

The bugs each have their own internal degree days calculator that is genetic. I think what happens is that the curc’s calculator is not exactly matching the apples. Its really close, because survival depends on it, but based on this year they seem to be off. They woke up and laid the eggs at the right time, but the extended cool spell delayed the hatch a lot longer than it should have. The “program” of the curc was not designed for such a long cool spell after egg laying I guess. The apples kept on growing, more slowly but relatively faster than the curc egg development and they got enough ahead to crush the curc.

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I haven’t seen a single hit yet, but i haven’t checked today. Some of my cots are almost quarter size now, although they don’t seem to hit the cots hard ever…its always plums, pluots and nectarines…

I used to belong to a local group that had an IPM tracker for members - based on degree days. Thing is, the focus of the group was primarily on apples. So I was relying on the tracker until the day I checked my growing cots to find them covered with PC scars, while the tracker was saying there was no activity yet. Then the members of the group didn’t believe they were really PC scars, because the apples weren’t ready.

So far no hit for me either. It rained hard last night that mean I will have to re-spray Spec. Once and Done on the apples and peaches again.

Tony

I have seen some damage, but not so much. I sprayed previously with Triazicide. I will try to cut the fruits.

I think I’m going to switch to Sevin for stone fruits this year, particularly given that I’ll have almost no apples.

Apricots are 1-2 weeks ahead of apples in terms of the first PC damage - it sounds like your group didn’t have any apricot growers. One constant every year is the PC is there when the fruits are ready for them, every time without fail. I usually get some damage before my first spray because the PC are watching 24/7 and I’m only looking every few days. I’m not sure how they manage it, it seems like they wake up on the early side since they have to find a mate first; they must be twiddling their thumbs for several days just waiting to unload the eggs.

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Wonder if this bodes well for a population crash next year!!!

Mike

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It would be nice if the weird weather set the bugs back a couple years.

I did some thinning today on my two apples that set fruit and on my Superior plum. No curc damage for me so far. I’m hoping that being on top of the Surround in Year 1 means that the curc never finds me. haha. :wink:

I caught one codling moth on 4/26 but haven’t gotten any since, but the day after we went into the week long cold spell. I’m wondering if the lure all evaporated and it isn’t active anymore.

I found my first curc trail last night! I never thought it would be cool to actually find one. It was in a plum, it made it to the seed. Based on the inspections I have done, 98+% of the curc eggs are not taking off. Lets hope the moths get similarly hammered.

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I stripped off a ton of Puget Gold the other day and found no damage. I’m going to look again today. Its been cool, but not cold and very rainy. Highs near 70F are in the cards before a big weekend cold shot.

Lots of curc damage on my earliest fruit to set, chickasaw plum. Many of the very tiny fruitlets had multiple strikes. No damage on anything else. Luck? Funky weather?

No stings yet. I’ve sprayed most trees twice already - before and after bloom.

Something is gnawing small round holes in pearlets, but I think that’s not curcs.

Those smart little buggers, the rained has stopped and they came out hitting the fruits hard.

Tony

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I’ve been thinning/bagging apples over the last week and have seen little to no curculio damage. Some apples have marks but they don’t look like the telltale ‘u’ shape. Makes me happy, last year I barely had any apples they didn’t ruin! I haven’t gotten to my peach tree yet, though. Historically that’s been pretty safe.

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