Best to pick up the dropped apples. If they have curculio larvae, they will hatch and pupate in your ground.

Not all egg layings are successful so yes a spray now will help stop further layings that may be.

I pick up and burn the apples that have curculio egg layings.

I was wondering if the apples don't maintain their life on the tree, if the pupae die. i.e. say I cut the apple off and let it fall, the apple takes no more life from the tree. the pupae get no more - whatever they get from the growing apple.

I am on it for next year though. Those trees will be BLASTED from mid April to mid May with insecticide. Screw this sh!t.

Thanks myk1- I will do likewise. With napalm.

"I was wondering if the apples don't maintain their life on the tree, if the pupae die. i.e. say I cut the apple off and let it fall, the apple takes no more life from the tree. the pupae get no more - whatever they get from the growing apple."

I don't think so since they are the cause of a lot of fruit drop it has to be part of their cycle.

Imidan actually kills the larvae in the apple- triazide doesn't do this?

"Imidan actually kills the larvae in the apple- triazide doesn't do this?"

I didn't know anything did that until you got me searching.
I'd defer to Olpea but I'd say according to a chart I found no. Looks like the Organophosphates and Neonicotinoids do but Pyrethroids don't.

Hman, did you mean to pose that as a question? Or were you stating that Triazicide doesn't kill like Imidan?

It was a question and I thank Mykl for answering it while we wait for our technical adviser for a final word. I'm also grateful to know the neonics do as well because I'm using one this year as an Imidan sub. Now I just wonder about Avaunt.

Check out this link from MSU:

MSU: OPTIMIZING SPRAYS

I recall hearing that the curc cannot reproduce from apples - their mode is to eat into the seed of a stone fruit, eat the seed when they are about ready for a ride to the ground, which causes fruit to abort and drop in a week or so. On apples the self-thinning drop usually comes too early for the curc worm to be mature by then and if they don't drop the apples just grow deformed. This is because the curc can't get the apple to abort since the eating the single seed method is impossible.

Whether this is completely accurate I have no idea. I personally feel that some of the drops will come at a point where the curc is mature enough, but the vast majority of worms will not turn into adults.

By the way another thing to keep in mind when you have a lot of curc damage is generally the marks that are not crescent-shaped are usually just feeding and not egg-laying marks, and those apples can mature OK - they will have a nickel-sized spot on one side when mature but will taste fine. I thin out the crescents and then the non-crescents, and leave some non-crescents if I am about to overthin.

Scott

Where I often have a problem during thinning and bagging is telling the difference between a new codling moth sting and curc feeding spot.

Curc feedings tend to look like mini-bites taken out and CM stings look like jabs. If you wait awhile it is obvious because the CM worm when working will keep a hole open to let the chaff out. With Surround this turns the little apples brownish-white around the chaff-out-spot making them very easy to spot and remove. When bagging it is a more difficult call since you don't want to wait.

Scott

Scott, I really enjoy your subtle observations. Can't imagine anywhere else I could get similar anecdotes.

Usually I only find the curc worms in plums, so I think it's a pretty safe assumption that apples that stay on the tree crush the larvae but the apples are often still ruined. I first read of this in M. Phillip's book.

I'm bagging long before CM.

I have found live curculio larvae in small drops (I have at least 2 types of curculio). I think if the apples are left laying they are able to complete their life cycle.

When I was organic I'd wait for thinning because the curculio bit apples do seem to be what drops for me.

Exactly - I don't want to wait and let the pests get the fruit and I don't want to bag fruit they've already hit.

Regarding the kickback activity of Imidan, I'm a little late reading this thread and Frank posted the same research I've seen, and probably what Myk was also looking at.

This was discussed last year during PC season I believe. As a recap, Hman suggested phosmet might have curative activity. I couldn't see how that was possible since it has no systemic action and I suggested such. Then I read the MSU CAT alert below. It essentially contains the same MSU information Frank posted, only they posted it the next year too. After more discussion the thought was that enough of the compound can leak in the wound to kill the grub. Phosmet is highly toxic to curcs and apparently it takes a very small amount. Hman concluded that with a 2 week kickback and 7-10 day forward protective activity, it might be possible to reduce sprays of Imidan to one spray the whole curc season, which is sound logic.

However, I still find the MSU claim of 2 weeks kickback amazing. After a few days the crescent scars start to heal and so I can't see enough residue could enter the fruit to cause grub mortality. However, I'm sure the researchers tested have it. I wonder if it works quite that effectively in the field.

Here is a link that might be useful: May 2010 CAT Alert