North American Fruit Explorers mailing list at ibiblio

[Steve <sdw12986@aol.com>]

That makes sense. As I think more and more about what I see in my 
apples, I'm starting to doubt the idea that apples grow and crush the 
curculio larva. It seems to me that if the larva penetrated into the 
apple and then got crushed, there would have to be at least a tiny dead 
area under the scar. I don't remember that. It seems to me that the 
curculio scars are truly only skin deep. (I'll pay more attention to 
that in the future.)
Perhaps when we see mature apples with those scars, it's because either 
there was no egg, or the egg failed to hatch, or something happened to 
the larva before it could penetrate the fruit. (That something could be 
the weather, a predator, or the spray we used.) Perhaps the apples that 
had successful larval development all fell to the ground when they were 
small.

Steve in the Adirondacks

Mark Angermayer wrote:
> We don't seem to have a lot of curculio here, but everything I've read
> indicates it can reproduce in apples.  It emits a substance (maybe
> ethylene?) that tricks the tree into dropping the fruit.
>
> Mark
> KS