I’ve seen a huge difference in the amount of disease and insect damage on different Asian pear varieties – I’m not sure what all I’m seeing, but I’m pretty sure stink bug damage is a significant part of it – and I’m thinking about getting rid of the varieties that are suffering the most damage because I want to just invest my time in the varieties that naturally have fewer problems even if they’re not the very best tasting, but I’m wondering if the poor performing varieties are currently serving as a trap crop and that if I remove the varieties that the insects like best if they won’t go on to damage the varieties they’re mostly leaving alone now. Could that be the case with my Asian pears? Is it ever the case with any other fruit crops that keeping varieties that suffer from a lot of insect damage can draw insects away from other trees? I’ve read of people saying (whether it’s true or not) that mulberries can attract birds away from other crops.
I’ve had good luck with a variety called Moonglow (in Ohio). Seems to be resistant to Fireblight, which is one of the few problems I encounter here with pears. It bears in August, which is earlier than the other varieties we have. The pear is not large, but firm and sweet when ripe.
Oddly enough, I was just having the same thought this morning as I squashed aphids on my recently-grafted-and-not-exactly-thriving Edward VII apple tree (which seems to be a favorite of that particular pest, from what I’ve been seeing).
Will be interested to see what people have to say on this subject. It seems like the answer might depend on the behavior/life cycle of the specific pest in question.
I’ve noticed this with Japanese beetles and grapes. They attack my grape vine with full force when they come out. For about two weeks nothing else gets damaged, just the grape leaves. After the grape leaves become pretty much skeletons, they move on to plums. But until then they prefer grape leaves over anything else in my yard.
Aphids are often ‘deposited’ by ants…who farm the sweet sap/juice … may be totally random which cultivar the aphids work on … rather than a real susceptible apple variety. I’ve had aphids on maybe half a dozen of my 75 or so 2019 grafts…with 2 or 3 of the same variety, only one gets aphids.
Interesting. I feel like I do tend to see significantly more aphids on certain varieties (such as Kidd’s Orange Red, in addition to the Edward VII), and I think Alan has remarked that certain varieties (notably Cox, if I recall correctly) tend be subject to aphid damage. But my experience could be pretty random, as you say - I’m going off relatively limited data both in terms of numbers of trees and years of growing.
Specifically, one young grafted plant of each of these varieties has had aphids in past week or so…
….and I made more than one graft of all 3…but one plant of each had aphids.
About a month ago a couple plants got aphids…I didn’t write down the varieties at that time.
Interesting. Kidd’s has gotten aphids every year that I’ve had it - not tragically, but enough that I’ve learned to keep an eye out for it.
omg GALA. Talk about a trap tree. Its in the middle of my plantings and CM and PC go past other trees to hit it.
(No hating on Gala, it was my son’s favorite ,so i will have one for as long as i live)
I do believe even bugs have preferences. I have 3 Euro plum in a row 6-7 ft apart.
Castleton, Mirabelle and Coe’s Golden Drop. I’ve seen bite marks on OFM and PC in many Castleton and Coes’ but barely any bites on Mirabelle which is in the middle of the two. It clearly skips the Mirabell. Granted the Mirabelle fruit size is much smaller than the other two. They go after big targets. It goes to show you that bugs in my yard are no dummies.
Also, aphids attack my cherry tree first and always before any other fruit trees. I do believe some fruit trees and some varieties of the same fruit appear to attract bugs more than the others.
And Kidd’s and Gala are both Cox descendants so that may have something to do with it.
Trap crop vs bad variety is a hard thing to tell apart. Some varieties I thought were bad but grown in a different location (50’ away) they were fine. Location definitely matters, my back orchard is much more bug- and disease-prone due to less sun exposure.
I have had enough years watching aphids to believe they definitely have variety preferences. It is particularly noticeable on green plum aphids. They always start out on my Middleburg plum, only after it is covered will they move on to the trees that are overlapping with it. They have an order of preference they proceed in as well. French Prune is the last one.
True. Good point.
I should add that my Kidd’s have been pretty growable in spite of the aphids (and the fact that I don’t spray anything)*, so I don’t mean to knock them too hard. It’s just something I’ve noticed.
*Planning to do dormant oil of some kind in the future.
Same here, they start with the grapes, then move to the plums next. They never seem to bother with pears or apples. Maybe I have enough of the others to keep them satisfied. I have noticed they like knot weed a bunch as well.
PS. I was in the Philly area last weekend and noticed tent caterpillars everywhere. The trees next to the roads seem to be infested. Do you know of any strategies the state has to deal with these devils?