Online, in the "restoration" side of landscape installation, this has been a topic of much controversy for a while now. But it really needn't be so confusing. All one really needs to do is to both retain native woody plants on sites, to the fullest extent possible, and in turn, to plant native trees and shrubs wherever and whenever possible. There is nothing intrinsically different-in my view-to utilizing native species right along with non-invasive exotics within any given plan. We do it more than some might realize already.

But more generally, yes, the constant search for the blemish-free tree, the "perfect" shrub, is tending to run away from this obvious need on the part of our feathered friends-to have insects to eat. Native restoration-or whatever you want to call it-has been on this wavelength for a while now, eschewing the supposed perfection of old, the chemically-induced sterility of many a prized landscape of old. Things are indeed changing, albeit slowly.

+om

I am not in the landscape 'restoration' business (or only very tangentially) and I am certainly not in the forefront of new plant breeding introductions but I am very active in the horticulture industry and I have never heard of any bred-to-be pest resistant trees - disease resistant, yes, but insect resistant?? Never.

As far as I know, the only plants specifically bred to be pest resistant are those mega-agriculture crops like soy beans, corn or cotton that are genetically engineered to be resistant to specific insect pests. Since any sort of genetic engineering costs millions of dollars to achieve, it seems hardly likely that sort of financial investment would be made on any sort of plant material that didn't return a huge financial profit by its sale or harvesting, which trees and shrubs most certainly do not. Or that don't provide a major agricultural impact.

I may be way off base here - and if so, please enlighten me - but I think you are worrying needlessly. Disease resistance is an entirely different kettle of fish and a concept I have no arguments with but it is a much more narrow focus than to attempt to breed/hybridize trees to be resistant to the vast number of insects that inhabit our gardens and forests. Number 1, I just don't think it is possible/practical, and number 2, I seriously doubt much effort is being expended in this direction.

I do agree that planting native species can help to maintain an ecologically appropriate habitat for both beneficial and less desirable insects that birds of all types will feed on (they don't seem to distinguish between 'good' bugs and 'bad' bugs) and I try to encourage tolerance of minor insect damage to plants to avoid the unnecessary use of pesticides. But I have very little fear of a generation of 'pest-free' trees and shrubs flooding the nursery market and starving out the bird population. Just not gonna happen!!

I have faith in our insect "friends". Some insect eats everything. Once the Big Box stores promote a plant as one of the standards, eventually some insect that eats it will find it's way into the area. There are invasive plants resistant to native insects...but there are also plenty of invasive insects. I'm sure birds are fine eating Japanese beetles, gypsy moths, and Asian Longhorn Beetles.

If you are really concerned about a shortage of foliage-eating insects, plant a mix of native seed-grown plants from the area, crab apples, and other members of the genus Rosaceae. EVERYTHING seems to find them delicious.

With all our efforts focused on developing and planting trees that are resistant to pests.......

OP please explain further, give some examples.

People deliberately seek out plants resistant to insects and selectively plant them. Ginkgo is one of the most common examples...a tree that was very rare in the wild but is now all over the place in suburbia because most insects ignore it.

And there is lots of effort to breed or find fruit trees less bothered by insects.

Crabapples Resistant to Apple Scab and Japanese Beetle in Indiana

I'm reminded of one Rhamnus cathartica-common buckthorn. Please, please insects, eat that POS! But of course, nothing touches it. I have one silly brother-in-law who, already (and immediately) having given up on controlling buckthorn on his hunting land, pronounced that the deer do eat it on his property. I'm thinking I'll stop out there in ten years and see how that's working out! Exotic, invasive, and the only plant part that does get consumed is, of course, the fruits, which, as the specific epithet may have you understanding, do not remain in the birds' digestive tracts very long.

+oM

I have to admit this threw me off as well: With all of our efforts focused on developing and planting trees that are resistant to pests,

Nonetheless, with all the chatter I see on the chat boards about pest infestations on X, Y, Z, not sure this is an issue.

Many, many more threats to birds than this. Eliminating wandering cats will save ~1B birds a year. Start there. Then powerlines, windows, cars - so many things higher on the list of bird worries...

Dan, I couldn't agree with you more than I already do about cats. For whatever reason, some change in society, it has become extremely common for just your average, every day neighbor to leave their cats wonder all day, every day. I'm not the killing kind, but I have to admit, I've thought about a well-placed bowl of antifreeze.

But more to the point, if this seems to you and some others as coming out of left field, that honestly says more about you than it does about the facts of the matter. Native plant enthusiasts are all about this issue-what insect life does a given plant type support? Questions like that. It is understood that if the base of the food web is off-kilter, we can't expect much to go well higher up the chain, and this is one, albeit legitimate part of that puzzle. If you were in my shoes, you would not be surprised to see this subject come to light.

Very generally, certain genera of plants seem to support more wildlife than do others. So, oaks are high on this list, and it's not just the mast (acorn) production for large herbivores, it's all the way down to what types of caterpillars, etc. feed on oaks (many) and therefore, what higher organisms are in turn able to derive sustenance from their existence. Maybe it will take a while, but this kind of discussion will become commonplace at some point.

+oM

My concern is across the Midwest, where the Emerald Ash Borer has left a barren landscape and we begin to replant with Manchurian ash cultivars because of their resistance to the borer and their likeness to the green and white ash that are gone. The replacements for Asian Longhorned Beetle are trees that the ALB does not like.

While I admit these may be two extremes, they are also the beginning of a new trend in breeding trees.

Yes, very much in its infancy, this whole area. Some-I occasionally include myself in this group-talk about "novel ecosystems". Very basically, we're not going to get things back to 1850.....or 1750...or whatever benchmark year one would use to set a time when things weren't messed up like they are now. So what do we do? In the east, where hemlock has been devastated by the woolly adelgid, do we import Asian hemlock genetics to at least have a somewhat-similar tree in our forests? Or do we mass plant Norway spruce because that species is a proven performer here in N. America......and somewhat fills the same niche? I'm not proposing these ideas as subjects of debate here on the Trees forum, but rather, to get folks thinking about where we may be headed. As it is, here in Wisconsin, ash trees are ultra-common, and I fear most spaces now occupied by green and white ashes especially, will be filled with junk buckthorn and non--native honeysuckles. This truly seems inevitable. Throw in a state government that couldn't care less about such matters, and well.....it's looking bleak.

+om

Putting my ecologist's hat on here, I can't picture an urban tree that may have resistance to ALB that, because of that resistance, won't host aphids and other herbivores for attendant carnivory. There is such an array of insects that practice herbivory that there is little to no danger that planting a certain tree won't result in herbivory.

More important in urban areas for insect and bird species diversity is urban heat, air pollution, noise, tree species diversity, impervious surfaces, understory canopy, fragmentation...

/ecologist's hat

There is, and has been, many efforts to develop insect-resistant trees...and for a variety of reasons. Food crops (like apple trees, mentioned above) and pest-insect-targeted species (there are more of this type all the time) are the two groups that come to mind. Insect-resistant tree technology does seem to significantly lag other insect-resistant plant (especially food crop) technology, but it does indeed exist!

Yes, there is concern among many people. Doug Tallamy, an entomology professor, details the issues in his very readable book, Bringing Nature Home: How You Can Sustain Wildlife with Native Plants. I'd highly recommend reading it and also including many native plants in your landscape. And don't freak out over insects that visit them.

Oaks are one genus Tallamy mentions that host many insects. I myself prefer to have smaller trees and bushes around my suburban lot and have included red twig dogwood, elderberry, hazelnut, and various native non-woody plants.

Bringing Nature Home: link: http://www.timberpress.com/books/bringing_nature_home/tallamy/9780881929928

Exactly-Doug Tallamy and the like^. I'm not 100% sold on Doug's world view, but we sure do overlap in places. And I think that when you see your 10,000th Callery pear, it's blemish-free foliage gleaming in the sun.....to use but one example...it's not so much that breeding work has been done in this direction, as that this factor-pest-free foliage-has been used as a selling point, and that this has directly went into the ad copy that has this tree taking over the continent. These are not figments of the imagination, and listing other travails that effect wild birds does not diminish this factor one bit. We're talking about no less than the bottom of the food chain. While one individual, in one locale, may not live to see the full ramifications of a continent given over to largely non-life-supporting plant types, that does not diminish the reality, any more than does the fact that one person's lifespan is too short to see a host of changes taking place on the landscape.

+oM

There's a double-edged sword effect. People who plant trees & shrubs without substantial pest problems may not use insecticides; those planting pest-plagued trees & shrubs may. Consider concerns of some that Imidacloprid can have serious effects on non-target species (e.g.: bees).

I've got a couple of young ginkgos in our yard, & a couple of young pecan trees, for example. Tent caterpillars are a problem (substantial defoliation) with the pecans; not so the gingkos.

People planting native species in part for insect food (& up the food chain) are probably a minority in the yard planting demographic. I see the concern about eroding the food chain base. I also see the benefit of encouraging less insecticide use.

Richard.

I love my cat but it has never killed a bird and never will. Cats belong inside except possibly in the rural places where farmers rely on cats to keep their barns rodent free without poisons. A feral cat is a disaster waiting to happen, really more a disaster that is happening. Almost as bad as the human trash where two humans produce more than two children and contribute to the overpopulation of the earth. One of the few things worse than that are the religions that encourage this behavior.

@ drrich2, yes, of course we can all agree that less pesticide usage is a good thing. but that presupposes that the owner of the native plant with the bug-eaten leaves is actively managing for this "pest" problem. They may in fact-and usually are not-doing so. But where this is happening, of course it brings another dimension into play.

If I come across on these pages as purist-in any sense-then I've not done a good job of explaining. I am simply saying that yes, there is support for the idea that a landscape increasingly composed of non-native, and largely non-preyed upon-tree and shrub species is a part of the problem happening at the base of the food chain. Nothing more.

+oM

all natives are host to atleast one lepidoptera so plant natives....