Thursday, September 03, 2015

Insect Super Heroes

Good bug. Bad bug. Sorting it all out for the home gardener can be confusing. Luckily for those of us in Oregon there's bug superstar Claudia Groth (also know as Dr. Dirt on Portland's KEX radio). I had the fortune of learning under her when I participated in the Master Gardener Program in 2013. I attended recently a class hosted by Portland Nursery where Claudia spoke about insect super heroes in the home garden.

Before we get down to business here is a link to a handy pocket guide .pdf (full color, too!) of common insects and what they look like at different stages of their lives. It's important to know, for example, what a lady beetle larvae looks like, for those are the voracious aphid eaters in the garden. The .pdf is free and sponsored by Oregon State University Extension Service, Oregon Tilth, and the Integrated Plant Protection Center. You can print it out, fold it up like a booklet, and keep it handy when you go into the garden to identify insects.


Claudia with a few flower props. The plants on the left all have benefits for insects. The grasses are year-round hiding places, but especially in winter for insects. Consider leaving them up through the winter to provide habitat before cutting them back.


The flowers Claudia showcased here all have something in common, i.e., it is easy to find the center of each bloom for insects. Hybrids and dahlias and fancy roses are pretty in the landscape, but it's difficult for an insect to locate the center and thus collect nectar and pollen. Small-flowered plants like Achillea millefolium or yarrow (the pinkish flower on the far right) are excellent sources of nourishment for dozens of insect species.

Why should we want insects in our gardens? And who are the superheroes? The answer to the first question is balance. There is such a thing in nature -- balance -- and it has been sorely missing, as there has been a significant reduction in habitat for insects and birds alike. Pesticide use has also taken its toll. In fact, insects have been moving their territories north at the rate of two miles per year for many years, according to Claudia. Maybe that explains the monarch caterpillar I found on my milkweed last summer. Open areas are quickly turning into strip malls, apartments and houses. A typical home with a green lawn and several shrubs and not a lot of diversity will support only a few insect species. A diverse range of plants with blooms throughout the year and different canopy levels will double that support level. Although not a lot of research has gone into home gardens and diversity, what little that is out there suggests this to be true. I know from my experience that the range of insects in my garden is surprising, to say the least. 

The second question is who are the good guys vs. the bad guys? The good guys are: Lady beetles, spiders, green and brown lacewings, predacious hoverflies, ground or "Carabid" beetles (they actually attack slugs!), damsel or "Nabid" bugs, parasitoid tachinid flies, rove beetles, predacious stink bugs, minute pirate bugs, assassin bugs, tiger beetles, big-eyed bugs, ambush bugs, soldier beetles, thread-waisted wasps, larger parasitoid wasps, vespid wasps (yellowjackets and hornets), and smaller parasitoid wasps. That's a long list. Let's just cover a few now, as there are more details about all of the insect super heroes in the .pdf link provided at the top of the page.

Also, if identifying insects in the garden, it is most helpful to obtain an inexpensive hand lens or loupe.

  • Lady beetles or ladybugs are fantastic aphid eaters. Aphids can do a lot of damage so thankfully lady beetles larvae are voracious aphid eaters as well as scale, spider mites, thrips and whitefly eggs. Their larvae look like orange-ish alligators. These are the ones that actually eat the aphids, so it's important to be able to recognize them. How to keep them around and how you can help: Provide pollen and nectar plants for adults to stick around and don't spray pesticides.
 These alligator-looking creatures are ladybug larvae. If you see them in the garden, that's a great sign. Photo courtesy of Willow Murawski.


Ladybug larvae with mom in the background. Photo courtesy of Laura Heldreth of the garden blog Gravy Lessons.


One more image - just to make sure we all know what they look like. Photo courtesy of Mindy Northrop of her home and garden blog Rindymae.

It is good to note that when looking at colonies of aphids, for example, if you see aphid corpses or husks, it's fairly safe to say that predators are about and you should allow them to finish the task at hand. 

  • Lacewings are similar to the lady beetle in that it's the larvae that do a lot of good in the garden. They eat scale, mealybugs, whiteflies, caterpillars, leafhoppers, and thrips. How you can help: Provide continuous blooms in the garden to keep adults around and don't use pesticides.
Although difficult to see, there is an adult lacewing on the stem of the flower.

  • Spiders are beneficial in the garden, too - although they are generalists, meaning they attack both destructive and beneficial insects. They are wonderful at keeping insect populations down - all part of balance in the garden. Here's a video from Portland Metro highlighting their benefits in the garden such as eating mosquitoes, yellow jackets, ants, flies, aphids and more. Protect them and you'll go a long way towards reducing unwanted insects. Help yourself by minimizing disturbance and leaving some debris piles in out of the way places in the garden and refrain from using pesticides.
 Daddy long legs (not technically a spider as they lack silk glands and venom) love to eat mites, aphids and caterpillars. Photographed blending in on an edelweiss flower.

  • Hover Flies eat aphids, scale, mealybugs, thrips and spider mites. Tachinid flies eat caterpillars, stink bug or moth larvae and eggs. How you can help is by providing continuous blooms in shallow, open flowers and reducing disturbances and refrain from using pesticides.
 A predacious hoverfly enjoying some sedum blossoms on the eco-roof.
Besides printing out and taking your handy insect pocket guide (from the .pdf link at the top of the page) with you in the garden, how can you tell a predator from a pest? Generally predators move very quickly. They have to to catch their prey.

Not all beneficial insects are hunters, however. There are, of course, pollinators such as butterflies, honey bees, and native mason bees. They may not keep other insects in check, but they do pollinate, a crucial step necessary for the success of thousands of food crops worldwide.

 Native mason bee in my backyard.

Monarch caterpillar on Asclepias speciosa or milkweed in my garden last summer. You can revisit that story by clicking here. We just had the one, but it was an event to celebrate.

So how do you attract them into your garden? With food, shelter and no pesticides.


FOOD
Food consists of the right kind of flowers as mentioned above. This is usually for the adult insects such as the lacewings, hoverflies and lady beetles, as the larvae are often the ones that eat the aphids and other pests (spiders, wasps, pirate bugs, beetles and others in their adult form do attack pests) . That is to say flowers whose centers, where nectar and pollen reside, are easy to find and access.

Single-petal flowers are best and small-flowered blooms are especially appreciated. Wildflowers such as blanket flower, goldenrod, coreopsis and yarrow are all excellent choices. Asters, sunflowers, daisies, alyssum, dill, fennel, parsley are all wonderful choices to add to the garden. Even allowing your veggies or herbs to go to seed, or at least a little bit of them, is very helpful. I will also mention to add water to the list of food sources, especially for bees. Providing even a small puddle somewhere in the garden is crucial to keeping them happy.

Chocolate cosmos and Sedum 'Matrona' pictured here. Both are often loaded with bees and other flying beneficial insects as the flower centers are very easy to locate.


Yarrow or Achillea millefolium is a wonderful host plants for many insect super heroes. 


The zinnia on the left has a nice open center, easy for insects to find. The one on the right, however, is more problematic.


Nice open center of a common marigold.


Blossom of native Spiraea betulifolia or birch-leaved spiraea. Multiple small, open blooms on a flat flower head. Perfect for insect foraging.


Flowers with small, multiple blooms and flat heads are especially attractive to insects foraging for pollen and nectar. Pictured here is Verbena bonariensis, which can be invasive in some regions, so use with caution.

A note about native plants and insects: Not all plants to attract insect super heroes need to be natives. Natives are wonderful, and I am their biggest cheerleader, however, I am also of the mind that there are many other great non-native plants that provide food and shelter for insects, as long as they are not invasive to your region. The best thing about native plants are the incredible host of insects they do attract which also attracts more bird diversity. It's the insects that parent birds feed their babies, not bird seed, so by having an insect-friendly garden you are also creating a bird-friendly garden. It's a win/win, as the birds also help to keep insect populations in check. BALANCE. That's the name of the game, remember? By providing a garden rich with biodiversity and multiple levels of vegetative growth (ground covers, small plants, large perennials, sub-shrubs, medium trees and large trees) you are inviting more balance into what is now the wild places for animal and insect life, our collective gardens. This is akin to giving them architecture - a place to live.

SHELTER
Shelter consists of grasses in the garden, leaving areas a little bit messy and reducing disturbances as much as possible. If you are constantly tilling your soil, you are killing some. Leaving undisturbed areas is crucial, and you don't have to leave a lot. A hidden out-of-sight corner of the garden will do. Also, leaving debris such as leaves, sticks and dry areas for insects to hide his helpful.


David contemplates the ultimate brush pile.


Some grasses that are appreciated are little bluestem, Roemer's fescue and slender wheatgrass. Shrubs include chokecherry, elderberry, willow, ceanothus, oceanspray and coyotebrush.


NO PESTICIDES
 Here in Portland you can take the "No Pesticides" pledge through Metro and receive this great sign for free! What a way to get the neighborhood talking and show that you can have a beautiful, balanced garden without using pesticides. If you are not local, you can still show your no pesticide pride by purchasing a sign directly, here's a link.


 By purchasing plants you know are not sprayed, you are one step ahead of the game. Locally Xera Plants is my champion for non-pesticide grown plants.

When a garden is in balance, pesticides are really something you don't need nor to think about. They are unnecessary. What a wonderful way to approach the garden and ultimately, the world. Pesticides don't discriminate. If you think that by spraying that mob of ants that's all you will kill, think again. Birds can eat those dead insects and ingest the poison. Other creatures might eat the ants, too. It blows in the wind from one place to another, landing at random. It can also eventually end up in the water table, then to rivers which empty into the oceans of the world. For something that's unnecessary, it's quite a risk impacting much more than our own little gardens.

Claudia also shared with me that she recently attended a gardening conference whereby many commercial growers told her that many of them have been pesticide-free for nearly 10 years. They are using insects in their greenhouses to control pests, much like you can buy a bag of ladybugs or praying mantis eggs for the home garden but on a much larger scale. What's happened is that these growers have created their own healthy eco-systems and no longer have to purchase insects; they are finding the greenhouses on their own from the wild. That gives me hope for the future.

By taking a few simple step, it is not only possible but quite likely that you can attract a host of beneficial insects which will in turn serve your garden well. Now that Claudia has shared her vast knowledge with me and ultimately with you all, hopefully there are bits of helpful information to get you on your way towards a beautiful and balanced garden.

Some additional resources:

Book: Farming with Native Beneficial Insects

Xerces Society

Book: Natural Enemies Handbook

Printable Brochure/Pocket Guide: Common Natural Enemies of Crop and Garden Pests


That's it for this week at Chickadee Gardens. As always, thank you for reading and until next time, happy gardening!








17 comments :

  1. What a post! Bravo! Only complaint: No mantis photos! :) I didn't know that hover flies ate anything other than nectar/pollen -- good info!

    I don't see any bugs as "bad" anymore -- they're the food for the predatory insects.

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    1. Aaah, well that's a good observation. I have never seen one in my garden, Alan. And you're right, bugs in balance are all ok by me :)

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  2. Great post! I really appreciated the long list of beneficials. I was surprised to see vespid wasps on it, like yellow jackets and hornets. I suppose if you have those living somewhere in your garden or on your house, in a spot where they can come and go without disturbance, it's ok. But they still make me nervous.

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    1. Thank you Alison! I'm thrilled you got something out of it. The wasps...yes, she did address this - that in an out of the way area they are great predators but she understands (we all do) that they're not so welcome at the picnic table with our sandwiches. They go for the meat. They make me a bit nervous, too to tell the truth.

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    1. Thank you, Kris! I appreciate you reading it and commenting!!

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  4. Great info Tamara, thank you! And nice to see a picture of Claudia, I usually bump into her around town at events but haven't seen her in awhile.

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    1. She's great! I adore her and appreciate her vast knowledge and expertise on so many subjects.

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  5. Thanks for the awesome post, T! This morning I made a little pile of twigs and cut out stumps in the back corner and covered it with smaller branches. I hope birds move in and not raccoons! Is there a way of building a brush pile that will make it more appealing to birds and less so for raccoons and rats?

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    1. You bet !! That's great - your twig pile. I hope birds move in, too. Wow, as far as not attracting rats and raccoons, I don't know....that's a good question. For insects it doesn't have to be too deep - but for birds? I don't know...maybe Audubon has suggestions. I'll see what they say.

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  6. Great post! I saw lady beetle larvae on my milkweed today, which was awesome since it's covered in aphids. But I do have a few caterpillars, too, so that's exciting! My garden isn't very tidy and there are lots of places for critters to hide.

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    1. Woo hoo! (in my best Homer Simpson voice)...that's great! And caterpillars as well as lady beetle larvae. You go, girl! :)

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  7. Bugs are fascinating creatures and now I know a lot more about them. Thanks!

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    1. Oh, I'm glad! They are fascinating indeed, whether creepy, crawly, fluttery or sting-y, they are cool.

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  8. Thanks for a terrific post! Bookmarking this one for the wealth of information (and searching your archives for bird feeder info, too -- thanks in advance!).

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    1. Thanks, Luisa! So glad you found it useful. Claudia is a fountain of knowledge. Bird feeder info, eh?...hmm...maybe the post about birds from this past winter??

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    2. Yes! I've found a number of your bird-related posts using that blog search feature up top. Full of info and great photos -- thanks!!

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