Eileen M. Stark's Blog, page 8
October 17, 2016
Pacific Northwest Native Plant of the Week: White spiraea (Spiraea betulifolia var. lucida)
Even though it’s growing and thriving in my front yard, it took an October trip to northeast Oregon’s Wallowa Mountains to remind me why I love white spiraea (AKA shiny-leaf spiraea or birch-leaf spiraea), or botanically speaking, Spiraea betulifolia var. lucida. In Latin, lucida means “bright,” or “to shine,” and shine it does.
Uncommon, small (as shrubs go, to about 3 feet tall), erect and deciduous, it’s a very attractive native plant that spreads slowly by rhizomes. Though its seeds are also perfectly capable of reproducing and may be distributed by birds, rodents, or wind, I find it’s not a strong self-sower.
Besides its small stature that allows it to fit into tight spots, it has many other attributes and I can’t imagine why it’s not planted more often in yards and gardens. In late spring to early summer, creamy-white flowers—sometimes with a pale pink blush—show up in flat-topped clusters, from 2 to 5 inches wide. With occasional deep summer watering, it will sometimes bloom during late summer and even autumn. And as the flowers mature they offer lovely, although fairly inconspicuous, golden brown seed heads that continue to captivate.
But the best is yet to come. Fall may be its best season when its oval to oblong toothed leaves turn gold, orange, red, and burgundy. The entire little shrub lights up above the dark, moist soil and fallen leaves beneath it.
How it grows
White spiraea naturally occurs in parts of western Canada, Washington and Oregon, and as far east as Minnesota. It grows along streams and lakes, in mountain grasslands and on the slopes of forests (especially rocky ones) both east and west of the Cascades, from sea level up to about 4,000 feet, although it can be found at higher elevations in moist forests. Since it’s best to grow native plants that are indigenous to your area, find out whether it occurs in your county with this USDA map.
Last week I was pleasantly surprised to find it in the Wallowa-Whitman National Forest along the Wallowa Lake Trail and the Hurricane Creek Trail near Joseph, Oregon, in forested areas that get quite dry in summer; its drought tolerance is likely due to its rhizomatous ways. Often surviving in burned areas, fire kills the aboveground part of the plant, but it resprouts from “surviving root crowns, and from rhizomes positioned 2 to 5 inches (5-13 cm) below the soil surface,” according to the US Forest Service. Along the Hurricane Creek Trail, which meanders through a burned area, white spiraea was joined by “pioneer” species like western yarrow (Achillea millefolium var. occidentalis), and western pearly everlasting (Anaphalis margaritacea).
Wildlife value
The flowers—often with an extended bloom time—offer pollen and/or nectar for pollinators such as native bees, syrphid (flower) flies, butterflies, wasps, and ants. Leaves and branches offer a bit of cover for small creatures, and fallen leaves protect the soil and overwintering invertebrates, which provide food for myriad other species. It’s reportedly rather unpalatable to mule deer and elk, for those of you wanting native plants that won’t disappear overnight.
Try it at home
White spiraea is a fantastic little shrub that can be used in the places that a large shrub would outgrow in a few years. It’s also quite versatile when it comes to both light and moisture conditions. It can handle quite a bit of shade to a fair amount of sun, but seems to do best in part shade. A restoration project in Montana found that the plants did much better on east or south-facing slopes, rather than west-facing slopes with hot afternoon sun. At the Portland community garden where I have a plot for growing veggies, white spiraea was planted (before I acquired my plot) in native beds that border the garden. The beds provide a little test because the sunlight the reaches them varies from just a little morning sun to about a half day of sun to nearly all-day sun. Echoing the Montana study, the spiraeas that thrive are in the partly shaded area; many of the ones planted in a narrow sunny strip along a hot concrete walkway died due to heat and drought, while those that remain in that strip just barely hang on despite my best efforts with extra water and compost.
Plant them about 3 feet apart and at least 3 feet from walkways, since they will eventually spread and you don’t want to be constantly pruning them back. Amending soil with some organic matter (like compost) will help them get established, although they are quite tolerant of clay soil, and they do well with rocks. Mulch them with a natural mulch (like leaves) and keep them well watered the first 2 to 3 years, after which they should be quite drought tolerant (unless you have them in hot afternoon sun, which I don’t advise!).
Grab a partner
Grow it with its associated species that also naturally occurred in your area, to help provide an eco-functional space for wildlife. It naturally occurs within Douglas-fir, grand fir, ponderosa pine, and lodgepole pine communities. Though shrubs and perennials in those communities are far too numerous to list here, consider serviceberry (Amelanchier alnifolia), red-twig dogwood (Cornus sericea), blue elderberry (Sambucus nigra ssp. caerulea), and Cascade Oregon grape (Mahonia nervosa). As always, buy plants that come from locally-sourced material at reputable nurseries.
To leave a comment, click on post’s title
PNW Plant of the Week: White spiraea (Spiraea betulifolia var. lucida)
Even though it’s growing and thriving in my front yard, it took an October trip to northeast Oregon’s Wallowa Mountains to remind me why I love white spiraea (AKA shiny-leaf spiraea or birch-leaf spiraea), or botanically speaking, Spiraea betulifolia var. lucida. In Latin, lucida means “bright,” or “to shine,” and shine it does.
Uncommon, small (as shrubs go, to about 3 feet tall), erect and deciduous, it’s a very attractive native plant that spreads slowly by rhizomes. Though its seeds are also perfectly capable of reproducing and may be distributed by birds, rodents, or wind, I find it’s not a strong self-sower.
Besides its small stature that allows it to fit into tight spots, it has many other attributes and I can’t imagine why it’s not planted more often in yards and gardens. In late spring to early summer, creamy-white flowers—sometimes with a pale pink blush—show up in flat-topped clusters, from 2 to 5 inches wide. With occasional deep summer watering, it will sometimes bloom during late summer and even autumn. And as the flowers mature they offer lovely, although fairly inconspicuous, brownish seed heads that continue to captivate.
But the best is yet to come. Fall may be its best season when its oval to oblong toothed leaves turn gold, orange, red, and burgundy. The entire little shrub lights up above the dark, moist soil and fallen leaves beneath it.
How it grows
White spiraea naturally occurs in parts of western Canada, Washington and Oregon, east to Minnesota, along streams and lakes, in mountain grasslands and the slopes of forests (especially rocky ones) both east and west of the Cascades. It’ll grow from sea level up to about 4,000 feet, although it can be found at higher elevations in moist forests. Since it’s best to grow native plants that are indigenous to your area, find out whether it occurs in your area with this USDA map.
Last week I was pleasantly surprised to find it in the Wallowa-Whitman National Forest along the Wallowa Lake Trail and the Hurricane Creek Trail near Joseph, Oregon, in forested areas that get quite dry in summer; its drought tolerance is likely due to its rhizomatous ways. Often surviving in burned areas, fire kills the aboveground part of the plant, but it resprouts from “surviving root crowns, and from rhizomes positioned 2 to 5 inches (5-13 cm) below the soil surface,” according to the US Forest Service. Along the Hurricane Creek Trail, which meanders through a burned area, white spiraea was joined by “pioneer” species like western yarrow (Achillea millefolium var. occidentalis), and western pearly everlasting (Anaphalis margaritacea).
Wildlife value
The flowers—often with an extended bloom time—offer pollen and/or nectar for pollinators such as native bees, syrphid (flower) flies, butterflies, wasps, and ants. Leaves and branches offer a bit of cover for small creatures, and fallen leaves protect the soil and overwintering invertebrates, which provide food for myriad other species. It’s reportedly rather unpalatable to mule deer and elk, for those of you wanting native plants that won’t disappear overnight.
Try it at home
White spiraea is a fantastic little shrub that can be used in the places that a large shrub would outgrow in a few years. It’s also quite versatile when it comes to both light and moisture conditions. It can handle quite a bit of shade to a fair amount of sun, but seems to do best in part shade. A restoration project in Montana found that the plants did much better on east or south-facing slopes, rather than west-facing slopes with hot afternoon sun. At the Portland community garden where I have a plot for growing veggies, white spiraea was planted (before I acquired my plot) in native beds that border the garden. The beds provide a little test because the sunlight the reaches them varies from just a little morning sun to about a half day of sun to nearly all-day sun. Echoing the Montana study, the spiraeas that thrive are in the partly shaded area; many of the ones planted in a narrow sunny strip along a hot concrete walkway died due to heat and drought, while those that remain in that strip just barely hang on despite my best efforts with extra water and compost.
Plant them about 3 feet apart and at least 3 feet from walkways, since they will eventually spread and you don’t want to be constantly pruning them back. Amending soil with some organic matter (like compost) will help them get established, although they are quite tolerant of clay soil, and they do well with rocks. Mulch them with a natural mulch (like leaves) and keep them well watered the first 2 to 3 years, after which they should be quite drought tolerant (unless you have them in hot afternoon sun, which I don’t advise!).
Grab a partner
Grow it with its associated species that also naturally occurred in your area, to help provide an eco-functional space for wildlife. It naturally occurs within Douglas-fir, grand fir, ponderosa pine, and lodgepole pine communities. Though shrubs and perennials in those communities are far too numerous to list here, consider serviceberry (Amelanchier alnifolia), red-twig dogwood (Cornus sericea), blue elderberry (Sambucus nigra ssp. caerulea), and Cascade Oregon grape (Mahonia nervosa). As always, buy plants that come from locally-sourced material at reputable nurseries.
To leave a comment, click on post’s title
October 4, 2016
Pacific Northwest Native Plant of the Week: Graceful cinquefoil (Potentilla gracilis)
Also called slender cinquefoil or western cinquefoil, Potentilla gracilis is a perennial wildflower. It naturally occurs over much of western and northern North America at low to high elevations, mostly in moist prairie and savanna ecosystems, but also in open forests and subalpine meadows. Growing from a woody crown, it has sharply divided, oval, deep green leaves with hairy, silver undersides and somewhat erect inflorescences with bright to pale yellow 5-petaled flowers that bloom from early to late summer.
Closely-related species include Potentilla glandulosa (sticky cinquefoil), with cream to pale yellow flowers, and Potentilla pulcherrima, which grows in montane regions. The latter’s common name, beautiful cinquefoil, comes from the Latin pulcherrima, which means “very beautiful” (aren’t they all?). Both occur mainly in western U.S. and Canada. There are many other species of Potentilla, but P. gracilis and P. glandulosa are the most common west of the Cascades and are the most likely to be found for sale at nurseries.
Wildlife value
Native bees, butterflies, syrphid flies, and other beneficial insects are attracted to the flowers. Graceful cinquefoil is also a host plant for the caterpillars of butterflies such as the two-banded checkered skipper.
Try it at home
Graceful cinquefoil does best in moist, well-drained soil that’s rich in organic matter, in full to part sun. Since it’s not a tall plant and only grows to about 2 feet wide, site it where it won’t be heavily shaded by other plants. You can also grow native cinquefoil in a container, but be sure it gets enough moisture. Associated species include Cascara, Oregon ash, checker mallow, Oregon iris, native lupines, and other moisture loving plants. Summer water is essential until it’s established, but even afterwards it will do best with supplemental water during the hot, dry part of summer. More info here.
To leave a comment, click on post’s title
PNW Plant of the Week: Graceful cinquefoil (Potentilla gracilis)
Also called slender cinquefoil or western cinquefoil, Potentilla gracilis is a perennial wildflower. It naturally occurs over much of western and northern North America at low to high elevations, mostly in moist prairie and savanna ecosystems, but also in open forests and subalpine meadows. Growing from a woody crown, it has sharply divided, oval, deep green leaves with hairy, silver undersides and somewhat erect inflorescences with bright to pale yellow 5-petaled flowers that bloom from early to late summer.
Closely-related species include Potentilla glandulosa (sticky cinquefoil), with cream to pale yellow flowers, and Potentilla pulcherrima, which grows in montane regions. The latter’s common name, beautiful cinquefoil, comes from the Latin pulcherrima, which means “very beautiful” (aren’t they all?). Both occur mainly in western U.S. and Canada. There are many other species of Potentilla, but P. gracilis and P. glandulosa are the most common west of the Cascades and are the most likely to be found for sale at nurseries.
Wildlife value
Native bees, butterflies, syrphid flies, and other beneficial insects are attracted to the flowers. Graceful cinquefoil is also a host plant for the caterpillars of butterflies such as the two-banded checkered skipper.
Try it at home
Graceful cinquefoil does best in moist, well-drained soil that’s rich in organic matter, in full to part sun. Since it’s not a tall plant and only grows to about 2 feet wide, site it where it won’t be heavily shaded by other plants. You can also grow native cinquefoil in a container, but be sure it gets enough moisture. Associated species include Cascara, Oregon ash, checker mallow, Oregon iris, native lupines, and other moisture loving plants. Summer water is essential until it’s established, but even afterwards it will do best with supplemental water during the hot, dry part of summer. More info here.
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September 21, 2016
Cultivating Compassion in the Garden (and Beyond)
Whether they’re hidden within fur farms or factory farms or other atrocious places—mistreated and maligned for profit—or in plain sight and struggling within unraveling ecosystems that disappear a little more each day, the suffering of non-human animals due to our expansion and behavior is everywhere. On an ecological level, the most devastating consequence of our ubiquitous presence is the disappearance of wild species that just need to be left alone. They want to live on, and in peace, just as we do. They have just as much right to exist without harm and suffering as we do.
Habitat destruction (including that caused by climate change) is not painless and is the main threat to most wild flora and fauna—less than four percent of original U.S. forests remain; oceans are dying; waterways are heavily polluted with toxics; a new study shows that in the past 20 years we’ve managed to destroy a tenth of the earth’s wild areas. Half of North American bird species are predicted to go extinct by the end of this century and some especially sensitive amphibians are already there. We’re the most invasive, destructive, and over-consuming species ever to walk the earth, and it’s costing us the earth as well as our health and happiness.
Our big brains are burdensome as we thoughtlessly invent things that damage and destroy, but they’re also an asset when we realize our obligation to protect and sustain. Habits of exploitation can be broken. We can stop pretending that everything is fine or beyond our control, and realize that we are very much a part of nature. We don’t have to, for example, conform to having manicured, high maintenance, lawn-dominated landscapes that require massive chemical and fossil fuel applications just because other people have them. We can make choices based on caring what happens to those downstream, just as we wish those upstream would to do to us.
When our species was young, we weren’t separated from nature. Even now, within our bubbles that disconnect, we enter this world not with a fear of natural processes and wild creatures, but with an intense curiosity. But as kids we learn to be fearful—we’re taught to fear the proverbial “big bad wolf,” and trepidation of wildlife and natural processes continue throughout many people’s lives. Education can help change that, and even awaken us to the awe-inspiring, interconnected layers that nature has fashioned over eons of evolution.
Photo courtesy Predator Defense
Just as essential is empathy for other species (that is, looking at their world from their point of view, with compassion). It may be our most important capability and what is sorely needed to bring some balance to the earth’s members. When we allow empathy to guide our choices and practices, we act selflessly and gain empowerment along the way. Changing our ways isn’t always difficult and some changes can be very simple; it just takes some thought and a little motivation. With compassion we can defiantly say “no” to synthetic toxic chemicals crafted by mega corporations that discriminate against other species and seek to control the natural world, “no” to wasteful monoculture lawns, and “no” to merely decorative plants with zero wildlife appeal. Say “yes” to planning gardens that not only look pretty but also benefit and sustain other species, “yes” to keeping Fluffy and Fido away from birds, “yes” to keeping outdoor lights off and making windows visible to birds, and “yes” to initiatives and politicians that seek to preserve and protect natural areas. There are, of course, countless other ways to express compassion for the planet outside the garden.
It’s easy to think that the war against wildlife—from the microorganisms within degraded soil to persecuted predators trying to survive on a human-dominated planet—is happening somewhere “out there.” While a huge percentage of wild lands are dominated by livestock ranching that has “caused more damage than the chainsaw and bulldozer combined,” urban and suburban spaces—including the roughly 40 million acres of land that’s currently lawn—offer an important conservation opportunity and a way for us to personally provide for others right at home.
It’s equally easy to be pulled down by the ticking extinction clock, but once we turn our backs on conventional gardening, we become part of a conversion—or revolution, if you will—that is proactive. Learn how healthy, balanced ecosystems function; watch native plants (especially when grown with others that co-occur in the 
area) attract and support a diversity of native insects and other creatures; recognize the bees and the flower flies and the birds that depend directly or indirectly on those plant communities; discover their life cycle and how to keep them healthy and protected. Plant trees, let the leaves do their thing, allow the dead wood to stay, and forget about pesticides and synthetic fertilizers. If we do all that we’ll find ourselves more connected and caring even more about what happens within the dwindling, wilder ecosystems on this beautiful planet, and wondering how even more beautiful it will be if more of us empathize with others’ lives.
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September 19, 2016
Pacific Northwest Native Plant of the Week: Goatsbeard (Aruncus dioicus)
I finally managed to take out a very large hosta plant in my front yard. I really hate removing healthy noninvasive plants, however nonnative they may be, especially when they’re pretty. But we all know that “pretty is as pretty does,” right? Being from northeast Asia, it really had no function here other than looking nice with those ultra-inflated leaves. I don’t think I’d ever seen even a honeybee on it’s blossoms, let alone a native bee. Plus, it was overpowering a fern that belongs in this neck o’ the woods.
In its place now is a goatsbeard (Aruncus dioicus) plant that had volunteered in the back yard, courtesy its frisky goatsbeard parents. Also known as “bride’s feathers,” it’s actually much more eye-catching, and with ecological function that hostas can only dream about. It also fits well into the shade-loving native spread near the north side of my house, sharing space with a surprisingly robust western maidenhair fern (Adiantum aleuticum), an evergreen huckleberry (Vaccinium ovatum), a lonesome goatsbeard, and assorted other native ferns and ground cover, all of which can be found growing with it in nature.
Goatsbeard’s compound, pointy, toothed leaves have a texture all their own and are particularly fetching in spring when they’re new. In early to mid-summer the main show begins when tall, feathery plumes composed of tiny, creamy-white flowers rise above the foliage. Male plants are more spectacular in flower than female, but regardless of gender, it offers a lovely presence in shaded to partly-shaded borders, under tall trees, or as a deciduous screen or short hedge.
Wildlife value
Goatsbeard attracts quite a few insect species, including native bees, syrphid flies, teeny tiny beetles that I don’t know the name of, and—if you’re lucky—mourning cloak butterflies (your odds will increase if you already grow their host plants, which include native willow, birch, hawthorn, wild rose). Small birds may eat the seeds, so leave the spent flowers to overwinter.
Try it at home
Found in most of western Washington, Oregon, and northern California, goatsbeard naturally occurs along streams and in moist meadows and forests, but also sometimes in disturbed areas such as roadsides. As such, it likes moist, rich soil (add compost!). Although it does best with at least a half day of shade, it can be grown in more sun in cooler, more northerly locations. Goatsbeard eventually will form a large clump, 3 to 6 feet tall and as wide, so space plants about four feet apart. Grow it with associates (those that naturally grow together and depend on each other), including Douglas-fir, western hemlock, western red cedar, vine maple, deer fern, maidenhair fern, inside-out flower, and western trillium. Enjoy!
To leave a comment, click on post’s title
PNW Plant of the Week: Goatsbeard (Aruncus dioicus)
I finally managed to take out a very large hosta plant in my front yard. I really hate removing healthy noninvasive plants, however nonnative they may be, especially when they’re pretty, but we all know that “pretty is as pretty does,” right? Being from northeast Asia, it really had no function here other than looking nice with those ultra-inflated leaves. I don’t think I’d ever seen even a honeybee on it, let alone a native bee. Plus, it was overpowering a fern that belongs in this neck o’ the woods.
In its place now is a goatsbeard (Aruncus dioicus) plant that had volunteered in the back yard, courtesy some frisky goatsbeard plants. Also known as “bride’s feathers,” it’s actually much more eye-catching, and with ecological function that hostas can only dream about. It also fits well into the shade-loving native spread near the north side of my house, sharing space with a surprisingly robust western maidenhair fern (Adiantum aleuticum), an evergreen huckleberry (Vaccinium ovatum), a lonesome goatsbeard, and assorted other native ferns and ground cover, all of which can be found growing with it in nature.
Goatsbeard’s compound, pointy, toothed leaves have a texture all their own and are particularly fetching in spring when they’re new. In early to mid-summer the show begins when tall, feathery plumes composed of tiny, creamy-white flowers rise above the foliage. Male plants are more spectacular in flower than female, but regardless of gender, it offers a lovely presence in shaded to partly-shaded borders, under tall trees, or as a deciduous screen or short hedge.
Wildlife value
Goatsbeard attracts quite a few insect species, including native bees, syrphid flies, teeny tiny beetles that I don’t know the name of, and—if you’re lucky—mourning cloak butterflies (your odds will increase if you already grow their host plants, which include native willow, birch, hawthorn, wild rose). Small birds may eat the seeds, so leave the spent flowers to overwinter.
Try it at home
Found in most of western Washington, Oregon, and northern California, goatsbeard naturally occurs along streams and in moist meadows and forests, but also sometimes in disturbed areas such as roadsides. As such, it likes moist, rich soil (add compost!). Although it does best with at least a half day of shade, it can be grown in more sun in cooler, more northerly locations. Goatsbeard eventually will form a large clump, 3 to 6 feet tall and as wide, so space plants about four feet apart. Plants associates (those that naturally grow together and depend on each other) include Douglas-fir, western hemlock, western red cedar, vine maple, deer fern, maidenhair fern, inside-out flower, and western trillium. Enjoy!
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July 24, 2016
An Underappreciated Insect: The Syrphid Fly
Toxomerus occidentals (female), slurping nectar on showy fleabane (Erigeron specious)
Syrphid flies, also called flower flies, are true flies in the order Diptera, family Syrphidae. Some can be recognized by their ability to dart around and hover in the air in one place, wings nearly invisible, as they search for flowers on which to feed—somewhat like a tiny helicopter, but much more gracefully. This flair led to their other common name, hover fly. They come in various shapes and sizes (typically 1/4 to 3/4 inch); the tiny ones require a hand lens or macro lens to get a good look. And when you do, you will be amazed at the beautiful patterns and bright colors that often serve to mimic dangerous looking bees or wasps and fool predators like birds into leaving them alone (but don’t worry, they couldn’t sting you if they wanted to!).
Syrphids in the genus Spilomyia often mimic wasps, with vivid yellow and black patterns and modified antennae.
Multi-functional
Not needing to carry and store pollen for their young (like most bees do) doesn’t prevent them from being extremely important pollinators. Researchers have found that although syrphid flies pollinate less effectively per flower visit, they visit flowers more often, resulting in essentially the same pollination services as bees. And, it’s thought that they may be more tolerant of the landscape changes that we humans insist on than bees are.
But syrphid flies are not only important as pollinators in gardens, organic farms, and wild areas. During their immature stage, most that are found in gardens and nearly half of all syrphid fly species worldwide are voracious consumers of aphids, scale insects, and other soft-bodied pests. In coastal Central California, researchers compared romaine lettuce sprayed with an insecticide and lettuce without insecticide. They found that syrphid larvae were primarily responsible for suppressing aphids in organic romaine lettuce, and called the sprayed lettuce “unmarketable.” Other types of syrphid fly larvae are either scavengers that clean up in ant, bee, and wasp nests, feeders of plant material, tree sap, and fungi, or decomposers that feed on decaying organic matter. To add to their achievements, larvae are reportedly more effective in cool weather than most other such predators.
Myathropa florea, male. Larvae feed on bacteria at the base of trees or in decaying leaves.
Life Cycle
Females lay their tiny, elongated eggs singly on leaves (typically near aphid colonies, so food is within reach), and they hatch in a few days. Tapered, grub-like larvae are blind and legless. The mouths of aphid-eaters are equipped with triple-pointed darts that enable them to pierce and suck their prey dry. At maturation, the larvae are promoted to the soil to become pupa and, eventually, adult flies. Their life cycle takes several weeks; typically there are three generations per year in the Northwest. Most syrphid flies overwinter as larvae in leaf litter—yet another reason to not remove fallen leaves from soil!
Close encounters
The best way to spot these helpful, colorful little insects in your garden is to move slowly and quietly, and observe carefully. Sometimes all I have to do is pause next to a group of flat-topped flowers (white or yellow ones seem to be their favorites), and within a few minutes one or two will show up to eat (and to dazzle me—in morning sunlight these exceptional little pollinators shimmer!). I’ve photographed six different species in my yard, and I’ve just started. With about 6,000 species in 200 genera worldwide, I hope to encounter many more of these fascinating little flyers in the years to come.
To avoid confusion with bees and wasps, just remember that syrphid flies have huge compound eyes (which help to determine their gender—female eyes are spaced slightly apart while males’ come together on the top of their head); their bodies are sometimes flatter than bees and wasps; their antennae are very short; they don’t carry pollen around like most bees do; they have one pair of wings (unlike bees and wasps that have two pairs). The second pair of wings of flies has been reduced to two little knobs called halteres, which can be seen in the photo below. They function like tiny gyroscopes that allow them to stay balanced by detecting and correcting changes in rotation while flying, and enable their zippy acrobatic flights.
Although the mouth parts of syrphids vary between species, allowing different species to access nectar in differently shaped flowers, their typical mouth is basically a retractable extension with a spongelike tip that can soak up either nectar or pollen. The species that have this can only feed on open flowers that have easily accessible nectar. Some species have a modified mouth that allows them to feed at tubular flowers.
The halteres can be seen at the base of the wings.
Conservation
Syrphid flies have been studied very little in the U.S., but European research has shown that species diversity has fallen in areas of intensive human activity. According to the Xerces Society, in Britain, seven of the 22 flies for which Biodiversity Action Plans have been prepared are syrphid flies. Given the substantial loss of pollinators induced by habitat loss, alien species and climate change, and the profusion of others in danger of extinction, there is a real need to conserve all types of wild pollinator communities.
Providing for these flies is similar to most other pollinators: A variety of flowers from spring till fall for adults, and appropriate habitat for egg laying and larval development and overwintering. Attract and nurture syrphid flies with a diversity of native plants that provide a lot of nectar and pollen (females need pollen to produce eggs). In the Pacific Northwest, try yarrow (Achillea millefolium var. millefolium), stonecrop (Sedum spp.), goldenrod (Solidago canadensis), blue-eyed grass (Sisyrinchium spp.), fleabane (Erigeron spp.), white spiraea (Spiraea betulifolia var. lucida), mock orange (Philadelphus lewisii), and aster (Symphiotrichum spp.). The flowers of chamomile, dill, parsley, and other garden herbs with flat-topped flowers are also very attractive to them, as is the pollen of grasses and sedges that’s often available early in the season. Allow leaf litter and downed wood to remain on soil.
If you have an aphid problem on some plants, remember that predatory insects that keep pests at acceptable levels need prey like aphids. Always inspect aphid colonies for syrphid fly larvae before even thinking about control, even “organic” remedies. Use plain water to spray off aphids (that can’t climb back on), if necessary. Don’t use insecticides, to which syrphid flies and other creatures are very sensitive.
Syrphus opinator (female) on white spiraea (Spiraea betulifolia var. lucida)
Eristalis sp. on yarrow (Achillea millefolium var. occidentalis)
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July 20, 2016
Beyond Bees: The Underappreciated Pollinators
The majority of flowering plants evolved to take advantage of insects, and depend on them (and less commonly, other animals or wind) to fertilize their flowers, facilitate gene flow, and prevent inbreeding. Bees might be the most obvious pollinators, and on a warm summer day it seems flowers and bees are made for each other. Native bees are considered to be the most important pollinators (move over, honeybees) and are invaluable members of natural systems. But other capable pollinators—like butterflies and moths, hummingbirds, wasps, ants, and herbivorous fruit bats—share the pollen distribution workload, and offer ecological benefits as well. Less well known are the thrips, beetles, mosquitoes (yes, you read that right), and flies that actually are quite accomplished pollinators. Distributing pollen may be a sideline for them, but they often excel because they don’t take pollen back to their nests, as most bees do.
Thrips go way back—to the Permian period, over 250 million years ago—but get a bad rap because of a few species that threaten crops. Studies show that they are strong pollinators of some plants, particularly early in the season when most other pollinators aren’t around.
The adult ornate checkered beetle (Trichomes oranatus) feeds on flowers such as wild buckwheat (Eriogonum spp.) and helps transfer pollen from anther to stigma.
Beetles are particularly important in semi-arid parts of the world and have a highly developed sense of smell. They are expert and essential pollinators, according to the Forest Service, and also were around millions of years before bees appeared. Like many species of birds, bees, and butterflies, beetles are in danger of extinction. The International Union for Conservation of Nature lists over 70 beetle species as endangered. The main threats include habitat destruction, chemical pollutants (e.g., pesticides), displacement by introduced species, and hybridization with other species.
Although many flies (order Diptera) are recorded as flower visitors, relatively little is known about pollination by flies, compared to others like bees, birds, and bats. Many flies are strong pollinators, including syrphid flies (which deserve their own special post—coming soon!) and some of the tachinid flies, which are the most diverse family of the order Diptera (true flies). As adults, they are flower visitors, feeding on nectar and/or pollen. In their larval stages, many species help to control insects that we consider pests.
Pollination by insects is usually mutually beneficial. Here, a fly (Suillia spp.) attracted to bear grass (Xerophyllum tenax) receives a pollen reward and the flower gets fertilized.
While I’m not advocating the nurture of mosquitoes in your garden (the females do suck blood and can carry disease, after all), it’s noteworthy that mosquitoes, like all insects, do have a role in natural systems. Their primary source of food is flower nectar (with males eating nothing but nectar) and they buzzily and incidentally carry pollen from flower to flower. Plants like goldenrod (Solidago spp.) use mosquitoes as pollinators, as do orchids of northern latitudes, grasses, and many other types of plants. And they are a source of food for birds, fish, amphibians, spiders, bats, dragonfly larvae, and other animals.
How you can help a variety of pollinators
Within our increasingly fragmented landscapes, gardens that provide pollen and nectar-rich plants, as well as nesting and overwintering sites, can create critical habitat and connections for pollinators and other creatures. No space is too small, and when in close proximity to other larger gardens, natural areas, or greenways that sustain native plant populations appropriate to the region, its value deepens.
◊ Choose natives that occur naturally in your area, or at least heirloom ornamentals (rather than newer hybrids that may not provide sufficient or appropriate nutrients that native species do). Some garden herbs like cilantro, parsley, and dill attract some pollinators.
◊ Avoid nonnative invasive species like “butterfly bush” (Buddleia davidii).
◊ Provide structure and layering in the form of native trees and shrubs that provide food, cover and nesting sites for various pollinators.
◊ Plan for continuous flowering, spring through fall. Early spring nectar is particularly important for early-emerging queen bumble bees and other solitary bees, as well as flies and beetles.
◊ Choose a variety of plants that differ in the size, shape, and color of blossoms to attract a variety of pollinators. Arrange perennials in drifts or swaths of at least three of a kind, rather than singly here and there. Don’t forget that trees and shrubs produce flowers!
◊ Stay away from pesticides and other chemicals. Insecticides, herbicides, fungicides, and synthetic fertilizers are particularly harmful to sensitive pollinators. Don’t purchase plants pre-treated with neonicotinoids; if you’re unsure, ask.
◊ Don’t be too neat. Leaf litter, downed wood (tree snags or piles of branches), and other natural detritus provide essential nesting habitat and overwintering sites for pollinators or their larvae. Leave some open areas of non-compacted, bare soil for ground nesters.
◊ Grow butterfly host plants that provide food and habitat for their young. Find out which species frequent your area and grow the native plants they need
◊ Provide shallow water and some moist soil. A shallow pie plate or flowerpot saucer, filled with gravel or small rocks allows insects to drink without drowning. Butterflies and moths (Lepidoptera) need muddy or sandy puddles to obtain water and nutrients. Add a dash of salt to be sure male Lepidoptera get enough sodium prior to mating.
June 15, 2016
Attract Ladybird Beetles (“Ladybugs”) to Your Northwest Garden Humanely
The little western blood-red ladybird beetle (Cycloneda polite)—one of about 90 species throughout the Pacific Northwest and about 6,000 species worldwide—is small (4 – 5 mm), but like most others in the Coccinellidae family, is a voracious consumer of aphids, scale insects, and mites (a few species eat fungi). Revered for centuries due to their role as a pest controller, ladybird beetles at one time were even thought to have supernatural powers. The “lady” for whom they were named was the “Virgin Mary.” Once you have these native predators in your garden you’ll want to keep them, and there’s an easy way to do that.
But first, a little about these endearing little insects, the vast majority of which are beneficial: The most obvious ladybird beetles (often called “ladybugs” in North America, although they are not true bugs) evolved a brightly colored shell to exhibit what biologists call aposematic (warning) coloration, which functions to repel and warn predators that they taste awful (they produce toxic and unpalatable alkaloids). The “eyespots” on their pronotum (that covers the thorax) are a form of mimicry, possibly to further deceive a predator by appearing dangerous, or by adding to the inedibility factor. Their actual face is the little black and white portion with brown antennae. The western ladybird beetle is plain and without spots, but some species have remarkable color patterns that vary greatly and make identification difficult. Other species lack dramatic coloration.
Life Cycle
Adults are commonly seen on plants in spring and summer, foraging for their small invertebrate prey (often aphids), although they will eat nectar, water, or honeydew (the sugary secretion from insects like aphids and white flies) when food is scarce. They overwinter by hibernating in large clusters, often spending the winter under leaf litter, rocks, downed wood, or other debris. If they get into your house in autumn as temperatures plummet, don’t kill them. Since they need cool temperatures and moisture during the winter (which our homes lack), place them back outside. In hard to reach places (like ceilings) I suggest fastening a piece of lightweight fabric (perhaps a lightweight sock or piece of nylon stocking) onto the end of a vacuum cleaner hose with a rubber band, so that an inch or two of fabric protrudes into the hose. Then, with the power turned down (if possible), quickly suck them into the fabric, remove the fabric and beetles, and release them under a pile of leaves outdoors. It may help to caulk cracks and crevices around doors and windows and repair any damaged siding that’s allowing them to get in.
Ladybird beetle larvae are long and flat and usually covered with little spines, spots and stripes and resemble tiny alligators. They are sometimes mistaken for pests, but they are completely harmless to humans. They’re usually found in or near aphid colonies. After feeding on insects for several weeks, the larvae typically pupate on leaves. Some species produce several generations per year, while others have only one. During the summer, all stages may be seen.
How to Acquire
The best way to get these hungry predators into your garden isn’t to purchase them, but to provide native habitat and not use insecticides. The “ladybird food” that they need comes from native plants that naturally attract prey insects. In my yard I notice Cycloneda polita (pictured) on lupine (Lupinus spp.), western bleeding heart (Dicentra formosa), and fleabane (Erigeron spp.).
In the early 1900’s, literally tons of Asian beetles were collected and shipped to agricultural fields. Over half died during shipments and most of the rest quickly dispersed before the wretched experiment finally ended. Today, ladybird beetles are again popular, but beware the ramifications. According to Judy and Peter Haggard, authors of “Insects of the Pacific Northwest” (Timber Press, 2006), the commercial exploitation of ladybird beetles involves collecting them while they are hibernating, which can be devastating to their populations. “Those innocent-looking mesh bags … in the local garden shop actually represent a cruel and unconscionable practice: ladybird beetles sold in retail stores are usually exposed to high temperatures, low humidity, and no food for weeks. Even if they survive until bought and released, they are often so weakened, they die soon after being released.” And the ones that do survive usually quickly disperse to areas other than your yard.
In addition, the beetles commercially sold are typically not native species and, as such, are a serious threat to native insect species including native lady beetles. According to the Oregon Department of Agriculture, “Even species native to North America but collected outside of Oregon should not be released because they may carry diseases and parasites not found in Oregon.”
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