Meta-predator meta-narrative: The portrait of a lady

Lady beetles have been breeding like crazy in our garden this summer. It has been an education to observe their life cycle, from larva to adult, and it has been a pleasure to watch them flourish. I can only hope there are enough aphids in the garden to support them in their hundreds. We had a small window of about two weeks in the end of May when aphid infestations could be found in certain crops: in the wheat, quinoa and poppies primarily. But it didn't take long for the Lady Beetles to catch up.

Here is the life cycle of the Seven Spotted Lady Beetle, our most numerous species: Adult, lays eggs in favorable sites.

Larva, roams widely, preying primarily on aphids among other things.
Larva transforms into a pupa, and while attatching itself to a leaf, it does yoga exercises, stretching up to the sun, then down into resting position.

The pupa turn from yellow to this color patterning and stay put, about a week, before emerging as adults.

When pupation is complete, the beetle emerges...

yellow and tender as a newborn.

They seem to hang around the pupa casing until their shell begins to harden, trying out their newly acquired wings.

Just about the time they get their spots and start to turn from yellow to red, they abandon the dried casing, striking out into the garden for food.

Aphids on a wheat stalk.

The balance between predator and prey is never static, population densities are always changing, typically following a pattern of alternating boom and bust. In the biological study of ecological communities, it has been observed that when prey populations spike, it will trigger a population explosion of predators, who will typically over-extend the limits of their food resources. Prey species will dwindle, followed by dwindling predator numbers. It's like a game of tag, predator population density seeming to lag behind. As I've mentioned before, it is this lag time that we, as gardeners, must make up for, keeping pest populations under control until the predators can catch up, and either take over for our job, or more typically, complement our efforts to keep pests in balance. And even trickier a gardener must allow enough pest/prey species to survive in order to encourage and support the lagging predators, without letting pests get out of control, damaging the food crops and exponentially exploding in the next generation. It is this balance that I am learning, and observing as I watch the relationship between the aphids and the Lady beetles in my garden.

Recent biology studies into the relationship between predator and prey have revealed some counter-intuitive interactions. The first study I heard (on a radio science show) on this topic, looked into the re-introduction of wolves into parks where they had been locally eradicated for decades. It was thought previously, as it would seem by my description above of the cyclical tag game, that the predators in any given area were a result of the number and type of prey in that area, and that the prey were a result of the availability and abundance of forage. So it was surprising for biologists to discover that it is the predator who largely shapes the landscape, and not the other way around.

To summarize the study, in the absence of predators, the elk and deer had browsed un-harassed, and therefore had selected feed and feeding areas along waterways and streams, to the point where young willows and other trees were grazed down, and stream banks were beginning to erode, and in some places, even dry up. Without predators, the herds grazed the land in different patterns, effecting the landscape and the flora. When the wolves were re-introduced, herds had to return to grazing in open landscapes where they could remain watchful. They shied away from dense clusters of trees, and only approached more exposed waterways where they could stay alert to the ever present danger, minimizing the sites where they entered the water. In a matter of years, the willows regained the stream banks, held the erosion, and kept the waters cool and flowing for the fish and amphibians. Grassland, and meadows started to open again, and clusters of young trees were allowed to grow into forests, supporting the diversity of birds, each of which depend of a specific variance of habitat.

This first study into the impact of wolves on the ecological community from which they had previously been evicted, led to further studies into the impact of predators on the landscape. A study into the impact of spiders on the flora of pastures and meadows revealed the same counter-intuitive result: the presence of spiders changed the feeding habits of insects, which selected for certain plant species that would otherwise be grazed down by herbivorous insects. So perhaps we have the tag-game inverted, and should rather look at it as predators in the lead, with prey species fitting into the spaces where they can best survive, and the landscape as the result of this interaction.

It is interesting to think upon a gardener as a sort of meta-predator in the garden. The landscape, or garden, is the direct result of the gardener's selection of insects and varieties of plants. All other predators are there as guests and allies, dependent on the gardener for prey and habitat. I can see this type of relationship in my garden, never more so than when I hand-pick certain pest species. Patrolling the garden every day for Colorado Potato Beetles and larva, and Imported Cabbage Moth caterpillars, I feel very much like a predator. These are the two pests in my garden that are both visible and can be easily hand-picked, and both can do a lot of damage to foliage if left unchecked. And because I have daily observations of the pest populations, I am also able to observe the populations of predators, which leads me to learn more about enlisting and encouraging the specific predators. This kind of daily observation also teaches me a lot about the life cycles, and seasonal cycles, of these insects (or avian, amphibious and reptilian predators).

I sometimes see my job in the garden as Ecological Wildlife Management. I try to keep things in balance, using a variety of techniques such as row cover and physical barriers, but the most effective techniques are preventative and supportive. (I find the same is true for our own physical health as is true for the garden health.) Prevention techniques revolve around proper rotation, and often require it, for example, in my second year of gardening, I put row cover over a spring crop of radishes to protect from Flea Beetles, but had not managed my rotations correctly. Not yet understanding the life cycle of Flea Beetles, I quickly found that the first generation of Flea Beetles emerged from the soil, under the row cover. I have never yet used an insecticide, and will continue to view it as a last result. Insecticides, including the Organically acceptable plant derivatives, resemble anti-biotics in their inability to distinguish between harmful pests and beneficial insects. And insecticides work against any supportive measures to encourage an intact biosphere of beneficial predators and their prey.

A garden invites intimate interactions with the garden ecology. While reading a 1977 Organic Gardening and Farming magazine, I came across an article written by a woman who understood this intimate relationship. She had been handpicking Hornworm caterpillars from her tomato plants, and stomping them underfoot, when she came across a parasitized caterpillar. She left this one to hatch out the parasitic wasps inside, but was inspired to collect the rest of the caterpillars into a tall bucket. She left the bucket in the garden, and continued to collect and feed the pests. The parasitic wasps had access to an abundance of hosts, and it did not take long before she was hatching out dozens and then hundreds of beneficial wasps.

When I walk through the potato patch and find more Lady beetles and larvae than I can find Colorado Potato beetles, I look at that as the best crop insurance that money can't buy. The toads and Garter snakes have provided the same invaluable crop insurance against slugs in the market garden this year. With 20 inches of rain between June and July, our garden would be overrun with slugs if not for these hungry predators. And I am happy to report that Lady Beetles will continue to find other sources of food when the aphids run short, including the eggs of moths and other beetles, and small invertebrates, which may explain the dramatic reduction in hatching Colorado Potato Beetles since the Lady Beetle population has exploded. I am beginning to find them in the Brassica plot, hoping they will find the Imported Cabbage Moth eggs to be a tasty treat, between the occasional aphid meal.

Busy as a bee

Been canning and harvesting for the market garden this week, so I'll leave you with some pictures from the garden.

Bumble bees are in abundance this summer, busy pollinating the garden. This one was snoozing in the Meadow Sweet, beauty rest.

Some of my favorite predators. We have had more aphids this year than normal, never to pest levels, but it has kept the Lady Beetles eating and breeding in the garden. We have about 4 distinct Lady Beetle species, and each look distinct in their larval stage as well.

I think this is the Seven-Spotted Lady Beetle larva, the commonly recognized red beetle with seven black spots.

The blooming of the carrot flowers always seem to hearald the first Tachinid flies of the season. Welcome.

And this is the first Green Lacewing I've seen in our garden, probably due to the attractive numbers of aphids this year.

Syrphid Fly, again in the carrot flowers. A welcome parasatoid.

We also have a family of Garter Snakes in the hay bale shelter, originally left for the toads. Still plenty of toads in the garden, but there was one particularly fat Garter Snake that probably didn't get fat on slugs alone. Hopefully the snakes don't get all the toads! Both the snakes and the toads have been keeping the numerous slugs in check this wet summer.

Our very own Fritillary visited our garden. Too bad it picked a rather ragged looking Cosmo flower for it's close-up shot.

The Hollyhocks are blooming, and were buzzing with Bumble Bees this morning.


As are the poppy flowers. Gorgeous to grow, and delicious seeds for the kitchen as well.

Growing by degrees

The food cycle has finally reversed flow, there is more food coming into the house than we are able to eat... time to stock the pantry. Without a greenhouse, our stored food supplies need to last until the third week of July. It can be a struggle, and usually means relying on spring greens, grains, eggs and dairy for the better part of June and July after the last of the root crops and potatoes. And I always put away more than enough canned green beans to cover the gaps before those first glorious snow peas are ready in early July.

Although we planted each of these crops about three weeks earlier than last year, our first harvests are no more than a week to a few days earlier. I, of course, had my hopes up for a logical three-week-earlier harvest. But every season is unique. In doing some research, I happened across the phrase "Growing Degree Days". It is a unit used to measure or predict the first bloom or maturity of a crop, or the emergence of an insect or pest. Temperature is one of the most crucial elements in crop growth, and generally triggers most of the cycles of the insect world. And we have had an abnormally cool June and July. Especially July. Our nights have averaged at 10C (50F) instead of the normal 16-18C (60-65F). Only a few crops will continue to thrive with these nighttime lows, such as peas and Cole crops. Roots, onions and potatoes slowed down. And heat lovers: beans, tomatoes, peppers, squash and cucumbers just hung around, waiting.

Growing Degree Days can easily be calculated (go to the link above at Wikipedia), by keeping track of the maximum and minimum temperatures, which I have been doing for years, in my garden records. Each crop or insect has a cumulative requirement of heat, or Growing Degree Units to flower, reach maturity or hatch out. It will be interesting to use this unit in the future, to calculate and predict crop maturity or expected pest emergence, in an ever changing climate.

According to planting dates, we should have had our first new potatoes July 1st, instead of July 22nd, which shows that the cool weather set back the growing season by three weeks. Quite significant. But our first taste of potatoes, since the last wrinkled-ones in mid-June, was well worth the wait: Yukons, one large golden potato snuck out from each plant in a row. Boy they taste good. It's kind of a nice break, not eating potatoes in the gap between the last wrinkled, sprouting aliens, and the new, apple-crisp crop. Like cleaning the palette. After all, we do eat our share of potatoes over the winter. And come June we have an abundance of eggs so I can make all of the pasta I dreamed of making in the winter egg-drought.

Likewise, there is nothing like that first sun-warmed tomato... We savored, half each, on a bed of lettuce and snow peas, with a yogurt-dill-cilantro dressing.
Broccoli won't be far behind... I usually can't resist snapping off the first head and eating it right there in the garden.

The larger carrots can be selectively pulled from the row, making room and giving sunlight to the stragglers from replanting the gaps. I couldn't resist pulling a few early parsnips to go with the feast. The smell of freshly pulled parsnip roots and leaves reminds me of coconut. Didn't have any coconut milk in the house, but this is what the aroma inspired: carrots and parsnips sliced, steamed, cooked in butter, with chopped mint, peppermint and finely chopped dates. New favorite.


Our last carrot planting was later than usual, after the cutworms marched through, taking two May re-plantings with them, I was too discouraged to plant again, until after we put the cutworm fence around the fallowed, cutworm free plot. The first week of July started with a flood and ended with a drought, I planted the carrots between 1" rains, and then the weather turned hot and dry, forming a crust on the surface of the soil. Larger seeds would not be worried by this, but tender carrot seedlings can really struggle with obstructions. And the heat was to continue for a week, so I experimented with laying a fine layer of hay over the beds, aiming for 50% coverage, like shade-cloth, to bring the soil moisture back to the surface and soften the soil, allowing the seeds easy emergence.

It worked beautifully, the carrots poked up between the mulch, and it has worked to suppress some of the early weeds. As the crop emerges, I gently part the mulch and concentrate it between the rows to further suppress weeds.

Nature walk

My Nana is a special lady, full of character and one tough cookie. She showed me how a woman can do anything she puts her heart into, and my Nana put her full heart into life. And though it seems too early, I'm losing my Nana, and she is heading for a new adventure in that place beyond this life, and we are making our last goodbyes.

Nana was a farm girl in Montana, she tells me stories of her and her sister bringing the Jersey cows home from pasture, out of the valley, up over the ridge in the evening, sometimes even riding the old dears part of the way back. Nana saw in me a kindred spirit, although I grew up in the city, I was always "her nature girl". My favorite times spent with her were on our yearly family reunion camping trip, celebrated every year in August for almost 20 years straight.

Nana and I would take the trail from the campgrounds to the coast together, walking through the filtered light of the pines. The landscape changed gradually over the 2 mile walk, the forest would end, and open up to wild grass and shrub land, getting rockier and more open as we reached the ocean's edge, then up the coast a ways, on the tumbled salt-sprayed boulders of the Northern California coast. And each place held treasures that we would collect. The forest offered Blue Jay feathers, creeping forest flowers, mushrooms, leaves, along with the bubbling brook with a small foot bridge where we could look for fish or frogs, fallen logs where snakes might hide, and always the canopy full of calling Jays and Crows. The grassland offered wildflowers of every hue, along with wispy grass seedheads, and my favorite Lamb's Ears, so soft, I would rub the leaves and think of bunny ears. We walked quiet and alert through the grass land, hoping to spot a grazing deer or elk.

Nana held the treasures that we gathered as we walked. She taught me how to call the ducks with Goose Grass held between our palms. She would hold my hand, or I would walk ahead, leading the way and moving between all of the beauty I found in the natural world around us, so different from rows of houses and lawns, beauty I knew she saw and loved, too. Nana held each unique bouquet of treasures on our walk. As if it were a great work of art, we would arrange it and fill it out with complementary colors and textures from the familiar palette of our nature walk. She made it feel special to me as a girl, these moments that are now incomparably precious to me, looking back.

The coast line held many treasures of rock, shell and seaweed, ocean tossed wood and glass. These treasures were usually pocketed and poured over when we reached our favorite rock, where the rest of the family gathered with food and feast. Nana and I took the walking path together. As Nana settled into the family routine of serving and seating and talk and laughter, I would scamper about the tidepools and rocks. There was always a starfish or hermit crab to bring back and share with her, always a seal bobbing in the waves to point out, always a seagull overhead, nagging for a scrap of the feast. And she always listened and looked, and saw what I showed her. Thank you Nana for showing me life, and sharing in it's discovery with me. I'll always be your nature girl.

Blooming

I do love vegetable flowers, and watching them unfold gives me more than an aesthetic satisfaction because the edible fruits are soon to follow.

We have potato flowers in varying shades from white to pink to lavender to blue, depending on the variety and corresponding with the color of the potato skin. As soon as these flowers begin to die back, I can begin to excavate some of the treasure trove beneath.
Pea flowers are short lived and delicate creatures. This time of year, the pods seem to grow by inches straight out of the newly opened blossoms.
Bean flowers remind me of orchids, perhaps the homely cousin, but beautiful still. And they continue to flower as young bean pods form, promising a reliable harvest, enough to put away for winter.

Pumpkin and squash flowers glow like lanterns in the bare spring garden, and not surprisingly, they never fail to attract interesting insects for nectar, prey or shelter.

Some flowers are a harvest in themselves, brightening and enlivening salads or garnishing meals. These Nasturtiums have a nearly addictive peppery tang.

And some vegetable flower are only ever seen in the seed saving garden. This globe of tiny onion flowers is wrapped in paper like the bulb below.
But for pure show, no vegetable flower can compete with the infinite variety of plants, bred and shared generation after generation, for the simple delight and surprising complexity of it's flower. Marigolds, Cosmos, Calendula and Hollyhocks have found gaps and corners in our vegetable garden, my selection based on their hardiness and ease of growing.

But nothing brings more insects to the garden than the homely flowers of dill, cilantro, caraway and carrot.

On Safari

After one entire week without a single ray of sun, we breathed a deep sigh of relief and exhilaration when the clouds and heavy fog finally broke this morning. I could just feel the plants growing, the robins and wood thrushes broke into a loud chorus, and my downcast mood was instantaneously replaced by the same chatter and activity as the birds and the bees. What a difference a little sunshine makes!

And just in time too, the peas were beginning to rot at the tips, due to water-logged roots, the first crop to show water stress in our garden.

Not much has been going on in the garden these last few weeks, with little to weed and even less to harvest, I've been going on safari. We walk the garden every day, to watch for signs of insect damage or disease. This is often done in the course of harvesting ripened produce and weeding, but I also keep a close eye on insect diversity, dispersal and populations in the garden as a part of my own experiment on how well beneficial insects are able to control pest insect numbers.

And it's a jungle out there. I have found a number of new and interesting critters, along with familiar allies. And for some reason or another, the most biologically diverse and productive area of the garden has been in the potato patch. I suspect it is the universal allure of the plump and slow-moving Colorado Potato Beetle larvae. The always remind me of the insect world's equivalent of a herd of grazing cows, and what wolf or coyote can resist?

We handpick the adult beetles (from 5-20 a day), and squish the little larvae when we see them, but surprisingly few larvae are either hatching or growing very large due to the numerous predators.
Including this Harvestman (or Daddy Longlegs), they are general predators and scavengers. I think he had his eyes on that plump potato beetle larva through the foliage in the distance.

Even the eggs are being eaten by something or other, it's hard to know who... they do look pretty tasty.

It could be these Long-Legged Flies, numerous in the potato patch, they will eat both eggs and beetle larvae.

Another friend, spotted often resting in the dense foliage of the potato patch, this Slug-Killing Fly or Marsh Fly (of the Tetanocera family). They are parasites of slugs and snails, of which there are plenty due to the wet spring. Adults lay their eggs on slugs and snails, and feed on nectar or pollen, offered by the blooming potato flowers.

Another predator found hunting the potato jungle, an Ichneumonoid Wasp. This rather homely specimen does not compare to the more graceful and colorful Braconid Wasp spotted in the garden, and too elusive to photograph.

Outside of the potato patch, carrot flowers never fail to attract allies. The metallic and pastel shades of this Predatory Stink Bug or Spined Soldier Bug contrast well with the budding carrot flower, rather pretty isn't it? Not only pretty, but a very good ally in the garden, with an appetite for some of the most discouraging pests. "Over 100 species in many families have been reported as prey. Prime targets are immature insects. Reported prey include the larvae of Mexican bean beetle, European corn borer, diamondback moth, corn earworm, beet armyworm, fall armyworm, cabbage looper, imported cabbageworm, Colorado potato beetle, velvetbean caterpillar, and flea beetles."

Everyone loves a Lady Beetle. Even those who are squeamish about bugs cannot find much fault with this Seven-Spotted Lady Beetle. It's probably the absence of any creepy looking legs, antennae, stingers, proboscis, spines or slime that win the hearts of every gardener. We don't have many aphids in our garden, but there's always a Lady Beetle or two around. Mostly these and the Three-Banded Lady Beetle.

Scavenging the ground level of the garden, I can hardly disturb the soil without finding one of these hard-working Ground Beetles. This is the largest, and earliest emerging Ground Beetle species in our garden. But it has been accompanied by two or three other species, including a smaller bronze colored one, and a smaller plain black one.

And this iridescent species. This picture shows off their mouth parts, wouldn't want to be a soft-bodied insect in their way. They have been doing very well this year, feeding on the abundance of cutworms in the soil. I often disturb one dining on a grub, and in one heavily infested bed, where I found 100 cutworms, I disturbed about 25 Ground Beetles. Not a bad predator to prey ratio.

Also numerous and widespread are these mother Wolf Spiders. They are general scavengers, will catch prey or eat insect eggs in the soil, including Grasshopper eggs. From what I've read, dozens of little bitty-spiders will emerge from these egg sacs, and the mother spider will continue to carry them around on her back until they are large enough to fend for themselves. I find about one of these sack-toting mothers about every 100 square foot of garden, so there will likely be hundreds of hungry teenage spiders, scavenging the garden soil this summer.

Another maternal insect, the White-Margined Burrowing Bug. She is not a predator, but caught my attention with the dozen or so nymphs riding around on her back. They are related to the Stink Bug (or True Bug), but burrow in the ground instead of staying in the canopy like their cousins. And they verge on the pest side, as sap suckers, or root eaters, but are not known as a major pest.
And for a finale, the strangest critter found in the garden this spring: Strauzia longipennis, the Sunflower Maggot Fly. Entomologists must have a sense of humor. *giggle* Not surprisingly, it was found on the sunflowers, laying eggs on the undersides of the leaves. The eggs will develop into maggots, eating leaves or seeds, depending on the species. Until I hunted down the identification of this particular insect, I was unaware that sunflowers had a specific pest (besides Blue Jays), so I will be watching for any maggots or leaf damage on my sunflowers.

I hope you have enjoyed this safari tour of hunters and hunted in the garden. Keep prowling around in your own.

Overall, I am each year, impressed with the diversity and population of predators, scavengers and parasites in our garden. And to encourage their cooperation I have been researching their specific life cycles, food and overwintering needs. I have found that all the information I need can be searched on the net, but it is not compiled, all on one site, that I can continue to refer back to when needed. So I am keeping the information I collect on two spreadsheets, one for beneficials and one for pests, specific to my own garden bio-diversity. I am sure they will prove to be handy reference charts while planning, rotating, planting and cultivating the garden.

Included in the pest chart I have a column for each of the following: Taxonomic Family name, Visible Crop Damage, Feeds on as larva, Feeds on as adult, Natural Enemies, Hosts On, Life Cycle, Overwinters As, Control Methods. The beneficials chart includes columns for each of the following: Taxonomic Family name, Feeds on as larva, Feeds on as adult, Hosts On, Life Cycle, Overwinters As, Attracted or Maintained by. In these charts I list my own experiences with controlling or attracting insects, as well as methods established by generations of gardeners. You may find this a helpful tool in your own garden.

A Cutworm Fence: protecting row crops from cutworm damage

Putting physical barriers, such as tin-foil or paper collars, around transplants is a common method of controlling cutworm damage. As immature larvae, especially in large numbers, the cutworms prefer small emerging seedlings, the kinds of row crops usually directly seeded into the garden. As the cutworms grow larger, they correspondingly prefer larger stems, including transplants which can easily be protected with collars or other physical barriers such as toothpicks or small nails stuck into the soil next to the stem.

To protect our emerging seedlings, such as carrots, parsnips, beets, greens and herbs, we built a cutworm fence as a physical barrier. We dug a 4 inch trench around the area, and drove small posts into the ground every 10-15 feet. A number of different materials could be used for the fence: plastic, feed bags, fabric, anything that will not let the cutworm pass through. We happen to have a large roll of woven fabric, similar to row cover, but in the future we would prefer heavy plastic (like the kind mini-homes are wrapped in, and can be diverted from the waste stream) because it is slick and more durable in the soil. The fabric was stapled to the posts, holding it taut to keep from sagging. It stretches 4 inches below the soil, and 6 inches above.

The cutworms can climb a short way onto the plant, but after observing them in our tin collection can, they cannot climb a vertical surface above 2-3 inches. And although they do burrow in the soil to feed, we have not seen any below 2-3 inches deep, and they do not travel below the soil.

We have observed that the cutworms quickly move from crop to crop within the garden. After we tilled under a heavily damaged crop of beet seedlings infested with cutworms, we noticed, only days later, that no cutworms could be found in the soil where no food was present. Therefore, we can easily exclude them from ground where we intend to sow direct seeded row crops by fallowing the ground in the spring, and constructing a cutworm fence prior to planting.

Since this barrier was erected after planting, we carefully cultivated the area and removed any cutworms we found, including disturbing the soil around the base of each plant by hand. We had been doing this regularly to control the population of cutworms in the garden, but this time, we can be sure that more will not move in from other areas of the garden. Most of the rest of the garden crops are either too large to cut (such as the beans and peas), or protected by nails along the stems (such as the transplants).

Cutworms travel above ground, mostly during the night, and can cover some distance searching for food. Though it does make them vulnerable to predators such as our fat and happy American Toad. We are currently building a small toad pool in the garden to encourage them to breed here.
The morning after we put up the cutworm fence, we were happy to discover very little damage overnight. The herbs were untouched, and only a few carrot and parsnip leaves had been cut, exposing the location of the remaining cutworms. Thank goodness, it seems that my war with the cutworms is drawing to an end. Practicing organic and ecological gardening means out-smarting, and out-maneuvering pests and diseases. I tend to be of the disposition to lock horns and butt heads directly with my pest-sized opponent, but this time it was simply wearing me down. So I learned an important lesson in gardening: to be nimble and adaptable in technique and method, to use my intellect instead of sheer determination and will-power. Determination got me through the steep beginner's learning curve, but now that I've got a few seasons under my belt, it's time to sharpen my tools and think like a gardener!
Other-where's in the garden, the perennial herb garden is flourishing, providing my first cut of Oregano, Thyme, Catnip and Alfalfa to dry for winter use.
We are also welcoming the butterflies back to the North. Including this White Admiral,

and a Monarch look-a-like: the Eastern Viceroy.