Natural events, July 2016

Featured this month:

  • Predatory stink bugs to the rescue
  • Japanese beetle report
  • Black rat snake nest
  • Plants with milky sap
  • Fungi galore
  • Grazing strategy

Weather recap: July started very wet, then turned hot and steamy, tending towards dry by the end of the month. Between the morning of July 2 and the morning of July 3, we received 5.81″ of rain, an amount that would usually result in a real mess. Runoff was a problem during intense downpours, but overall the landscape soaked up the water remarkably quickly, a testament to just how dry June was and how thirsty the flora was. The temperature never broke 100ºF, but the heat index did repeatedly. We don’t remember ever going through so many soggy, icky, sweat-soaked changes of clothes as we did this July.

Quiz: Are the landscapes in the photos below overgrazed, well grazed, or undergrazed? And by what animal(s)? Answers at the end of the post.

july_natural_grazing

july_natural_pred_bug

As the early July rains faded, I realized that the weeds had taken off in the asparagus patch, so I went to work weeding. While doing so, I noticed some predatory action on the larvae of Asparagus Beetles (Crioceris asparagi). The photo on the left shows an Anchor Stink Bug (Stiretrus anchorago) feeding on an Asparagus Beetle larva. The photo on the right shows another individual of the species; color apparently can vary widely (see bugguide.net). I saw more of these bugs in the asparagus patch at other times during the month, and qualitatively I feel that they’ve reduced the Asparagus Beetle population. If so, hooray! Later in the month, I found a couple of these in the potato patch in the vicinity of some larvae of Colorado potato beetles (Leptinotarsai sp.), a hopeful sign.

What’s especially exciting is that, according to Bug Guide, these will also prey on the larvae of Japanese Beetles. But if they have been, we couldn’t tell: we’ve had our worst year ever for Japanese Beetles. By mid-July, some of our fruit trees were being badly skeletonized (below left). On the other hand, the beetle damage to the domestic blackberries (below right) was relatively minor, thankfully, and it was a great blackberry year (wild and domestic).

july_japanese_beetlesApple trees (especially Sundance), our sweet cherry tree, grape vines, and Kentucky Wonder pole beans were particularly hard hit. In past years, we’ve achieved sufficient control by knocking beetles into buckets of water each morning. Not this year; we finally experienced an outbreak at a level that risked permanent damage to fruit trees, and we opted to take more extreme measures.

1) We sprayed kaolin clay (brand name Surround) on orchard plantings that were showing damage (except blackberries which we were actively harvesting). The clay physically irritates the beetles and makes the treated plants less attractive as a feeding site. With even just one application, it was quite successful at protecting the plants, at least until it rained too much, at which point reapplication was necessary.

2) We decided to try a trap, which lures the beetles in using a combination of pheremone and floral scent. Had I realized just how nasty the lure smells, I might not have bought the thing. We positioned it >100 feet from plantings we wanted to protect. It was effective at collecting lots of beetles (often pounds per day), though it did not seem to meaningfully reduce the beetle pressure elsewhere on the farm. Probably the only real benefit is that it provided food and entertainment for the chickens, simultaneously saving us some money on purchased feed. We’re not sure if we’ll use one of these traps again, but if we do, this suggestion of setting up the trap as an automatic chicken feeder is one we might follow.

july_natural_snake_nestBack in June, as I was weeding some flowers near our potato planting, I watched a Black Rat Snake acting especially territorial. At one point, she had her hind end in a hole and head and upper body up out of it. I was just a few feet away, yet she was quite intent on staying put. She hung out in the area for a few days, and we watched her slither through the potato plants a day or two later. I suspected she might have been laying eggs in that hole, but I didn’t want to disturb the nest. Eventually, though, something else did. On July 23 we took the upper photo of a nest had been partially dug up, though many eggs still remained unharmed and in the ground. That didn’t last long. Two days later, we found the remaining eggs destroyed, with partially developed snakes–superficially looking a whole lot like big earthworms–scattered on the ground among the remnant egg shells. Too bad we didn’t think to set up a trail camera to find out who did it.

Now for an abrupt change of subject: plants with milky colored sap. This is a characteristic that can help with the identification of plants, and it is one that is likely to be familiar to gardeners who are accustomed to cruelly ripping plants out of the ground.july_natural_euphorbiaceaeIn some cases, sap from weeds is something that requires caution on the part of gardeners. One of our planting areas had had a number of different spurge species (genus Euphorbia in the family Euphorbiaceae). Various sources indicate that sap from plants in this genus can be irritating to the skin (though we haven’t had problems) and very problematic if it gets into an eye (something we take care to avoid). The photo in the center shows Toothed Spurge (Euphorbia dentata), a plant we had never noticed until about three years ago. Apparently, it is increasing in Missouri, and we can thank Big Ag for that, since it is reportedly glyphosate resistant. We don’t know how we in particular ended up with it; had we just not noticed it before, was there a residual seed bank, or did it disperse here from a Big Ag field? But we do know that when we’re driving around, we routinely see fields loaded with herbicide-resistant weeds that are churning out seed, and not all of that seed is going to stay in the fields where it was produced. july_natural_milkweedThe milkweed family is probably the most obvious family of white-sap producers. We had three species blooming here in July, as shown above. Toxins from the milkweed’s latex famously provide protection to Monarch butterflies, whose caterpillars feed exclusively on milkweed. (Monarch numbers, by the way, have seemed low this year, but we did observe both caterpillars and adults, especially towards the end of the month.) july_dogbane_and_climb_milkwdDogbane (left) is a relative of milkweed, and like milkweed, it has milky sap (center photo). The Climbing Milkweed (Cynanchum laeve) on the right is in the milkweed family proper, yet the sap is not milky.july_natural_lettuceNot all plants that produce white sap are poisonous, though. The genus Lactuca (Latin for milk) contains garden lettuce (L. sativa, shown flowering in the photo at left and the upper photo in the second column) as well as a collection of wild lettuce species (all other photos). The flower color (yellow or blue), sap color (white or tan), leaf shape, and leaf prickliness are some of the identifying characteristics used for species-level identification. Sap production on garden lettuce is typically low when the lettuce is at its tastiest; prolific sap flow is often a good indicator that harvest should’ve been done sooner. Deer seem to savor wild lettuce plants, and it is often hard to find any outside of our fences that haven’t been nibbled back. july_natural_sweet_potatoHere’s one more garden plant that exudes a milky sap: the sweet potato. The sap is visible in the vines and in fresh roots, and it seems to have no detrimental effects. Sweet potato leave are edible; we don’t care for them, but we love feeding them to goats during the harvest season. july_natural_milky_mushroomsMilk-like secretions aren’t restricted to the plant kingdom. Some mushrooms will ooze a milky substance from their gills when bruised. July gave us an extraordinary flush of mushrooms, and we found four milky species. Using Missouri’s Wild Mushrooms as our guide, we came up with the following IDs: Hygrophorus Milky (Lactarius hygrophoroides), left column. Indigo Milky (Lactarius indigo), upper center. Peppery Milky (Lactarius piperatus), lower center; not 100% certain on this ID, as I did not taste to confirm the hot-spicy flavor. Voluminous-latex Milky (Lactarius volemus), right column. Some of these are listed as choice edibles, but ended we up sticking to the familiar for harvest:july_natural_chanterellesChanterelles were abundant, as numerous as we’ve ever seen. We filled that large basket several times over, and we preserved excess through fermentation and in the freezer.july_natural_jelly_coral_fungiAmong the other fungal fruiting bodies we saw were jelly fungi (probably Exidia alba), Jellied False Coral (Tremellodendron pallidum), and coral (probably Artomyces pyxidatus). july_natural_misc_mushroomsSeeing the pulse of mushrooms in a range of shapes, sizes, and colors was pretty exciting. They’re a reminder of just how much is going on underground that we can’t see. The mushrooms are the showy, reproductive parts of fungi, but underground and in wood the all-important networks of fungal mycelium remain mostly out of sight, decomposing dead stuff, transporting nutrients, and in many cases forming important partnerships with living plants. One example of visible mycelium comes in the form of the white patches on the log in the lower right photo; these patches are composed of shiitake mycelium that have colonized the wood, which we inoculated this spring.

july_natural_goatsBack to the topic of milk-like secretions: Some come from plants and fungi, but actual milk comes only from mammals. We hosted a herd of dairy goats in July, and we very much enjoyed collecting and consuming that oh-so-tasty milk.

To return to the quiz question at the beginning of the post, the photo on the right was grazed by goats. They spent a couple of days on that patch of land, and they ate just about everything that was green and within reach. Though it looks beaten up temporarily, savannah ecosystems thrive on high intensity, short duration disturbance such as this. In contrast, the forest view shows an area that has had deer pressure continuously for some time. The understory is rather bare, and they repeatedly eat back their preferred foods, never giving those plants time to fully recover. So, the photo at left was (and is) overgrazed by deer, while the one on the right is well grazed by goats that have moved on to new ground.

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