A naked, living critter fully exposed to below-zero temperatures for 24 hours – with a pleasant, stiff breeze tossed in for good measure – should by most reckoning be dead. We know there’s science behind surviving such conditions, and that some creatures manufacture their own anti-freeze, which lowers the freezing point of their body fluids and allows them to survive. Still, seeing it happen firsthand is sort of like watching a good magician: the eyes and mind are saying, “I see it, but I don’t believe it,” even though we know there’s a rational explanation behind it all. » Continue Reading.
Posts Tagged ‘insects’
During a mild winter in our northern forests, there are those of us who cheer our lower heating bills and those who scan the forecast, hoping for cold and snow. In a classic El Niño year like this one, when we often get unseasonably mild weather well into February, there are winners and losers in the natural world, too.
El Niño refers to a natural warming of Pacific waters. This phenomenon occurs every three to seven years, when prevailing trade winds, which drive the direction and force of ocean currents, slow down. As a result, cold water from the depths doesn’t get mixed with surface water, the ocean’s surface temperature rises, and global weather patterns can be altered. This year’s strong El Niño is being complemented by a low pressure system in the far north – called the Arctic oscillation – that’s keeping polar air trapped around the North Pole. » Continue Reading.
By December, foliage season is long over for us humans, but it’s peak season under the water. Last month, fallen leaves accumulated in our streams and rivers, starting a process that’s critical for the nourishment of everything from caddisflies on up the food chain to eagles and even people. In fact, most of the Northeast stream food supply originates in the form of fallen leaves.
The bright yellow and red piles that accumulate on river rocks and fallen branches are not nearly ready for consumption by discerning invertebrates. The witch’s brew of natural chemical compounds that discourages insects from eating green leaves on trees, can be just as repellent to creatures that scavenge freshly fallen leaves under water. First, cold water must leach out those chemicals. Imagine the process as soaking and re-soaking a teabag. During this period, the leaves are also colonized by microscopic organisms. For a hungry invertebrate, the cleansed layered leaves, covered in fungi, bacteria, and algae, make a sandwich Dagwood could be proud. » Continue Reading.
The oyster mushroom: delicious, frequently spotted on veggie pizzas, and predatory. That’s right. The hyphae of many fungi, including the oyster mushroom, attack and paralyze prey. Then, as R. Greg Thorn of Western University enthusiastically described, the fungi “grow down their throats and digest them from the inside.”
Oyster mushrooms live in the trunks of dead or dying hardwoods. A couple different species grow in the Northeast, each preferring different tree species. Pleurotus ostreatus, the oyster mushroom that you find in the grocery store, is the least picky about where it grows, and it puts out its fruiting bodies from spring to fall.
Because they live on dead trees, these fungi have limited access to nitrogen. Dead wood has plenty of cellulose and lignin, but very little nitrogen-containing protein. So, like carnivorous plants (which are actually omnivorous, despite the label), oyster mushrooms have evolved a bag of tricks to supplement their diet by attracting and consuming nitrogen-rich prey. » Continue Reading.
What’s round to oval-shaped, mostly orange, and is a common sight leading up to Halloween? Everyone knows the answer to that: Harmonia axyridis, obviously. Better known as the multicolored Asian lady beetle, this insect, while beneficial to gardens, is no treat when it masses by the hundreds on, and inside, homes in the fall.
Lady beetles, or lady bugs, are the darlings of small children everywhere. There are a number of native lady beetle species, which tend to be more reddish than orange, and they aren’t known to be nuisances in homes. Multicolored Asian lady beetles, however, are not as polite. » Continue Reading.
It was the dotted, orangey-yellow and black stripes that stood out, drawing my son’s gaze to the edge of the sandbox. A small caterpillar clung to the goutweed, munching away on the green leaves. At first we thought it was a monarch caterpillar, but the stripes weren’t quite right. Out came the field guide, where we discovered our caterpillar to be a future black swallowtail butterfly. After that first discovery, we suddenly noticed more caterpillars, both in that patch of goutweed and on the greens of the carrots in our late-summer garden.
The black swallowtail (Papilio polyxenes) is one of more than 500 swallowtails flitting about throughout the world. » Continue Reading.
If you tolerate these herpetological visitors – or better yet, encourage their presence – you’ll be less likely to share your garden with ravenous bugs, or bottles of pesticide. » Continue Reading.
Being an arborist, I’m of course very mindful of complexion. Things like bruises and blemishes catch my eye, in addition to scabs, cuts, and even those out-of-place whiskers that appear out of nowhere. It sounds like a description of my aging skin, but I’m talking about blotches, warts and cuts that accumulate on tree leaves over the summer.
I suppose if we had to stand outside day and night all season, our skin would develop issues too. Those who work or play much outdoors need to be concerned about skin spots that suddenly show up. With tree leaves, that’s not the case – even the ugliest “skin” condition is generally no cause for concern. » Continue Reading.
Imagine you had a power that allowed you to pick up nearby objects without actually touching them. Imagine this power could help you find and choose the best foods while shopping. Imagine you could use this power to communicate with your family. Bees have just such a power. It’s called electroreception, and it gives them the ability to perceive and respond to electrical fields.
Scientists have known since at least the 1970s that flying bees can pick up electrostatic charges as they move, but they didn’t know whether these charges had any practical value. Today, some suspect that electrostatic charge may be very useful to bees. » Continue Reading.
By definition, a weed is any plant growing where you don’t want it. To clarify, this holds true only in the garden beds or acreage under your cultivation. “Weeding” flowers in a park planter because they offend your sense of aesthetics is frowned upon.
To a plant, having “weed” embedded right in its name is probably akin to having a “Kick Me” sign on your back. Right out of the box there is bound to be a bit of prejudice against you, fair or unfair. Spotted knapweed, goutweed and Japanese knotweed are all pernicious invasive species, and deserve all the bad press they get. But occasionally an innocent bystander suffers from this name game. » Continue Reading.