Look but don’t touch: The thuggish, sluggish caterpillar

The Spiny Oak Slug, Euclea delphinii, is not a slug at all, but a flamboyantly decorated caterpillar, looking scared of its own shadow:


Can you see that it is wide and flat, not cylindrical like most caterpillars? Rows of yellow or orange stinging spines line the caterpillar from head to rear, with longer pairs at the head and the tail.  They have sharp black tips, shown in close-up below.

euclea delphinii,  spiny oak slug.

These venomous spines deter predators, and touching them is a mistake! They can be extremely painful. If you get a spine embedded in your skin, try to remove it with Scotchtape, and then use baking soda. Some people may even have an allergic reaction that needs medical attention. (Information from insectidentification.org)

My caterpillar was stationary, but slug caterpillars are so-called because they move rather like slugs. They lack any functional prolegs. Instead, they have suckers, and produce a sort of liquid silk lubricant,  so they move by undulating across the smooth leaf surface.   The Caterpillar Lab has a great video of one in motion:


And a final pose:

Yip John A Segur West





Got the blues

Western Maine is a low key, laid back sort of place, not flashy or full of itself. But these three birds seem to have escaped from exotic lands, flaunting their azure plumage in our Northern forests.

My first is (I think) an Eastern Bluebird, because he had a rusty belly when he flew up into a tree:

Eastern Bluebird

I do concede however, that I could be wrong: maybe he too is …. ..the same as my next bird.

My second is a male Indigo Bunting, Passerina cyanea, singing from the treetops on June 9th. This is completely typical: they sing from the highest point they can find, all summer.


There is a recoding and rather a good description of their song and how they learn it here:


I am so pleased someone named it the Indigo Bunting instead of the Blue Bunting: how often do you get to use the word indigo, unless you are reciting the colors of the rainbow, or are into natural dyes. And its Latin name is cyanea, after another great color word, cyan! When they are just fledged, the blue just peaks through their beige feathers, but this week this teenager was on the same tree that his father liked, two months ago, so I can  be confident of its identity.

Juvenile indigo bunting

My third is the American Bluejay, Cyanocitta cristata, noisy, arrogant, and a year-round resident up here.


He has a fine crest, not raised in this photo.

One last blue vision: a wild native Blue Flag Iris, Iris versicolor. There was a big clump in the swampy area at the edge of my beaver pond on June 10th, and although they are purplish blue, I consider them as qualifying for this post by virtue of their name:

Blue flag iris, I. versicolor

Look close, and  marvel:

Blue flag iris, I. versicolor

For me, these birds and flowers are a cure for the blues.

Beaver buffet

There was so much to tell you about in the spring that I saved this post to send during the dog days of summer, and here we are…

In spring, I expect to see beavers eating green stuff, but this one was still enjoying his hemlock twigs. He or she took it to the shallows, and delicately nibbled at the bark, or rather the cambium beneath the bark.

beaver on granny's pond

His technique reminds me of my grandson eating an ear of corn:

You can find the by-products all round the pond: sticks cut into a convenient length for moving and eating later (think packed lunch), and then denuded of their bark.

beaver on granny's pond

Sometimes they just eat it on the tree, and leave the tree standing:


In a few days he was back, in the same place, this time with a large white slice of what I think was the root of a cattail (called bulrush in England). These roots (or rather rhizomes) are nutritious, with roughly the protein content of maize or rice.

Beaver eating cattail root

You can see how dexterous they are, though of course they do not have opposable thumbs:

Beaver eating cattail root

The roots of aquatic plants are one of their favorite foods at this time of year, and you can see them floating around the edge of the pond, the result of their depredations.

Spatterdock root eatern by beavers

In this video you can hear him chewing, above the background noise of the stream cascading over the dam:

I have not seen him for many weeks, but I am hoping he returns in the fall, getting his lodge and his food supplies ready for winter. Watch this space.


The gardener’s nemesis

Not every post can be about elegant swallows. Sometimes what catches my attention is less obviously appealing.

My father hated greenflies, because they attacked his beloved roses. Greenflies are a type of aphid, and here in Maine we have a number of different species, in a rainbow of colors, including the bright yellow Oleander Aphid, Aphis nerii, common on milkweed:


and these ruby red ones, probably Uroleucon nigrotuberculatum.


If you can suspend your distaste, they turn out to be rather interesting.  They reproduce partly by parthogenesis: the adult female produces live young, clones, without the need of a male. In the autumn, they also reproduce sexually: rather like modern humans, there is no one right way.

Although most aphids don’t have wings, as you can see in the photos above, if the neighborhood gets too crowded the female cleverly gives birth to some offspring with wings, and these then fly off to populate a new plant instead of adding to the throngs on the current one.  The biggest one below has wings:


If you are a gardener, you are no fan of aphids, but if you are an ant, your attitude is entirely different! Some species of ants actually farm aphids for their honeydew:

Ants farming aphids

The aphid sucks sap from the plant, sometimes in huge quantities. Because it can’t digest it all, it excretes a sweet sugary liquid, called honeydew. The ants use their antennae to stroke the aphids, which encourages the secretion of the honeydew, which the ants then drink. The aphids below are tiny, but just visible on the leaf stalk, and the top ant is reaching out to stroke one:


The aphids benefit because the ants protect them from predators such as ladybugs, and also move them from wilting to healthy plants. In some species, the ants will store aphid eggs in their nests through the winter and then put them back on the plants in the spring. This partnership is an example of what biologists call mutualism, since both parties benefit from the arrangement.

The spiky cornicles that project from the abdomen are used to exude pheromones for defense purposes; the honeydew is, rather off-puttingly, exuded from the rectum!

If you have read this far, congratulations: you too are obsessed by natural minutiae.

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