More pieces of the green bug puzzle

Hugh Griffith, of the Lulu Island Blog, left a comment on my last post, Aphid in Sheep's Clothing, suggesting that the woolly green bugs I have been trying to identify may be flatid pale green planthoppers.

The bug, in the nude, as I saw it on Wednesday.

Off I went, to research immature planthoppers. And some of the nymphs are woolly, just like woolly aphids. They have those funny little winglets. Some are even green. But none were quite like what I had.

I had put the tray of leaves and bugs outside on the patio. After I had looked at too many jpegs of planthoppers, I went out to look over the real thing again, and incidentally, to see if they had survived my manipulations. They had. But one looked different, even to the naked eye; the little brown winglets now looked larger, and white.

I brought it inside to the light and grabbed the camera right away. Which was fortunate, or I would have missed this:

First photo; about 2 minutes after I had discovered the change. The white wings are already larger. Note, on the left, the exoskeleton, with wool, that he had just vacated; I had caught him in the final moments of molting. His eyes and antennae are white, he's lost his goggles, that black tail end is gone, and now he has some sort of pale brown tubing at the rear.
A minute later; the wings are longer already. Having trouble with the lighting.


Barely another minute: now the wings are well beyond the tail structure.Wings straightening up. He now seems much larger than the little shell he came out of, just minutes before.
Total time, from first glimpse to final photo, about 5 minutes. After this, he just sat there. I went to look over the photos. When I came back, much later, after supper, etc., he hadn't changed much, except that the antennae were no longer transparent.


There is no trace of his previous eye and tail markings, although the body shape is similar, and he is still that brilliant green. The eyes, depending on the light, are now brownish or white.

I looked again, at photos of treehoppers. Most of them seem to have solid-colour wings, but there are a few similar to mine. He looks something like a whitebacked planthopper, which is present here in BC, but much greener. He resembles, in some ways, the Ormenaria rufifascia, from Florida, but without the orange head striping, and with paler, silvery wings.

So, I think I am dropping the idea of a woolly aphid, and running with an indetermined species of planthopper.*

And I am still left with the questions: why? What function, if any, does that woolly, waxy blanket serve? And does the planthopper exude honeydew, like the aphid? Because those leaves definitely became sticky; or is that due to the wax?

The more I learn, the more mysteries I find.

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Update: The big guns have spoken.

Dr. Hamilton identified my photos on Bug Guide as Psyllidae, otherwise known as plantlice. So the breakdown goes: Insects (Insecta) » Winged Insects (Pterygota) » True Bugs, Cicadas, Hoppers, Aphids and Allies (Hemiptera) » Plant-parasitic Hemipterans (Sternorrhyncha) » Psylloidea » Psyllidae.

These insects (one of the planthoppers) are very "host specific" (Wikipedia); they feed on one species or a small group only. So it was important to note that I found these on alder. Googling Psyllidae and alder, and looking at another series of photos, both of nymphs and adults, I come up with Psylla alni as the closest match. Still not exactly the same, but near enough to know I am on the right track. Finally.

Phew!

And look at this stunning photo of a nymph of Psylla alni, under its coating of fiber! (Copyrighted.)

Aphid in Sheep's Clothing

I will never grow up. I am still asking small-child questions: "What is this?" "What does it do?" "Why?"

The green bugs Laurie brought me the other day have been keeping me busy. Google was little help, this time; I had nothing to go on, other than "green bug, alder, cottonwood". I posted my photos, such as they were, on Bug Guide; the next morning, a commenter said they looked like "woolly aphids". Back to Google, to research woolly aphids on alder.
First, I discovered that woolly aphids produce their own "blanket"; it is not cottonwood fiber, even though it looks similar, and is also coating leaves in the vicinity. Instead, it is a waxy substance that they exude from the anus, as other aphids exude honeydew.

I compared a cottonwood twig, with seeds and fiber, with the fiber from the bugs. The cottonwood was not quite as white, silkier to the touch and more "feathery". Fiber from the suspected aphids was sticky; cottonwood fiber was sticky only when it had already come into contact with the leaves where the bugs were. So that checked out.

But then I ran into problems. The woolly alder aphid is common in BC, is covered with a white, sticky fibrous blanket, migrates from maple to alder in early summer, and eventually covers the leaves with a sticky nectar which leads to the growth of a blackish mold. Check, check, check, check and check. Except that all the photos of woolly alder aphids without the coating were nothing like mine. Wrong colour, wrong eyes, wrong shape.
A close-up of my bug, shorn of its "wool". Note the little wings or wing covers; he beat those winglets, but never managed to fly with them. Also note the absense of visible mouth parts or pincers. And the "goggles"; black circles around the eyes, as though written on with a felt pen. The tail is black, but in two sections, with the rear-ward one being slightly greyer. You can see where the wool is produced; a small bit still sticks there. (Ignore that red fiber: it's a piece of my carpet.)

I looked at hundreds of photos of woolly aphids, of all sorts; none of the denuded bugs were anything like mine.

Could something else mimic these? Something that, under the disguising blanket, turn out to be another beast? A predator? A "wolf in sheep's clothing," in miniature?

In the New Westminster Library, I searched the indexes of insect books for "woolly aphid". Mostly, it wasn't there, or referred to one or two lines of text. But there was a new (to the library; it's from 2003) book: For Love of Insects, by Thomas Eisner. And it has 20 pages on woolly aphids, a mimic, and its interactions with the aphids and the ants that "farm" them.

The green lacewing larvae prey on woolly aphids. Some of these are known as "trash bugs"; they purposefully coat themselves with bits of debris, including food leftovers. Eisner discovered some of these that took the waxy fibers from the woolly aphids, and covered themselves with them, until they could pass for a large aphid themselves.

He pulled the covering off some of these, the same way I had with my bugs, and watched. They immediately set about covering themselves again, grabbing pieces and twisting around to place them on their spiked backs until they were completely disguised again. (I went back and looked at the bugs I had stripped the day before; they were also back to normal, sheep ready for the shearing.)

Ants are well known for their talents as aphid farmers. They will stand guard over their herd of aphids, protecting them from wasps and other invaders, including humans, and "milking" the aphids for honeydew by stroking them with their antennae. The woolly aphids also produce this honeydew, along with the wool, and are shepherded by ants for this purpose.

The green lacewing larvae escape the notice of the ants by stealing the waxy fibers from the aphids they will be preying on. Eisner and his staff stripped the larvae and placed them back in the colony of aphids; ants attacked them right away. Some they killed outright, others they carried away and threw off the branch. A few were eaten. But an ant that bit a larva coated with fiber got a mouthful, and retreated to clean himself off. After a few attempts, they ignored the larvae.

So: were my bugs lacewings? If so, it was odd that I hadn't seen any lacewing eggs anywhere; these are noticeable, because they lay them one at a time on top of a 1/2 inch stalk. To me, they would look at first glance like one variety of slime mold, which I keep a lookout for.

And none of the lacewing larvae looked anything like my bugs, either.

Besides, all the lacewing larvae that I could find, and all the descriptions, mention the large mouthparts , the "powerful jaws" "like ice tongs". My bugs have no visible mouthparts at all, no matter what position I prodded them into. And smooth bodies, with no spikes.

So, what are they? I still don't know. For now, I'm going with "woolly aphid". But not the woolly alder aphid, nor either of the two invasive woolly aphids here in BC, the woolly balsam aphid and the woolly hemlock aphid.

A "normal", non-woolly aphid, on another leaf from the same tree, for comparison purposes.