Aphids on oat grass

As I was taking my oat grass guttation pictures, I kept an eye out for cute critters on my newly planted grass. And, of course, there were some:

A small family of green aphids stands on the end of a stalk of tack oat grass, {Avena sativa}, that has a tiny drop of clear water at the tip (because it is guttating due to high-humidity).  There is one larger aphid (most likely a wingless parthenogenetically reproducing female, possibly a fundatrix) and six smaller aphids (probably her offspring / babies).  I'm not certain what species of aphid these are, but they may be {Diuraphis noxia}, the Russian Wheat Aphid.  Aphids are phloem feeding parasites, so this isn't a good sign for the grass, but I think they're absolutely adorable with their spindly little legs, long antennae, and red eyes.  So cute! Having just a couple of blades of grass blurred out of focus in the background gives context without distracting from the aphids.  The scale bar (lower-right) is 1mm long; a version of this image without the scale bar is available upon request. (Marc C. Perkins)
Home on the range: A small family of green aphids on an oat grass {Avena sativa} leaf. The scale bar (lower-right) is 1mm long.

That’s a young family of aphids, just starting out in life. Aphids are phloem-feeding plant parasites, so they’re sittin’ there having lunch.  They have a proboscis they insert into the leaf’s phloem vessels, which they then drink like a soda through a straw. Phloem is just about as nutritious as soda, so aphids have serious problems getting enough nutrition and dealing with the sugar overload, but that’s the topic for another post (and probably another blog …).

The larger aphid is almost certainly a parthenogentically reproducing female. She reproduces asexually, creating more daughter offspring from just her own unfertilized eggs. Yes, kids, that does mean that she can have baby aphids without any daddy aphids around.

So, the six smaller aphids (called nymphs until they mature) are almost certainly her offspring. The mother will keep producing more and more offspring asexually, and these offspring themselves will almost certainly be able to parthenogentically reproduce as well1. That grass stalk won’t be happy for long.

It can often be hard to tell from web-sized images how much detail is contained in the original capture. Since I know you’re thinking that these aphids are adorably cute, here’s a crop of the image above focusing on them (see the same crop as a larger image here):

This is a severe crop of my original "Home on the Range" image, highlighting the detail visible on the aphids.  A small family of green aphids stands on the end of a stalk of tack oat grass, {Avena sativa}, that has a tiny drop of clear water at the tip (because it is guttating due to high-humidity).  There is one larger aphid (most likely a wingless parthenogenetically reproducing female, possibly a fundatrix) and six smaller aphids (probably her offspring / babies).  I'm not certain what species of aphid these are, but they may be {Diuraphis noxia}, the Russian Wheat Aphid.  The scale bar (lower-right) is 1mm long; a version of this image without the scale bar is available upon request. (Marc C. Perkins)
Crop of my "Home on the Range" image; the scale bar is still 1mm long.

I’m not certain what species these aphids are, but I suspect they may be Diuraphis noxia, the Russian Wheat Aphid.

Oh, and the small drop of water at the tip of the grass stalk is there because the grass is guttating – exuding water from its tip due to root pressure. I write about that more in this post.

1 Winged and/or sexually reproducing individuals can also be born, typically when environmental conditions change dramatically (e.g., the onset of winter, or depletion of the food source).

More pictures

To see more of my botany-related pictures, head to my Botany Demonstrations gallery.

2 thoughts on “Aphids on oat grass

  1. I’m certainly no aphid expert, but I did a project with greenbugs (a common aphid species) last summer, and after hours under the microscope I think I have a fair handle on recognizing them. These look remarkably similar. Species is Schizaphis graminum. Amazing photograph anyway, your blog seems great!

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