Sow-Thistle Aphids - Uroleucon sonchi

sow thistle: aphid heaven

When I had a lot of lady beetle larvae to feed, I quickly discovered that Sonchus was the go-to plant for aphids! I'd find them up around the flower buds, inside the flowers, hiding where the leaves met the stem - absolutely everywhere! A lot of the ones I saw looked like this, but there were also some pale-green ones that the beetles especially liked. (I never reared any of those aphids to adult because there were never any left!)

It's a tall, fast-growing, weedy plant that springs up in sidewalk cracks all over the city, which is very useful to the urban aphid-collector. I had to grab insect chow on my way to and from work, and I could see Sonchus growing a block away.

I found a lot of gorgeous orange predatory midge larvae on them, too, more than on any other kind of aphid-infested plant. Maybe the flowers were particularly attractive to the adult midges. I'll have to pay more attention next summer!

… Abigail Parker, 23 December, 2009 - 1:52pm

Me too!

I can't wait for next summer. I'm going to make an effort to pay more attention to the small plants that are usually considered 'weeds'...I bet I've missed many small insects in the past. Thank you for your comment, Abby!

… Mandy Howe, 23 December, 2009 - 10:21pm

Moved

Moved from Aphids. Uroleucon sonchi only feeds on sow-thistle, so your veggies are safe from these.

… Charley Eiseman, 22 October, 2009 - 4:58pm

Thanks Charley

That is good to know! It looks like you had to make a guide page for them? I always see 'guide pages submitted by this contributor' on other peoples' BugGuide page...do they earn that link by physically making the guide page or from submitting a bug that doesn't have a page yet?

… Mandy Howe, 22 October, 2009 - 10:20pm

The former

Whichever editor actually creates the node for the guide page gets the "guide page contributed by" link. That can be a little misleading if you don't know what it means, because sometimes the editor who "contributes" the guide page does nothing beyond creating the node, and then other editors actually make it a guide page by filling in the information--these are the "additional contributions by" links.

You can see who submitted the first picture for any species (you, in this case!) by clicking the "images" tab and looking at the image that appears last.

When you're scrolling through an editor's "guide pages submitted by this contributor" section, any images that that person submitted for guide pages they created will be displayed, whether they're the first image of that species or not.

… Charley Eiseman, 27 October, 2009 - 12:13am

Thanks, Charley

I understand now. Thanks! I've been wondering about this for a while now.

… Mandy Howe, 27 October, 2009 - 1:44am

Moved

Moved from ID Request.

… Mandy Howe, 21 October, 2009 - 11:47am

Aphids are tough to ID

Hope you get lucky with these. Knowing the plant they're on can be most helpful. I think you've done all you can, except wait patiently.

… Ron Hemberger, 21 October, 2009 - 11:13am

I had a feeling...

...that would be the case. I'm a patient person though and I've got a long time till the next planting season, so I'll keep my fingers crossed. I'll maybe even do some snoopin' around at the library for some aphid books. :)

… Mandy Howe, 21 October, 2009 - 11:38am

Dandelion-like, but not dandelion

The involucre of different-sized, upright bracts (phyllaries) looks like sow-thistle, Sonchus (see photos of involucre). The involucre of dandelion consists of only two sets of bracts, the outer ones distinctly smaller and reflexed. There are three species of Sonchus; you would need a view of the stem to tell them apart.

… John Pearson, 21 October, 2009 - 9:45pm

Beautiful! Thank you

Having the wrong food plant listed could totally change what the aphid's ID might be and I did have it wrong! As soon as I saw the photo of Sonchus I knew that's what it really was. For the majority of my life, I thought those plants were just a different type of Dandelion. But now I can see how different they are. Thanks again!

… Mandy Howe, 21 October, 2009 - 9:54pm