Saturday, October 2, 2010

It's Not a Yellow Lady Bug

spotted cucumber beetle (Diabrotica undecimpunctata howardi)
The Japanese beetles and earwigs are gone, you heave a sigh of relief.   But don't relax - just when you thought the garden was safe, here come the cucumber beetles to eat virtually any yellow flower.  They migrate from the South, arriving in the Northern States in midsummer.  These nasty little pests resemble slim, yellow lady bugs with their small, spotted bodies.  I don't grow cucumbers, but that hasn't stopped hordes of them from descending on the Solidago 'Fireworks' (goldenrod).  They're also feasting on the big ex-asters, Symphyotrichum novae-angliae (pictured above), Symphyotrichum oblongifolius 'October Skies', and Symphyotrichum laeve 'Bluebird' (smooth blue aster).  What's curious is that they don't seem interested in a seedling of 'Bluebird' with slightly smaller flowers.  They also don't bother Solidago 'Dansolitlem' (Little Lemon™),  Symphyotrichum ericoides 'Snowflurry', or the wildings out back, all of which have small flowers.

Take a good look at your larger flowered asters.  If the ray petals are missing or mangled, you probably have an infestation of cucumber beetles. I've been hand-catching and squishing the little buggers, but there has to be a better way, short of growing only small flowered ex-asters and goldenrods.  The only suggestions for organic controls I've come across are floating row covers (not going to work for ornamental plants), and yellow sticky traps, which I fear might trap bees.  

14 comments:

Dee @ Red Dirt Ramblings said...

These little creatures are a menace in the south for the incubate beneath the soil eating roots while the adults eat the tops of flours and other plants. No, they're so not beneficial.~~Dee

Darla said...

Oh dear, the garden battle continues..

Gail said...

I've seen them in my garden and must go on squish patrol this AM! Thanks, MMD for the update. gail

rambleonrose said...

I am not familiar with these, but I will be sure to check my S. laeves. I have Short's asters that are blooming like crazy and are pretty small, as are my goldenrods. So hopefully we're safe.

Morning Glories in Round Rock said...

I see these nasty critters in my garden all summer. Do they have any natural preditors?

Patty said...

Perhaps I am too far north. I don't think I have ever seen one of these cucumber beetles. Kinda cute tho'.

meemsnyc said...

Wow, they do look like ladybugs. Too bad they are pests.

Carol said...

Yes, just when we thought cooler weather meant fewer insect attacks...

jodi (bloomingwriter) said...

The little devils. I don't grow cucumbers so don't have a problem with them, but I know what chaos they bring into other gardeners' lives. Haven't seen them on any of my asters, either. Squishing is a very therapeutic way of dealing with things...

Rose said...

I realize I have these, too, MMD. Most of my plants already have holes in them from other insect infestations, so maybe that's why they're heading for the asters and the goldenrod--they're the only plants left!

Mr. McGregor's Daughter said...

MGRR - I don't know if anything eats cucumber beetles, but I suspect not.

The Whimsical Gardener said...

It's so disappointing to see anything with an appetite like that in the garden. Last year I had an infestation of Leaf Cutter Ants behind my home/garden and they literally took down half the plants along the fence! It was heart-breaking. All has since recovered but I've constantly got my open for them.

lbc flower delivery philippines said...

Pretty post! I like the way beetle eat the flower. Thanks for sharing this post. Looking forward for your next post.

-yumi-

flower Philippines said...

Oh! I love flowers so colorful. I also try to collect flowers and put it in a cute vase. I enjoyed reading your article. It makes a lot of sense. Thanks for sharing.


toni