Ladybugs vs. Aphids: Last One Standing

ladybug on Allium

Last bug standing?

I mentioned last week that I would be heading to the garden center for another batch of living ladybugs.  My lovely, onion-scented Allium is dripping in aphids and soot.  Ick, yuck and blech!

The first batch of ladybugs made some progress, but now all but one or two are gone.  They didn’t even leave a note to say why.

Where did they go?  The tasty aphid smorgasbord remains.   What’s an organic gardener to do?

Then I read this from OurWaterOurWorld.org:

Tolerate low to moderate numbers of aphids as long as they aren’t causing noticeable plant damage. There is a reason for this: aphids have many natural enemies such as spiders, ladybugs, lacewings and minute parasitoids (tiny non-stinging wasps) that often keep aphid numbers below damaging levels. These beneficial insects rarely appear on the scene until after aphids have begun attacking plants. This “lag-time” can be a day or two or as long as several weeks. As the season progresses, aphid control by these natural enemies improves because more natural enemies are attracted to your garden and more stay to breed.

So…I’m taking the wait and see approach as I keep a close eye on the plant.

Meanwhile, I’m trying to identify a different set of insects on my beloved pumpkins.  Stop by later this week for a look-see.  I bet you can hardly wait. 😉

Thrips: It’s What’s For Breakfast!

The garden thrips are on notice! Lacewings are on the scene.

A small packet of lacewing eggs arrived yesterday by mail. The packet contained an unimpressive looking plastic bag that, to the naked eye, looked like a bag of sawdust. My eyes aren’t what they used to be so I examined the bag closely with my nifty light-up magnifying glass, a gift from Bruce and Shirley. Still no sign of those eggs. The instructions reassured me that the eggs were in there and would be “hatching any minute” if they hadn’t done so already. Well then, no time to waste!

After dinner, my husband watered the affected plants and the Magnolia tree and we set out the eggs. Seriously, it felt like a practical joke because I couldn’t see anything but the sawdust.

The instructions suggest stapling a paper cup to a tree leaf and filling it with some of the eggs.  That was the hardest part.  I’m clumsy, so trying to staple the bottom of a paper cup to a thin leaf at the top of a tree was…challenging. We scattered the rest of the eggs at the base of the plants.

Guess what? As of this morning, a few already hatched. The packet contained “1,000 eggs” though how you could have counted is anyone’s guess.  I hope the emerging larva are hungry.

We ordered our beneficial insects via the Internet from Orcon (Organic Control, Inc.) based in Los Angeles. If you live outside the states, search under “beneficial garden insects” for a source near you. Introducing the appropriate beneficial insect to your garden is safe for plants, people and pets, reducing the need for dangerous and toxic pesticides.

Garden Fail: Scale

Our purple tulip Magnolia has scale, an infestation as repulsive as it sounds. It’s equally harmful and can ultimately kill the tree if left unchecked. We’ve been researching organic solutions, preferring beneficial insects if possible.

From the reading I’ve done, the scale may have been present months ago.  Beautiful blossoms covered the Magnolia last spring, with no signs of the scale.  In late June, however, I noticed some damage to of the leaves of the inner tree and only then did I discover the scale.  We have all the tell-tale signs, now that I know what to look for:

  • Crusty bumps along the branches
  • Sticky leaves caused by scale excretions
  • Ants on the leaves.  They eat the sweet excretions and are known to defend the scale since they provide a food source.

Here are a few more details from the College of Agriculture Sciences at Penn State:

Magnolia scales are usually massed on the undersides of 1 and 2-year-old twigs, with heavy infestations completely encrusting branches. Other indicators of a scale infestation include reduced foliage and flower production, undersized leaves and twigs, and a black sooty mold on the foliage. After digesting the plant fluid, the scale excretes a clear sticky liquid called honeydew, which provides an ideal substrate for the black sooty mold fungus to develop. Magnolia scale infestations often go unnoticed until the leaves and twigs of the host plant turn black with sooty mold. The honeydew also provides a food source, attracting ants, bees, wasps and flies.

Healthy Magnolia Branch

Healthy Magnolia Branch

Scale Infestation on Magnolia Branch

Scale Infestation on Magnolia Branch

Ants eat the excreted Honeydew

Ants Eating the Excreted Honeydew

The more I read, the more discouraged I become. Even the less organic solutions are often ineffective.  I read an extensive article saying that Predatory Beetles worked well, only to learn they are no longer commercially available.  Aphytis melinus is another possibility, and probably our next, best option. Pruning away the worst of the branches seems like a good idea, too.  I would hate to have this spread to our larger magnolia just a few feet away.

Suggestions welcome!

The Ladybug Diet

Water First to Disperse the Pests

Water First

Weight Watchers teaches you to eat well, and South Beach helps break sugar cravings, but have you heard of the Ladybug Diet?  Those red-spotted beauties consume several times their body weight, ridding your roses of numerous garden pests.  I wish I could consume several times my body weight in a day and remain looking as fresh as the Coccinella septempunctata.

Ladybugs, also referred to as ladybirds, eat Aphids, Spider Mites, Thrips, White Fly and other harmful pests.  They are a boon to organic gardeners and a treat for the youngsters in the house, who enjoy setting them out at dusk.

Most garden centers now sell containers of live lady bugs.  I bought ours at Almaden Valley Nursery. Keep them in a cool place during the day when they’re inactive.

Tuesday night we watered the infested plant, cut open the mesh bag and offered them dinner.  By morning, they had done a decent job eradicating the pests.   Some years it takes two “applications” to wipe out the aphids or flies, but it’s always a treat to see hundreds of them gathered in one place so we don’t mind.

Ladybugs and Aphids

Ladybugs and Aphids

Garden Lady's: Nature's Pest Control

Garden Lady’s: Nature’s Pest Control

Dinner Awaits

Dinner Awaits

It's 9:00.  Do you know where your ladybugs are?

It’s 9:00. Do you know where your ladybugs are?

Read more about these farming heroes and the origin of the ladybug rhyme at Animal Planet.