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. 😉

It’s a Bug’s Life

Confession time.

Are you ready?

I’ve got some mad skills but they have little to do with gardening. I excel at raising insects and bugs.  Not to toot my own horn, but I think I might qualify for ‘Top Incubator of Garden Pests.’

Don’t believe me?  Come take a look:

After chatting you up about my gorgeous coleus, and my plans to take cuttings for next year, I found this:

Spider Mites or Whitefly?

Spider Mites or Whitefly?

I’m not sure if I have whiteflies or spider mites or both, but boy are they prolific. While watering the plant this evening, I removed a large, partially eaten leaf. When I turned it over, I could see that a small family had moved in. In just a week’s time, they spread to half of the plant’s leaves and part of the soil. Damn I’m good!

Next up, aphids.  Why settle for a hundred aphids when a gazillion will do?  The more the merrier, I always say.  I noticed a bit of ‘black soot’ on the stems of my soon to bloom Allium, but I just walked right on by.  Might as well let the aphids settle in first.

aphids

Aphids

By the time I made it to the garden center for a batch of ladybugs, the party was well under way.  The ladybugs arrive in a container saying pre-fed.  Huh? I guess all that good aphid food will just go to waste.

DSC_0017

Aphids, and the ladybugs that love them

Saving the best for last, will you take a look at that Scale?  I diligently removed all traces of scale earlier in the year while the tree was dormant.  I manually scraped the scale into a bucket, then went back over the young branches with warm soap and water.  I run a tight ship here. I cleaned those branches top to bottom to get the tree ready for the new residents.  They moved in early this summer, and show no signs of leaving.  In fact, it looks like they’ve invited a few guests.

scale on magnolia

Scale

In case you’re interested:

Viburnum Tinus: Odoriferous With a Side of Thrips

A row of Viburnum Tinus grow below the window of our den. The plants fill the space nicely between the ramp to the deck and our house. It’s a good-looking shrub, producing pretty flowers and berries during the winter months.  But…that smell.

We naively thought the pungent smell was coming from under the house. I thought a small animal might have died in the crawl space. My husband thought a neighborhood cat was spraying and tried a deterrent in the immediate area. The smell was so overpowering when we opened our window in the spring that we started keeping it closed while we researched the cause.

Viburnum tinus

Viburnum tinus, early buds

Viburnum tinus, buds

Viburnum tinus, small buds look like stars and beads

Last summer we noticed the lower leaves were a grayish brown. Turns out we had thrips. Was that what caused the smell?  We ordered beneficial insects (the larvae eat the thrips), reassured that we had good insectary sunflowers nearby for the mature adults. Further, I heavily pruned the lower branches, cutting away as much damage as possible. I hauled all the underbrush away from the plants to allow air circulation.

I noticed today that the thrips are back (along with the tell-tale brown leaves) though the plant continues to grow, flower and fruit.  I did a little research, and it seems the smell and the thrips are exclusive. According to Plants For a Future  the tinus “plants give off an offensive smell in wet weather.” Several writers on the forums describe it as something a dog left.

That’s it! At long last we have our answer. Now what to do about that odoriferous smell?

Viburnum tinus

Viburnum tinus, opening blooms

Viburnum tinus

Viburnum tinus, flowering white

Viburnum tinus berries

Viburnum tinus berries (inedible)

Wasp’s Nest Under the Eaves

I’m fascinated and disturbed by the wasp’s nest under the eaves.  They picked a high-traffic area to set up house, right outside our back door.  Two years ago they chose a similar spot, but I was able to remove the nest within a day.  I annoyed two of them, but the nest was empty so they grudgingly relocated without a fuss.

Wasp's Nest

This nest filled up quickly, with several adults keeping watch.

According to National Geographic:

“Despite the fear they sometimes evoke, wasps are extremely beneficial to humans. Nearly every pest insect on Earth is preyed upon by a wasp species, either for food or as a host for its parasitic larvae. Wasps are so adept at controlling pest populations that the agriculture industry now regularly deploys them to protect crops.”

I’m still trying to control the spread of scale and thrips in the front garden and imagine these wasps could help.  Just yesterday I clipped away a few wheelbarrow loads of brown, stained under-growth from the thrips infestation.  I moved on to the Magnolia to do battle with the remaining scale.  The purchased lacewings emerged and presumable got to work, but the damaged leaves had to be removed.

Should the wasp’s nest stay or go? Further reading in an article from Purdue University suggests leaving the nest intact.

Most home owners do not realize that wasp nests are cleaned out each fall by the wasps themselves. The empty nests contain nothing but the outside paper shell at that time. This too will break down and disintegrate through the winter. Wasps never re-use the same nest from season to season, so letting mother nature take care of them through time, is usually the best control method we have.

For now, that’s exactly what we plan to do.

•More about wasps from National Geographic.
•Leaving the nest: a perspective from Purdue University Plant and Pest Diagnostic Lab.

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.

And Then There Were Thrips

It’s been a month of pests for Gardening Nirvana as we’ve worked our way through aphids, scale and now thrips. Three different plants, three different pests, all living within a few feet of each other.

Foreground (emerging sunflowers); under window (Viburnum tinus), right of photo (scale-infected Magnolia)

Thrips now reside on the lower leaves of the Viburnum tinus immediately outside of our home office window.  It took us two summers to figure out what that…uh…pungent smell was.  We knew it was organic in nature, but it was so odoriferous, we assumed a small animal had died under the house or deck.  The smell eventually went away, the plants looked fine and we didn’t give it another thought.

Spring rolled around again, then summer and…that smell!  Aren’t you glad you are only reading about it?  The damage seemed to be happening at the base of the shrubs and along the back, making me wonder if it was lack of air circulation.  My husband’s sleuthing and a magnifying glass revealed that yes, we had a third infestation on our hands: thrips.

Plant Damage

Plant Damage

Thrips

Thrips

Through the wonder of the Internet and our postal service, a shipment of lacewing eggs, nested in bran, is headed for our front door.  When the tiny larvae emerge they feast on the thrips.  Adults need nectar and pollen to survive, so it’s important to have insectary plants in your garden to support the adult population.  The exciting news is that my sunflowers will flower within the next week or so, providing pollen to the emerging adults.  They like Cosmos and Sweet Alyssum, too, also growing our the garden.

Resources:

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!