Mealy bug infestation - Orchid Board

Dumb chemist · #1 08-05-2010, 10:11 AM

Last year, my greenhouse came down with a mealy bug infestation. Now, the tough leaf orchids (i.e. Cattleyas) were hardly touched but I cannot say the same for the softer leaf ones. I tried different sprays and found one that did seem to work. But, it still was not 100% effective at eliminating this pest as I still found infected plants now and then over last winter.
After this spring, the mealy bug infestation seems to have disappeared on its own! Obviously, I was happy at seeing this.

In looking at the plants, I found jumping spiders in amongst them. Do jumping spiders consider mealy bugs a food source? If so, they are more than welcome to live in my collection.

UKCat · #2 08-05-2010, 10:39 AM

If you consider how big a newly hatched spiderling is it is a possability that they would find mealy bugs quite yummy ... we can hope

I would be happy to have any kind of spiders in amoungst my orchids as they do keep down some of the larger pests too.

PaphMadMan · #3 08-05-2010, 11:07 AM

Just a word of caution. Mealy bugs are almost never gone forever. They can be present at a very low level until suddenly they re-appear with a vengence. Hard leaved types like Cattleya might seem like they aren't a problem, but if there are any loose sheaths around rhizomes and bases of psuedobulbs they often hide there, and can be on the roots too. Spiders might help, but keep watching.

Dumb chemist · #4 08-05-2010, 11:20 AM

I agree that mealy bugs are among the hardest pest to eliminate. One info source said that their eggs can be spread by air currents. Of course, I have 2 fans in the greenhouse for air circulation.

They particularly liked a pitcher plant I had (the operative word is 'had'). It didn't take more than 2 days for the plant to be covered in their white web.

I did have a success with eliminating them from a christmas cactus. The spray I used is available from Lowe's and has edible fish oil in it as one active ingredient. Unfortunately, the spray's smell is like a fish market on a hot day and the ice maker is broken.

Does anyone know of a systemic insecticide for mealy bugs? With over a 100 plants, using a spray bottle can take a long time, not reach every place on the plants and be expensive.

RobS · #5 08-05-2010, 11:36 AM

When you mention web I think more of spider mite.

But mealy bug can be treated systemically by Admire.

Brotherly Monkey · #6 08-05-2010, 11:43 AM

Quote:

Originally Posted by RobS

When you mention web I think more of spider mite.

But mealy bug can be treated systemically by Admire.

won't Orthene handle mealy bug infestations?

Izzie · #7 08-05-2010, 11:50 AM

Quote:

Originally Posted by Brotherly Monkey

won't Orthene handle mealy bug infestations?

In my experience, any systemic is a little late in the game once my plants are already covered, especially the plants where it is hard to cover all of the leaf area to get to all of the pests. But that's just how it is on my end, with conditions so conducive to this pest.

ETA: again, correcting myself. (I haven't had coffee yet, give me a break!)
"this pest" = spider mites outside.

Though I have this similar problem with mealies inside. So far, I've kept them at bay with dousings of soapy water.

I wonder if buying a bag of those lady bugs to scatter outside would help with the mites....

RobS · #8 08-05-2010, 11:55 AM

Orthene should work to I have no experience with this product but do with Admire. I would never try any chemical on all of my orchids at the same time. Also for Admire I've seen some limited negative side effect on some plants in full growth (still better then the mealies). I don't know if Orthene is safe on orchids.

Brotherly Monkey · #9 08-05-2010, 12:49 PM

Quote:

Originally Posted by Izzie

In my experience, any systemic is a little late in the game once my plants are already covered, especially the plants where it is hard to cover all of the leaf area to get to all of the pests. But that's just how it is on my end, with conditions so conducive to this pest.

ETA: again, correcting myself. (I haven't had coffee yet, give me a break!)
"this pest" = spider mites outside.

Though I have this similar problem with mealies inside. So far, I've kept them at bay with dousings of soapy water.

I wonder if buying a bag of those lady bugs to scatter outside would help with the mites....

Izzie, most systemics don't work well on mites, and tend to only respond to specifically formulated miticides.

Using floromite should deal with any outbreak, and being that it lasts in the plant's system for a month, should require only one application

Izzie · #10 08-05-2010, 11:49 AM

I know someone on here uses a jumping spider as pest control in their greenhouse.

Mealies are the bane of my existence. I HATE them. They are SO hard to get rid of in my garden outside with it being so hot and dry. I've gone through a few different products and remedies- hope you have better luck than me!

ETA: wow. Go me. While I've been saying "mealie" I've meant, "spider mite".

Mealies: bane of my existence on orchids INSIDE.
Mites: bane of my existence on orchids and entire garden OUTSIDE.

my bad.