Ugh, bugs - Orchid Board

jkofferdahl · #1 05-01-2017, 05:13 PM

In the many years I’ve grown orchids, I’ve come to fear two things more than any other problem that might affect my plants. Whenever a new grower sees an issue with an orchid their first concern is VIRUS! Viruses do happen and I suppose we’ll all encounter a viral plant at some point or another (and may never even realize it), it’s my experience that they’re pretty rare in small, personal collections (though in such a collection they could quickly decimate). The two things I most fear are mealybugs and scale. Both are capable of rapidly infecting an entire collection, and because they don’t necessarily do long-term damage to a plant we are forced into all-out warfare against these insects.

Today, as you may have guessed, I found scale on a plant, Phal. deliciosa. Finding it brings me to a question, or thought, which is that I’ve never quite been able to determine a “patient zero” with scale. Sure, I remember once, some years ago, receiving two Phals from a well-known grower with scale on them, but this was, in my experience, an exceptional instance. The Phal in question today has been, like the few other instances I’ve battled scale, in my collection for a long, long time – the source is not relevant because it’s been happily living among my other plants for about 2 years. How, then, did scale enter my house and get on this plant? The number of individual scaleybugs I removed by hand (well, Q-tip and alcohol) surprised me, as I’d not noticed ANY before today.

This, of course, led me to begin an investigation. I received four plants on Saturday, but these plants arrived too recently for the infected Phal to have picked it up from them. Naturally, then, they were the first plants I inspected (yet again – I ALWAYS inspect plants when they arrive – even from LOC or Peter!!). They are, of course, as clean as a plant from LOC (or Peter) always is. So I inspected other more recent arrivals, all of which are also clean. I should stop my narrative a second here to note that yes, when a new plant arrives I isolate it, regardless of the seller, and also thoroughly inspect it (I even use a magnifier lamp) to be sure it’s OK. Those newest plants I mentioned are still in isolation, despite knowing that they’re fine. Also, most recent arrivals are miniatures which grow not just in a different area but in an area in a different room of my house.

Anyway, I’ve spent a good two hours using a proverbial fine-toothed comb (OK, my vision is poor, but with a magnifier I can see just fine) inspecting all of the orchids in my kitchen grow window, where deliciosa lives. Nothing. I regularly treat the plants in the area with a dusting of diatomaceous earth, which, in over a year, has kept the area bug free. The ONLY plant on which I’ve been able to find scale is this one. Somehow, then, it has to be the patient zero – and hopefully will be the only patient! Naturally I’m not convinced, and expect to find scale elsewhere! However, I haven’t yet.

And that leads my thoughts in two directions. First, is scale something which could hitchhike on an insect and then get onto a plant? I’m not an entomologist (took a class in college), but have heard of such, though it doesn’t seem likely. Second, is scale an insect which could find a comfy place to basically hibernate for a year or more before deciding that conditions were right to come out? Have others experienced a seemingly untraceable infestation of scale?

estación seca · #2 05-01-2017, 05:24 PM

Since you've used a mechanical means of control requiring contact with the DE to kill, any insects hiding deeply in crevices, or under dead material, might be able to avoid contact, and might survive.

I don't know how much temperature variability your growing area has through the year. Scale often appear and spread when it warms up in the spring.

Leafmite · #3 05-01-2017, 05:37 PM

The crawlers of scale can hitchhike on anything, including clothes, other insects and anything else. They are tiny enough to crawl through small crevices. And, if just one escapes harm, eventually, you will find them again.

jkofferdahl · #4 05-01-2017, 06:52 PM

It's interesting, and I'm probably overthinking it. The scale was there, I demolished them and treated the plant. I was really surprised to find the infestation. I suppose the warming temperatures could have something to do with the appearance, and with windows open there will be insects coming in from outdoors. I would just like to find the original source, though I doubt I'll even know.

Dollythehun · #5 05-01-2017, 07:25 PM

ES is correct. I have been fighting them for a long time. I always inspect the plants when I water them because even though I haven't seen it in a year, that doesn't mean the crawlers aren't playing possum.

Leafmite · #6 05-01-2017, 09:24 PM

I had the mealy bug explosion last week as well as scale on the bay laurel and Sapodilla so I immediately ordered lady bugs and lace wings (Through Amazon!). I released them today and the lady bugs were working over the plants for the past few hours. Many have flown away but some remain and, no doubt, will leave larvae behind. The lacewing larvae are difficult to see once they are released but they are highly effective. If anyone is interested:

Amazon.com : 1, 500 Live Ladybugs & 2 Praying Mantis Eggs in Pouch & 1000 Green Lacewing Eggs Includes Ladybug Life Cycle Poster : Patio, Lawn & Garden

The kit looks geared for children but I doubt the plants will mind. They came very quickly, thankfully.

---------- Post added at 08:24 PM ---------- Previous post was at 08:22 PM ----------

Quote:

Originally Posted by Dollythehun

ES is correct. I have been fighting them for a long time. I always inspect the plants when I water them because even though I haven't seen it in a year, that doesn't mean the crawlers aren't playing possum.

If you miss just one.....

jkofferdahl · #7 05-01-2017, 09:43 PM

My first choice for pest control is the use of beneficial insects. Unfortunately, in a small house with two small growing areas, beneficial insects would pretty quickly run out of prey. I tried it once with a few mantises, but after a month had to move all but one (we named him Thor) outdoors. Thor himself had to move on when he was about 3 1/2 inches because the food just wasn't there.

That was a long aside. Point is, beneficial insects aren't practical in this case. That is what initially led me to the use of DE as a preventative. Sadly, DE kills both the good bugs and the bad. The only time I use insecticides if when there is no other option. Like with scale.

dounoharm · #8 05-01-2017, 09:54 PM

dr bonners peppermint soap....great stuff! mixed with some diatomaceous earth makes a really deadly contact bug killer....I use that a lot as I have veggies in the gh in the spring...I cant do the more toxic chems till the veggies go out...and a dusting of the diatomaceous earth occasionally just on general principle.....

for the orchids, a nice toxic 3 in 1 spray about every 3 weeks, whether I need it or not....

AnonYMouse · #9 05-01-2017, 11:50 PM

I was told by the nursery bug guy that scale and ants go together. I don't remember what/how (ants carry them)? Anyway, ant control was his point.

I've had a couple of deliveries of mealies from reputable vendors and I see them outside. My Citrus hystrix gets scale and I go after them with the cinnamon concoction. I get reddish mite buildup if I don't shower the chids occasionally. Have been lucky so far.

jkofferdahl · #10 05-02-2017, 12:33 AM

Quote:

Originally Posted by dounoharm

dr bonners peppermint soap....great stuff! mixed with some diatomaceous earth makes a really deadly contact bug killer....I use that a lot as I have veggies in the gh in the spring...I cant do the more toxic chems till the veggies go out...and a dusting of the diatomaceous earth occasionally just on general principle.....

for the orchids, a nice toxic 3 in 1 spray about every 3 weeks, whether I need it or not....

I'm not familiar with Dr. Bonners. Gotta look into it. I sometimes mix a bit of sugar with the DE to attract bugs.

---------- Post added at 11:33 PM ---------- Previous post was at 11:31 PM ----------

Quote:

Originally Posted by AnonYMouse

I was told by the nursery bug guy that scale and ants go together. I don't remember what/how (ants carry them)? Anyway, ant control was his point.

I've had a couple of deliveries of mealies from reputable vendors and I see them outside. My Citrus hystrix gets scale and I go after them with the cinnamon concoction. I get reddish mite buildup if I don't shower the chids occasionally. Have been lucky so far.

And I'm so glad that you mentioned ants! As soon as I read that I remembered hearing it before, from other gardeners. And this is Ant Season in Georgia (April through October).

I think my next DE application will contain sugar. And ant poison, just to be sure.