Friday, September 25, 2015

Anthurium no. 0212 "Rogue" / Predatory Mite Report

Not a lot to say about Rogue; he's1 yet another in the very long line of red / yellow blooms. Larger than a lot of them are on their first attempt, which I suppose is good, but also the spathe margins are kinked in spots, which is less good.

The leaves are really nice; broader and flatter than most.

Not crazy about the overall habit; the internodal distance is longer than I would like to see, and he flops over and gets tangled in other plants.

I'm not sure whether Rogue is a keeper or not. I do really like the leaves, but not well enough to be thinking about promoting him to a 6-inch pot. So probably not a plant I'm going to keep around for a long time, but he gets to stay for now.

In other news, enough time has now passed that I think I can start making some tentative assessments of the predatory mites. Supposedly they take 3 or 4 weeks to establish a population; I'm writing exactly four weeks after I applied them.

Overall: very disappointed. I wasn't even expecting eradication of the thrips; I would have been satisfied with a reduction. But I'm not even seeing that. It's as if I'd never done anything at all.

I'd called the company (Green the day after applying the mites, because I was concerned that maybe they'd mailed me duds -- when they first arrived, I'd dumped out a little of the material onto a paper plate, with the intention of getting a photo of a mite to post to the blog, but I only saw one speck actually moving around, and it was moving too quickly for the camera to focus on, so I gave up. I'd also seen one mobile speck in the material I dumped out onto the plants, but aside from those two, which I assumed were mites, I didn't spot anything moving at any point. So I became concerned (I'd paid for 50,000 mites, after all -- if all 50,000 were supposed to be mobile adult mites, and I only got 2, then obviously I hadn't gotten what I'd paid for and I was prepared to complain. The woman I talked to on the phone said that no, the mites in the container were supposed to be in a range of life stages, from eggs up to adults, so obviously I wasn't going to see 50,000 little mites moving around. (She also seemed confused or surprised that I said I'd seen any of them moving, but whatever.)

Somewhat reassured, I decided to give them three or four weeks to get established -- a different predatory mite vendor said that the thrips population wouldn't even start to drop until 3 weeks had passed -- but I'm still not seeing any mites moving around on the plants, and the thrips are as numerous as ever, so I think I have to call it an expensive failure.

So what went wrong? Did I get dead mites? Did I apply them incorrectly? Do they not work indoors?

Did I get dead mites? Possibly. At least mostly-dead mites, conceivably. Even with a mix of life stages represented in the container, I'd really expect to see more than two adults moving around, so it's kind of suspicious to begin with. Under the microscope,2 a month later, I do see things here and there that look like they could be mite corpses, but I have still not spotted anything that looks like a living mite, and even the corpses are pretty few and far. So this is plausible to me, but I can't be sure, and even if I were sure I couldn't prove it.

Did I apply them incorrectly? Again, possibly, though I feel like I applied them as well as I was capable of. The instructions said to release them at sundown, on the day of receipt, by gently tapping them out of the bottle onto the plants' leaves, concentrating on the areas with the worst infestation, and then leave the container near the plants so any mites left in the container can crawl out. I didn't do the sundown part (the reasoning being that the instructions were probably written for people who were planning to use them outside, where there's a pronounced daily swing in temperature, which didn't apply in my case), but I did follow the other instructions. When I called the company to ask about the mites not moving, I was told that it would be a good idea to buy and apply a second batch about two weeks after the first. That advice wasn't on the website, but a number of other sites include instructions along those lines as well, so I don't think she was inventing it on the spot or anything. That may even have been a good idea, but the one batch was expensive enough ($63.70, including shipping), and I already had my doubts as to whether I'd received live mites the first time, so I wasn't real keen on the idea of doubling down on that.

(If two treatments are required for the product to work, then they shouldn't be selling single treatments in the first place: you should be paying for one batch of mites, and then a second batch a couple weeks later, as a single transaction. In my opinion.)

Do they not work indoors? Also plausible. Among the sites that bother to say anything about temperature, there's pretty solid agreement that the mites can be stored temporarily at 50-60F (10-16C), but in order to do anything useful, the temperature needs to be at least 70F (21C). Not a problem here, where the whole house is maintained around 72F / 22C at all times. Humidity is a bigger concern: though Green Methods doesn't have any advice in that regard, other sites say "moderate" humidity, or 75-90% humidity. The basement in general, I'm sure, doesn't have 75% humidity as a matter of course, but it is humid down there, and the Anthuriums are grouped closely together and get watered weekly, so I'd expect the humidity near the plants, at least, to be high for an indoor environment, if not 75-90% high. Which, again, if this is necessary for the mites to be effective, then Green Methods should say so on their site, and they don't.

So now I'm unsure what to do. Do I complain and try to get my money back? Do I double my investment and get a second container? (Maybe from a different source?) Do I continue to wait, hoping against all odds that maybe the mites will kick into gear and be effective after all? Maybe it's time to give up on the dream of thripslessness. (Maybe I already have.) In any event, I can't recommend predatory mites as a solution for indoor pest problems.


1 (Rogue is another drag king. Though if you'd rather think about the female X-Man character, I can't stop you.)
2 I didn't check with the microscope at the time. Maybe I should have.
I have been watering extremely carefully, so as to minimize any chances to knock the mites off of the leaves or whatever, which means that some of the vermiculite from the original container is still sitting on the leaves. I've stuck clear tape to the leaves and then pulled it off, to check out the situation without knocking all the material off: this also holds any thrips and mites in place so they can't crawl, jump, or fly off before I get a chance to look at them.


Ivynettle said...

Too bad. :( I really hoped they would work for you.

Roxane Babin said...

That's sad, I would have loved to hear about that natural predator experiment used indoors. It seems to me you got mostly dead mites, since eggs should be difficult to see, and adults do move and out of 50k one expects more than a couple living adults. I hope you will try again sometime.