The battle of the scale (not the diet kind)

For those regular readers of RGO you may remember that I have been battling
the nasties over the year. The mealies have been gone now for over a year
and my phals really improved. I can't say it's because they aren't being
dragged down by mealies or whether its the change in fertilizer to the MSU
formulation from Ray. In either case I have the best looking an branching
spikes I've every had in my collection. Thanks Ray and Enstar II!
The Enstar took out the hard brown scale that was around a few of the
plants. I don't think it was much of an infestation but I did have problems
with it on a couple of the Oncidiums and Encyclia. I haven't seen hard
scale in over a year now. I don't miss popping those hard shells like
bubble wrap.
The real war was with the soft scale. I tried all the contact stuff from
the bottle, malathion, orthene, Enstar II, and other stinky stuff. It
would knock them down but they would just pop up somewhere else. It was
like a game of wack-a-mole in the arcade.
Last summer I bought the Bayer Advanced Tree & Shrub Insect Control
Concentrate. At first I didn't do my arithmetic correctly and was applying
it at a reduced rate and didn't see any affect. After returning to the
calculator I realized my mistake and I applied it at a rate of 1 oz per
gallon through the dos-a-matic injection system. I did this for three
consecutive weeks of watering in August.
Since this is a systemic and must be sucked up by the roots of the plant I
thought three weeks of application would insure that the plants carried the
insecticide throughout the entire plant. According to the label when used
on trees and shrubs it is effective for an entire year. In October I
thought I saw another outbreak of scale and applied another application but
have decided that I only saw eggs hatching.
The eggs of the scale seem to last many months. Five months after
application I do not find any live adult scale. On the older growths and
deep in the sheaths I do find crawlers. When I find them I clean them up
immediately.
My hypothesis is that the eggs were unaffected by the drenching with the
Bayer solution. Those eggs hatch where they were hidden on the older
growths. The crawlers start out looking for a place to start sucking and
get the residual of the poison still pulsing through the plant. They seem
to swarm form a mound about 1/2 of an inch across. I haven't found any
scale on new growths just on aging older canes and pseudobulbs.
In my previous attempts I was able to kill the live scale but a couple of
months later the eggs would hatch and soon infest the collection. With the
systemic in the plant over a longer period these eggs hatch but have nothing
to eat and soon die. The older growths did not suck up the systemic
insecticide as well as the new growths. The new growth has a higher
concentration of insecticide so if the crawler was blown into one of the new
growths it is quickly poisoned.
Any thoughts about this from the more experienced grower who have won the
battle of the scale?
Good Growing,
Gene
Reply to
Gene Schurg
As far as I know, you are the only person who has ever won the battle of the scale...
My experiences have been similar to yours, but I hadn't connected the dots to long lived scale eggs. That is as good a hypothesis as any. I thoroughly sprayed with three week apart applications of similar chemicals (the bayer spray and a different IGR called Distance) late this fall. I've seen a couple isolated outbreaks of boisduval scale on a few plants, mainly plants hanging high where it is a bit warmer. But in general the scale load is greatly reduced, I have to really work to find any. Which is a step in the right direction. I have seen a couple more outbreaks of mealy bug in some odd places (on phals, not paphs), which I'm not sure I understand since I nuked every plant in the greenhouse. I'm hoping that this summer when I can spread things apart a great deal more that I can win the final battle.
I'm making the final push, we'll fill in the trenches and let the poppies grow this fall.
Reply to
Rob
Rob,
It is interesting that you could be observing the same thing as I. Did you spray or drench with the Bayer product? Did you water between applications where the plants could suck up water without the chemicals?
We can beat these monsters!
Gene
Reply to
Gene Schurg
I tried a drench (trash can and pump with hose) with just the bayer for three consecutive weeks in early summer. That didn't work, or at least not completely. When I added the IGR into the mix, it was applied as a spray to the point of complete saturation of as much leaf surface as possible (top and bottom), again for three consecutive weeks, within a couple hours after watering the greenhouse in my normal way. I'm not sure of the rationale of that, but I did have one. It made sense to water before so that I wouldn't wash out chemical before it had a chance to be absorbed, and I thought that perhaps the leaves would be more actively transpiring right after a nice watering and more susceptible to absorbing chemical.
Distance is supposed to have translaminar systemic activity (absorbed through the leaves), which is one of the reasons I picked it. I don't think EnstarII is systemic (I could be wrong). It is about the same cost, but you have to buy a whole quart... They target the same pathway.
And actually, come to think of it, I used orthene instead of imidocloprid for the first two weeks. Both have systemic activity. I was worried that the bugs were becoming resistant to repeated imidocloprid treatment, and I hadn't used orthene in a while. This way I was hoping to get the resistant ones in the first two passes, and get the longer residual of the imidocloprid on the last one. And orthene is cheap... Probably a stupid idea.
Reply to
Rob
Gene & Rob,
I have a question for both of you. Thankfully, scale is generally not a huge problem for me. I see it now and then, but seldom, really. And I have never seen anything that I could identify as crawling scale. When I *have* had scale, it appears attached to the plant, having sunk its wicked fangs in already. Thorough searches have not produced anything further.
Am I missing something?
Diana
Reply to
Diana Kulaga
I don't think one can ever WIN the war against bugs; especially if you grow in a greenhouse or outdoors or indoors near windows and doors and you live on a planet with an active (or even ailing) biosphere. You may have quiet periods with few visible problems but new infestations will always find a way to the food and shelter we call our orchid collection. Vigilance is required. Never ending vigilance. The best that can be hoped for is containment and control, NOT eradication: unless you plan to destroy the whole biosphere...
Reply to
al
Diana,
When the momma scale mates with the daddy scale the momma lays eggs under her shell. At some point the momma scale dies and protects the eggs with her shell which gets leathery and dry. After some time the eggs hatch and a bunch of small whitish dusty looking babies crawl out from under the shell and look for a nice leaf to attach to. These are the crawlers. In large quantities they could be mistaken for mealie bugs.
Gene
imidocloprid
Reply to
Gene Schurg
Hi Gene,
You might find this site helpful.
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Based on what is says, the timing seems right for the October outbreak to be from eggs not killed. Not much will kill a bug in all the life cycles.
I do not think you can assume you will get a years coverage from a single spraying. The label you are reading was written for a seasonal plant with seasonal bugs. Based on what I have seen assume 4 to 6 weeks.
I have used this chemical to fight fungus gnats. I talked with the rep and he recommend monthly sprayings. The label tells you to limit sprayings to 2 per growth cycle (I am doing this from memory so this might not be exactly right). I was afraid that too much of a good thing would lead to color breaks, so I never followed his advice and followed the label limits. With three drenches you hit them pretty hard; I am interested to know much color breaking you see in your Phals this winter. Aug is a pretty safe month to be hitting Phals with systemics so there is a good chance you will not see any.
Pat
Reply to
Pat Brennan
Thanks for this info Pat & Gene, yes I have seen plenty of the dreaded Boisduval! I had colour break & mutant looking flowers when I used a systemic call Cygon a number of years ago. (No longer available) Have used Ortho WP along with Neem. Have not tried the Bayer product? I have been using Enstar II along with Mavrik & so far the best results for me. I think the Mavrik is a topical treatment but the two are mixed together. I mark & tag plants specially treated & document g/h sprays etc.
Now I am one that always experiments & have found that you have to keep on a strict regimen forever or the buggers come back. I have unpotted a scale infested plant, cleaned every bit of potting mix, trimmed old roots etc., sprayed any visible bugs with alcohol, then left this plant soaking in the Enstar/Mavrik solution over night & the next day there were little white babies trying to escape. Unbelievable, the float & creep to the sides of the bowl!!! So my point being they are never gone. Happy debugging,
Reply to
wendy7
Dianna,
After all this is "G" rated newsgroup. We can't be too graphic.
How's this "When the hot young masculine scale comes upon a sweet curvy babe of a scale....."
Gene
Reply to
Gene Schurg
Wendy,
You probably don't need to try the Bayer product. Imidacloprid is the chemical that kills the bugs in both Mavrik and the Bayer Shrub & Brush. Mavrik is available in a far more concentated product so it costs more but goes much further.
From what I have read do not rely on it to kill mites. Plants treated with Imidacloprid may even attract them. Maybe that's why I have (or had if the soap worked) them.
Bob
Reply to
Bob Walsh
I was checking my poison cabinet & noticed that I will soon be out of Mavrik. So could someone tell me what to look for in the Bayer product section. As I recall the Mavrik & Enstar II cost me over $100 so if the Bayer is cheaper then that would be great.
Reply to
wendy7
Wendy,
I forget where you live. I find this at Lowes or Home Depot in the garden section. The Bayer Advanced Tree and Shrub Insect Control comes in a blue quart bottle for about $18.00. They also make a rose spray in the same line that is of lesser concentration but I used the tree and shrub stuff.
A 32 oz bottle will make 32 gallons of mix at one oz to the gallon.
Gene
Reply to
Gene Schurg

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