Scale or mites? Know thy enemy!

[MBM7]

So after wondering for a long while what was causing my lepismium cruciforme (its a flat variety, formerly classified as rhipsalis cruciformus) to sort of wither away, especially the new growth, I think I've finally discovered the culprit. The problem was I didnt really know what to look for, as the scale bumps are much smaller than what I've seen on the internet. I've seen the males or tiny white little larvae moving around, but up to this point I had been unable to identify the females that develop the circular armor/shield.

I'm going to attach some photos to confirm that this really is scale. Assuming that you guys confirm my diagnosis, I have some questions:
1) It seems that most of the bumps are not big and round as per this topic viewtopic.php?t=27535. In other words, some of the little bumps seem to be very small while others are a little larger. Is this normal? I suppose it also depends upon the exact species of scale.
2) Withered frosty/brown areas covering larger areas are visible on some stems. Are these areas withering because the scale is literally sucking out the lifegiving juices and dessicating the stem? Do these areas occur right underneath the scale or not neccesarily?
3) Sometimes it looks like there are brownish lesions but no scale insect present. Perhaps these are areas where the female scale was sucking for some time, died, and then fell off the stem?
4) How long do adult females live for? Do they typically die off after they kill off all of the living tissue underneath?

IMG_5546.jpg (104.39 KiB) Viewed 1065 times

IMG_5547.jpg (128.14 KiB) Viewed 1065 times

IMG_5548.jpg (128.52 KiB) Viewed 1065 times

IMG_5549.jpg (116.15 KiB) Viewed 1065 times

Moving onto control:
1)I've seen a recommendation to treat scale on epiphyllum (I'm assuming this also works on rhipsalis) with a solution of 50% water and 50% isopropyl alcohol and a few drops of dish detergent - http://www.pacificepiphyllum.com/epiphy ... sts-scale/ Does anyone have any experience with this? It seems like several applications are neccesary and I'm guessing it mainly would kill the males and crawlers.
2)I've also seen a lot of recommendations to hose off the plants. Is this intended to dislodge female scale or just the males and crawlers which are not so strongly attached? After scraping some of these bumps off I have a hard time believing anything less than a pressure washer would dislodge the females.
3) If I decide to go with a systemic insecticide is there one I can use that will kill the scale but does not harm beneficial insects? The plants are indoors so there are not many insects but I have noticed jumping spiders which Im sure help with the small amount of thrips.
4) Could I apply the sistemic insecticide now as it seems most of my plants (they are indoors), are still actively growing?

Thank you in advance for any and all help!

[MBM7]

Hey guys, after reading through Steve Johnson's post on various insect infestations I'm wondering if I have a flat mite problem. I think I would have seen red mites, and I've only seen one little spider web, but I think it was just a regular spider. I also should mention that this issue has been slowly progressing over the last 3-4 months.

[hegar]

Hello MBM7,
I think, that you could rule out mites, but you may be dealing with scales or mealybugs. Unfortunately, even after electronically magnifying your images to the maximum extent, I am not certain, that there are indeed scale insects present. Image 5549 does seem to have three roundish shapes on the lower side of the big lesion. However, these spots become blurred and I could not make a positive determination.

Harald

[MBM7]

Hey Hegar, I will try to take another photo when I get a chance. What makes you think that I could rule out mites? Also, I think we can safely rule out mealybugs, I'm sure I would have spotted them were they present.

[hegar]

Hello MBM7,
I thought, that most likely you would be able to spot mites and also thrips. The white coloration could be caused by the presence of armored scale insects or the waxy cover of mealybugs. These insects stay in place and are covered, which makes it harder to detect them.
There are also a few fungi, which produce white mycelial thread. You probably have heard of powdery mildew and downy mildews. Also, I have encountered white fluffy mycelium produced by the hyphomycete fungus Fusarium.
With the camera you do have it is very difficult, if not impossible, to determine what caused the white discoloration on the cactus stems.

Harald

[MBM7]

Hey Hegar I'm still planning on trying to get a better picture for you. I'm going to need to use the macro mode on the DSLR because the iphone just doesn't cut it. I'm actually becoming skeptical this is scale as I just removed true scale from an e. anguliger and had an up close look at it. Of course perhaps it is possible that this is a different species of scale then that which is commonly found on epiphyllum? I haven't been able to observe any white mycelium but I'll keep a lookout.

One thought I had today is that perhaps the dry stems are just that, dried out stems. On the one hand this seems hard to imagine as I water this plant every 4-5 days. On the other hand, it has a very small pot and the plant is very root bound, there are literally roots coming up out of the soil looking for moisture. I'm wondering that since the ¨plant¨ is actually composed of many different cuttings, lets say 10 cuttings, perhaps the cuttings are competing furiously against each other for water? Thoughts?