Hello there!!
I have a crew of eight little cactus pals, and I have to admit that I am not the best cactus mom-- I definitely did not do enough research before I started growing! But now, I'm trying to rectify that by learning lots about my little friends!
A while back, two of my cacti started growing white fuzz. I thought it was normal so I let it happen, but recently got worried and did some research. I learned that the problem was a mealybug infestation, and quickly treated the two with isopropyl alcohol. I then found mealybugs (to a significantly lesser degree) on three other cacti and treated them as well.
The three that didn't have bad infestations now seem to be doing well, as far as I can tell. The other two, however, are not doing well.
The first one seems to have had some damage done by the bugs to the top of his body. Some of his little bumps (the pieces the spines are attached to? I apologize for not having the correct terminology) are very dead and pretty gross looking, and he has some sickly looking spots between the bumps farther down his body. He also has a pretty mean lean but I figured that was an issue with needing some extra support until the roots get stronger.
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
The second cactus can't seem to get rid of his mealybugs completely-- I keep finding more! He also has weird little fuzzy white spots in between his bumpy things that don't look particularly healthy.
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
My third sick cactus (I feel terrible for being such a poor cactus owner!!) was my first and I love him dearly!! He recently started losing some of his growths, and one of the bodies is significantly less sturdy than it should be. It's a little bit shrivelled, but the growths coming off of it seem to be fine!
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
Any and all advice on how to heal my ailing pals would be greatly greatly appreciated!!
Sickly Little Friends! (mealybugs and then some?)
Re: Sickly Little Friends! (mealybugs and then some?)
For the third one it looks like an Opuntia microdaysis that's been dipped in dye to color the spines. It's also rather etiolated on those new growths. If you could find a place for it (and perhaps the others as well) where it gets stronger light then that would help.
Here's some general care info:
http://cactiguide.com/growcacti/
http://cactiguide.com/cactipests/
Here's some general care info:
http://cactiguide.com/growcacti/
http://cactiguide.com/cactipests/
Re: Sickly Little Friends! (mealybugs and then some?)
Hello Kira,
you definitely do have a problem on your hands with those mealybugs. These insects are very tenacious and I have tried several ways to kill them. Most of the time, their population bounced right back though. These little devils lay their egg masses right in the areoles, where the cactus already does have white fuzz, making them hard to spot. Also, the hatched offspring, called crawlers, tends to disperse rather easily. If you do use alcohol, you will need to be very vigilant and treat the plants again and again.
In my opinion, a chemical treatment with a systemic insecticide works best. You can water it in or spray it onto the plant, which absorbs the pesticide. Unless the mealybugs have developed resistance to the insecticide, they should be killed, when feeding off the plant.
I also wonder about the odd color of the base cladode of your prickly pear cactus. Some of the fungicides do have that color or a similar one.
I would handle that pad with gloves, just to be on the safe side. The Opuntia microdasys does need to be exposed to more light, just like toadstar indicates. The abnormal, spindly growth is caused by insufficient light.
Harald
you definitely do have a problem on your hands with those mealybugs. These insects are very tenacious and I have tried several ways to kill them. Most of the time, their population bounced right back though. These little devils lay their egg masses right in the areoles, where the cactus already does have white fuzz, making them hard to spot. Also, the hatched offspring, called crawlers, tends to disperse rather easily. If you do use alcohol, you will need to be very vigilant and treat the plants again and again.
In my opinion, a chemical treatment with a systemic insecticide works best. You can water it in or spray it onto the plant, which absorbs the pesticide. Unless the mealybugs have developed resistance to the insecticide, they should be killed, when feeding off the plant.
I also wonder about the odd color of the base cladode of your prickly pear cactus. Some of the fungicides do have that color or a similar one.
I would handle that pad with gloves, just to be on the safe side. The Opuntia microdasys does need to be exposed to more light, just like toadstar indicates. The abnormal, spindly growth is caused by insufficient light.
Harald
Re: Sickly Little Friends! (mealybugs and then some?)
Thank you both so much for the info!! My house doesn't get much light so I've been moving my little pals outside into the sun on warmer days, hopefully that helps!!
One last question: what should I do about the damaged part of the first cactus listed? Should I just leave it there, or is there something else I can do to help it regrow?
One last question: what should I do about the damaged part of the first cactus listed? Should I just leave it there, or is there something else I can do to help it regrow?
-
greenknight
- Posts: 4818
- Joined: Tue Apr 30, 2013 4:18 am
- Location: SW Washington State zone 8b
Re: Sickly Little Friends! (mealybugs and then some?)
Not much you can do about the damage on that first cactus. They can't regrow dead tubercles (that's what the bumps in the skin of the cactus are called, the fuzzy tuft the spines grow out of is called an areole), there's just going to be a scar. You could cut off the tip of the cactus, but that would also leave a scar, and it would remove the growth point (which appears to still be alive) causing the plant to branch out. The scarred areas tend to shrink up a bit, it won't look so bad once the plant has grown beyond it - I would leave it be.
The lean may not fix itself - it's a Mammillaria, and they lack the woody structure of the tall columnar species. They tend to lay down and grow as a trailing plant if they get too tall in proportion to their width. You can either support it permanently, or let it sprawl. It looks to me like Mammillaria magnifica, which is a species that's usually stout enough that it doesn't lay down, plus it forms a clump whose stems help to support each other. Yours is a bit etiolated, though (stretched out from growing in low light). The clump that grows up around it may eventually be able to support it without the stake. - http://www.llifle.com/Encyclopedia/CACT ... _magnifica
The lean may not fix itself - it's a Mammillaria, and they lack the woody structure of the tall columnar species. They tend to lay down and grow as a trailing plant if they get too tall in proportion to their width. You can either support it permanently, or let it sprawl. It looks to me like Mammillaria magnifica, which is a species that's usually stout enough that it doesn't lay down, plus it forms a clump whose stems help to support each other. Yours is a bit etiolated, though (stretched out from growing in low light). The clump that grows up around it may eventually be able to support it without the stake. - http://www.llifle.com/Encyclopedia/CACT ... _magnifica
Spence 
Re: Sickly Little Friends! (mealybugs and then some?)
Hello again!!
I had hoped all was well with these three plants, but we're having some pretty bad problems over here. As it turns out, I'm very bad with plants!! Today I finally managed to acquire perlite (I've been away all summer) and mix up some potting mixture with adequate drainage, and this is what I saw:
The first cactus is doing very well! The mealybugs have been apparently eradicated and he's growing on the top. This is the good news!!
The first bad news is that my opuntia microdasys is getting a lot worse. One of the lil guys seems to be doing great!! The condition of the other one has rapidly grown worse. He is soft, shriveling up at the top, and shows black spots. I was unable to separate them any more without using force. How should I go about this? They are currently sitting in a cool, dry place as instructed.
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
The third cactus, my mammillaria spinosissima, broke my heart today. As I very gently attempted to remove him from the pot (completely as instructed, I was very gentle!!), he completely broke away from his roots. Is it possible to tell the cause of his death? Also, would it be possible to cut away the dead bit and attempt to save him?
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
I had hoped all was well with these three plants, but we're having some pretty bad problems over here. As it turns out, I'm very bad with plants!! Today I finally managed to acquire perlite (I've been away all summer) and mix up some potting mixture with adequate drainage, and this is what I saw:
The first cactus is doing very well! The mealybugs have been apparently eradicated and he's growing on the top. This is the good news!!
The first bad news is that my opuntia microdasys is getting a lot worse. One of the lil guys seems to be doing great!! The condition of the other one has rapidly grown worse. He is soft, shriveling up at the top, and shows black spots. I was unable to separate them any more without using force. How should I go about this? They are currently sitting in a cool, dry place as instructed.
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
The third cactus, my mammillaria spinosissima, broke my heart today. As I very gently attempted to remove him from the pot (completely as instructed, I was very gentle!!), he completely broke away from his roots. Is it possible to tell the cause of his death? Also, would it be possible to cut away the dead bit and attempt to save him?
https://drive.google.com/file/d/0B6XC0S ... sp=sharing
Re: Sickly Little Friends! (mealybugs and then some?)
Hello Kira,
Opuntia microdasys fortunately are not only easy to grow, but also quite resilient plants. The cladodes (pads) do have a narrow part between them. This feature is present to allow the vegetative spread of the plant. You could either twist the pad and it should separate at this weak spot or you can go ahead and use a knife. The latter is the best way, especially if the cladodes are very big. Cutting the flattened stem piece at the constricted point also leaves a smooth wound, which will heal a little better. Place the stem section you want to grow on its side for about a week, to give it time to heal the wound and form a callus layer. Then you can plant the pad. It will even form roots, if you place it flat on the growing medium.
About the Mammillaria spinosissima I can only guess, what the problem was. Either the soil was bone dry and had a high clay content, or the plant was root-bound, or the root had rotted off and was in a state of decay.
You only posted one digital image, showing the base of the plant with the missing main root. How does the above ground portion of the cactus look?
I think, I do see a green looking stem. If that is the case, your plant may still be salvageable. If the root did rot, however, there is a good chance, that the bacterium or fungus has invaded the stem of your plant. In that case you will need to do surgery, which oftentimes will not result in saving your cactus. It would just be a desperate attempt with nothing to lose. Check to bottom of the cactus. Is it soft, or does it have the same feel as the rest of the plant? If it is soft, that would be bad news and indicate, that a rot has set in. In that case, you would need to cut the rotten part off and keep removing discolored tissue, until you do not see any discoloration. For good measure, it would even be a good idea to sterilize the knife and make one final cut about 1/2 to 1 inch above the last cut. Then you would let the cut heal, by laying the plant on its side for a week or so.
If there is no rot, your plant would most likely form new roots, if placed back into the soil. The torn part at the base should be treated just like described above.
Harald
Opuntia microdasys fortunately are not only easy to grow, but also quite resilient plants. The cladodes (pads) do have a narrow part between them. This feature is present to allow the vegetative spread of the plant. You could either twist the pad and it should separate at this weak spot or you can go ahead and use a knife. The latter is the best way, especially if the cladodes are very big. Cutting the flattened stem piece at the constricted point also leaves a smooth wound, which will heal a little better. Place the stem section you want to grow on its side for about a week, to give it time to heal the wound and form a callus layer. Then you can plant the pad. It will even form roots, if you place it flat on the growing medium.
About the Mammillaria spinosissima I can only guess, what the problem was. Either the soil was bone dry and had a high clay content, or the plant was root-bound, or the root had rotted off and was in a state of decay.
You only posted one digital image, showing the base of the plant with the missing main root. How does the above ground portion of the cactus look?
I think, I do see a green looking stem. If that is the case, your plant may still be salvageable. If the root did rot, however, there is a good chance, that the bacterium or fungus has invaded the stem of your plant. In that case you will need to do surgery, which oftentimes will not result in saving your cactus. It would just be a desperate attempt with nothing to lose. Check to bottom of the cactus. Is it soft, or does it have the same feel as the rest of the plant? If it is soft, that would be bad news and indicate, that a rot has set in. In that case, you would need to cut the rotten part off and keep removing discolored tissue, until you do not see any discoloration. For good measure, it would even be a good idea to sterilize the knife and make one final cut about 1/2 to 1 inch above the last cut. Then you would let the cut heal, by laying the plant on its side for a week or so.
If there is no rot, your plant would most likely form new roots, if placed back into the soil. The torn part at the base should be treated just like described above.
Harald
Re: Sickly Little Friends! (mealybugs and then some?)
Thank you so much for the information!!
I'm a bit confused about your suggestions for my bunny ear. What part am I cutting? Just the shrivelled bit at the top? Or the whole pad?
As for the second plant, the body itself looks very healthy, which is what confused me so much about his demise! I don't believe any rot is present-- I think he was most likely root bound, considering my lack of experience and the fact that every plant I've bought from that grower has been root bound. Should I make a cut anyway, or just leave the plant for a week of so then place him back in the soil to form new roots?
Thank you so much again!!
I'm a bit confused about your suggestions for my bunny ear. What part am I cutting? Just the shrivelled bit at the top? Or the whole pad?
As for the second plant, the body itself looks very healthy, which is what confused me so much about his demise! I don't believe any rot is present-- I think he was most likely root bound, considering my lack of experience and the fact that every plant I've bought from that grower has been root bound. Should I make a cut anyway, or just leave the plant for a week of so then place him back in the soil to form new roots?
Thank you so much again!!
Re: Sickly Little Friends! (mealybugs and then some?)
Hello Kira,
With a prickly pear cactus (Opuntia sp.) that does have small pads, you can go ahead and just twist the pad. It will break off at the narrow (constricted) part, which connects one pad to the other. The place to cut is the narrow part at the base of the pad. That part is not flattened like the pad itself, but round in shape. There is a natural weak spot in that region. If an animal were to run into a prickly pear cactus with enough force, the pad would break off at that location. You could also use a knife with a clean blade and cut through the stem section. A smooth cut is better for the healing process than a frazzled one. However, this kind of cactus is forgiving. Either way will be fine. If in nature a pad is broken off and falls to the ground, the pad will form roots from the areoles touching the ground. Where I live, prickly pear cacti are quite common and can be almost considered to be invasive plants. So you cannot do anything that would easily kill them.
As for the Mammillaria spinosissima, if the bottom of the plant is firm. All you did lose was the major root (tap root). After the wound has healed, you can go ahead and place the plant back into a pot. However, do not keep the soil too wet, because the plant is not able to take in much water, until new roots have formed. You do not want the cactus base to be sitting in mud. I have noticed, that cacti will even form roots, if they are not in contact with soil. However, those roots will die off, if they do not have a place to go.
Harald
With a prickly pear cactus (Opuntia sp.) that does have small pads, you can go ahead and just twist the pad. It will break off at the narrow (constricted) part, which connects one pad to the other. The place to cut is the narrow part at the base of the pad. That part is not flattened like the pad itself, but round in shape. There is a natural weak spot in that region. If an animal were to run into a prickly pear cactus with enough force, the pad would break off at that location. You could also use a knife with a clean blade and cut through the stem section. A smooth cut is better for the healing process than a frazzled one. However, this kind of cactus is forgiving. Either way will be fine. If in nature a pad is broken off and falls to the ground, the pad will form roots from the areoles touching the ground. Where I live, prickly pear cacti are quite common and can be almost considered to be invasive plants. So you cannot do anything that would easily kill them.
As for the Mammillaria spinosissima, if the bottom of the plant is firm. All you did lose was the major root (tap root). After the wound has healed, you can go ahead and place the plant back into a pot. However, do not keep the soil too wet, because the plant is not able to take in much water, until new roots have formed. You do not want the cactus base to be sitting in mud. I have noticed, that cacti will even form roots, if they are not in contact with soil. However, those roots will die off, if they do not have a place to go.
Harald