Cactus Advice

[hegar]

Now, after giving some cactus advice repeatedly, I also want to ask someone on this forum what their thoughts are about three of my cacti.
The first is a Mammillaria grahamii, that I purchased only in April of this year. Although it is flowering right now, I noticed, that the side that does receive the afternoon sun is not round like the opposite side. I hope, of course, that this does not indicate a rot and pending death of the plant.
What would you do? Should I dig the plant up, which would perhaps set it back or just leave it in place?
The second plant is my big Gymnocalycium baldianum. This cactus has flowered beautifully for several years and this year took a turn for the worse. We did have a long string of 100 plus degree Fahrenheit temperatures without any rain. The sun can be brutal. The plant has lost all its grey-green regular color. Do you think, that it will revive or is it a goner?
The third question is about a large Echinocactus texensis plant. I do have a big ant colony, that decided to live right where it is. They have formed a mound of sand around the cactus and covered part of it. The nearby Tephrocactus papyracanthus plants are almost totally covered.
Should I not worry and perhaps just fight the ants or would it be best to dig up the big cactus and check out its root system. I had ants do their business near a Leuchtenbergia principis plant and that cactus went downhill and died. Do ants kill cacti at times or are they just a nuisance?
I am attaching digital images showing all three plants the way they looked today.

Harald

[cactushobbyman]

The Mammillaria grahamii may have received some damage to the growth point. Maybe it is starting to pup. Hard to tell from picture. The Gymnocalycium baldianum does appear to be toast, dig it up and check. If your lucky, maybe a real bad case of sun burn. Ants, we are on our 8th day over a hundred degrees and the ants just keep going. With me, I will disturb the mound and let them attack, then spray. I use RAID. If they come back I will repeat. Some of the spray gets on the plant; so far no damage, but outside in my yard with full sun it's hard to find a plant without sunburn or other damage. I water every two weeks in my garden so I'll use granular bait also. They appear to be more active after a good watering. I also notice September and October they make an extra effort to invade my house. If we are lucky we get a good rain about that time.

[Steve Johnson]

The Gymnocalycium baldianum does appear to be toast, dig it up and check.

Sadly, I have to concur with CHM on this one. Harald, if you wouldn't mind some shameless self-promotion, I'll show you something disturbingly similar on a Weingartia I lost:

http://www.cactiguide.com/forum/viewtop ... 40#p324654" onclick="window.open(this.href);return false;

Ants in and of themselves are not cactus pests, although they will feast on fruit if/when the fruits split open and show their moist, sweet contents. Not the worst thing in the world, but ants can be a potential problem since they act as vectors for the transmission of mealies (as they also do with aphids). With cacti being grown in the ground, IMO that would be enough to warrant taking remedial action if possible.

[Ivan C]

Ants in and of themselves are not cactus pests, ...

I have to disagree, Steve. I have had ants nibble and do quite a bit of damage to the roots on a couple of very old Echinocactus grusonii for the last couple of years. My solution was to fill a 50gal pail with water and add dish detergent. I dunk the grusonii in and leave it soaking for hours. It still requires a strong water spray once removed to completely clean it of ants. Then, of course I leave it for 2-3 weeks to completely dry. I also set ant traps after and that work quite well. I also have the same problem and solution to my Haworthia attenuata. For some reason the ants love these two especially, but I have to be vigilant because once you move them from their home they scramble to find/make a new one.

[hegar]

Thank you very much for the advice thus far. I am going to enjoy the Mammillaria grahamii plant at least until it is finishing its flowering cycle. There are a few more buds that should open up within the next few days. The plant was a cactus that was rescued from the bulldozer by one of our cactus club members. I purchased it in April for $3.00.
The Gymnocalycium baldianum plant I will leave in the ground for perhaps a couple of months longer, before I am going to yank it out. I too do not have much hope, especially, because my "purple Echinocereus pentalophus" is already showing some green on its stems. The G. baldianum plant had been in place for four or five years and had grown considerably larger than when I purchased it. However, this summer did have so many successive super hot days in a row and the tree, that used to give it filtered light is slowly dying, allowing more light than usual to reach the cacti underneath. Its vividly bright red colored blossoms will be missed and I hope, that I can find a replacement plant.
I looked at your Weingartia brevispina plant, Steve, and it looks like it has been boiled. What a shame!
I most likely will try to eliminate the ants. As Ivan notes, I too have the suspicion, that ants are not always either beneficial or neutral to plant life. I know, that these insects do move and protect aphids, in order to feed on the honey dew that these insects excrete. I also could imagine, that ants will chew through plant roots, if they are in the way of their underground home.
Earlier in the year, ants were all around my Ariocarpus spp. plants, piling up mounds of sand on top and around them.
I did give them a good dose of insecticide and they seem to have died or moved on. I rather have them near the big Echinocactus texensis, but I still do not even like them anywhere near my cacti.

Harald