I have seen many kinds of succulents deformed by the ravages of mealy bugs.

I have seen cactus also deformed by mealy bug activities. I have talked

about mealy bugs in general, but now I would like to address spine mealies.

I have seen my share of ‘spine mealies’. I was at a large commercial cactus

nursery one time and an entire 90-foot-long bench of plants was covered in

white ‘spine mealy bugs.’ I was horrified as were some other people in the

group that was there. I am sure that the owner had taken care of spraying

the bugs, but I do not know for sure. It was not till I joined a cactus club

that I heard of spine mealy bugs. (This was about 40 years ago that I joined

a Cactus and Succulent Society. (I think some people get upset when it is

called a cactus club). Where I lived before, I had never even heard of a

cactus club or succulent society as they are called. I think people looked

down on anyone that had a cactus plant that had spine mealy bugs or any kind

of mealy bugs. If anyone brought a plant in for the mini-show or even a

regular show and sale and it had even one white spot that looked like a

mealy bug, the plant was banned.

 

Spine mealy bugs are a terrible thing for a cactus plant to have on them. I

got to thinking about spine mealies and wondering where they come from. I

have seen that they can show up overnight. I have not seen one with wings so

how can a plant that has no mealies one day be covered the next day? Why is

it a lot of the time they are only confined to one plant? Root mealies, I

know get their food from drilling holes in the roots and sucking them dry.

But what do the spine mealies live on?

 

I got a strong magnifying glass and I found a spine mealy that was willing

to talk. I saw that it was carrying several tools and some water bottles. I

asked Mrs. Bug what she was up to. She said she was going out on a nice

large spine and was going to drill several holes in the nail hard, dry spine

to tap it for juice to drink. You know, like people do sugar maple trees to

get the sap for syrup.  She showed me the hand drill and the bits she uses.

She also takes some corks to stop up the holes she drills so they will not

leak and let the spine go dry. When she has all her containers full of spine

juice, she can go hide and drink all she wants when she wants. I asked her

why all the spine mealies were left hanging on the spines. She explained

that those things people call spine mealies are only egg cases that are hung

on the spines to dry and to have a place for the eggs to hatch.

 

Now as you can probably tell that is almost a true story. For there is no

such thing as a spine mealy bug- or spine mealie- or spine mealies! If a

person happens to see a live mealy bug on a spine it is either going out to

lay eggs or it has laid eggs and is heading for cover of wool or whatever

other place it can hide for the day, before it goes back down to the roots.

In all my years of growing cactus I have never seen a mealy bug sucking any

sap out of a spine. The spines may grow for a little while after emerging

from the grow point of the plant. But they are too hard for any mealy bug to

stick its snout in. After emerging the spines very soon become hard and they

get as hard as nails. They are stiff and as they harden; they get very hard

and there is no sap in them for mealy bugs to feed on! What are called spine

mealies are really root mealy bug egg cases. Root mealies that have come up

at night to lay their eggs in sacks they glue on the spines. The eggs are

laid in a sack that hangs on the spines. It is these egg sacks that people

are calling spine mealies.

 

Mealy bugs are like aphids; they find soft plant material and they stick

their snout in the area and they then feed on sap of the plant. Mealy bugs

will feed on about every plant on earth if they have a chance. Our neighbors

had an apple tree, the trunk was white with mealy bugs. The tree was removed

roots and all. For over 40 years I have heard of two kinds of mealy bugs.

Root mealies and spine mealies. For succulent growers, cactus are

succulents, but most cactus growers do not call their cactus succulents, In

the minds of pure cactus growers, those plants with leaves and caudex, are

referred to as cabbages and turnips. They are succulents. Even the plants

like Euphorbia and other plants that have spines people still call them

cactus. People that go to a store and see a display of only succulents still

think all the plants are cactus even if there is not a cactus plant there. I

have seen many people call Lithops cactus. I think the most common succulent

that is called a cactus is the common every day Echeveria. Mealy bugs love

any cactus or succulent that they can stick their snout into and start

sucking its juices. The nice juicy leaves of Echeveria and succulent stems

of Stapelia seem to be some of the favorite plants’ mealy bugs like to suck

on, though any soft skinned plant will do.

 

Years ago, I worked in a cactus and succulent nursery. I mainly took care of

the cactus as the succulents were the owner’s wife’s babies. When I went

after mealybugs on the cactus I was not allowed to go after any on the

succulents. One time I watched as she delt with mealy bugs on a rare

Echeveria. I had pointed out to her that the plant had mealybugs on it. That

did not go over very well, she said that she would cure that problem. Back

in those dark ages, rubbing alcohol mixed 50/50 with water was the going way

to rid a plant of mealybugs. She sprayed the plant with the 50/50 mix. (I

worked at the nursery two days a week and on occasion three days) I did all

the watering of the cactus plants which took up about ¾ of the plants in the

business. After being gone the rest of the week when I came in the next

Monday morning, I saw that there were mealy bugs on the plant again. This

time the owner’s wife took the plant in the back and sprayed each leaf top

and bottom. She must have done a good job for the next week there were no

mealy bugs on the plant. But the next week the bugs were back, and quite a

lot of them, and they also were on an adjacent plant. I mentioned the bugs,

the plants just disappeared like magic for I never saw them again.

 

In the war against mealy bugs back as far as I can remember, the stand by

treatment was and still is 50% rubbing alcohol and 50% water. This is in a

spray bottle and you spray the bugs you can see. (That is mainly the egg

cases which the eggs may have already hatched.) Some people, that may only

have a few plants, will use a Q-tip dipped in the alcohol/water mix and they

will touch each mealy they see.  After trying that several times, eons ago,

I gave up on that. A friend that has a large nursery told me that she saw a

live mealy bug walking on the table where she was working. She put a drop of

alcohol on it, the bug stopped in its tracks in an instant. She said that

after about fifteen minutes she looked and the alcohol had evaporated and

the mealy bug was walking away. I believed the person for she is not up to

lying about such things. I also gave up on straight alcohol as it seemed to

do no good on any of my plants. Back in what seems like the dark ages people

started talking about using a systemic product called Cygon 2E. That was a

brand name for Dimethoate, a good systemic soil soak and spray.  In its love

for its citizens of the good old USA, the government figured we are too

stupid to know how to use the stuff and so off the market it went, that was

quite a few years ago. I got a permit and for years used dimethoate, it is

used for mealy bugs at a rate of 1 pint to 100 gallons of water. I would

fill a 55-gallon barrel with 50 gallons of water with 1 cup of dimethoate.

Using a sump pump I went after mealy bugs.  The dimethoate is good but it

sure stinks. I have now found a product that is quite concentrated and to 50

gallons of water, ¾ of an ounce is used. It is a contact and systemic poison

for the mealy bugs. I have talked to people that complain that they can

never get rid of the mealy bugs. They use a systemic and the bugs disappear

for a week or more and then they are back.

 

Over the years I wondered about how well the dimethoate was doing. I thought

it was doing good but was I getting enough of it in to the plants. Let us

say that you have a Turbinicarpus polaskii that is 1 inch in diameter. You

see mealy bugs on it and you have a barrel of what I call bug juice mixed

up. You water the plant with the mix and you make sure the plant is soaked

and that the root ball is soaked. The plant is in a 2.75-inch pot. If you

are lucky enough that one watering will poison the plant enough for the

mealy bugs to be killed. A plant the size of a grapefruit or even one the

size of a cantaloupe, will one watering of systemic be enough to poison the

plant enough to kill all mealybugs?? I say “NO!” Two things are going on,

one is, the plant is mostly water and even if the plant is in a 6-inch pot,

that one watering will not give enough poison to poison the entire plant.

With one watering the plant may get just enough poison to make the bugs

sick. Watered like that, the mealy bugs may only get immune to the poison,

as does happen. The other thing is when people water, they see the water

start to flow out the bottom of the pot, they figure the soil is soaked

through and through. About 98% of the time this is not the case at all. Only

the outer portion of the root ball had gotten wet or maybe even only damp.

Any mealy bug it comes in contact with will be killed the rest go right on

living to suck the plant dry.

 

50 years ago, I had a Homalocephala texensis that was over 6 inches in

diameter, I could not get that plant to healthy up. I tried and tried using

different ‘tricks’ of the trade, nothing, not even full-strength fertilizer

would help the plant to get healthy. At the time I was using a granular

systemic that worked very well on smaller plants. After about a year and

half I got mad and dumped the plant out of the pot and removed the soil.

Where the roots grow from the plant, the plant was concave all around the

root. In that concave area was a city of mealy bugs. The area was about 4.5

inches across and in deepest place the bugs were ½ of an inch deep. The ring

of mealy was about an inch and a half wide. That day was mass murder of

mealy bugs. I still have that plant and it is the largest Homalocephala

texensis that I have seen.

 

I started watering with, to me, a new product (Imidacloprid) and I really

poured the water to the plants. The water flowed out the bottom of the pots.

I know that when a root ball has dried for two or more weeks that it shrinks

and the water will flow down the outside of the root ball and the inside of

the pot. The first watering will only swell the root ball a bit and maybe

enough so the water does not flow out so easy. Several fillings of the pot

and most people figure the entire root ball is wet. I have taken 2.75 inch

up to 6-inch diameter pots and dumped the plants out an hour after being

watered. The water may have soaked in ½ to ¾ of an inch into the root ball,

the soil in the middle of the root ball was dry as powder. When I poured the

water to the plants over and over, I started to notice mealy bug egg cases

on plants I have never seen a mealy bug or the egg cases on before. I figure

that the bugs were there all the time but never showed up on the plant.

 

One thing I did notice was most of the plants started looking much better

after the 4th soaking with the systemic poison. It was frustrating to have

so many plants suddenly have mealy bug egg cases on them. But it let me know

that I was finally making head way on killing mealy bugs. I have seen that

when a plant is really watered even with only water the mealy bug egg cases

will show up on the plants. Another thing I discovered is watering with

systemic or poison will also make mealy bugs head for the spines to lay

eggs. In the one case the bugs may think they are being flooded and better

get top side and lay eggs. In the other case they can get just enough poison

that they get sick and head up to lay eggs.

 

I have a Coryphantha elephantidens form that has just sat and none nothing

for some years. Then I noticed that the main stem was dying. I meant to take

it and inspect it but did not get around to it. After watering with the

systemic bug juice over and over I saw the plant needed some help. I tipped

the pot on its side and the plant fell out for most of the plant had nothing

in the way of roots. The plant came out as several different stems. Some had

no roots and others had a root it was trying to grow since the killing of

the mealy bugs. The underside of the stems was white with dead mealy bugs. I

mixed up some strong systemic and dipped the plants about five times each

stem. I let them soak for about a half hour. When dry I soaked them again. I

did that for two days. As I hate mealy bugs and when I figured they were

more than dead, I went and blew the mealy bugs off the plants with

compressed air. (It was mostly mealy bug egg cases and a few dead mealy

bugs). I blew a lot of them off but some are really glued on the plant.

 

Photo 1 is the root end of a stem; it was white with ‘mealy bugs and egg

cases.’ I blew most off before I thought I should have photographed the

stems before blowing the bugs away. If you look closely, you can see a lot

of what looks like mealy bugs mainly on the spines. Those are not mealy bugs

but mealy bug egg cases glued to the spines. These egg cases are glued on so

firm that they have to be scraped off one at a time. Also notice that the

stem has no main root. The mealy bugs sucked the root dry and what was left

rotted away. There are nubbins of roots that started to grow after the mealy

bugs were poisoned. Photo 2 is the top of that stem and there are mealy bug

egg cases glued to the spines and even in the growing center.

 

Photo 3 is of another stem. This stem was worked over by the bugs like the

stem in photo 1. This stem tried to make a new main root; it also was being

attacked by the mealy bugs. Most of the feeder roots are only short nubbins

for they could not grow while being sucked on. Photo 4 is the same plant

showing lots of egg cases even after I blew 90 % of them away. This shows

that the glue the bugs use is quite strong for I used 120 PSI of air and it

would not blow the cases away. Photo 5 is of another stem. This one had the

fewest of the mealy bug egg cases on it. It did manage to grow three tap

roots from beside where the main tap root had been. Even these roots show

damage from mealy bugs working on them. Photo 6 is the top of that stem and

it is easy to see that the mealy bugs even got to the growing point of this

stem. Photo 7 is an offset from one of the stems. It is about an inch in

diameter and it tried to grow roots and the mealy bugs also kept its roots

from growing. What looks like mealy bugs are egg cases. The mealy bug got

some poison and decided to go up and lay eggs, if they got any eggs in those

small cases I do not know. But those really small egg cases show that the

mealy bugs were in a rush to lay eggs before they died.

 

Mealy bugs are not spine mealy bugs. The bugs cannot stick their snout in a

dry hard spine to suck sap out of it. There is no sap, water, juice, milk or

any other liquid in a hard dry spine for any mealy to feed on. The mealy

bugs are on the roots where they live till time to go up and lay eggs. They

glue an egg sack to a spine and then they go back down to the roots. If you

water a plant really well the bugs will make for the top of the plant as

fast as they can to lay eggs in case they are drowned. The same happens with

systemic poison, the bugs sense something is wrong and head up the plant to

lay their eggs before it is too late. Notice in these photos the egg cases

are small the bugs tried to lay eggs and made egg cases but did not or could

not lay the eggs for the cases were not filled. If a mealy bug figures it is

time to lay eggs and they are not being drowned or poisoned the egg cases

will be to about 8 to 10 mm long and filled with eggs.