Q. I planted a Sephora secundiflora in my backyard
about 17 years ago. Today, I noticed many of the stems are infested with an
insect that looks like a type of scale to me. The stems and leaves below the
infested stems look wet and sticky. The
pavers underneath the plant are also wet and sticky.
about 17 years ago. Today, I noticed many of the stems are infested with an
insect that looks like a type of scale to me. The stems and leaves below the
infested stems look wet and sticky. The
pavers underneath the plant are also wet and sticky.
 |
| Those small red bumps on the branches of Texas Mountain Laurel, Sophora secundiflora, are insects |
A. Your picture helped
tremendously.
tremendously.
Those red bumps are scale insects
Yes, you are correct. These brown, round bumps on the stems are scale
insects. I have never seen these on Sophora,
Texas Mount Laurel, before and I could find no reports of scale insects on this
tree from anywhere. Scale insects provide a food for ant colonies, as do
aphids. It’s mostly sugar from plant sap. That’s the sticky wetness you are
seeing. Ants have a vested interest in protecting and colonizing ant and scale
populations because of this sugary, sticky wetness.
insects. I have never seen these on Sophora,
Texas Mount Laurel, before and I could find no reports of scale insects on this
tree from anywhere. Scale insects provide a food for ant colonies, as do
aphids. It’s mostly sugar from plant sap. That’s the sticky wetness you are
seeing. Ants have a vested interest in protecting and colonizing ant and scale
populations because of this sugary, sticky wetness.
 |
| Horticultural oils are pesticides made, typically, from a refined mineral oil. |
.
The most effective control of scale insects are repeat stem
sprays of horticultural oils. These sprays should be applied several times during
the cooler times of the growing season. Combine this spray with ant control in
the same area.
sprays of horticultural oils. These sprays should be applied several times during
the cooler times of the growing season. Combine this spray with ant control in
the same area.
 |
| Aphids and ants on apricot in Tajikistan |
Ants move scale insects around, much like they do aphids,
to different plant parts and even different plants. They contribute to the
spread of scale insects in trees and shrubs and can turn a minor problem into a
major problem in a couple of months.
to different plant parts and even different plants. They contribute to the
spread of scale insects in trees and shrubs and can turn a minor problem into a
major problem in a couple of months.
 |
| Some Amdro products are ant baits and can be used to kill an ant colony that is spreading and protecting insects producing sugary exudates like scale, aphids and others. |
Controlling ants
When
controlling ants, use a poison bait in locations where there are problems. If
there are no problems, no control treatment is necessary. Ants play a positive role
in protecting plants from other insects.
controlling ants, use a poison bait in locations where there are problems. If
there are no problems, no control treatment is necessary. Ants play a positive role
in protecting plants from other insects.
An insecticide called Amdro, an ant bait, has been
effective in controlling the spread of aphids by controlling ant colonies. I
see no reason why this treatment would not also control the spread of scale
insects. You can find Amdro ant bait at any garden center or nursery.
effective in controlling the spread of aphids by controlling ant colonies. I
see no reason why this treatment would not also control the spread of scale
insects. You can find Amdro ant bait at any garden center or nursery.
Most of our ants live in the ground in colonies. Identify
the soil opening or openings to these ant colonies and spread 15 or 20 granules
on top of an ant mound. Ants take this poisonous bait into the underground nest
where it kills the entire population in 24 to 48 hours. The area where it’s
applied must stay dry for 24 to 48 hours to work. Make sure the label of this
product fits the needs at your site before applying it.
the soil opening or openings to these ant colonies and spread 15 or 20 granules
on top of an ant mound. Ants take this poisonous bait into the underground nest
where it kills the entire population in 24 to 48 hours. The area where it’s
applied must stay dry for 24 to 48 hours to work. Make sure the label of this
product fits the needs at your site before applying it.
When to spray horticultural oil
Horticultural oils are sprayed over the entire tree, top
to bottom, if temperatures are below 90° F and no flowers are present.
Repeating this spray three or four times during the growing season provides
nearly 100% control of scale insects.
to bottom, if temperatures are below 90° F and no flowers are present.
Repeating this spray three or four times during the growing season provides
nearly 100% control of scale insects.
Follow-up with soap and water sprays
Apply soap and water
sprays to the tree 7 to 10 days after the horticultural oil application. Soap
and water sprays kill any young nymphs that eluded the oil application. Remember,
soap and water sprays, just like oil applications kill all insects sprayed,
good or bad. Direct soap and water and oil sprays only to locations where there
are problems.
On my Texas Mountain Laurel, every year, I get caterpillars that form webs and eat the leaves. Any advise on controlling those? I just try to cut the leaves off that they are on, but they do damage every year.
Every spring, my Texas Mountain Laurel is attacked by caterpillars, so I spray the tree. In years past, I have used an insecticide, but when it blooms bees are present so I switched to bacillus thuringiensis (Bt) which does harm other beneficial insects. It seems to have worked better than other approaches this year. The damage was negligible.
another person responded about controlling caterpillars in Texas Mountain Laurel so I didn't reply to you right away. I posted something about it awhile back
http://xtremehorticulture.blogspot.com/2014/06/caterpillar-webbing-on-texas-mountain.html