Just the word causes fear in the minds of many orchid hobbyists. The safest approach is to use common
sense. That means don't drink it, don't get any on your body, don't breathe it, and make the exposure no
longer than necessary. Most insecticides that are available at you neighborhood nurseries are fairly safe
to use. Again, that's with common sense. Most insecticide labels won't list orchids as one of the plants that
can be sprayed with it. If it ornamental plants listed then it should be O.K. for orchids, so don't let this
worry you. I'm not going to list any certain type of insecticide to use. You should find this out for yourself
by talking to an experienced grower to learn what insecticides to use for a particular pest.
You should stay from any insecticide that isn't available from your neighborhood nursery. There
are many brands on the market that are available to commercial growers or to people with special permits.
These are the ones that you shouldn't fool with.
The label on insecticide containers will tell you how poisonous it is. The label that says CAUTION is
the least poisonous of the insecticides. Next is the label with WARNING on it. This is the middle of the road
poisonous. The greatest danger in insecticides is the label that says DANGER on it. These are the deadly
ones. So, stay with the ones with "CAUTION" on the label.
There are two basic types of insecticides that are being used by hobbyists. The CONTACT type
and the SYSTEMIC type. The contact type is just that, it must make contact with the insect to kill it. If the
insect is on the bottom of the leaf and you only spray the top then you haven't done any good and wasted
your time. The systemic type means that the plant absorbs the chemical into the internal parts of the plant
and kills the insect from the inside out. The insect draws in the chemical and dies (hopefully). That may be
a problem. Does an orchid absorb enough chemical through the leaf surface to be effective? I don't think
so. You would have to drench the whole plant, pot, roots, and foliage to be effective. If you use a stronger
dosage of chemical you just might screw up the plant. Use only what the label calls for. One of the more
popular systemic insecticides is now labeled as a soil drench.
That brings up another problem, the growth cycle of any insect. They start mostly as an egg, then
hatch out to a larva stage and then develop into an adult bug. Most insecticides will only kill one of these
stages of growth. Kill out the adults and there are still the eggs and the larva developing. So it becomes
necessary to spray at least three times to cover all the three stages (bug generation) of insect growth. It
helps to know the life cycle of the bug you are trying to eradicate. Then you can time your sprays
accordingly. I try to spray once a week for three weeks in a row. Then wait three weeks and see how
effective it was. If insects are still with you then repeat as necessary. If you get the infestation under
control then do a preventative spraying about every 3 months. More in the summer and less in the winter.
There has always been the question, should I spray even if I don't see any insects? I think you should
because once the damage to your plants has occurred it's too late and this is what we don't want. It's like
the old saying, "Shut the gate after the horse is gone". Maintaining a clean orchid collection is with effort.
The orchid collection that is in dire need of repotting is usually the buggiest. Repotting your plants helps
them stay clean and healthy.
The greatest danger in using insecticides is to the farm worker and the nursery worker who is
exposed for long periods and day after day. For you: Read the label, and be sure to wear rubber (latex)
gloves for sure. Don't use spray equipment that puts out a mist. The best kind is a hose-end spray mixer
that puts out a fan shaped spray. These will put out a lot of mixed spray in a very short time. In just a few
minutes you can be done and out of the area.
This is a very basic explanation of insecticide use without naming any brand. Remember to read
the label and use only the amount that the label calls for any certain insect. If the label doesn't list the
insect you want to eradicate then don't use it, it won't be effective.
Change to a different type often so the insect won't get use to the same one. Most insects will build
up immunity to an insecticide if used too often.
Well, that's about enough of sticking my neck out about a subject so sensitive. If you still don't want
to use a chemical insecticide and you only have a few plants, then use some mild soapy water and a soft
brush to clean the bugs off your plants. You probably won't completely get rid of the bugs, but you will feel
good about yourself. Don't use a stiff brush, you might break the surface of the plant and could spread
viruses this way. Oh my!, Viruses!, another problem, oh well, it's been said that orchid growing isn't easy.
By: Richard Swift
Insectcide
From Calwest Tropical Supply
May 6,2011
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