Don’t worry! It is rare for a pest outbreak to result in the death of a plant. Sometimes it is best to cut your losses and chuck the plant out, but that’s the exception, not the rule. The key is vigilance, using your chosen method of pest control promptly and targeted properly. It is about population management, not eradication. An obvious but usually overlooked tip is to make sure your plants don’t touch each other and to wash your hands and tools regularly during your maintenance routine.
Take time to pick up and inspect each of your specimens thoroughly every fortnight. Look under leaves, between pseudobulbs, check the base of the pot. Remove papery leaf sheaths to take away hiding places. You can also consider putting your plants in the shower for a good wash. This will clear dust from them as well as dislodging quite a wide range of pests and drowning them. If you’re brave enough to join your plants in the shower, your soapy suds will help.
I have tried every chemical control under the sun in my effort to eradicate pests and I have found that none of them work particularly well, many of them damage the plants more than the pests do, and they are becoming increasingly expensive. I have found through experience that a very small arsenal of relatively harmless household chemicals will do the trick for most pests.
Methylated spirit It is always a good idea to have a bottle of methylated spirit/rubbing alcohol on hand for sterilisation of tools and to dip cotton wool in for hard-to-reach areas on plants. This method is very good at killing pests and the alcohol evaporates away, desiccating the pests with it. Critters such as mealy bug and scale insect are very good at hiding in hard-to-reach areas, but alcohol is even better than water at getting into those places. Use it with caution though, because it can mark plants unless properly diluted.
Soapy water Soapy water is by far and away the most effective form of pest control in my arsenal. It lowers the surface tension of the water and drowns critters. You can use any reasonably unscented soap for this. I did read that detergents should be avoided but I see no reason for this. Washing up liquid works well. You want the water to feel ‘soapy’ between your fingers. You can buy specialist products that are soap based to do this job, but they are expensive and to my mind, not so effective. Most recently I am using unscented washing liquid, such as is used for clothes. It comes in a little dissolvable sachet and will fill two spray bottles with solution of the correct strength. You must be persistent with it, though, and spray every time you see evidence of pests, and you should also be thorough and spray every part of the plant that you can until it drips. For persistent attacks of scale, you can use an old toothbrush dipped in soapy water to gently clean rhizomes and pseudobulbs – very useful on Cattleya and other more robust plants. Be careful not to spray flower buds or open flowers with anything as even water can mark them.
Carnivorous Plants. A novel way of controlling some pests (and fuelling our plant habit) is to grow a few carnivorous plants alongside our orchids. They are very good at attracting and consuming flying insects, especially fungus gnats and I imagine they would be useful for some types of thrips, too. There will be no control of mealy bugs or scale via this method. If you grow warm as I do, consider varieties of Nepenthes or Pinguicula which will enjoy similar conditions to your orchids. If you grow cooler, you can grow Dionaea, Sarracenia or Drosera. Be aware that these types may require a winter rest period, but this should coincide nicely with that required by your orchids.
