PESTS & DISEASES
What To Look Out For!
Regular inspections of your Masdevallia will help identify any potential problems with regards to pest and diseases. Healthy plants are less likely to have problems with pests, fungal or bacterial infections or indeed viruses.
On arrival you should segregate new plants from the rest of your collection for about 2-3 weeks, I use SB Plant Invigorator on all new plants entering my greenhouse, just as a precaution to ensure they are not bringing in any parasites, or pests.
Remember pests are more active when the atmosphere is warm and dry and if you are growing plants in the home spray them every morning with tepid or R.O. water and/or stand them on a tray of pebbles with a small amount of water in to help with humidity. If you can, ensure there is good air movement around your plants as fungal problems are far less prevalent where there is good air circulation / Movement.
PESTS: The main pests you are likely to encounter are aphids, spider mites, scale insect and mealy bug. Believe me all growers at some point in their lives will have some sort of infestation and I for one recently had a bad outbreak of Boisduval Brown Scale recently show on my YouTube channel video (16) well worth a watch.
Thin leaf plants such as Masdevallia attract spider mites and aphids. You can check for spider mites by looking at the underside of the foliage which will appear to be silvery in colour as opposed to green. They are very small so difficult to see with the naked eye but a small magnifying glass will make these visible or a fine misting spray may show up their webs. Aphids are much more visible and familiar and secrete a sugary liquid which can turn into a black and unsightly fungus You can treat both spider mite and aphids by using a good quality pesticide, I use SB Invigorator on all my Masdevallia which seems to treat almost all types of pests, remember to follow the manufactures instructions and repeat the treatment after 10-14 days.
Tip! A good indicator is if you see ants on your plants, they are more than likely after the sugary liquid left by the Aphids, so have a good look at your plants.
scale insects can appear at any time, which can be either soft or hard shelled insects that are attached to the foliage of your Masdevallia leaves. Mealy bug is a soft bodied insect which looks like a very small wood louse and usually is visible as a cotton wool like material on the underside of the leaf, stems, sheaths, or indeed in the potting media. The best way to treat scale insect and mealy bug is by spray with a systemic insecticide like provado, much the same as with spider mites and aphids. If the extent of the mealy bug problem is small and localised you can use a cotton bud soaked with some Rubbing Alcohol to wipe away the insect. Other growers have their own methods for example a soapy water solution, I’ve tried this and found it did not control the infestation, basically from the old book school of orchid growing. So, get rid at the first sighting.
DISEASES: Most diseases are spread through insects so make sure your plant is pest free and when re-potting your plant always obtain your Media from a reputable seller / supplier. You should always use new pots or clean old ones in a diluted solution of bleach and, if you use any cutting tools, make sure they are sterilised before and after use either a naked flame from a gas lighter or rubbing alcohol.
Tip! Sterilise cutting implements before & after each cut, this way you will ensure you are not transferring the disease to other plants in your collection.
There are a number of diseases that affect Masdevallia orchids although in most cases the cause is as a result of unsatisfactory growing conditions, (your environment) If you follow the guidance at the top of this page you should avoid most of the problems but if you are unfortunate to suffer any problems the removal of infected plant (Quarantine area) may stop it from spreading. However, if your plant develops marks on the foliage and you do not know what they are you would be well advised to seek out an orchid expert.