Bugs & What to Do About ‘Em
If you have orchids, you have bugs – at least, once in a while.
They’re tiny and sneaky, so it’s important to check your plants as you water them, so you can curtail any infestations before they get serious.
For me, bugs tend to show up more often in the winter, as my windows aren’t open. Orchids need air circulation and indoors, I sometimes forget to turn on a fan to compensate.
This month, I’ve encountered a double-dose of gross:
Mealybugs (seen above) look like white powder or cotton, often burrowed into the angles where leaves connect with stems. They suck the juices – and therefore, nutrients – right out of the leaves.
Scale (seen at right) is an insect related to the mealybug, although they look nothing alike. The type of scale I've seen most often is a tiny, brown dot found on the undersides of orchid leaves. 
Luckily, killing these pests is fairly easy. Just wipe them off the orchid using cotton swabs and rubbing alcohol. I prefer the cotton swabs used for cosmetics – pointed at one end, round and flat at the other. Leave no leaf unturned; don’t stop until you’re sure you get every last one!
To keep bugs away, some folks spray their orchids with a Neem oil solution; others spray a solution of rubbing alcohol (1 part) to water (9 parts) or use insecticidal soap. You'll find a good summary of tips (if you can handle the photos – ugh!) on the Get Busy Gardening website.
The most important thing is to isolate the infected orchid so the bugs don’t spread to your other plants. I’ve designated one windowsill as “the hospital,” far away from the others, where buggy ones go to heal up. I check them more often, spray them regularly, and they don’t rejoin the general population until I’m certain they are pest-free.
It’s also a good idea to isolate any new orchids you bring into your home or greenhouse until you’re sure they don’t have bugs. Getting rid of them is a real pain – but it makes much more sense than getting rid of what would otherwise be a beautiful, healthy plant.