The Cattleya fly is one of the most ruinous of pests that can assault your orchids.. In fact, this pest is closely associated with orchids rather than any other family of plant, as you could readily guess from its scientific name, Eurytoma orchidearum.
Cattleya flies deposit their eggs in the young growths of the orchid plant. The eggs hatch and then nymphs (or maggots) hatch and begin to feed voraciously. These nymphs soon swell to a huge size within the orchid’s bulbs. One signal that these maggots are doing their damage is that the bulbs will swell and become club-shaped at the part where the pests are eating.
Eventually, the hungry little nymphs are changed into adult flies, which chew their way through the fleshy bulbs to the outside. The flies are black in color, with clear wings, and measure around a quarter of an inch long. Unfortunatelyy, by the time you spot them it could be too late to salvage some of your plants. Nevertheless, you should always attempt to kill the flies before they can lay eggs in your remaining undamaged plants.
If you have plants that are already infested, the best course is to cut off any bulbs that are seen to be swelling more than seems natural. Then just drop the nymph or maggot into some water to drown it. It is discouraging to have to slice away a plant’s promising young growth, but it is better than leaving your other plants exposed to attack by the pest. With luck, the plant that you had to do “surgery” on will grow a new bulb in place of the old one.
Here’s a little good news, though, as far as these harmful little pests. They are fortunately not especially common, and most orchid growers will never see them. Still, it makes good sense to inspect every new orchid for the tell-tale signs of these flies and their maggots. Besides looking out for abnormally enlarged bulbs where the fly’s nymphs might be feeding, inspect for minute holes where a female fly’s ovipositor might have inserted her eggs into the orchid. If you don’t see any such signs, you are probably safe from Cattleya flies.
To be truly successful growing orchids it is important to know how to deal with all the possible threats to your plants, including insects. It isn’t as tricky to grow orchids as many people apparently believe, especially if you first read up on how to properly care for these fascinating plants.
The most accurate and clear guide to expert orchid care, in my opinion, is Orchid Care Expert by Nigel Howard, which is available to be downloaded from the web. Mr. Howard’s ebook is a thorough course, enlightening for beginners and more seasoned fanciers alike. Also, visit theOrchid Secrets site, which has a growing library of postings on many aspects of orchid cultivation.