Feb 15th, 2009
The Fly that Injects Its Eggs Into Orchids
The Cattleya fly is among the the most ruinous of pests that can assault your orchid greenhouse.. As a matter of fact, this pest is intimately 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 orchid plant’s young growths. The eggs hatch, with the nymphs (or maggots) going to work right away, feeding voraciously. The nymphs quickly grow to a grotesque size inside the bulbs. One signal that these maggots are doing their dirty work is that the bulbs will swell becoming club-shaped at the part where the pests are munching away.
Finally, the nymphs metamorphose into adult flies, which munch their way to the outside by chewing through the flesh of the bulbs. Adult flies are black, have clear wings, and are approximately a quarter inch in length. Unfortunately, by the time you see them it could be too late to rescue some of your plants. Nonetheless, you should attempt to kill the flies before they can get a chance to inject their eggs into your remaining healthy plants.
If you have plants that are already infested, the best remedy is to cut away any bulbs that are seen to be swelling more than seems natural. Then, drop the nymph or maggot into a bowl of 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 some luck, that plant that you did surgery to will produce a new bulb in place of the old one.
Now for the good news about Cattleya flies. They are actually not very common, and most orchid cultivators will never encounter them. Regardless, it is just good practice to carefully examine every new orchid for the signs of these flies and their maggots. Besides looking out for abnormally enlarged bulbs where the fly’s nymphs might be eating, inspect for tiny holes where a female fly’s ovipositor might have inserted eggs into the plant. Absent such signs, you probably do not have a Cattleya fly problem.
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 want to believe, especially if you first read up on how to properly care for these fascinating plants.
The most accurate and clear guide to today’s orchid gardening, many growers agree, is Orchid Care Expert by Nigel Howard, which is available to be downloaded online. Mr. Howard’s guide is a complete course all to itself, suitable for the novice as well as the more experienced. Also, visit the Orchid Secrets website, which is publishing a growing library of information on many aspects of orchid cultivation.
