I am new and have a problem with thrips!
 

Greetings to everyone!

My name is Renate and I live in Southern California, thankfully retired! I have grown orchids for about 4 years, but I know not much! Aside from a few scales, which I have been able to control by picking them off, I have a real problem with thrips that live in the potting mix of several pots. I would like to drench the pots in an insecticide solution. Is it safe to use malathion, even if the plants are currently blooming? They are mostly phalaenopsis, a couple of dendrobiums, a phrag, a couple of oncidiums.

I know that I will love this site as soon as I become more familiar with it. I look forward to chatting with some of you!

Renate

First let me say "Welcome to Orchidboard"!

I spray with Orthene for thrips. You have to spray once a week for three weeks to really get rid of them.

I try not to spray the flowers and do it in the early morning or late evening when the plants are cool. Add a drop or two of dish soap in with the Orthene.

I have never used Malathion, so maybe others will be along to comment on that.

:hello , Welcome to Orchidboard!!

I don't really think that it's thrips you're dealing with. They don't live in the potting mix, they live on the foliage and flowers.Thrips are also hard to notice as they are only 1-2mm long. How big are the bugs you are seeing?

They may be fungus gnats. The larvae live in the mix and the adults look and behave like fruit flies.

My concern is that the thrips and their larvae are living in the potting medium. That's why I am inquiting about a drench.

I have limited experience with orchids, but I do know a thrip when I see one. They are easily visible on a black tray under the pot. What I am looking for is information on drenching the pot.
I have always had problems with thrips on my African Violets. They come in from outside.
But thanks for your reply!

:hello Renate and welcome! I live in south Florida and thrips can be a spring time problem here. Martin Motes is a local expert who sends out a very helpful monthly newsletter (this mainly is for growing outside in South Florida) but here is his advice from the April newsletter:

"The warmth of April, alas, stimulates the growth of bugs as well as plants. Both thrips and mites thrive in the dry heat of April. Liquid dishwashing soap (at 2 oz per gal) will control both but be mindful that soap should not be applied to plants that are suffering from drought stress. Be sure that your plants are well hydrated before you apply soap. Water them extra hard the day before. To be effective soap must be used profusely. The plants should be washed in the solution to the point of wetting every nook and cranny of both the plant and its container. Only such thorough treatment can reach the reclusive thrips and be sure to touch all of the ever prolific mites. A second treatment at 7-10 days is necessary to control mites and a miticide such as Kelthane might be advised. Orthene which is the insecticide of choice for thrips (because of its residual action) is compatible with many miticides. Check with your county agent if in doubt." Hope that helps! ;)