Amany, this is interesting; I had the same problem with one of my Dieffenbachias awhile back. I went through all my plant books and searched through the internet - nothing. I never found out what these pests were back when I was dealing with them; still haven't. Anyhow, I washed the leaves of the plant and then soaked it for about fifteen minutes in a mild soap solution. I repeated this treatment two extra times and never saw them again. I checked the plants that it was next to and they hadn't been infected. This was about seven or eight months ago, so if they're migrating to another plant, they're taking a heck of a long time...LOL.

The infected Dieffenbachia had been newly-purchased and I'm sure that it came home with those pests. I'd bought a lot of plants during that period and hadn't been careful about inspecting them before taking them home. Thankfully, the problem was one that could be taken care of. Let's hope I learned my lesson... :)

Anyhow, I'm eager to see what the members on this forum will come up with. I'd really like to finally find out what the problem was. In all my years of growing houseplants, I've never seen these bugs before, and I've dealt with my fair share of pests!

They could be aphids.

Hi. Thanks for your responses.

Water_roots, I have never seen these bugs before either. jajm4, they don't look like the pictures of aphids I've seen online. I'm not sure what they are.

At any rate, I'll just keep spraying them down with soapy water for a few weeks. I hope they don't return or show up in another plant.

There's the possibility they might be thrips. Thrips can be green, brown, or black, are thinner and faster than aphids, and leave little black round fecal deposits. They rasp at the leaf surface and tend to leave brownish or silvery patches.

If that sounds like what you have, you can treat them like you would aphids. I like to both spray them with soap/alcohol/water mixture and use a soil systemic. Sometimes they can reappear when the next generation pops into being.

Whatever you have, good luck!

Hi Water Roots,

Did you soak the whole plant in soapy water or just the leaves?

Thanks,

Newby