Hi. I posted the same message with a photo on a different forum. I couldn't post a photo with this message because I didn't have the resizing software at the time. I suspect that they are butterfly eggs. I found one in my grapefruit mint yesterday. Didn't have my camera with me, or else I would have taken a photo it. Here is a link that might be useful: Insect eggs (57 k)

Thanks for the response.....The black things are hard and cannot be squished and they are easy to just brush off the lilies....Most appear at the joint where the leaf grows out of the stem and in some places there is only one and in others, there appears to be a cluster of the little black "cannonballs"....Can anyone shed any light here??? Joyce

Have had issues with brown sticky bug larvae all over the window screens for a while. Anything I tried to remove it either flat out didn't work , or, worked but also removed the color from the aluminum screen from dark gray to bright aluminum. Finally this fall tried using clorox spray and cleaner for tubs and showers. UNBELIEVABLE!!! Spray the insect larvae from both sides and brush both side with a tooth brush. Wipe clean and repeat. Then brush the whole screen with a dust pan brush and it looks brand new. Also trying another trick of spraying the screens with deep woods off before this happens next year. Supposed to keep the bugs off the screens.

You could just yank the plants and set them aside, somewhere out of the way. These types of wasps are pretty secretive, they tend to crawl around on plants hunting for things to eat (most eat caterpillars, which is why they are good to keep around). They are the type that fly around up where we would see them. They look like any other paper nest building wasp only they are usually much smaller. The nest just need to be kept out of the rain, which is why they are on the underside of the leaf. They should hatch soon and wander off.