I'd say that the first picture, with the Pentas, shows an infestation of aphids. The rosemary appears to have mealybugs.

If you do a quick Google image search, you can verify it....the images are a little wonky.

Possibly Aphids and maybe scale. Simplest method of control is a sharp spray of water.

http://ucipm.ucdavis.edu/PMG/PESTNOTES/pn7404.html

kimmq is kimmsr

I saw a mealy bug. I just squish them with my fingers. If you have alot of them use a cotton ball that was soaked in rubbing alcohol. Rub it all over the plant. Especially under the leaves.

If mealy bugs are present control can also be achieved with a sharp spray of water. Keep in mind that any poison meant to control insect pests could also do harm to the insects that predate them.

Rubbing alcohol has been shown to be quite harmful to plants.

kimmq is kimmsr.

Kimm, you are sooooo wrong. Sharp sprays of water will do nothing for scale or mealybugs or whiteflies. I know that you READ such recommendations, but it doesn't work in practice. Honestly, it doesn't work.

Also, alcohol is a highly successful remedy for many pest infestations on many plant species. It does NOT damage most plants when diluted properly. I've used it and recommended its use for 30-40 years. My method is to prepare a solution of one part isopropyl to three or four parts water. In a hand sprayer, it can be misted on the underside of leaves and in the nooks and crannies where these pests hide.

The alcohol must come into direct contact with the pest and will evaporate away in a very short time, causing very little, if any, problems for beneficials.

Avoid using alcohol dilutions in the direct sun, and on very sensitive plants. Do a 24 hour leaf test before spraying those plants.

Alcohol dilutions can help control aphids, spider mites, scale crawlers, mealybugs, whitefly nymphs, and more.

Ah well, rhizo, I guess then that the people at Michigan State University, the University of California, and numerous other agricultural research schools have little idea of what they are talking about.

kimmq is kimmsr

I'd like to see a link to those places showing a sharp spray of water controls scale or mealybugs or whiteflies.

tj

I'm sure that such reccomendations exist, but they certainly have no basis on facts.

Nor does the hint that alcohol, as a rule, will harm plants.

kimmsr, I was a master gardener for 4 years with the University of Florida. I know they test everything and post the results. After working at one garden center up north and three nurseries down south. I beg to differ. Hands on knowledge and experience wins hands down in my book.

A sharp spray of water, not a mist, can knock the mealy bugs off plants just as it will knock Aphids off the plant, and will not do harm to any mealy bug destroyers or other predators that might be there which other methods, horticultural oils and pesticides, will. The water spray will not kill the wee buggers, just knock them off the plant.

FYI, zzackey. I completed the requirements for Master Gardener in 2001 and for Advanced Master Gardener in 2003 and was active in the program until 2010 when my Asthma made working around flowers really problematic. Since the Ag schools do not get much funding from water sources you probably will not find much about using that material in any research papers.

kimmq is kimmsr.

"Since the Ag schools do not get much funding from water sources you probably will not find much about using that material in any research papers."

Kimmsr, that is, without a doubt, the silliest thing I've ever heard you say. Oh my.....really?

One of the beauties of isopropyl alcohol spraying is that you can often see the bugs killed immediately, and know if you have missed any. There are some plants bothered by mealy bugs which are not suitable for spraying; African violets are a notable example. You can, however, dab the bugs on such plants with alcohol to remove them.

kimmsr: you might have been thinking about methanol which can be quite hazardous to both the plant and the one spraying; isopropyl sprays are a quite well established, and known effective solution for many plants. In my own experience I have had reasonable success spraying off some aphids with water, but have not found that water sprays are effective at removing mealy bugs or scale. I would be interested to see research which documents the effectiveness of water sprays on scale and mealy bugs because it would help enlighten me on what technique is used. Even the most forceful sprays I can muster would not remove these pests. What are the references referred to at Michigan State and UC?

Renais

http://www.ipm.iastate.edu/ipm/hortnews/2004/2-27-2004/mealybugs.html

Yes that's mealy bugs for sure. I used isopropanol and it saved my heavily infested azalea. Forceful water spray may work but depends on the size of the plant and scale of infestation, it can be very tedious. Besides, I find strong streams of water often damage the already weakened plants. And not as effective as isopropanol. Just my experience.