Hi. Old thread but I think it exaggerates how easily mealies spread. These quotes are from this Masters Thesis: "The first mealybug instars do not move very far by crawling and rarely reach an adjacent vine in this manner" "Of all the stages in mealybug development, first instars are the most mobile since mealybugs tend to settle as soon as they encounter dense areas of trichomes or cracks in the shoot of vines " "Thus, long distance (between-vine) dispersal is limited to wind dispersal (e.g. natural or spray induced air flows), and by contact by humans (pruners, gloves, spray equipment, etc.), or potentially other animals in the field." "A recent study on the grape mealybug (P. maritimus) by Grasswitz & James (2008) looked at movement of mealybugs over a three-year time span. During the three years, they found mealybugs are capable of walking on vines in the field up to 90 cm from their origin point of release; however, most were found walking considerably shorter distances." So it seems to me the conclusion is that if you keep the plants 1.5 m apart then no mealy crawler will crawl between them (and with slighty less distances they might but not likely). And that what you have to worry about is wind/drafts and above all humans (and animals) who touch the plant. I also read somewhere someone stating pesticides don't work fast enough compared to how fast mealies reproduce but I don't think that's the case, I think the limitation of e g neonicotinoids like Imidacloprid is that the systemic action isn't strong enough due to (A) not reaching sufficient concentration in general and (B) not reaching sufficient concentration at some part of the plants where the bugs are. One way to address that might be to increase concentration of solution, but Imidacloprid doesn't have very good water solubility, I suggest switching to a different neonicotinoid with better solubility of which Dinotefuran (sold as Safari) is by far the best. Another thing to consider is that there are hundreds of different mealybugs of which some are more common and in tests some pesticides work best on some of these and some other on others which you can see here. As you can see, sometimes Safari has rating 5 and sometimes TriStar, even though both are neonicotionoids. Personally I wonder if this might have to do only with concentration, since all neonicotioids do have the same mode of action. But to be on the safe síde, maybe: First spray with Imidacloprid or Thiacloprid (whichever is available in your country) and cover every square mm of visible sides of plant and both sides of leaves since it also has contact action which is faster than the systemic activity (and this spray is easy to find, and will buy you time to find Safari, and limit amount of crawlers around meanwhile), 1-2 weeks later treat with Safari drench (possibly overdose), 10-14 days later leach the soil (using clean water, 2-3 pot volumes) then add fertilizer sticks with Acetamiprid (easy to find). Instead or in addition to "3" you might want to try Pyrifluquinazon spray (sold as Rycar) and/or Spirotetramat drench (sold as Kontos). Kontos, Rycar and Safari are not available except to professionals but you can find it by googling. If you need to repeat treatment, you should use a pesticide with a different mode of action like Rycar or Kontos. Kontos works very well on some mealies according to this (p59). If you have experience that contradicts this then please let us now. I can at least compare to spidermites based on experience: Above someone said that mites spread even more than mealies, but I have seen more than once how even a few millimeters between plant branches keeps them from spreading to the next plant (at least if the infected leaf is not above the other one). Good luck.

One can use IPM (Integrated Pest Management) which says to use the least toxic product that will kill the pests. It recommends organic control but also suggests the least toxic insecticide that will do the job. Meaning, one doesn't go to the cabinet and get an insecticide that kills everything it comes into contact with. It also suggests limiting the spray to the infected area and only when the pests are present. This is just common sense, but many people spray to prevent insect pests which may cause some to build up a resistance to a particular insecticide. If we all used IPM, there'd be no problem but we usually go for the big guns right away. When I give programs and the topic of insecticides comes up, I recommend IPM. I'll recommend putting up with insect damage but if one has to spray make sure the label lists the pest and mix at the dilution rate listed on the label. Not all of us are willing to walk past an insect damaged bud or leaf. I figure the insects need to eat also and I choose butterflies and birds over insecticides. It takes a few years to get to a good balance of nature and just one insecticide application can take you back to square one. But if one has a perfect leaf or bloom phobia and they have to spray insecticide, use common sense. Remember also, you can sterilize your garden but if you're the only one in your neighbor hood doing it, you'll soon get the buggers back. It then turns into a vicious cycle. Then if you try to let the predatory insects keep your bad insects under control, remember they won't return until they have something to eat. This means you'll have damage again until they arrive in sufficent numbers to make a difference. Caterpillars eat leaves and many turn into butterflies. I'm not going to stand on a soapbox and say spraying any insecticides is terrible. I'll tell people what works for me then let them make the choice. Taking a hard line against insecticides is not much different than entolling the virtues of fresh human waste as a home fertilizer or insect/fungus spray. We all know how we felt about that! The leaves on my General Jacqueminot look like lace from rose slugs but I'm willing to put up with it. Not everyone is!

Carolyn: Thanks for responding. I'd love it if you could figure out what's going on. I plan to see if my county extension can help, too, but I can't get to a phone during their hours for a few more days yet. I don't have a measurement for the humidity, unfortunately. I can say that in my house, a drink with ice develops condensation, my hair does not get staticy easily, and when the outside temp is around 20 or lower, my double-hung windows have condensation in a one-inch strip just above the joint between upper and lower windows. Until this week, I had the grow light sitting on a milk crate, so the light was hitting the plants from straight-on, sunset style. I finally got my ceiling beams located and some hardware installed and the light has been pointing down for about 4 days. It was when I moved things around in order to hang the light that I saw the white patches and how bad the aphids were in some spots. I've been spraying with soapy water so much now, the humidity may have increased! (Only one tomato had a lot of aphids, but I'm spraying that guy and all the non-tomato plants twice a day now) Thanks a lot for any help you can give, zeke

Summers... It probably sounds more time consuming because I put it into steps. It pretty much like this... really just takes about 5 minutes. quick spray with a hose or spray bottle or whatever...5-10 seconds for each rose... at the most. 5 seconds to cut a hole in the bag. 10-30 seconds to put the ladybug bag over the aphid covered cane/leaves/bud and for the lady bugs to crawl out onto it and eat the aphids. Just do that at each spot you want the ladybugs to go to town. Here.... spraying them off with water would take forever. Dealing with the hose. Ugh. Spraying under all the leaves. And water here is still expensive, even after all the rain we have had. Plus spraying them off with water really just doesn't seem to work here. They're just back the next day.