I discovered a few weeks ago that one of my climbing roses released clouds of 'white flies' into the air when I was pruning it. A few days ago I discovered the same on my native Nootka rose, even though it is at least 30' away from the first discovery. I have about half a dozen other hybrid roses that so far are not affected. As it is now mid-fall, should I attempt to eradicate the pest, or wait until spring, hoping the life cycle is over. Whatever the case, I'd like to treat with the most natural non-chemical means possible. I live in the Lower Mainland of BC, zone 8, with little frost (at least in recent years). Any advice? Thanks. Christine
It's the white fly larvae that cause the damage. They have piercing mouth parts which enable them to suck sap from the plant. The adults fly around, reproduce and lay eggs on other leaves or other plants. It can infest just about any types of plants. They are pesky little characters and can be difficult to get rid of. By some biological quirk, the adult white flies seem to be attracted by the color yellow . You could put up a white fly trap, which are bright yellow glue traps, on the plant that is infested. You can probably get these at your local nursery supplies. If not, get an article that is yellow in colour and waterproof - yellow plastic plates or cups will do nicely - and paint the surfaces of these with something sticky and gooey like tanglefoot. Hang these up in the vicinity of the infested plant. The other option for control is to spray insecticidal soap. This is probably the least toxic of all the spray-on options. You do need to spray very frequently - once every 2-3 days - as long as there are still adult white flies darting around. This is because their reproductive cycle is extremely short - newly lid egss hatch in a short 2 days. If you don't get on top of the population, you will fight a losing battle. The spraying can be reduced to once a week once you don't see any more adults flying around. At this time of the year, putting up traps would probably suffice, as what you would like to achieve is to minimise the number of overwintering eggs that the adults will lay. Once the rose have gone completely dormant, give a good applicaton of dormant spray (lime sulphur and oil), and repeat in late winter or early spring before the buds sell up. I found a nice on-line article on white flies and white fly control. Remeber that this article is on a website selling pest control products. You do not have to use the "heavy stuff" if you do not feel comfortable.
Thank you very much for your quick reply. I had no idea white fly was such a troublesome pest. I have some Safer insecticidal soap, and will start spraying in the morning, and get some traps going. By the way, the rose which was first infected is yellow and fragrant. I also read the article you referenced and was interested to read about the citrus connection, as I think this pest might have been introduced into my garden on a kaffir lime that I purchased in the summer. Thanks again, Weekend Gardener. Christine
Sounds like leafhoppers. You can tell by looking closely at the individual insects. Whiteflies look like moths with small heads and broad wings, whereas leafhoppers have proportionately bigger, pointed heads and slender wings.
Thank you, Ron. I did some research this afternoon, and I think you are right. At least leafhopper sounds like less of a problem than white fly. I found a good article on leafhopper published by the Seattle Rose Society http://www.bmi.net/roseguy/gblfhop.html. I've included the link in case anyone else has the same problem. Interestingly, we did clear some blackberry that I didn't even realize was taking over the back of the garage. So as they refer to bramble as a common host, maybe these little hoppers hopped over to my roses from the now gone berry brambles. Christine
