The following statement was made in this thread on April 29, 2009: "It has been demonstrated by natural root grafting at UC Davis, but then only on rootstock plants just a few inches from each other, in the nursery row, and then only on mutiflora." In 2007 Golino et.al. at U.C. Davis published a paper on this subject. The abstract is at: http://www.actahort.org/books/751/751_26.htm In the full paper, the following is stated (page 29-30): "Field Spread in Scion Cultivars To test further for the occurrence of virus spread trials were conducted on over 300 plants each of three scion cultivars, Double Delight, Iceberg, and Queen Elizabeth. Rooted cuttings were planted approximately 30 cm apart in rows in the field, grown for one year and alternate plants were graft-inoculated as described above with one of three virus accessions: 1) ROS98.36, 2) ROS98.27, and 3) ROS70.7, which were 1) a source of PNRSV that caused bright yellow chlorosis in the spring; 2) a source of ApMV, and 3) a source of a naturally-occurring mixed infection of ApMV and PNRSV, respectively. Plants were pruned yearly using shears that were cleaned between each plant by dipping in 10% bleach solution. Bushes were observed for symptoms periodically and ELISA tested for PNRSV and ApMV in the spring for two years. All non-inoculated plants that tested positive were re-sampled and tested to confirm the result." In the conclusion section (page 221) the following was stated: "In scion varieties, transmission rates two years postinoculation ranged from 0 to 25% depending on virus and cultivar. Queen Elizabeth had the lowest percent infection of all the varieties at an average 5% for all three viruses; Iceberg had the highest for a scion cultivar at 13% average for the viruses (Table 4). These differences correlate with the cultivars relative root vigor. It is possible that a larger, more vigorous root system would increase the chance of forming a root graft with an adjacent plant. R. multiflora has a more vigorous root system than all three scion cultivars tested and within the scions, Iceberg is more vigorous than Queen Elizabeth and Double Delight." -------------------------------- I do not understand why someone would make the April 29 statement. Especially since on April 30, 2009 the same writer states: "If one actually looks up Golino's paper in Acta Horticulturae......." ----------------------------------- Please also note that not all types of mechanical transmission were ruled out in the 2007 paper since the observed rate of spread was higher in the unpruned bushes than in the pruned bushes. In another PNRSV infected plant, hops, this is attributed, in part, to the branches of neighboring plants rubbing against each other. Golino et.al. acknowledge this as they state (page 220-221): "The possibility remains that spread occurred by mechanical transmission due to contact between the leaves of the closely spaced plants and experiments are underway to test that putative mechanism of spread."

Oh yikes, and yuch. I hope someone will correct me if I'm wrong but that looks like giant whitefly. I haven't seen it myself (and I hope it stays south of me :) ) Some info you may find helpful - Here is a link that might be useful: Giant Whitefly - ucdavis

I saw one in my Perle D’or and according to the insect app it’s the oriental beetle (not the Japanese beetle) ...I usually let beetles be in the garden but this time I didn’t want to risk to have another pest on roses. I found another today on the Havana Blues geranium...same fate, cup of soapy water ah well. See if yours it’s a match to the pdf description, google images too. http://cues.cfans.umn.edu/old/Web/247OrientalBeetle.pdf

It could be redwoods. It could be palm trees. It could be fig trees. It could be banyon trees. It could be apple trees. It could be giant sequoia trees. . . .