RHA Newsletter 10(1): 8 (Spring 1979)
If I had only known sooner
by Percy H. Wright

When I began rose hybridising, which was away back about 1932, I had no idea that there was, or could be, a rose species which the rose curculio did not bother. If I had known then what I know now about the possibility of breeding roses immune to the curculio, my contribution to the development of hardy shrub roses that are capable of flowering abundantly in spite of the hordes of these pests that fly about in our dry Saskatchewan climate, my contribution to rosedom could have been made many years sooner.

The rose species which is not troubled by the curculio is R. laxa, Retzius, a tetraploid from Kazakhstan in Central Asia. The so called 'Ross Rambler', a native of the Himalayan Mountains, is a close relative, and appears to be equally immune, I acquired Rosa laxa only about 20 years ago, but I have had the "Ross Rose" for about 50 years, and yet, somehow, for some reason I cannot explain, I failed to notice its immunity to the curculio until three years ago, I first noticed the immunity, or near-immunity, among some of my hybrids of R. laxa later; they appear to be about 98% immune.

The curculio, apparently very unlike the plum curculio, thrives only in semi-arid areas, In years when there is rain and high humidity for about a month before the date of bloom, this beetle does not have much of a chance, In prairie Canada, it is much worse in the grasslands than in the park or semi-wooded country. Someone could make a survey of all the drier States of the U.S.A. and come up with a map showing where this beetle is a serious pest, and where it is an occasional pest. Such a map would be welcomed by rose lovers, I assume, over a very considerable part of the Great Plains area.

Why are some roses not bothered by this pest? I wish I knew. In the meantime, I suggest that it may be because the bugs do not recognize the "smell" of the leaves as being right. Presumably the rose curculio does not occur in Central Asia, or these bugs would have learned to recognize it as a rose, and thus a possible prey, aeons ago. After we produce "immune" varieties here, how many generations will it take the curculio beetle, to "catch on"?

Perhaps, as a result of this little item, rose growers all over the western areas of the U.S.A, will write RHA headquarters to give the information about the prevalence of the curculio in their respective districts.