Pear psylla: In abandoned orchards
AuthorsP. H. Westigard
H. F. Madsen
Authors AffiliationsP. H. Westigard is Assistant Entomologist, Oregon State University, formerly Junior Research Entomologist in the Experiment Station, University of California, Berkeley;; H. F. Madsen is Associate Professor and Associate Entomologist in the Experiment Station, U.C., Berkeley.
Hilgardia 17(1):6-9. DOI:10.3733/ca.v017n01p6. January 1963.
Abandoned orchards studied during the 1962 season showed substantial variation in their ability to support heavy populations of the pear psylla. There were indications that trees abandoned for several years may have arrived at a point where biological control factors will control the densities of this pest. The removal of single trees or of entire orchards that had been in this neglected state for several years is, therefore, of questionable value. However, in those orchards left unsprayed for only one or two years, psylla populations did reach high densities. Under these high summer population levels, several psylla adults were captured on traps placed considerable distances from the orchard. This greatly increases the danger from abandoned orchards in the adequate control of this pest in commercial plantings.
Also in this issue:Characters, distribution, and food plants of phlepsid leafhopper vectors of California aster-yellows virus
The relation of pear psylla to pear decline … greenhouse tests
Orchard tests substantiate: Role of pear psylla in pear decline
Control of pear psylla: With oils and oil-pyrethrins
Phytotron modification: Admits more sunlight through plastic panels
Vetch green manure increases rice yields: …Proper depth and timing of incorporation allows maximum results
Granulated insecticides superior to sprays for: Alfalfa weevil control
Field maturity—seed yield—shatter loss for: Potomac orchardgrass and hardinggrass
Evidence of nonspecific transmission of California aster-yellows virus by leafhoppers