. Cooperative economic insect report. Insect pests Control United States Periodicals. - 30 - INSECTS NOT KNOWN TO OCCUR IN THE UNITED STATES APPLE SUCKER (Psylla mali Schmidberger) Economic Importance: Apple sucker is a serious pest of apple in many European countries and has caused considerable concern in orchards in the provinces of Nova Scotia and New Brunswick, Canada, in some years. It is considered one of the most serious pests of apple in Norway. A study conducted in the lower Elbe region of Germany in 1925 showed P. mali to be the most important factor in decreased apple yields in that
. Cooperative economic insect report. Insect pests Control United States Periodicals. - 30 - INSECTS NOT KNOWN TO OCCUR IN THE UNITED STATES APPLE SUCKER (Psylla mali Schmidberger) Economic Importance: Apple sucker is a serious pest of apple in many European countries and has caused considerable concern in orchards in the provinces of Nova Scotia and New Brunswick, Canada, in some years. It is considered one of the most serious pests of apple in Norway. A study conducted in the lower Elbe region of Germany in 1925 showed P. mali to be the most important factor in decreased apple yields in that area. Populations were so abundant in the Havel River fruit district of that country in 1920 that most of the apples failed to ripen. England has recorded as much as 70 percent damage to the apple crop in some areas. Among other countries reporting severe damage are Sweden, Denmark, Switzerland and Russia. Following discovery of the psyllidin Nova Scotia in 1919, damaging infestations were reported during the next decade in that area; however, in recent years most infestations have been light to medium although a few severe infestations occurred in 1955. Infestations cause shriveling of blossoms and yellowing and dropping of foliage. They are of greatest importance when blossom ing and fruit-set are light to Apple Sucker Damage to Apple Twig and Fruit. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. Bureau of Entomology and Plant Quarantine; United States. Plant Pest Control Branch; United States. Plant Pest Control Division; United States. Animal and Plant Health Inspection Service. Plant Protection and Quarantine Programs. Washington, D. C. : U. S. Dept. of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
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