TY - JOUR AU - Lynn, C. D. AU - Jensen, F. L. AU - Flaherty, D. L. TI - Leafhopper Treatment Levels for: Thompson seedless grapes used for raisins or wine JF - California Agriculture JO - Calif Agr Y1 - 1965/04/01 VL - 19 IS - 4 SP - 4 EP - 5 PB - University of California Agriculture and Nature Resources SN - 0008-0845 UR - http://www.ucanr.edu/sites/calagjournal/archive/?article=ca.v019n04p4 AB - Preliminary results of field studies on economic treatment levels for control of grape leafhoppers indicate that many growers in the San Joaquin Valley use insecticides unnecessarily because they lack accurate knowledge of insect population levels. Thompson Seedless grapes also appear to be more tolerant of nymph populations than expected. Results also have shown that some insecticides result in a severe build-up of spider mite populations, and further screening is necessary to find materials with least harmful side effects on beneficial parasites and predators.