Biological control in integrated pest management systems for apple and pear orchards.
In trials in orchards in 1987-89 in Italy, various strategies were tested for the control of Cydia pomonella, Pandemis cerasana, Archips podanus (which were important on apple and pear), Psylla pyri [Cacopsylla pyri] (which was important on pear) and the more minor pests Dysaphis plantaginea, Quadraspidiotus perniciosus and Leucoptera malifoliella. Integrated control strategies were defined as 'classic' (rational use of azinphos-methyl, quinalphos, vamidothion, oxydemeton-methyl, DNOC and amitraz), 'intermediate' (involving growth regulators (fenoxycarb, diflubenzuron and teflubenzuron) and Bacillus thuringiensis subsp. kurstaki) and 'advanced' (with minimal use of chemicals and greater use of bioinsecticides including granulosis virus against C. pomonella). The amounts of damage to fruits were similar when intermediate and classic strategies were used (about 4%) but were slightly greater when the advanced strategy was used (about 6%). The advanced strategy required a greater number of applications, as the biopesticides had a shorter persistence than chemicals. The amounts of chemicals sprayed were reduced by 90-100% and 75-90% in the advanced and intermediate strategies, resp., as compared to in the classic strategy. This paper was presented at a conference on integrated plant protection in orchards held in Gödöllő, Hungary, from 13 July to 5 August 1990.