Komparativni učinak različitih insekticida i kaolina na smanjenu brojnost populacije Cacopsylla pyri L.

Abstract

Cacopsylla pyri L. (Hemiptera: Psyllidae) is one of the most serious economic pear pests in Eastern Croatia. Previous methods of pear control in the Republic of Croatia have led to the development of an insect population resistant to certain active ingredients. The objectives of this two-year study were to determine the optimal number of treatments for psylla control based on the monitoring of pest life cycle and to determine the effectiveness of processed kaolin in controlling the pear psylla in comparison with other chemical insecticides in four different treatments (T1. IPM-integrated protection program – diflubenzuron, spirotetramat, abamectin, acetamprid; T2. acrinatrin + abamectin, T3. kaolin clay, T4. control treatment). The research was conducted in 2017 and 2018 in a six-year-old experimental pear orchard on three varieties (Williams, Conference, and Abate Fetel). Monitoring of the pest population and its development was performed by visual inspection on two one-year shoots per tree of each variety in all replicates. The T1 treatment demonstrated the highest efficiency, between 84-95%, depending on the year, while the kaolin treatment had the lowest one, but it varied greatly from one year to the other (37-71%).

Natural Enemies of the Pear Psylla, Cacopsylla pyri (Hemiptera: Psyllidae), and the Possibilities for Its Biological Control: A Case Study Review in the Western Balkan Countries

“…The effectiveness of the treatment depended greatly on weather conditions and ranged from 37% in 2018 to 71% in 2017. In 2017, when the high effectiveness of kaolin clay was achieved, the results were very similar to those of chemical insecticides in terms of the number of eggs and different stages of larvae, while in 2018, these values were statistically significantly lower for kaolin clay [13]. This research concluded that kaolin clay should not be used alone, but its application within an integrated pest management practice yields very good results.…”

“…In specific research, this true bug was present when organophosphorus insecticides were excluded from the treatment programme, while it was not found in the year when this group of insecticides was used. The use of kaolin-based preparations as a repellent for the pear psylla is effective and safer for natural enemies [13,47].…”

“…This is explained by the fact that C. pyri quickly develops resistance to the active ingredients, and the honeydew significantly protects the pest from the effects of applied insecticides [9]. Due to the emergence of resistance, the number of treatments during vegetation often increases, averaging from 5 to 10 times per vegetation [13]. Although chemical control measures are still the most common approach for controlling pear pests on a global scale, modern agriculture, primarily due to increasing consumer concerns about food safety and pesticide residues in final products, gives preference to integrated pest management (IPM) and, above all, biological pest control in pear orchards [14,15].…”