EMERGENCE TIMING OF OVERWINTERED ADULTS LAID EGGS AND CONTROL EFFECT BY ECO-FRIENDLY MATERIALS TO CACOPSYLLA PYRICOLA

The pear sucker (Cacopsylla pyricola) is the most important insect pest in Korea. The hatching rates of eggs of overwintered adults were observed at 10, 13, 18, and 22°C. The liner model about temperature and the developmental rate of the eggs was drawn as Y=0.00277X+0.00146 (Y = developmental rate, X = temperature). The developmental threshold temperature for eggs was assumed about -0.83°C. The egg hatching timing over 50% in function of the accumulated temperature by day maximum temperature of 6°C from 1 February in 2011, 2012 and 2013 was 424.3, 367.8, and 429.8°C, respectively. This was 3 to 7 days before full blooming in pear orchard.
Otherwise, the abamectin 1.8Ec, lime sulfer, machine oil and 13 kinds of eco-friendly materials did not show the control effect to the eggs. On mixed stages of pear suckers, there were 4 kinds of eco-friendly materials with over 90% control values such as the mixture of Azadiractin A+B, Nimbin, Salanin, Meliantriol and Vepol after two applications on 21 May and 5 June in the pear growing season in 2012.