• Korean journal of applied entomology
• /
• v.35 no.3
• /
• pp.243-248
• /
• 1996

This study was conducted to select the acaricides selective to H. axyridis and examine the effects on phytophagous mites and natural enemies after application of selected acaricides in the apple orchard. All the acaricides tested were more toxic to T. urticae and P. ulmi than to H. axyridis, and also were more toxic to egg than to the larva and adult of H. myridis. Azocyclotin and fenpropathrin were the highest and lowest selective acaricides to H. axyridk, respectively. The density of phytophagous mites was high affected by frequency of acaricide application. Significant difference in the changes of the density of natural enemies was not be observed according to frequency of acaricide application and kinds of acaricide. Acaricide treatment showed high effect on the population densities of A. womersleyi and Oriur spp., while less effect on Chrysopa spp.

• Korean journal of applied entomology
• /
• v.60 no.1
• /
• pp.63-70
• /
• 2021

Two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) is one of the major pests in apple orchards. TSSM was known to show different population dynamics depending on apple cultivars. We tested the host plant preference and fitness of TSSM on the leaves of 3 apple cultivars, Fuji, Tsugaru, and Hongro. TSSM showed higher behavioral preference to Fuji than Tsugaru and Hongro, and showed a higher fecundity in Fuji. The immature development of this mite was the shortest in Fuji and longest in Hongro. Total fecundities were not significantly different among cultivars, but daily fecundity was higher and longevity was lower in Fuji. Hongro was the less preferred cultivar for TSSM, and showed the lowest fitness by life table parameters. These results could explain the possible mechanisms of differential population dynamics among apple cultivars. Further study including diverse apple cultivars currently available in Korea could help to deploy time- and cultivar- specific IPM tactics.