Abstract:

To study the interaction between Eriosoma lanigerum and apple trees， olfactory response of the aphid to different kinds of apple branches was tested by Y-olfactometer and volatiles from the branches were extracted with HS (Head-space) and measured with GC-MS. The result showed that E. lanigerum was differentially attracted by the odors from different kinds of apple branches during looking for host plants. Variety, Sansa showed the most intensive attraction with the average selection rate reaching to 71.25% and Red Fuji Spur， Jonagold， Fujiki 1 followed in sequence with the selection rate all above 60%. Attraction capacity of Red Chief Delicious was less than others and the average selection rate was only 56.75%. The major volatiles of Sansa were E-3-Hexen-1-ol (14.74%)， Formic acid and hexyl ester (9.52%) and they were all more than that in other varieties relatively. The major volatiles of Red Chief Delicious were 4-methyl-1，3-pentadiene (16.37%) and Z-3-Hexen-1-ol，acetate (10.27%) and were also more than that in other varieties. Formic acid， hexyl ester and Z-3-Hexen-1-ol were preliminarily confirmed to be the important substances for attracting woolly apple aphid， but 4-methyl-1，3-pentadiene and Z-3-hexen-1-ol，acetate were not.

Key words: Eriosoma lanigerum, apple branch, Y-olfactometer, volatiles, GC-MS