EFFICIENCY OF ATTRACTIVE TRAPS IN THE FIGHT AGAINST BYTURUS TOMENTOSUS IN RASPBERRIES: EXAMPLES FROM SWITZERLAND, SCOTLAND AND NORWAY

The raspberry beetle (Byturus tomentosus DeGeer) is one of the major pests in European raspberry production. The Scottish Crop Research Institute (now part of the James Hutton Institute) has developed a trap with a combination of colour and plant odour that attracts adult beetles of both sexes. Capturing a large number of beetles before raspberry flowering could lead to less fruit damage. In Switzerland, 50 traps per ha were deployed before flowering in 2008-11 in raspberry plantations located 1300 metres above sea level. The traps were compared with a standard recommended insecticide treatment. The beetles were active earlier than expected, and trapping should start at least 4 weeks before flowering. During 4 years of trapping in one of the Swiss plots, fruit damage has decreased by 60%. In Scotland, traps deployed within protected crops at 50/ha in a lattice design were more effective than traps deployed outside the tunnel. A single host volatile attractant (B) was more effective than a different host volatile (A) released simultaneously. The level of control using the IPM system gave control of fruit damage equivalent to current recommended insecticide sprays and enabled growers to detect pest ‘hot spots’ inside and outside the tunnels. In Norway, controlling raspberry beetle with traps alone has proven difficult, probably due to high immigration rates from surrounding wild raspberry during flowering, when traps are less attractive. Comparisons of various trap designs, plant odours and deployment heights demonstrated that the commercially available ‘click panel’ funnel trap with bee net and plant odour ‘B’ is as efficient as earlier prototypes, and that varying the trap deployment height between 1.0 and 1.6 m inside plantations, or between 1.0 and 2.0 m outside plantations, does not influence the number of beetles caught. These results confirm that the Scottish traps are valuable as monitoring tools, and also indicate that they could be used for integrated or organic control of raspberry beetle in areas with little wild Rubus.