Fruit entomological research at The James Hutton Institute has been established since the mid-1960s and is largely targeted at cane fruits (Rubus and Rubus hybrids) and to a lesser degree at Ribes (currants), although some of the pest work can and will be relevant to other crops.
Recently there have been rapid changes in raspberry agronomy in Northern Britain. Most producers have gone from large scale, open field and relatively low value raspberry crops for processing, to a smaller protected and semi-protected crops producing high quality fresh fruit for the retail market. These changes have brought about changes in pest burden and control strategies. Similarly, the desire for low or zero pesticide residues in fruit crops has led to the development of strategies to manage pest with the minimal amount of pesticides and investigations into novel pest management strategies.
Of the major raspberry pests, the large and small raspberry aphids (Amphorophora idaei and Aphis idaei) (because of the viruses they transmit and risk as fruit contaminants) and raspberry beetle (Byturus tomentosus) (because of the fruit quality problems they induce) are probably the most important. Less important, but increasing in frequency, are raspberry cane midge (Resseliella theobaldi) and the associated disease complex ‘Midge Blight’, wingless weevils (both the vine weevil (Otiorhynchus sulcatus) and the clay-coloured weevil (Otiorhynchus singularis) and the Eriophyid mite, raspberry leaf and bud mite (Phyllocoptes gracilis).
Ribes crops have similar production pressures to raspberry. The number of approved insecticides and acaricides is very severely limited. The major pest of blackcurrant (R. nigrum) is the blackcurrant gall mite (Cecidophyopsis ribis). This Eriophyid mite is the vector of blackcurrant reversion virus and causes severe loss due to the loss of fruiting buds. With the recent release of the mite resistant cultivar Ben Hope and the presence of several resistant blackcurrant cultivars, the pressure to find alternative acaricides should lessen. Blackcurrant leaf curling midge (Dasineura tetensi) and aphids remain as problems.
Our research is targeted at understanding the behaviour and biology of several of the major pests and understanding the interaction with the plants at above and below ground. Plant attractant research has led to the development of traps for raspberry beetle and may be developed for other pests. In the longer term our research is leading to improved IPM strategies for raspberry and Ribes.