Hill, M.G., Mauchline, N.A., Cheng, C.H., & Connolly, P.G. 2007 Measuring the resistance of Actinidia chinensis to armoured scale insects.. VI International Symposium on Kiwifruit, Rotorua, New Zealand ISHS Acta Horticulturae 753

Notes: ISHS Acta Horticulturae 753, VI International Symposium on Kiwifruit, Rotorua, New Zealand 2007 With the continuing reduction in acceptability and availability of synthetic insecticides, it is important that future cultivars of kiwifruit incorporate acceptable levels of resistance to insect pests. Most broad-spectrum insecticides applied to commercial kiwifruit in New Zealand are for the control of two species of armoured scale insect (Hemiptera: Diaspididae), greedy scale (Hemiberlesia rapax) and latania scale (H. lataniae), which infest bark, leaves and fruit. This paper reports the findings of preliminary studies to test the hypothesis that kiwifruit germplasm differs in its susceptibility to attack by armoured scale insects. Preliminary observations of the number of scale insect adults on the fruit of vines from 31 Actinidia chinensis families in 2002 showed significant differences in scale insect infestation between families. The numbers of scale insects on fruit and leaves of vines from 25 A. chinensis families were more closely assessed in 2003. There were large differences in the level of scale insect infestation on leaves and fruit between selections. Both measures of scale insect attack showed moderate levels of heritability. A comparison of scale insect numbers on leaves and fruit with a range of fruit characters from a previous study on the same vines (Cheng et al., 2004) showed moderate to strong negative correlations between scale numbers on leaves and fruit, and fruit soluble solids, dry matter and glucose concentration at harvest. Greedy and latania scale showed different responses to the germplasm.