Blank, R.H., Gill, G.S.C., & Dow, B.W. 1999 Armoured scale (Hemiptera : Diaspididae) distribution in kiwifruit blocks with reference to shelter.. New Zealand Journal of Crop and Horticultural Science 27(1): 1-12.
Notes: Armoured scale insect (Hemiberlesia rapax; H. lataniae; Aspidiotus nerii Hemiptera: Diaspididae) leaf infestations were monitored from rows of kiwifruit (Actinidia deliciosa (A.Chev.) C.F. Liang et A.R. Ferguson var. deliciosa) vines in three blocks at each of 11 sites, at 3-8 times from December until May. The relationship of scale leaf infestation with distance across kiwifruit blocks (scale distribution) was analysed using different regression models. Scale distributions were best described using linear models for 26 kiwifruit blocks and for seven blocks using quadratic models. Scale distributions derived using live scale followed similar patterns to those derived from total scale. Overall 53% of sites or blocks had significant linear or quadratic scale distributions. Kiwifruit blocks with high scale infestations invariably had significant scale distributions whereas those with low infestations had non-significant distributions. The finding of significant relationships using regression models with parallel lines or curves for different sampling times at some sites, showed scale distributions hold throughout the season. In the simplest situation scale infestations were highest in kiwifruit rows adjacent to alternative host plants and declined linearly away from the scale source. These findings were consistent with the hypothesis that scale distributions were caused by the aerial dispersal of crawlers from alternative host plants.