Reconstructions of defoliation by larch bud moth (LBM,Zeiraphera dinianaGn.) based on European larch (Larix deciduaMill.) treerings have unraveled outbreak patterns over exceptional temporal and spatial scales. In this study, we conducted tree-ring analyseson 105 increment cores of European larch from the Valais Alps, Switzerland. The well-documented history of LBM outbreaks inValais provided a solid baseline for evaluating the LBM defoliation signal in multiple tree-ring parameters. First, we used tree-ringwidth measurements along with regional records of LBM outbreaks to reconstruct the occurrence of these events at two siteswithin the Swiss Alps. Second, we measured earlywood width, latewood width and blue intensity, and compared these parameterswith tree-ring width to assess the capacity of each proxy to detect LBM defoliation. A total of six LBM outbreaks were reconstructedfor the two sites between AD 1850 and 2000. Growth suppression induced by LBM was, on average, highest in latewood width(59%), followed by total ring width (54%), earlywood width (51%) and blue intensity (26%). We show that latewood width andblue intensity can improve the temporal accuracy of LBM outbreak reconstructions, as both proxies systematically detected LBMdefoliation in thefirst year it occurred, as well as the differentiation between defoliation and non-defoliation years. This study intro-duces blue intensity as a promising new proxy of insect defoliation and encourages its use in conjunction with latewood width.