Neljä vuotta kansallista kirjanpainajaseurantaa: feromoniseurannan tulokset 2015 ja muita havaintoja

The Natural Resources Institute Finland (formerly Finnish Forest Research Institute) and the Finnish Forest Centre have monitored Ips typographus with pheromone traps (baited with Ipsowit ®-pheromones) in southern Finland during 2012–2015 following the methods applied in the other Nordic countries (Bakke et al. 1983; Weslien et al. 1989). The monitoring sites are shown in fig. 5-5. In 2013–2015 both Borregaard and Lindgren funnel traps were used; and the catches from Lindgren funnel traps were multiplied by 0.77 to correspond catches from Borregaard traps (Neuvonen et al. 2015). These values were used as a basis for areal estimates (See Figs. 5-5 & 5-6). The weather conditions during summers 2012–2014 in relation to Ips typographus swarming have been described earlier (Neuvonen et al., 2014, 2015; see also Fig. 5-2). During the spring 2015 the main swarming of Ips typographus started at the end of May or during the second week of June in southern Finland which was clearly later than during the preceding three years. The early summer 2015 was rather cool and especially in western Finland also rainy. Despite the cool early summer weather, in eastern Finland (Joensuu) fully developed filial beetles were observed at a warm site already on July 6th. Furthermore, July and August were warm, which gave good maturation conditions for beetles of the first brood as well as for sister broods. In most areas the median catches were about the same or somewhat lower in 2015 than in 2014 (Fig. 5-6, left).