Agricultural and Forest Entomology (2013) 15, 34-42

Fernanda Colombari, Martin L. Schroeder, Andrea Battisti and Massimo Faccoli (2013)
Spatio-temporal dynamics of an Ips acuminatus outbreak and implications for management
Agricultural and Forest Entomology 15 (1), 34-42
Abstract: Understanding spatio-temporal processes of bark beetle infestations is crucial for predicting beetle behaviour and aiding management decisions aiming to prevent or mitigate tree mortality. We recorded the spatial and temporal distribution of killed trees during the 5-year period of an Ips acuminatus outbreak.
Killed trees were always grouped in well-defined patches (infestation spots). In years of high population density, infestation spots were large and aggregated, whereas, in years of low density, infestation spots were small and weakly aggregated or randomly distributed within the study area.
Most trees were killed in the spring by beetles that had hibernated but, in some years, trees were also killed in the summer by new-generation beetles originating from spring attacks. Spring-killed trees always formed new infestation spots at new locations (i.e. spot proliferation). By contrast, summer-killed trees always occurred at the edge of active spots established in the spring, thus resulting in spot growth.
With regard to management strategies, the results obtained in the present study suggest that areas located in close proximity to infestations of the previous year should be prioritized for risk assessment. Because large spots account for most of the observed tree mortality, the cut-and-remove method should be focused on these spots as soon as crown discoloration appears in the summer. If applied timely, this strategy will remove the new-generation beetles originating from the spring attacks before they emerge and also reduce the risk of spot growth.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Fernanda Colombari, Andrea Battisti, Massimo Faccoli

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
damage/losses/economics

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ips acuminatus	Pine (Pinus)	Italy