Biorhythm paralleled release of pheromone by photothermal conversion for Long-term bark beetle control

The spruce bark beetle Ips typographus, as the most notorious pest in Eurasia spruce forest ecosystem, mainly feed on phloem of spruce tree trunk. The concealment of their habit makes regulation of insect population a difficulty to cope with, contributing to spruce forest recession, destruction of environment balance and forest transformation from carbon sinks into carbon source. Based on the cross point between the biorhythm of the I. typographus and photothermal material, description herein was a novel sunlight-triggered biorhythm-paralleled photothermal sponge (BPPS) for continuous control of I. typographus. Three steps including preparation of sugar template based porous polyurethane (PU) sponge, polypyrrole (PPy) modification and pheromone filling were involved in material manufacturing. The attractant and repellant agents were employed into the PU separately to realize a comprehensive regulation on I. typographus behavior. Laboratory simulation and forest field experiments illustrated that both the rapid release within a short period and long-term effectiveness in 21 days were verified. Due to the advantages of designability, cost-effectiveness and environmental friendliness of our sustained-release sponge, this manufacturing strategy offers great promise for generating photothermal responsive sustained-release material, shedding light on long-term control of injurious trunk borers and environmental protection.