Department of Entomology, University of California, Riverside, CA.
J Econ Entomol. 2020 Oct 16;113(5):2448-2457. doi: 10.1093/jee/toaa177.
Colonies of western drywood termites, Incisitermes minor (Hagen) (Blattodea: Kalotermitidae), are difficult to detect and treat due to their cryptic nature. The use of heated air to create lethal temperatures within infested wood serves as a nonchemical treatment option targeting whole structure or large portions of the structure. However, the presence of hard-to-heat areas and potential risk of damage for heat-sensitive items are recognized as important challenges. Here, we tested if a localized injection of volatile essential oil could be utilized to address the heat sink issue, potentially increasing the overall efficiency of heat treatments against drywood termites. Artificially infested wooden blocks were placed in several locations of the test building, and heat treatments were conducted. For the treatment group, a small amount of essential oil (methyl salicylate) was added in the blocks prior to the heat treatment. All blocks placed in uninsulated wall voids had 92-100% termite mortality by day 7. However, the presence of a large concrete wall in the subarea hindered heating of blocks therein, resulting 36-44% mortality by day 7 when there was no essential oil treatment. Incorporation of the essential oil substantially increased the control efficacy for the subarea, resulting in more than 90% mortality. This approach might also be helpful in reducing the risk of potential heat damage during heat treatment without compromising its control efficacy.
由于其隐蔽性，西部干木白蚁（Incisitermes minor (Hagen)）的蚁群很难被发现和处理。利用热空气在受感染的木材中产生致命温度，是一种针对整个结构或结构大部分区域的非化学处理选择。然而，存在难以加热的区域和对热敏感物品潜在的损坏风险，这被认为是重要的挑战。在这里，我们测试了局部注射挥发性精油是否可以用来解决热汇问题，从而提高针对干木白蚁的热处理的整体效率。将人工感染的木块放置在测试建筑物的几个位置，并进行热处理。对于处理组，在进行热处理之前，在木块中添加少量精油（水杨酸甲酯）。放置在未隔热的墙壁空隙中的所有木块在第 7 天达到了 92-100%的白蚁死亡率。然而，在分区内有一个大型混凝土墙，阻碍了其中木块的加热，当没有精油处理时，第 7 天的死亡率为 36-44%。精油的加入大大提高了分区的控制效果，死亡率超过 90%。这种方法还可能有助于降低热处理过程中潜在热损坏的风险，同时又不影响其控制效果。
