Termite bait products that contain chitin synthesis inhibitors (CSIs) protect structures from subterranean termites via colony elimination. A hallmark of CSI baits is their dose-independent lethal time, as workers exposed to a CSI do not die until they initiate the molting process. Due to this mode of action and termite behaviors such as trophallaxis and cannibalism, a relatively small quantity of ingested CSI can spread throughout an entire colony before secondary repellency or avoidance behaviors occur, ultimately resulting in total colony elimination. In the field, only a portion of a subterranean termite colony actively forages upon a CSI bait at any given time, suggesting that only a relatively small proportion of workers may need to feed upon a CSI bait for a colony to be eliminated. In the present study, we used varying proportions of workers from whole four-year-old laboratory-reared Coptotermes gestroi (Wasmann) colonies (~ 62,500 termites/colony on average) to determine what proportion of workers need to feed upon a CSI bait in order to achieve colony elimination. A range of 0% (control), 0.5%, 1%, 2.5%, and 5% of the total worker population of colonies was allowed to feed on a formulated 0.5% noviflumuron bait for five days before being returned to their colonies. Colony elimination was observed for all 5%-fed and four out of six 2.5%-fed colonies by 107 days after CSI exposure. Our results confirm that only a small subset of the worker population of a colony must feed upon a CSI bait to achieve subterranean termite colony elimination.

含有几丁质合成抑制剂 (CSI) 的白蚁诱饵产品通过菌落消除保护结构免受地下白蚁的侵害。CSI 诱饵的一个标志是它们的致死时间与剂量无关，因为暴露于 CSI 的工人在开始蜕皮过程之前不会死亡。由于这种行为方式和白蚁行为，例如嗜食和自相残杀，摄入相对少量的 CSI 可以在发生二次排斥或回避行为之前扩散到整个菌落，最终导致菌落完全消除。在野外，在任何给定时间，只有一部分地下白蚁群会主动使用 CSI 诱饵觅食，这表明可能只有相对较小比例的白蚁蚁群需要以 CSI 诱饵为食才能消灭白蚁群。在目前的研究中，Coptotermes gestroi (Wasmann) 菌落（平均约 62,500 只白蚁/菌落）以确定需要以 CSI 诱饵为食的工人比例，以实现菌落消除。在返回它们的菌落之前，允许 0%（对照）、0.5%、1%、2.5% 和 5% 的菌落总工人群体以配制的 0.5% noviflumuron 诱饵为食五天。在 CSI 暴露后 107 天，观察到所有 5% 喂养的菌落和六个 2.5% 喂养的菌落中的四个菌落消除。我们的结果证实，只有一小部分群体的工人人口必须以 CSI 诱饵为食，以实现地下白蚁群体的消除。