Abstract: Objective To investigate the changes in the water loss rate and palatability of cockroach-killing gel baits at different time after application. Methods Three commercially available common gel baits were selected: gel bait P (effective constituent: 2.15% imidacloprid), gel bait W (0.5% dinotefuran), and gel bait S (0.5% dinotefuran). Water loss rate was determined by weighing the gel baits over a period of 20 days. The palatability of gel baits to Blattella germanica was determined by observing the feeding behavior of cockroaches during the same period. The analysis of variance and non-parametric test were used to compare the water loss rate and palatability of the gel baits. Results The three gel baits were dotted indoors for 20 days. Water volatilization mainly occurred in the first day, and the water loss rate was (39.73±0.05)% for gel bait P, (32.49±0.04)% for gel bait W, and (22.99±0.16)% for gel bait S, with a statistical difference between the baits (F=179.966,P=0.005). The weight of the gel baits was generally unchanged during the following 20 days. Under the fresh condition, the feeding frequency and total feeding time of the three gel baits were in the order of P>W>S. The feeding frequency and total feeding time decreased over time for all the three baits. After 7 days, there were no statistical differences in feeding frequency and total feeding time between gel bait P [(14.33±3.54]times and (518.00±237.91) s, respectively) and gel bait W [(15.67±4.85)] times and (414.00±263.92) s, respectively) (F=0.246, P=0.631; F=0.428, P=0.528); both gel baits P and W showed statistically higher feeding frequencies and statistically longer total feeding time compared with gel bait S [(4.33±2.21)] times and (38.50±19.75) s, respectively) (F=14.038, P=0.002, P=0.001; F=7.536, P=0.007, P=0.034). After 14 days, gel bait P had better palatability than gel baits W and S. Conclusion The water loss of the gel baits mainly occurs in the first day after placement. The gel baits have the best palatability in the fresh state, and show different degrees of decreases in palatability with time. In general, gel baits P and W have the best palatability within 7 days. It was not found for the correlation between water loss rate and palatability for the three gel baits.

Key words: Blattella germanica, Gel bait, Water loss rate, Palatability

摘要： 目的 了解杀蟑胶饵在施药后不同时间的失水率及适口性变化情况。方法 采用称重法与取食行为分析法，对3种市售常见胶饵（胶饵P有效成分为2.15%吡虫啉，胶饵W和胶饵S有效成分均为0.5%呋虫胺）在20 d内失水率及其对德国小蠊适口性进行量化分析。采用方差分析和非参数检验法比较上述胶饵的失水率和适口性差异。结果 3种胶饵点布于室内环境20 d后，水分挥发主要集中在点布后第1天内，P、W和S失水率分别达到（39.73±0.05）%、（32.49±0.04）%和（22.99±0.16）%，且差异有统计学意义（F=179.966，P=0.005），在随后的20 d内胶饵重量基本保持不变。在新鲜状态（0 d）下，3种胶饵的被取食次数和总取食时间为P>W>S；随着胶饵点布时间的增长，取食次数和总取食时间均减少，7 d后，胶饵P的被取食次数〔（14.33±3.54）次〕和总取食时间〔（518.00±237.91） s〕与胶饵W〔（15.67±4.85）次和（414.00±263.92） s〕差异无统计学意义（F=0.246，P=0.631；F=0.428，P=0.528），但均优于胶饵S的被取食次数〔（4.33±2.21）次〕和总取食时间〔（38.50±19.75） s〕，且差异有统计学意义（F=14.038，P=0.002，P=0.001；F=7.536，P=0.007，P=0.034）；14 d后，胶饵P的适口性指标优于胶饵W和胶饵S。结论 胶饵在点布于环境后水分损失主要集中在第1天。新鲜状态下胶饵的适口性最好，随着时间延长，不同胶饵的适口性下降程度不同，总体来讲胶饵P和胶饵W在7 d内的适口性最好；未发现不同胶饵失水率与适口性之间的相关性。

关键词: 德国小蠊, 胶饵, 失水率, 适口性