Centro de Ensino Superior de Juiz de Fora, Juiz de Fora, MG, Brazil.
Parasitol Res. 2010 Feb;106(3):615-9. doi: 10.1007/s00436-009-1709-1.
The present work had the objective of evaluating the influence of different concentrations of thymol on the biological parameters of engorged females of Rhipicephalus (Boophilus) microplus and also its ovicide activity on eggs of this tick. In order to carry out the work, four groups were formed, each containing 20 engorged females, which were immersed for 5 min in different concentrations of thymol (1.0%, 1.5%, and 2.0%) and a control group (water + dimethylsulfoxide). The following biological parameters were observed: initial weight (mg); egg mass weight (mg); pre-oviposition, oviposition, and survival period (days); hatching percentage (%HP); egg production (%EPI) and nutritional (%NI) indexes; and the percentage of control (%C). In order to perform the second stage, thymol solutions were sprayed on the egg masses (50 mg). The parameters' initial weight and pre-oviposition did not present significant differences (p>0.05) among the groups. Thymol caused alterations in the parameters egg mass weight, oviposition, survival period, hatching percentage, EPI, and NI, presenting highly significant differences between the treatments and the control group (p<0.01). The control efficacy was higher than 95% in all the treatments, reaching 99% in the concentration of 2.0%. In the ovicide test, the hatching percentage was not affected in any of the treatments (p>0.05). In the second experiment, when eggs were treated directly, the thymol did not affect significantly this parameter. These results demonstrate that thymol showed deleterious action on most of the analyzed parameters; thus, it is possible to conclude that, in laboratorial conditions, this monoterpene was efficient in the control of engorged females of R. (B.) microplus.
本研究旨在评估不同浓度百里酚对饱血雌蜱 Rhipicephalus (Boophilus) microplus 的生物学参数的影响，以及其对该蜱卵的杀卵活性。为此，共设立了四个实验组，每组 20 只饱血雌蜱，分别浸泡在不同浓度的百里酚（1.0%、1.5%和 2.0%）和对照组（水+二甲基亚砜）中 5 分钟。观察了以下生物学参数：初始体重（mg）；卵质量重量（mg）；预产卵、产卵和存活期（天）；孵化率（%HP）；产卵率（%EPI）和营养指数（%NI）；以及对照（%C）。为了进行第二阶段，将百里酚溶液喷洒在卵块上（50mg）。各组的初始体重和预产卵期无显著差异（p>0.05）。百里酚导致卵质量重量、产卵、存活期、孵化率、EPI 和 NI 等参数发生变化，处理组与对照组之间存在极显著差异（p<0.01）。所有处理组的控制效果均高于 95%，在 2.0%的浓度下达到 99%。在杀卵试验中，各处理组的孵化率均未受到影响（p>0.05）。在第二个实验中，当直接处理卵时，百里酚对该参数无显著影响。这些结果表明，百里酚对大多数分析参数均具有有害作用；因此，可以得出结论，在实验室条件下，这种单萜对控制 R.（B.）microplus 饱血雌蜱有效。
