Abstract Reticulitermes grassei Clement is an Iberian subterranean termite whose feeding activity can damage both urban infrastructures and oak forests, becoming a main pest. In consequence, the development of new control methods compatible with the environmental conservation is a priority. Recently, techniques for termite control supported on the fact that the soil pH can be a chief factor in restricting termite populations have been explored. On this basis, we consider the possibility of taking advantage of certain current harmless silvicultural techniques, which also vary the soil pH, to control populations of R. grassei in natural environments. Before addressing this question, it was necessary to know the termite response to pH of substrate. For this instance, this work aimed to establish the range of pH in different zones of R. grassei nests and to determine the tolerance of this species to pH ranges outside of those observed in field. In addition, the effect of termite activity on soil pH is assessed. This research has been carried out from October 2018 to March 2019, in several natural areas from Cordoba (Spain). The results indicate that R. grassei preferably colonizes neutral or somewhat acid substrate, ranging from 5.4–7.5; the pH values in the inner nest increases towards the periphery. In addition, this species shows rather tolerance to alkaline substrate (pH ≤ 8.5). Nevertheless, it seems to be more sensitive to acid pH, being observed the lowest tolerance limit at pH≈ 4.5; if pH drops to 4.0, mortality is near 100 %. According to our results, the alkalization of substrate would not be a feasible procedure to control R. grassei populations in forest of southern Iberian Peninsula.

中文翻译：

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地下白蚁 Reticulitermes Grassei Clément (Isoptera: Rhinotermitidae) 对基质 pH 值的响应

摘要 Reticulitermes Grassei Clement 是一种伊比利亚地下白蚁，其觅食活动会破坏城市基础设施和橡树林，成为主要害虫。因此，开发与环境保护兼容的新控制方法是当务之急。最近，已经探索了基于土壤 pH 值可能是限制白蚁种群的主要因素这一事实的白蚁控制技术。在此基础上，我们考虑了利用某些当前无害的造林技术（这些技术也会改变土壤 pH 值）来控制自然环境中草丛生种群的可能性。在解决这个问题之前，有必要了解白蚁对基质 pH 值的反应。对于这种情况，这项工作旨在确定 R 不同区域的 pH 值范围。草巢并确定该物种对野外观察到的 pH 值范围以外的耐受性。此外，还评估了白蚁活动对土壤 pH 值的影响。这项研究于 2018 年 10 月至 2019 年 3 月在科尔多瓦（西班牙）的几个自然区域进行。结果表明，R.grassei 最好在中性或偏酸性底物上定植，范围为 5.4-7.5；巢内的 pH 值向外围增加。此外，该物种对碱性底物（pH ≤ 8.5）表现出相当的耐受性。然而，它似乎对酸性 pH 更敏感，在 pH≈4.5 时观察到最低耐受极限；如果 pH 值降至 4.0，死亡率接近 100%。根据我们的结果，底物的碱化不是控制 R 的可行程序。