The aim of our study was to determine the usefulness of mixtures of carvacrol and Bacillus thuringiensis crystalline proteins Cry against pests of two different species: Cydia pomonella L. (Lepidoptera: Tortricidae) and Spodoptera exigua Hübner (Lepidoptera: Noctuidae). The novelty of our work lies in showing the interactions between carvacrol and bacterial toxins against insect pests. Moreover, we have demonstrated that carvacrol applied via ingestion exerts toxicity against lepidopteran caterpillars. We have shown that the botanical compound and Cry proteins act in synergy and their mixtures are most effective in reducing the number of L1 and L3 larvae when B. thuringiensis toxins constitute up to 0.1% and 0.05% of the mixtures, respectively. Carvacrol and crystalline proteins act in synergy in these combinations and have the potential to be effective in protecting crops against lepidopteran pests. The nature of the interaction between the components depended on the proportion of their concentrations in the mixture. Mixtures containing Cry toxin concentrations equal or higher than 20% caused lower observed mortality of insects compared to the expected one. Furthermore, we showed that crystalline proteins of B. thuringiensis MPU B9, carvacrol and their mixture did not affect the morphology of insect haemocytes, and additionally, had no effect on the immune system.

中文翻译：

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香芹酚与苏云金芽孢杆菌结晶蛋白对小Cy虫和斜纹夜蛾的协同相互作用。

我们的研究目的是确定香芹酚和苏云金芽孢杆菌结晶蛋白Cry的混合物对两种不同物种的害虫的有用性：两个物种的Cydia pomonella L.（鳞翅目：Tortricidae）和Spodoptera exiguaHübner（鳞翅目：Noctuidae）。我们工作的新颖之处在于展示香芹酚和细菌毒素对害虫之间的相互作用。此外，我们已经证明，通过摄入施用香芹酚对鳞翅目毛虫有毒性。我们已经证明，当苏云金芽孢杆菌出现时，植物化合物和Cry蛋白协同作用，并且它们的混合物对于减少L1和L3幼虫的数量最有效。毒素分别占混合物的0.1％和0.05％。香芹酚和结晶蛋白在这些组合中起协同作用，并有可能有效保护作物免受鳞翅目害虫的侵害。组分之间相互作用的性质取决于它们在混合物中的浓度比例。与预期的相比，含有等于或高于20％的Cry毒素的混合物引起的昆虫观察到的死亡率更低。此外，我们表明苏云金芽孢杆菌MPU B9，香芹酚及其混合物的结晶蛋白不影响昆虫血细胞的形态，并且对免疫系统没有影响。