CBGP, Institut Agro Montpellier, INRAE, CIRAD, IRD, Univ. Montpellier, Montpellier, France.
CBGP, INRAE, CIRAD, IRD, Institut Agro Montpellier, Univ Montpellier, Montpellier, France.
Exp Appl Acarol. 2024 Oct;93(3):563-582. doi: 10.1007/s10493-024-00946-z. Epub 2024 Aug 1.
Tomato crops are attacked by several pests, including mites. While the main predatory mites are not effective enough to control mite pests, recent studies have shown encouraging results with the European endemic phytoseiid Typhlodromus (Anthoseius) recki. The first objective of the study was to assess the ability of this species to disperse along the tomato stem, considering six genotypes of Solanum lycopersicum, S. peruvianum and S. cheesmaniae with contrasted trichome numbers and types of stem trichomes, accuratetly characterised in a previous study. The second objective was to determine how predator morphological traits can explain dispersal along the tomato stem. For this, ambulatory dispersal ability of females (stem crossing rate success, hesitation and escape behavior, mobility periods) was tested in lab conditions on the eight Solanum genotypes, at four period of time after the predator introduction (10, 25, 55 and 100 min), with a video observation of 5 min at each period. The females were then mounted on slides and body length and width (at the fore hind, middle and back parts) measured. No effect of the tomato genotypes was observed on the dispersal ability of the predator. However, specimens that succeeded in crossing the stem, had a higher percentage of mobility time (79.36%) than those that failed (43.60%). Furthermore, body width at midbody (DSW2) and dorsal shield length (DSL) were negatively correlated with dispersal ability. The mean DSL and DSW2 of the females that succeed to cross were 342.3 and 160.9 μm, respectively vs. 345.6 and 164.9 μm, for females that did not succeed. This suggests that the more slender and relatively small the specimens, the more are mobile and able to successfully cross the stem. The number of glandular trichomes type (GT) VI and to a lesser extent GT I and IV, and non-glandular trichomes (NGT) II&III appear to limit dispersal. The GT VI seems to have a repellent effect. On the opposite, the number of NGT V were positively correlated with high mobility and stem crossing rates. Assuming that the main barrier to biological control efficiency is dispersal along tomato stems, these preliminary results should have implications for biological control success. The proportion of mites with 'optimal dimensions' appears to be low and further studies should be undertaken to better assess the proportion of mites with such ideal dimensions in different populations and also to determine whether these morphological traits are associated with different feeding abilities and/or abiotic conditions.
番茄作物受到多种害虫的侵袭，包括螨虫。虽然主要的捕食性螨虫不足以有效控制螨虫害虫，但最近的研究表明，欧洲特有植绥螨 Typhlodromus (Anthoseius) recki 有令人鼓舞的效果。该研究的第一个目标是评估该物种沿着番茄茎传播的能力，考虑到具有不同数量和类型的茎毛的六个番茄基因型，Solanum lycopersicum、S. peruvianum 和 S. cheesmaniae，这些特征在之前的研究中得到了准确的描述。第二个目标是确定捕食者形态特征如何解释沿着番茄茎的扩散。为此，在实验室条件下，对 8 种 Solanum 基因型上的雌性（茎交叉成功率、犹豫和逃避行为、移动期）的活动性进行了测试，在捕食者引入后的 4 个时间段（10、25、55 和 100 分钟）进行了测试，每个时间段进行 5 分钟的视频观察。然后将雌性固定在载玻片上，并测量体长和体宽（前、中、后部分）。番茄基因型对捕食者的扩散能力没有影响。然而，成功穿越茎的标本的移动时间比例（79.36%）高于失败的标本（43.60%）。此外，中体体宽（DSW2）和背盾长（DSL）与扩散能力呈负相关。成功穿越茎的雌性的平均 DSL 和 DSW2 分别为 342.3 和 160.9 μm，而未成功穿越茎的雌性的 DSL 和 DSW2 分别为 345.6 和 164.9 μm。这表明，体型更细、相对较小的标本移动性更强，更能成功地穿越茎。腺毛类型（GT）VI 的数量以及程度较小的 GT I 和 IV 和非腺毛（NGT）II&III 似乎限制了扩散。GT VI 似乎具有驱避作用。相反，NGT V 的数量与高移动性和茎交叉率呈正相关。假设生物防治效率的主要障碍是沿着番茄茎的扩散，这些初步结果应该对生物防治的成功产生影响。具有“最佳尺寸”的螨虫比例似乎较低，还需要进一步研究以更好地评估不同种群中具有这种理想尺寸的螨虫的比例，以及确定这些形态特征是否与不同的取食能力和/或非生物条件有关。
