Chuche Julien, Sauvion Nicolas, Thiéry Denis
INRA, UMR 1065 Santé et Agroécologie du Vignoble, Bordeaux Sciences Agro, ISVV, 33882 Villenave d'Ornon Cedex, France; Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland.
INRA, UMR 0385 Biologie et Génétique des Interactions Plantes-Parasites, Campus International de Baillarguet, Montpellier, France.
J Insect Physiol. 2017 Oct;102:62-72. doi: 10.1016/j.jinsphys.2017.01.014. Epub 2017 Jan 23.
In phytophagous piercing-sucking insects, salivary sheath-feeding species are often described as xylem- or phloem-sap feeding specialists. Because these two food sources have very different characteristics, two feeding tactics are often associated with this supposed specialization. Studying the feeding behavior of insects provides substantial information on their biology, ecology, and evolution. Furthermore, study of feeding behavior is of primary importance to elucidate the transmission ability of insects that act as vectors of plant pathogens. In this study, we compared the durations of ingestion performed in xylem versus phloem by a leafhopper species, Scaphoideus titanus Ball, 1932. This was done by characterizing and statistically analyzing electrical signals recorded using the electropenetrography technique, derived from the feeding behaviors of males and females. We identified three groups of S. titanus based on their feeding behavior: 1) a group that reached the phloem quickly and probed for a longer time in phloem tissue than the other groups, 2) a group that reached the xylem quickly and probed for a longer time in xylem tissue than the other groups, and 3) a group where individuals did not ingest much sap. In addition, the numbers and durations of waveforms representing ingestion of xylem and phloem saps differed significantly depending on the sex of the leafhopper, indicating that the two sexes exhibit different feeding behaviors. Males had longer phloem ingestion events than did females, which indicates that males are greater phloem feeders than females. These differences are discussed, specifically in relation to hypotheses about evolution of sap feeding and phytoplasma transmission from plant to plant.
在植食性刺吸式昆虫中，唾液鞘取食种类通常被描述为木质部或韧皮部汁液取食专家。由于这两种食物来源具有非常不同的特性，两种取食策略通常与这种假定的专业化相关联。研究昆虫的取食行为能提供有关其生物学、生态学和进化的大量信息。此外，研究取食行为对于阐明作为植物病原体传播媒介的昆虫的传播能力至关重要。在本研究中，我们比较了1932年命名的叶蝉物种葡萄斑叶蝉（Scaphoideus titanus Ball）在木质部和韧皮部的取食持续时间。这是通过对使用电穿透图技术记录的电信号进行特征描述和统计分析来完成的，这些电信号源自雄性和雌性的取食行为。我们根据葡萄斑叶蝉的取食行为将其分为三组：1）一组能快速到达韧皮部并在韧皮部组织中探测的时间比其他组更长；2）一组能快速到达木质部并在木质部组织中探测的时间比其他组更长；3）一组个体摄取的汁液不多。此外，代表木质部和韧皮部汁液摄取的波形数量和持续时间因叶蝉的性别而异，这表明两性表现出不同的取食行为。雄性韧皮部摄取事件的持续时间比雌性长，这表明雄性比雌性更倾向于取食韧皮部。我们讨论了这些差异，特别是与关于汁液取食进化和植物间植原体传播的假设相关的差异。
