Euplatypus parallelus (F.) (Coleoptera: Curculionidae) is one of the most invasive species of all the Platypodinae. It penetrates the xylem and oviposits in its host trees thereby weakening the trunk causing them to break under extreme conditions. Since the beetle has evolved effective drilling mouthparts enough to make wood tunnels, we used a field emission scanning electron microscopy to describe the sexual difference in mouthparts and forelegs morphology of the beetle. E. parallelus has chewing type mouthparts composed of a labrum, a pair of mandibles, a pair of maxillae, and a labium. In females, the size of maxillary palpi, submentum, prementum, and labial palpi are significantly larger than males. E. parallelus forelegs were walking type composed of procoxa, protrochanter, profemur, protibia, protarsus, and propretarsus. We observed no significant differences between the forelegs of males and females, but the procoxa of the males was slightly larger than that of females. The structural differences in mouthparts and forelegs between females and males indicated that females invest more time in gallery excavation than males. Possible functional relationships of these structures are discussed. These studies revealed the mechano-dynamic characteristics of E. parallelus and provided a theoretical basis for exploring the behavior of this beetle.

Euplatypus parallelus（F.）（Coleoptera：Curculionidae）是所有鸭嘴兽中最具入侵性的物种之一。它穿透木质部并在其寄主树中产卵，从而削弱树干，导致树干在极端条件下折断。由于甲虫已经进化出足够的有效钻孔口，可以制造木隧道，因此我们使用场发射扫描电子显微镜描述了甲虫的口部和前肢形态上的性别差异。E.parallelus有咀嚼型口器，由唇形，一对下颌，一对上颌和一个唇形组成。在女性中，上颌腕，下颌，前肠和唇唇的大小明显大于男性。平行大肠杆菌前肢为步行型，由procoxa，protrochanter，profemur，protibia，protarsus和propretarsus组成。我们观察到雄性和雌性的前腿之间没有显着差异，但是雄性的procoxa略大于雌性。雌性和雄性之间的口器和前肢的结构差异表明，雌性在画廊发掘上花费的时间比雄性要多。讨论了这些结构可能的功能关系。这些研究揭示了平行虫的机械动力学特性，并为探索该甲虫的行为提供了理论基础。