Kissing bugs (Hemiptera: Reduviidae: Triatominae) are able to bend their rod-like maxillae while searching for blood vessels in the tissue of their vertebrate hosts. Little is known about the working mechanisms of these bending movements and the distal opening of the food channel. We compared the morphological structure of the stylets (mandibles and maxillae) of four triatomine species and analyzed the feeding process of Dipetalogaster maxima (Uhler, 1894). The maxillae of triatomine bugs are interlocked by a tongue-and-groove system, allowing longitudinal sliding. While penetrating the host tissue, the animals perform rapid alternate back and forth movements of the maxillae. The resistance of the surrounding tissue pushes the asymmetric apex of the maxillae away from its straight path, i.e., if one individual maxilla is protracted alone, its tip curves inwards, and the other maxilla follows. Once a blood vessel is tapped, the spine-like tip of the left maxilla splays outwards. Apically, each of the maxillae features an abutment, the left one exhibiting a notch that presumably facilitates splaying. The mechanical interaction of the two maxillary abutments enables the distal opening of the food channel but might also support the movements of the maxillary bundle attributable to different bending moment distributions.

接吻的臭虫（半翅目：Reduviidae：Triatominae）能够弯曲杆状上颌，同时在脊椎动物宿主的组织中寻找血管。对于这些弯曲运动和食物通道的远侧开口的工作机理知之甚少。我们比较了四种三角藻种类的通心粉（下颌骨和上颌骨）的形态结构，并分析了最大的Dipetalogaster的取食过程（Uhle​​r，1894）。三角榫bug的上颚由舌沟系统互锁，从而允许纵向滑动。在穿透宿主组织的同时，动物进行上颌骨的快速交替来回运动。周围组织的阻力将上颌骨的不对称顶点推离其笔直路径，即，如果一个上颌骨单独伸出，其尖端向内弯曲，而另一上颌骨则跟随其后。轻拍血管后，左上颌骨的脊柱状尖端向外张开。根尖上，每个上颌都有一个基台，左上有一个可能有助于张开的凹口。