Cydianerus latruncularius (Perty, 1832) is a broad-nosed weevil (Entiminae) with South American distribution. In the past few years, some cases were observed where morphological modifications can occur on different populations of widely distributed species in various animal groups, including insects. Currently, geometric morphometrics is one of the most reliable and substantial ways to analyze shape variation among organisms. This technique is based on analysis of landmarks and their deviation on different individuals, identifying or not, conspicuous changes among them. It is a very useful tool to test shape variation among groups of organisms under different environmental pressures, whatever they might be. Knowing about the wide distribution and environmental diversity (Rainforests, Cerrado, Caatinga) occupied by C. latruncularius, the following research aims to discover if there are any shape patterns among sexes and individuals from different Brazilian ecosystems. Images of males and females’ pronotum, elytra and ventrite were landmarked in order to obtain morphological data which was then analyzed through MorphoJ software. Variations were found in all structures, which presented different results throughout the analysis. Pronotum proved to be a determinant structure to separate Amazonian populations from the others. The elytra formed groups only among males from Cerrado and Rainforests, while all females were overlapping. Also, the ventrites proved to be the best structures to describe sexual dimorphism. Geometric morphometrics of C. latruncularius allowed us to verify that the shape of different body parts varies in an independent way among them and are possibly influenced by the environment.

Cydianerus latruncularius（珀蒂，1832年）是南美分布的宽鼻象鼻虫（Entiminae）。在过去的几年中，观察到了一些情况，其中形态变化可能发生在包括昆虫在内的各种动物组中分布广泛的物种的不同种群上。当前，几何形态计量学是分析生物之间形状变化的最可靠，最实质的方法之一。该技术基于对地标及其在不同个体上的偏离的分析，可以识别或不识别它们之间的明显变化。这是一个非常有用的工具，可以测试在不同环境压力下的各种生物体之间的形状变化，无论它们可能是什么。了解被占领者的广泛分布和环境多样性（雨林，塞拉多，卡廷加）C. latruncularius，以下研究旨在发现来自巴西不同生态系统的性别和个体之间是否存在任何形态模式。为了获得形态学数据，对男性和女性的前胸膜，鞘翅和腹肌图像进行标记，然后通过MorphoJ软件对其进行分析。在所有结构中都发现了变异，在整个分析过程中呈现出不同的结果。Pronotum被证明是将亚马逊人口与其他人口区分开的决定性结构。鞘翅目只在Cerrado和Rainforests的雄性中形成群，而所有雌性则重叠。同样，腹肌被证明是描述性二态性的最佳结构。C. latruncularius的几何形态计量学 使我们能够验证不同身体部位之间的形状以独立的方式变化，并且可能受到环境的影响。