Tetragona Lepeletier & Serville is a genus of stingless bees with 14 recognized species occurring from Mexico to Argentina. The genus is characterized by velvety genal area, mesotibial spur present, and propodeal triangle glabrous. Within the genus, the truncata species group (T. truncata Moure and T. atahualpa sp. nov.) is characterized by worker metabasitarsus with posterior angle rounded and the mandible with two short teeth of similar length. Tetragona truncata is reported with new records for Ecuador (Napo and Orellana), Peru (Huánuco, Loreto, and San Martín), and Brazil (Acre [Rio Branco] and Tocantins [Itacá, Lizarda and Palmas]). In addition, T. atahualpa sp. nov. is described as a new species from regions of altitudes above 1,800 m in Colombia (Boyacá), Ecuador (Napo, Zamora-Chinchipe), and Peru (Pasco). We illustrate and discuss the identification of these two species.

Tetragona Lepeletier & Serville 是一种无刺蜜蜂属，有 14 种公认的物种，分布于墨西哥和阿根廷。该属的特点是有天鹅绒般的生殖区，存在胫骨骨刺和前三角无毛。在该属中，truncata物种组（T. truncata Moure 和T. atahualpa sp. nov.）的特征是后角为圆形的后颌骨和下颌骨具有两颗长度相似的短牙齿。据报道，Tetragona truncata在厄瓜多尔（Napo 和 Orellana）、秘鲁（Huánuco、Loreto 和 San Martín）和巴西（Acre [Rio Branco] 和 Tocantins [Itacá、Lizarda 和 Palmas]）都有新记录。此外，T. atahualpa sp. 十一月被描述为来自哥伦比亚 (Boyacá)、厄瓜多尔 (Napo、Zamora-Chinchipe) 和秘鲁 (Pasco) 海拔 1,800 m 以上地区的新物种。我们说明并讨论了这两个物种的鉴定。