Haematopoietic organs (HOs) in Lepidoptera are widely recognised as the source for at least two haemocyte types. With new specific markers for oenocytoids and spherule cells and a method to identify prohaemocytes, the haemocytes formed in and released by the HOs of Manduca sexta are characterised. Differentiation of HO-cells to haemocytes other than plasmatocytes and prohaemocytes neither occurs in the organ itself nor in cells released in vitro by the HOs. Differential labelling patterns evidence the existence of plasmatocyte subpopulations and prohaemocytes, which might represent a gradual differentiation of haemocytes within the organs. Prohaemocytes can be identified by PNA-labelling of the cell membrane. These prohaemocytes are found in circulation and in the HOs and are released by the organs. Circulating prohaemocytes possess characteristics for granular cells, plasmatocytes or oenocytoids while HO derived prohaemocytes share characteristics only with plasmatocytes. Ablation of the HOs diminishes the plasmatocyte and prohaemocyte number, indicating a true larval haematopoietic function.

鳞翅目中的造血器官 (HO) 被广泛认为是至少两种血细胞类型的来源。借助新的嗜细胞样细胞和小球细胞的特异性标记物以及一种识别原血细胞的方法，可以表征在Manduca sexta的 H2O 中形成和释放的血细胞。HO细胞分化为除浆细胞和原血细胞以外的血细胞既不发生在器官本身，也不发生在体外释放的细胞中由 HO。不同的标记模式证明了浆细胞亚群和原血细胞的存在，这可能代表了器官内血细胞的逐渐分化。原血细胞可以通过细胞膜的 PNA 标记来识别。这些原血细胞存在于循环和 HOS 中，并由器官释放。循环原血细胞具有颗粒细胞、浆细胞或类细胞的特征，而 H2O 衍生的原血细胞仅与浆细胞具有共同特征。H2Os 的消融减少了浆细胞和原血细胞数量，表明真正的幼虫造血功能。