Stylops advarians Pierce (Strepsiptera: Stylopidae) is a prevalent parasite of adult Andrena milwaukeensis Graenicher (Hymenoptera: Andrenidae) in Saskatoon, Saskatchewan, Canada. By dissecting adult bees and examining histological sections, we sought to determine how neotenic females of S. advarians impact female hosts of A. milwaukeensis anatomically. Adult bees with 1–3 females of S. advarians within their gasters were compared to nonstylopised bees (control). The presence of a single female parasite inhibited development of the host’s ovaries. The bee’s foregut shifted laterally when one parasite occupied the gaster and ventrally when two or three were present, thereby reducing the crop’s expandable capacity and the amount of nectar and pollen that stylopised bees can ingest. The midgut and hindgut were less significantly affected by stylopisation. Female parasites typically occupied the host’s gaster dorsolaterally, where each was supported by one of the host’s air sacs. If a third female parasite was present, she resided dorsally along the midline of the host’s gaster, mostly supported by the two female parasites to either side. Asynchronous development within neotenic female parasites was demonstrated, wherein mature first-instar larvae occupied the cephalothorax and abdomen at the same time that the adult female was still supporting multiple embryos.

Stylops advarians Pierce ( Streppsiptera : Stylopidae) 是加拿大萨斯喀彻温省萨斯卡通的成年Andrena milwaukeensis Graenicher (膜翅目: Andrenidae)的流行寄生虫。通过解剖成年蜜蜂和检查组织切片，我们试图确定S. advarians 的新生雌性如何在解剖学上影响A. milwaukeensis 的雌性宿主。有 1-3 只雌性S. advarians 的成年蜜蜂将它们的胃内与非风格化的蜜蜂（对照）进行比较。单个雌性寄生虫的存在抑制了宿主卵巢的发育。当一种寄生虫占据胃部时，蜜蜂的前肠会横向移动，当存在两三种寄生虫时，蜜蜂的前肠会向腹侧移动，从而降低了作物的可扩展能力以及异形蜜蜂可以摄取的花蜜和花粉量。中肠和后肠受异型化的影响较小。雌性寄生虫通常占据宿主背外侧的胃，其中每个都由宿主的一个气囊支撑。如果存在第三个雌性寄生虫，她会沿着宿主胃中线的背部栖息，大部分由两侧的两个雌性寄生虫支撑。证明了新生雌性寄生虫的异步发育，