Parathelohania is a genus of microsporidia that preferentially attacks Anopheline mosquitoes. This study explored some selective aspects of the epizootiology of Parathelohania iranica (Microsporidia: Amblyosporidae) in its malaria mosquito host Anopheles superpictus s.l. (Diptera: Culicidae). For this study, Sar-rok Village, a place adjacent to the type locality of the parasite, located at the central western part of Iran was visited twice a month to collect host larvae from mid-summer to mid-autumn of 2017–2021. Patent infections were detected by the whitish discoloration of the involved segments. Superficially uninfected larvae were reared up to 26 days in the insectary to elucidate hidden infections. Molecular investigation and laboratory trials were conducted to evaluate the possibility of secondary infections in subsequent days. Morphological characters were used to determine the sex of larvae and adults. Data were entered in SPSS 23.0 and analyzed with relevant statistical tests as needed. In total, 584 P. iranica infected larvae of An. superpictus s.l. were collected in the study years at day zero (D0). Extended observations in the insectary revealed that 849 larvae (84.2 %), 22 dead pupae (2.2 %), and 137 emerged adults (13.6 %) were also infected. In the first two years of the study, the mean infection rate for D0 and D0 + D1-D26 infections was 6.25 % and 15.6 %, respectively. Exposure experiments indicated that subsequent infections in larvae (D1-D26) were not affected by a possible source in the accompanying field water. Patent (D0) infections were seasonal and had about a month delay compared to the general population of larvae. Concealed infections of larvae (D1-D26) were significantly more frequent in late mosquito season (P < 0.01). It is proposed that the gradual decrease of ambient temperature and the shortening of day length postpones the growth and development of P. iranica in the affected larvae. Both sexes of larvae were involved and none of them survived beyond a couple of days. The frequency of infections in adult males (5.8 %) were significantly more than females (4 %) (P = 0.02). The infections of larvae were more common in the late mosquito season, and the infections of adults were more frequent in the early mosquito season. This suggests the relative importance of vertical and horizontal routes of transmission in early and late mosquito seasons, respectively. However, age-specific data revealed that only 26 % of hidden infections of larvae (D1-D26) were stemmed from I to II age group. This implies that the vertical route may be less efficient than the horizontal route in the transmission of P. iranica to the mosquito host. These inferences should be verified with further field and laboratory investigations.

Parathelohania是一种优先攻击按蚊的微孢子虫属。本研究探讨了Parathelohania iranica（微孢子虫：弱孢子科）在其疟蚊宿主Anopheles superpictus中的动物流行病学的一些选择性方面sl（双翅目：蚊科）。在这项研究中，在 2017 年至 2021 年的仲夏至仲秋期间，每月访问伊朗中西部与寄生虫模式产地相邻的 Sar-rok 村两次，以收集寄主幼虫。通过相关部分的白色变色检测到专利感染。将表面未感染的幼虫在昆虫室中饲养长达 26 天，以阐明隐藏的感染。进行了分子研究和实验室试验，以评估随后几天发生继发感染的可能性。形态特征用于确定幼虫和成虫的性别。数据输入SPSS 23.0，并根据需要进行相关统计检验分析。总共有 584 个P. iranica感染了An 的幼虫。超级图片sl 是在研究年的第零天 (D0) 收集的。对昆虫的进一步观察显示，849 只幼虫 (84.2%)、22 只死蛹 (2.2%) 和 137 只羽化成虫 (13.6%) 也被感染。在研究的前两年，D0 和 D0 + D1-D26 感染的平均感染率分别为 6.25% 和 15.6%。暴露实验表明，幼虫 (D1-D26) 的后续感染不受伴随田间水中可能来源的影响。专利 (D0) 感染是季节性的，与一般幼虫种群相比有大约一个月的延迟。隐蔽感染幼虫 (D1-D26) 在蚊季后期明显更频繁 ( P < 0.01)。提出环境温度的逐渐降低和日照长度的缩短延迟了受影响幼虫中P. iranica的生长发育。两性幼虫都参与其中，没有一只存活超过几天。成年男性的感染频率 (5.8 %) 明显高于女性 (4 %) ( P = 0.02）。幼虫感染多见于蚊季后期，成虫感染多见于蚊季初期。这表明垂直和水平传播途径分别在早期和晚期蚊子季节中的相对重要性。然而，特定年龄的数据显示，只有 26% 的幼虫 (D1-D26) 隐藏感染来自 I 至 II 年龄组。这意味着在将P. iranica传播给蚊子宿主时，垂直途径可能不如水平途径有效。应通过进一步的实地和实验室调查来验证这些推论。