Developmental synchrony of Ascogregarina taiwanensis (Apicomplexa: Lecudinidae) within Aedes albopictus (Diptera: Cuclicidae).

Development of Ascogregarina taiwanensis Lien & Levine was synchronized with its host, the Asian tiger mosquito, Aedes albopictus (Skuse). Trophozoites of the parasite migrate to the Malpighian tubules where the gamonts fuse to form gametocysts and later mature oocysts. In this study, we observed that water temperature, which alters the development time of mosquito larvae, also affected parasite development. A. taiwanensis developed in a shorter time at 29 degrees C, whereas at 14 degrees C, the development was extended to as long as 17 d. Few mature oocysts were produced at 29 degrees C, although gametocysts occasionally were found in the lumen of Malpighian tubules. In contrast, gametocysts did not develop at 14 degrees C unless pupation occurred. Stage transformation of the parasite was determined by the metamorphosis of the mosquito host. Gametocyst formation occurred earlier when infected larvae were injected with an appropriate concentration of 20-hydroxyecdysone, indicating this molting hormone was involved in regulating the synchronous development of A. taiwanensis in its mosquito host.