The Effects of Plagiorchis noblei Metacercariae on the Development and Survival of Aedes aegypti Larvae in the Laboratory

Abstract

Plagiorchis noblei infections impair the survival and development of fourth instar Aedes aegypti larvae. Mortality during the larval and pupal stages reached 92%, and 60% of the emerging adults were malformed. The metacercariae interfere with pupation and the emergence of adults. Larvae and pupae that fail to transform to the next developmental stage within the normal time characteristically persist for extended periods, but invariably die without transforming. Whereas 82% of the control larvae gave rise to functional adults, only 4% of infected larvae managed to do so. Such effects may facilitate the transmission of the parasite.

The influence of larval density, food stress, and parasitism on the bionomics of the dengue vector Aedes aegypti (Diptera: Culicidae): implications for integrated vector management

“…Our PEL treatment is classified as “light” by both Schwab et al (2003) and Lowenberger and Rau (1994b) who used more than double the cercariae/ml exposure concentration that we employed. We opted for inducing lower levels of parasitism to increase the probability that infected individuals would survive to eclosion and be fit enough to undergo normal reproductive activity to enable observation of sub‐lethal effects of parasitism (Dempster et al 1986). Conversely, heavily parasitized Ae.…”

“…One‐time individual exposure of Ae. aegypti larvae to P. elegans xiphidiocercariae can result in parasitism levels sufficient to kill pre‐imago stages and produce impaired and moribund adults (Dempster et al 1986, Lowenberger and Rau 1994a). Thus, both continuous and one‐time exposure of Ae.…”

Effects ofPlagiorchis elegans(Trematoda: Plagiorchiidae) Infection on the Carbohydrate Metabolism of Fourth InstarAedes aegypti(Diptera: Culicidae)

“…The change in trehalase activity as a result of parasitism is consistent with the delayed development of Ae. aegypti larvae infected with Plagiorchis metacercariae as reported by Dempster et al (1986).…”

The Impact of Selective Oviposition and Infection with <I>Plagiorchis elegans</I> on <I>Aedes aegypti</I> Pre-Imago Population Dynamics at Optimal Food Availability

“…This supports the results of Rau et al (1991). Because early instars and pupae are less susceptible to cercarial acquisition (Dempster et al 1986), such high levels of mortality are most likely because of the accumulation of metacercariae during the late larval stages. The lethal effects are deferred until pupation and adult emergence.…”

“…Parasitized mosquito populations experience elevated pre-imago mortality, greatly reduced adult emergence, and severe developmental abnormalities (Dempster et al 1986). Asexual production of the parasite occurs within the tissues of its molluscan Þrst intermediate host and results in the daily release of large numbers of the entomopathogenic cercariae into the aquatic environment (Blankespoor 1974).…”