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

Abstract

Infection of fourth-instar Aedes aegypti (L.) with the entomopathogenic digenean Plagiorchis elegans (Rudolphi) alters the carbohydrate metabolism of the insect. Within 24 h of cercarial penetration, total body extracts of infected fourth instars exhibited decreased trehalase activity, increased trehalose-6-phosphatase activity, and a concomitant accumulation of trehalose when compared with uninfected larvae. The amounts of glucose, glycogen and lipids, and the activity of glycogen phosphorylase a were similar in extracts of infected and control larvae. The predominant fatty acids, in both control and infected larvae, were C 18:0, C 18:1, and C 18:3. There were no significant differences in the types or proportions of fatty acids found in control and infected larvae. Parasitic infection is discussed in terms of impaired trehalose metabolism.

Hidden diversity: parasites of stream arthropods

“…For example, microsporidians can substantially influence their hosts’ population structure and cycles (e.g. Kohler & Hoiland, ; Terry et al ., ), the trematode P. elegans can modify the carbohydrate metabolism and the oviposition behaviour of its arthropod host (Lowenberger & Rau, ; Wallage, Niven & Rau, ; Nguyen, Dutilleul & Rau, ), and acanthocephalans often manipulate their intermediate hosts to increase trophic transmission to the respective definitive host (Taraschewski, ; Sures, ). Several studies also point out the interactive effect of two parasites in a single host (Cézilly, Perrot‐Minnot & Rigaud, ), underlining the need to know all parasites in an ecosystem that might have an influence on the host populations.…”

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

“…The difference in total carbohydrate reserves between CM and PEL pupae is interesting and further study is required to understand whether parasitism with P. elegans affects specific carbohydrates crucial to larval development or oogenesis. Parasite–induced increases in haemolymph trehalose concentrations, coupled with an inhibition of trehalase activity may lead to low glucose availability for metabolic processes and may create anorexia in the larvae (Wallage et al 2001). Parasitized individuals compete with endoparasites for specific nutrients, competition that may deplete nutrients required for specific physiological processes.…”

Utilization of pre-existing energy stores of female Aedes aegypti mosquitoes during the first gonotrophic cycle

“…In the fourth instar Ae. aegypti larvae, most of fatty acids are C18:0, C18:1 and C18:3 (Wallage et al, 2001), and the rate of lipid synthesis was highest in the early fourth instar larvae and decreased shortly before pupation (Timmermann and Briegel, 1999). Thus, we decided to use [1-14 C]-oleic acids as a component of larval diet in the early fourth instar larvae of Ae.…”