Résumé
Environmental unpredictability challenges the transmission success of
vector-borne parasites like Plasmodium, whose fitness depends on
synchronizing gametocyte production with vector availability. Although
mosquito bites are known to trigger Plasmodium responses, it remains
unclear whether parasites respond specifically to competent vectors or
adopt a generalist strategy. We experimentally infected birds with the
avian malaria parasite Plasmodium relictum and exposed them to bites from
either a competent (Culex quinquefasciatus) or a non-competent (Anopheles
gambiae) vector species. Both exposures induced a rise in parasitaemia,
but the response was significantly stronger to the non-competent species.
Host inflammatory, humoral, and stress markers remained similar across
mosquito treatments, implying that unidentified physiological cues may
underlie the parasite's response. No species-specific modulation of
gametocyte conversion rate or sex ratio was observed. These findings
suggest that P. relictum does not discriminate between mosquito species,
instead employing a generalist, possibly bet-hedging strategy in response
to any mosquito bite. Our results highlight the importance of mosquito
community composition in shaping parasite transmission dynamics. If
non-vector mosquitoes enhance Plasmodium transmission investment, shifts
in vector assemblages due to climate change or control measures may have
unanticipated effects on disease ecology.