Haemoproteus infections (Haemosporida, Haemoproteidae) kill bird-biting mosquitoes

Abstract

Haemoproteus parasites (Haemosporida, Haemoproteidae) are widespread; some species cause severe diseases in avian hosts. Heavy Haemoproteus infections are often lethal for biting midges (Ceratopogonidae), which transmit avian haemoproteids, but there is no information regarding detrimental effect on other blood-sucking insects. We examined effects of Haemoproteus tartakovskyi (lineage hSISKIN1), Haemoproteus lanii (lineages hRB1and hRBS2) and Haemoproteus balmorali (lineage hCOLL3) on the survival of Ochlerotatus cantans, a widespread Eurasian mosquito. Wild-caught females were infected by allowing them to feed on naturally infected birds with light (0.01%) and high (3.0-9.6%) parasitaemia. Mosquitoes fed on uninfected birds were used as controls. Both experimental and control groups were maintained under the same laboratory conditions until 20 days post-exposure (dpe). Dead insects were counted daily and used for parasitological examination and PCR-based testing. No difference was discernible in the survival rate of control mosquitoes and those fed on meal with light parasitaemia. There was a highly significant difference in the survival rate between the control group and all groups fed on meals with high parasitaemia, with the greatest mortality reported 1-3 dpe. For 4 dpe, the percentage of survived control mosquitoes (88%) was 2.2-, 3.6- and 4-fold greater than that of groups fed on meals with high parasitaemia of H. balmorali, H. tartakovskyi and H. lanii, respectively. Numerous ookinetes were observed in the gut area and adjacent tissues located in the head, thorax and abdomen of infected insects 0.5-1 dpe. The migrating parasites damage organs throughout the entire body of mosquitoes; that is the main reason of mortality. To the end of this study, 46% of mosquitoes survived in control group, but the survival rates of experimental mosquitoes fed on meals with high parasitaemia were between 2.6- and 5.8-fold lower. This study indicates that widespread Haemoproteus infections are markedly virulent for bird-biting mosquitoes, which rapidly die after feeding on heavily infected blood meals.

Do mosquitoes transmit the avian malaria-like parasite Haemoproteus? An experimental test of vector competence using mosquito saliva

“…Previous studies using direct observational (microscope) and molecular (PCR) techniques found intermediate stages (i.e. ookinetes and oocysts) of Haemoproteus parasites in the head, thorax and/or abdomen of Ochlerotatus cantans mosquitoes from 4–6 dpe onwards, but presence of sporozoites was not recorded [51, 52]. By contrast, we found no evidence of Haemoproteus DNA in the head-thorax of the mosquitoes analysed.…”

Description, molecular characterisation, diagnostics and life cycle of Plasmodium elongatum (lineage pERIRUB01), the virulent avian malaria parasite

“…Abortive development happens when a parasite invades a host, in which it can develop only partially, and cannot complete its full life cycle, resulting in the absence of infective stages, i.e. gametocytes (in birds) or sporozoites in vectors (Olias et al, 2011;Valkiūnas et al, 2014).…”

Haemoproteus spp. and Leucocytozoon californicus Coinfection in a Merlin (Falco colombarius)

“…Each smear was examined through 100-150 fields at low magnification (400X) and then at least 100 fields at high magnification (1000X). The measurements of parasite and infected host cells were made based on morphometric parameters of gametocytes as previously proposed, i.e., the length, width, and area of macrogametocytes and microgametocytes, parasite nucleus, and area of host cell parasite complex [20]. The parameters were determined using a semiautomated morphometric system (LAS 4.1, Leica Microsystems, Wetzlar, Germany) and statistically analysed using IBM SPSS Statistics 21 system.…”