Susceptibility of ten species of mosquito larvae to the parasitic nematode Romanomermis iyengari and its development

Abstract

Ten species of mosquitoes (Diptera: Culicidae) from five genera were exposed to preparasites of the tropical mermithid nematode species Romanomermis iyengari (Welch) (Nematoda: Mermithidae), a strain isolated in 1978 from Pondicherry. By exposing mosquito larvae during the second instar, nematode infection was invariably lethal, the rate being highest in Culex sitiens Wiedemann (95%) followed by Cx. quinquefasciatus Say (90%), Aedes aegypti (L.) (79%), Anopheles subpictus Grassi (64%), Ae. albopictus (Skuse) and Armigeres subalbatus Coquillett (62%), Cx. tritaeniorhynchus Giles (57%), Mansonia annulifera (Theobald) (46%), An. stephensi Liston (40%) and An. culicifacies Giles (36%). When fourth-instar larvae were exposed, the infection was highest in Ar. subalbatus (66%), followed by An. stephensi (52%), Cx. quinquefasciatus (47%), Ae. aegypti and An. subpictus (42%), Ae. albopictus (30%), An. culicifacies (29%), Cx. sitiens (24%), Cx. tritaeniorhynchus (19%) and Ma. annulifera (8%), with 2-45% of infected culicines surviving to adulthood. The parasitic phase of the nematode lasted 5-7 days in all the host species, yielding 1.1-3.2 parasites per II instar and 1.1-2.5 parasites per IV instar. The overall output of parasites per 100 mosquito larvae (infected + uninfected) was highest for Ae. aegypti when mosquitoes were exposed during II instar (2.53 parasites/larva) and for Ar. subalbatus when mosquitoes were exposed during IV instar (1.65/larva), and lowest for Ma. annulifera exposed during IV instar (0.09/larva). For routine laboratory culture of R. iyengari it is convenient to employ Cx. quinquefasciatus as the host yielding 90-190 parasites/100 larva.

Host range of the parasite Strelkovimermis spiculatus(Nematoda: Mermithidae) in Argentina mosquitoes

“…The number of nematodes emerging from each mosquito larvae in the present work was less than four parasites per infected mosquito larva with the single exception of P. cyanecens , where double this value was recorded. A lower value was obtained for the mermithids Romanomermis culicivorax and Romanomermis iyengari in natural populations of mosquitoes, which does not exceed three (Santamarina et al 1992, Paily and Balaraman 2000, Perez‐Pacheco et al 2004, 2009). The reasons for the high number of nematodes that emerged from P. cyanecens larvae in our study are not known.…”

Perspectives of vector management in the control and elimination of vector-borne zoonoses

“…gambiae , Anopheles culicifacies , Anopheles stephensi , Anopheles subpictus , Armigeres subalbatus , Culex pipiens, Culex quinquefasciatus, Culex sitiens, Culex tritaeniorhynchus, and Mansonia annulifera ), Diximermis peterseni (against Anopheles crucians , Anopheles quadrimaculatus , and Anopheles punctipennis ) and Strelkovimermis spiculatus (against Aedes albifasciatus and Cx. pipiens ; Petersen and Willis, 1974 ; Levy and Miller, 1977 ; Poinar and Camino, 1986 ; Santamarina Mijares and Perez Pacheco, 1997 ; Paily and Balaraman, 2000 ; Sanad et al, 2013 , 2017 ; Abagli and Alavo, 2019 ; Abagli et al, 2019 ). However, the lack of culturable mermithids hinders mass application of this nematode as a biocontrol agent ( Kendie, 2020 ).…”

“…The emerged post-parasite stage then molts into the free-living adult to reproduce and lay eggs. Multiple mermithids may repeatedly infect an already infected larva, giving rise to a phenomenon called superparasitism (Sanad et al, 2017) Petersen and Willis, 1974;Levy and Miller, 1977;Poinar and Camino, 1986;Santamarina Mijares and Perez Pacheco, 1997;Paily and Balaraman, 2000;Sanad et al, 2013Sanad et al, , 2017. However, the lack of culturable mermithids hinders mass application of this nematode as a biocontrol agent (Kendie, 2020).…”

Mosquito-Borne Diseases Emergence/Resurgence and How to Effectively Control It Biologically

“…quinquefasciatus, and An. gambiae [226][227][228][229]. As they are naturally adapted to their host, such nematodes are highly specific to theirs hosts, which they can kill by producing high levels of parasitism.…”