Producción masiva de Romanomermis iyengari (Nematoda: Mermithidae) y su aplicación en criaderos de anofelinos en Boa Vista (Roraima), Brasil

Abstract

In order to begin mass producing the nematode Romanomermis iyengari Welch, a bioprocessing plant was designed and set up on the grounds of Universidad Federal in the State of Roraima, Brazil, after reaching an agreement with the State's Health Department. The objective of this paper was to establish the basic process for mass breeding the parasite in order to apply it to anopheline breeding sites. Cultures were obtained at a rate of 68 during every seven-day cycle, making for a total of 272 cultures a month. Before treatments were applied in the field, laboratory tests were conducted that showed the great susceptibility of anopheline larvae to infestation by R. iyengari, with parasitism rates ranging from 71 to 98%. In order to assess the parasitizing capacity of R. iyengari in actual field conditions, 12 natural anopheline breeding sites were chosen, each ranging in size between 50 and 450 m2. The species Anopheles albitarsis Lynch-Arribálzaga and Anopheles rondoni Neiva-Pinto were detected there, at densities that ranged from 34 to 66 larvae/m2. The biolarvicide was sprayed in all 12 breeding sites with a domestically manufactured pump set at a pressure of two atmospheres and a dose of 2,000 preparasites/m2. Seven days after treatments were performed, anopheline populations were markedly reduced (85 to 97%). Results obtained point to the feasibility of using R. iyengari to control larval populations of both species of anophelines.

Efficacy of the mermithid nematode, Romanomermis iyengari, for the biocontrol of Anopheles gambiae, the major malaria vector in sub-Saharan Africa

“…Various authors have reported similar levels of larval density reduction following the release of R. iyengari in countries such as Cuba and Mexico [14–16, 20, 21, 25–28]. Distinctive feature of the present study is that various nematode concentrations were tested, and results showed that there was no significant difference between these concentrations in the Anopheles and the mixed breeding sites.…”

“…albitarsis and An. rondoni populations were reduced by 85–97% [16]. Despite the effectiveness of R. iyengari in regions where the climate is comparable to that of malaria endemic countries, this nematode has never been used in experiments in Africa, which accounts for 91% of deaths caused by malaria [17].…”

Susceptibilidad de las larvas de Aedes aegypti al parasitismo por Romanomermis culicivorax en condiciones de laboratorio y de campo en Oaxaca, México

“…(13). Hay publicados otros resultados positivos sobre la aplicación de mermítidos para el control de las poblaciones larvarias de mosquitos de importancia médico-epidemiológica (14,15), que, al igual que los resultados del presente estudio, indican que el uso de mermítidos podría constituir un método más para alternar con algunos larvicidas químicos como el abate, sobre todo si se tiene en cuenta que un estudio reciente de 102 muestras de A. aegypti procedentes de 16 países, desde Sudamérica hasta las Bahamas, pasando por la cadena de islas del Caribe, evidenció la resistencia manifestada por esta especie tanto al larvicida abate (temephos) como al adulticida malathión, que se han venido utilizando durante los últimos 30 años (16).…”

Microorganismes entomopathogènes, prédateurs et parasites des moustiques: Perspectives pour la lutte raisonnée contre les vecteurs du paludisme en Afrique sub-saharienne

“…Au Cuba, un pays à climat tropical, des essais en milieu naturel ont démontré que R. iyengari décime les populations de différentes espèces de moustiques (Santamarina et al, 1993 ;Santamarina et Mijares, 1995 ;Santamarina et al, 1996). Au Mexique et au Brésil également, il a été démontré que R. iyengari parasite et tue les moustiques vecteurs de maladies y compris diverses espèces d'anophèles (Santamarina et al, 1999 ;Santamarina et Bellini, 2000). On connait aujourd'hui plus de 30 espèces de moustiques susceptibles à l'infection de R. iyengari (Platzer, 2007).…”