Nematodes as a biological alternative for the control of disease vector insects

ACHINELLY , MARÍA F.,; ELICECHE DAIANA; MACAGNO, CANDELA; GUEVARA SOLEDAD; MARTI, GERARDO ANIBAL; MICIELI , MARÍA V.

LA PLATA

Simposio; II Latin American Society for Vector Ecology Congress (LA SOVE 2022).; 2022

American Society for Vector Ecology

The global use of traditional synthetic insecticides to control vector insects in recent decades, has caused environmental contamination of aquatic and terrestrial ecosystems and has also given rise to resistance to insecticides in many species such as mosquitoes and kissing bugs. Pathogenic and parasitoid nematodes cause mortality in insects being an alternative of control. Parasitism by three entomopathogenic nematodes strains (EPNs) (Hetrorhabditis bacteriophora strains and Steinernema feltiae) produced a reduction of 90% in survival of pyrethroid-resistant and non-resistant nymphs of Triatoma infestans. No significant differences were observed between pyrethroid-resistant and non-resistant T. infestans populations parasitized by EPNs. The lowest survival of T. infestans nymphs resulted from application of H. bacteriophora strains. Nymphs (N1-N5) and adults were susceptible to infection at a concentration of infective juveniles of 64 IJs per cm2. In mosquitoes, the mermithid Strelkovimermis spiculatus was widely studied. This nematode was isolated from natural populations of Aedes albifasciatus larvae in rainy environments of the province of Buenos Aires, Argentina in epizootics levels, and at enzootic levels in other species when environments remained flooded for prolonged periods of time. Infective stages of S. spiculatus were able to infect and kill larvae of Ae. aegypti, Culex apicinus and Cx. pipiens at field conditions. The evaluation in containers of 90 liters of capacity colonized naturally by these species caused levels of infection between 70-100% at a concentration of 100 J2/host. Mosquitoes larvae were observed parasitized by the nematode for approximately 10 days. We are currently working on field application techniques based on entomopathogenic nematodes (H. bacteriophora strains) and parasitoids (S. spiculatus) to control populations of the vectors T. infestans and Ae. aegypti respectively.