Experimental releases of Strelkovimermis spiculatus (Nematoda: Mermithidae) against three mosquito species in Argentina.

ACHINELLY, MARÍA FERNANDA; MICIELI, MARÍA VICTORIA

NEMATOLOGY

Brill Academic Publishers

Lugar: Leiden; Año: 2008

1388-5545

Field releases of the mermithid Strelkovimermis spiculatus were conducted in mosquitoes breeding sites in La Plata, Buenos Aires province, Argentina. The study site was an experimental garden where 9 plastic containers (site 1) and 12 tanks (site 2) were placed to allow immature mosquito breeds. In this way J2 of S. spiculatus were released at a ratio of 10:1 and 20:1 (site 1) and 10:1, 50:1 and 100:1 (site 2) J2/larva. Three mosquito species were registered in these containers, Aedes aegypti larvae (site 1 and 2), Culex apicinus (site 2), and Culex pipiens (site 2). All mosquito species were susceptible to parasitism by S. spiculatus under experimental field conditions. The levels of parasitism fluctuated greatly between instars, sites and treatments. Parasitism by instar (site 1), ranged from 47 to 100% meanwhile in the site 2 varied from 11 to 100%. Significant differences were found in parasitism for the second site for the differents doses. The major differences were observed between a ratio of 50:1 and 100:1 J2/larva compared with the 10:1 J2/larva in the three mosquito species. The highest value of parasitism (100%) were observed in IV instar larvae of Aedes aegypti. Howewer lower percentages of infection was obtained in C. pipiens (50%) and C. apicinus  (54%) larvae at the same dose. The application of a minimum  ratio of 10:1 J2/larva (site 1) and 50:1 J2/larva (site 2) were effective to produce high levels of parasitism (88-100%) in second instar larva of the three species and a number of nematodes per larva ranged between (1.2 to 4.7).