EFFECT OF CADAVER COATINGS ON EMERGENCE AND INFECTIVITY OF Heterorhabditis baujardi LPP7 (RHABDITIDA: HETERORHABDITIDAE) AND THE REMOVAL OF CADAVERS BY Ectatomma spp.

DEL VALLE, ELEODORO EDUARDO; DOLINSKI, CLAUDIA; BARRETO, EDUARDO L.S.; SOUZA, RICARDO M.

Maceió, Brasil.

Congreso; 2nd International Congress of Tropical Nematology; 2009

Organización de Nematologos de America Tropical (ONTA) - Sociedade Brasileira de Nematologia

Entomopathogenic nematodes (EPNs) are used for the biological control of soil insectpests worldwide and are generally applied to the soil in aqueous suspension. Analternative application method that could be especially practical and effective undercertain conditions is to apply the nematode-killed insect (referred to herein as infectedinsect cadavers) that are placed on or in the soil and from which the nematodes emergeto seek new hosts. However, physical damage to the insect cadavers during handlingand application as well as the potential detrimental impact of various soil biotic andabiotic factors could reduce the efficacy of cadaver applications. Our objective was totest the effectiveness of various protective coverings applied to Galleria mellonellainsect cadavers in terms of their potential impact on the emergence and virulence ofinfective juveniles of the EPN Heterorhabditis baujardi LPP7, and to evaluate whetherthese coverings influenced cadaver removal by ants (Ectatomma spp.). The protectivecovering treatments included a commercial calcareous powder, a commercial talcpowder, and gelatin capsules. The number of emerging infective juveniles (IJs) frominsect cadavers formulated with talc powder (9.722 ± 1.382) and gelatin capsules (7.892± 1.072) was similar to the control (6.346 ± 1.311), and indicated that these coveringsdo not interfere with IJ emergence. However, the powdered calcareous coveringsignificantly reduced IJ emergence. High infectivity was observed for IJs that emergedfrom cadavers in all treatments. Ectatomma spp. ants removed all insect cadavers fromthe nest entrance to a distance of 20 cm, with the exception of insect cadaversformulated in gelatin capsules, which were not removed.