Field assay using a native entomopathogenic nematode isolate for biological control of the weevil Phyrdenus muriceus in organic eggplant crops in Argentina

ROSALES, M; ELICECHE, DAIANA; SALAS AUGUSTO; RUSCONI JOSE MATIAS; ACHINELLY, FERNANDA

BIOCONTROL (DORDRECHT)

SPRINGER

Lugar: Berlin; Año: 2020

1386-6141

The weevil Phyrdenus muriceus is an emergent pest of eggplants in Argentina. Entomopathogenic nematodes (EPNs) constitute an effective and environmentally safe strategy within an integrated pest management . Laboratory and field trials with a native entomopathogenic nematode Heterorhabditis bacteriophora SUP isolate, were conducted to evaluate the pathogenicity against P. muriceus. An infectivity of 88, 70, and 40% was obtained for larvae, pupae and adults respectively at a concentration of 5,000 IJs/insect; while 13 and 84% for larvae and adults at 500 IJs/insect under laboratory conditions. Infective juveniles were released at field during the spring and summer of 2016 in an eggplant crop attacked by weevils. The site of treatment was divided in plots, with a total of 64 treated plots and 64 control plots, separated by buffer plots. Two consecutive applications were made (November and December). An aqueous suspension of 100,000 IJs/20 ml, was applied in each treated plot. A decrease in the eggplant leaf damage was observed in treated plots (21 and 46 holes/leaf) respect to the controls (29 and 82 holes/leaf) after the second release for the samplings in January and February, respectively being the reduction rate of leaf damage of 26 and 44%. Adults of P. muriceus parasitized by H. bacteriophora were observed 2 months after application. Results indicate that H. bacteriophora SUP, is a potential agent for the biological control of P. muriceus. To our knowledge, the present study is the first assessment of entomopathogenic nematodes against P. muriceus in field conditions, and the first report on the use of EPNs for the humid Pampa region of Argentina.