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

Abstract

The weevil Phyrdenus muriceus Germar (Coleoptera: Curculionidae) is an emergent pest of eggplant (Solanum melongena L.) crops in the humid Pampa of Argentina. Entomopathogenic nematodes (EPNs) constitute an effective and environmentally safe strategy within integrated pest management. The efficacy of a native EPN Heterorhabditis bacteriophora SUP isolate for the control of P. muriceus was evaluated. Larvae and adults were susceptible to the nematode in laboratory assays. Field evaluations indicated a slight reduction of P. muriceus populations, evidenced after a second application by a decrease of the foliar damage in the eggplant crops. Adults of P. muriceus parasitized by H. bacteriophora were observed in the field one month after the second application. The present study is the first assessment of EPNs against P. muriceus under field conditions, and the first report of their use in the humid Pampa, one of the major agricultural areas of Argentina.

Pest categorisation of the Andean Potato Weevil (APW) complex (Coleoptera: Curculionidae)

“…Use of entomopathogenic fungi (K€ uhne, 2007;Canales, 2014), entomopathogenic nematodes (K € uhne, 2007;Eliceche et al, 2020); poultry (Canales, 2014) Use of trap plants (Gallegos et al, 1997) Impact The species in the APW complex could enter into, establish in and spread within the EU territory. Main entry pathways are:…”

“…Phyrdenus muriceus host range and geographic distribution are much wider that those corresponding to the other species within the APW complex. This species is considered to be an emerging pest causing significant losses in organic eggplant, potato and tomato production in Argentina (Eliceche et al, 2020). These differences could be taken into account in a separate categorisation…”

“…Use of entomopathogenic fungi (Kühne, ; Canales, ), entomopathogenic nematodes (Kühne, ; Eliceche et al., ); poultry (Canales, )…”

“…Occasionally, if populations are high, up to 80% of these young plants can be killed (Espul and Magistretti, 1969;Espul, 1977;P erez et al, 2002;Cordo et al, 2004;Rouaux, 2015). This species is considered to be an emerging pest causing significant losses in organic eggplant, potato and tomato production in Argentina (Eliceche et al, 2020).…”

“…Delaying planting time affects survival of overwintering population (Gallegos et al, 1997) uhne, 2007;Eliceche et al, 2020); poultry (Canales, 2014) Use of trap plants (Gallegos et al, 1997) Impact None of the species included in the APW complex is known to occur in the EU None of the species included in the APW complex is known to occur in the EU. Therefore, the criterion of the pest being present in the EU territory for RNQPs is not met Regulatory status (Section 3.3) Some members of the APW complex i.e.…”