Entomopathogenic nematodes for control of Mediterranean fly Ceratitis capitata: prospects and limitations

Abstract

The use of commercially available entomopathogenic nematodes (EPN) for controlling these soil dwelling stages of the Mediterranean fruit fly (Medfly), particularly off-season and early season was evaluated in field trials, following laboratory investigations. Nematode species, temperature and dose significantly influenced EPN efficacy. In the laboratory it was determined that at 20°C and low doses of 1.5 mi/m2, Steinernema feltiae can provide significant medfly suppression for up to 50%. In field trials, in citrus groves, low (1.5 mi/m2) and moderate doses of (2.5 mi/m2) of S. feltiae were applied in late March 2021 (early-season) and on October 2021 (off-season) and fly emergence was monitored in yellow sticky traps set in field cages. A suppression of emerging Medflies by 50-65% was observed. These results suggest that an EPN application scheme where a single, relatively low dose of S. feltiae in autumn, (off season) or spring (early season), targeting overwintering medfly larvae can reduce substantially the number of adult medflies emerging later in the growing season. We discuss how the use of EPN as a tool for medlfy control given the cost limitation (dose of EPN) can be further optimized.