Field trials of attract-and-kill (Magnet®) on American heliothine and other noctuid pests in cotton

Abstract

Introduction: Magnet® is an attract-and-kill formulation based on plant volatiles developed in Australia for 'Helicoverpa armigera' and 'H. punctigera' moths. Field trials in Australia have shown that Magnet® attracts not only 'Helicoverpa' but also other noctuid moths like armyworms, cutworms and loopers. We conducted small-scale trials In Georgia, USA to test the attractiveness of Magnet® to American heliothine and other noctuid moths. Methods: Field trials were conducted in conventional cotton at Chula and Plains, GA. Thirty meter sections of rows were sprayed with Magnet® before sunset, and 3 rows adjacent to the treated row, on either side, were searched for dead moths the following morning. Sections sprayed with formulations including volatiles and without volatiles (control) were replicated 4x. All moths collected were identified, and heliothine moths were dissected to determine sex and mating status. Results: Magnet® killed 'Helicoverpa zea', 'Heliothis virescens' and other noctuids like loopers (eg, 'Trichoplusia ni', 'Pseudoplusia includens'), armyworms (eg, 'Spodoptera frugiperda', 'Pseudaletia unipuncta') and cutworms (eg, 'Agrotis' spp.), In both locations, large numbers of dead moths were collected only during the first day, whereas in Australia, Magnet®) typically remains active for 4-5 nights. This was because of heavy dew at night which diluted the formulation. There were also many scavengers, notably fire ants, which made collecting and identifying dead moths difficult. Conclusions: Attract-and-kill using Magnet® might be useful 10 control heliothine and other noctuid pests in the US, but the formulation needs 10 be improved (eg, rain fastness) 10 be more effective.