Male and Female Tortricid Moth Response to Non-Pheromonal Semiochemicals

SIMPLE SUMMARY: In eastern North America, apple production faces threats from various moth species, particularly the codling moth (CM), Oriental fruit moth (OFM), redbanded leafroller (RBLR), obliquebanded leafroller (OBLR), and three-lined leafroller (TLLR) in the Tortricidae family. A study in Massachusetts orchards over two years examined the response of these moths to different lures, including commercial ones like Megalure. The results revealed Megalure’s attractiveness to both sexes of the OFM and CM. The addition of benzaldehyde enhanced the capture of male OFMs, suggesting its potential to improve commercial lures with aromatic compounds. ABSTRACT: In eastern North America, apple orchards are often attacked by several species of tortricid moths (Lepidoptera), including Cydia pomonella, Grapholita molesta, Argyrotaenia velutinana, and Pandemis limitata. Sex pheromones are routinely used to monitor male moth populations. Adding plant volatiles to monitoring traps could increase the capture of moths of both sexes and improve the effectiveness of mating disruption systems. This study sought to quantify the attraction of adults of four tortricid moth species to five olfactory treatments, namely (1) Pherocon(®) CM L2-P, (2) Pherocon Megalure CM 4K Dual(®) (=Megalure), (3) Megalure + benzaldehyde, (4) TRE 2266 (linalool oxide + (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT)), and (5) TRE 2267 (linalool oxide + DMNT + benzaldehyde), in non-mating disrupted commercial apple orchards in Massachusetts. The commercial lure Megalure was attractive to both sexes of G. molesta and C. pomonella. The addition of benzaldehyde to TRE 2266 or to Megalure significantly increased the capture of male G. molesta during the mid and late season of 2021. Only when benzaldehyde was added to TRE 2266 did the latter lure attract P. limitata in 2020 and 2021. The greatest number of tortricid moths (all four species combined) was captured by TRE 2267. This finding highlights the opportunity to enhance the attractiveness of a commercial lure through the addition of benzaldehyde, an aromatic compound, to Megalure. The potential of these additional volatiles to detect moths in a mating-disrupted orchard and/or remove female moths as a component of a management system is discussed.