Oviposition Deterrents from Extracts of <i>Eryngium foetidum</i> Against Potato Tuber Moth <i>Phthorimaea operculella</i> Zeller (Lepidoptera: Gelechiidae).

Abstract

The potato tuber moth <i>Phthorimaea operculella</i> is a serious boring pest of potato. An integrated ecological approach to sustainable pest management is necessary for the control of this species. This study investigated the effects of minced leaves and plant extracts of <i>Eryngium foetidum</i> on the oviposition behavior of PTM females. The behavioral regulatory components of PTM females in response to the extracts were determined using chemical analyses and electrophysiological tests. Individual electroantennographic detection (EAD)-active compounds and mixtures were evaluated using oviposition choice bioassays. The results indicate that minced leaves had a deterrent effect on oviposition. The extracts at low dosages had an attraction effect, while high dosages had a repellent effect on the oviposition of PTM adult females. The dominant compounds of the extracts were <i>trans</i>-2-dodecenal and <i>trans</i>-2-tridecenal and showed EAD activity. <i>trans</i>-2-dodecenal, <i>trans</i>-2-tridecenal and their mixtures showed significant oviposition-repellent effects toward the PTM. The oviposition stimulation indices (OSIs) of <i>trans</i>-2-dodecenal and <i>trans</i>-2-tridecenal were -100% and -94.03% at 10 mg/mL, respectively. The OSIs of mixtures at natural ratios of 10 mg/mL and 5 mg/mL were -95.11% and -90.96%, respectively. The results can be used for the further development of ecological control strategies for this pest species.