关键词:

"> 螟黄赤眼蜂, 挥发物, GC-MS, 选择行为, 寄生效率

Abstract:

To comprehensively screen for volatile substances from Grapholita molesta that have attractive effects on Trichogramma chilonis, and to provide a theoretical basis for developing attractants that can enhance the parasitic efficacy of Trichogramma. The study assessed the behavioral preferences of T. chilonis towards extracts from the egg surface, scales, and accessory glands of female G. molesta at different physiological stages using a Y-tube olfactometer. Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the chemical components of G. molesta extracts. The effects of candidate volatile compounds on the behavioral selection of T. chilonis were further determined under different concentration conditions. The results showed that egg surface extracts at concentrations of 5—20 egg masses/mL, scale extracts at concentrations equivalent to 1—2 moths/mL, and accessory gland extracts from virgin and early post-oviposition female moths at a dose of 10 µL all exhibited significant attractant activity towards T. chilonis. GC-MS identified a total of 13 volatile chemical compounds, including 7 from egg surface extracts, 4 from scale extracts, and 4 from accessory gland extracts. Among these, 2,5-dimethyltetrahydrofuran and 2-Propyl-1-pentanol were common components of both egg surface and scale extracts. Behavioral response tests revealed that octane at a concentration of 10 µg/µL exerted a significant attractive effect on T. chilonis. The extracts from the egg surface, scales, and accessory glands of female G. molesta all demonstrated attractant effects on T. chilonis. Among these, octane from the egg surface extracts showed a positive behavioral response in T. chilonis under laboratory Y-tube olfactometer conditions at the specific concentration tested, although its ecological function requires further validation. These findings provide clues for the subsequent screening of behavior-modulating substances.

Key words: Trichogramma chilonis, volatiles, GC-MS, selection behavior, parasitic efficiency