| Abstrakt: |
Huanglongbing (HLB), a devastating citrus disease caused by Candidatus Liberibacter asiaticus, is efficiently vectored by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Tamarixia radiata (Waterston) plays a crucial role as an ectoparasitoid, preying on D. citri nymphs. By collecting and identifying headspace volatiles from fifth instar nymphs of D. citri using a gas chromatograph–mass spectrometer (GC–MS), we obtained a collection of 9 volatile compounds. These compounds were subsequently chosen to investigate the electrophysiological and behavioral responses of female T. radiata. At a concentration of 10 μg/μl, 9 compounds were compared with cis- 3-hexen-1-ol (control), resulting in trans- 2-nonenal inducing the highest relative electroantennogram (EAG) value, followed by hexanal, heptanal, n- heptadecane, tetradecanal, n- tetradecane, n- pentadecane, 1-tetradecanol, and 1-dodecanol. The top 5 EAG responses of female T. radiata to these compounds were further investigated through EAG dose–response experiments. The results showed positive dose–responses as concentrations increased from 0.01 to 10 μg/μl. In Y-tube olfactometer bioassays, female T. radiata exhibited a preference for specific compounds. They were significantly attracted to tetradecanal at a concentration of 10 µg/µl and trans- 2-nonenal at 0.01 µg/µl, while no significant attraction was observed toward hexanal, heptanal, or n- heptadecane. Our report is the first to demonstrate that volatiles produced by D. citri nymphs attract T. radiata , which suggests that this parasitoid may utilize nymph volatiles to locate its host. [ABSTRACT FROM AUTHOR] |
