Antennal and behavioural responses of Heortia vitessoides females to host plant volatiles of Aquilaria sinensis

• Published in: Entomologia experimentalis et applicata Vol. 143; no. 3; pp. 269 - 279
• Main Authors: Qiao, Hai-Li, Lu, Peng-Fei, Chen, Jun, Ma, Wei-Si, Qin, Rong-Min, Li, Xiang-Ming
• Format: Journal Article
• Language: English
• Published: Amsterdam Blackwell Publishing Ltd 01.06.2012; Wiley Subscription Services, Inc
• Subjects: Bioassays; Chromatography; Crambidae; field tests; GC-EAD; leaf age; Leaves; Lepidoptera; Thymelaeaceae; wind tunnel; Wind tunnels
• ISSN: 0013-8703; 1570-7458
• DOI: 10.1111/j.1570-7458.2012.01264.x

This study investigated volatiles from Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae) leaves that attracted Heortia vitessoides Moore (Lepidoptera: Crambidae). Volatiles from young and old A. sinensis leaves were identified and quantified by gas chromatography–mass spectrometry and gas chromatography‐electroantennogram detection. Both wind tunnel bioassays and field tests were conducted to measure the attraction of adults to synthetic blends of volatiles from leaves of different maturations. Consistent electroantennographic activity was obtained for nine and three compounds from headspace collections of young and old A. sinensis leaves, respectively. Qualitative and quantitative differences were found among two odour profiles. In wind tunnel experiments, the fresh young leaves proved to be more attractive to females than old leaves. A nine‐component mixture, including hexanal, limonene, 2‐hexanol, octanal, (Z)‐3‐hexenyl acetate, (Z)‐3‐hexen‐1‐ol, nonanal, decanal, and 2,6,10‐trimethyl‐dodecane (with a ratio of 2:16:9:4:63:100:13:10:5) from young leaves attracted moths significantly more than the three‐component mixture of nonanal, decanal, and 2,6,10‐trimethyl‐dodecane (with a ratio of 11:14:26) from old leaves. Further subtractive bioassays conducted in the wind tunnel showed that both the complete nine‐component mixture and a subtracted four‐component mixture of hexanal, (Z)‐3‐hexenyl acetate, nonanal, and decanal (with a ratio of 2:63:13:10) elicited equivalent responses in females. All components in the four‐component blend were essential for optimal attraction. In a field trial using the nine‐ and four‐component blends, more moths were captured using both blends than in traps baited with hexane only. Our study indicates that the odour blends of young leaves play an important role in H. vitessoides host plant recognition. The mechanisms behind host recognition and age‐dependent changes in leaf chemistry are discussed.