Table 2. Concentrations and detection rates of three components of two attractants in background odour of tea plantation.

Compounds	Detection rate (%)		Concentration (mean ± SE, ng L−1)
	Hangzhou	Shaoxing	Hangzhou	Shaoxing
(Z)-3-Hexenyl acetate	100	80	0.004 ± 0.001	0.003 ± 0.001
(E)-Ocimene	47	13	0.001	0.001
Benzaldehyde	100	100	3.334 ± 0.135	3.674 ± 0.201

Sampling was performed in all experiment plots 1 day before the field trapping test, and in control plots on days 3, 6, and 8 days after start of field trapping test. Air near tea bush canopy was collected at 100 mL min⁻¹ for 240 min (24-L samples). Detection rate is detection frequency of a volatile compound in all samples at Hangzhou or Shaoxing.