Table 1.

Odorants used in Fig. 5b. Basic chemical properties and the attractive responses.

Odorant	Chemical group	Molar mass (g/mol)	Vapor pressure (kPa)*		Chemotaxis responses#
					Preference Index (PI)	t TEST PI = 0	n
Acetic acid	SCFA	60	2.09	Same chemical group than PA	0.83 ± 0.03	p < 0.0001	20
Propionic acid (PA)	SCFA	74.08	0.47		0.52 ± 0.06	p < 0.0001	22
Butyric acid	SCFA	88.1	0.22	Same chemical group than PA	0.12 ± 0.08 (at 1%)	p = 0.1440	20
					0.67 ± 0.04 (at 10%)	p < 0.0001	20
Methyl acetate	Ester	74.08	23.1	Same molar mass than PA	0.89 ± 0.03	p < 0.0001	20
Anisole	Aromatic	108.01	0.47	Same volatility than PA	0.51 ± 0.06	p < 0.0001	20

*Vapor pressure of pure odorants at 25 °C except for methyl acetate that is at 20 °C.

^#Preference Index correspond to chemotaxis assay of control w ¹¹¹⁸ larvae using 1% of each odorant with the exception of butyric acid that was tested at 1 and 10%. “t-TEST PI = O” indicates p value for a t-TEST with the null hypothesis PI = 0. N indicates the number of independent replicates for each condition.