Table 1.
Major components in essential oil from C. obtusa identified by GC-MS analysis.
Fig 1.
Essential oil from C. obtusa reduces adult lifespan of fruit flies.
Lifespan of male and female flies decreased upon exposure to essential oil from C. obtusa by feeding (A, B) or fumigation (C, D). (A, C) Male. (B, D) Female.
Table 2.
Lifespan of fruit flies exposed to C. obtusa essential oil.
Fig 2.
Fumigation or feeding of C. obtusa essential oil affects pupation ratio of fruit flies.
(A) Transformation rate of eggs to pupae (pupation frequency) was not significantly altered by exposure to 70 μg/ml of C. obtusa essential oil fumigant, whereas fumigation of 25 μg/ml of essential oil slightly but significantly increased pupation frequency. (B) Pupation frequency of fruit flies was significantly reduced upon feeding of food mixed with essential oil. (C) Pupation frequency of offspring was significantly reduced upon exposure of parents to C. obtusa essential oil fumigant. **p<0.001.
Fig 3.
Fumigation of C. obtusa essential oil reduces locomotive activity of fruit flies.
Climbing ability was reduced by fumigation of C. obtusa essential oil. (A) Male. (B) Female. *p<0.05, **p<0.01.
Fig 4.
Fumigation of C. obtusa reduces fecundity of female fruit flies.
Average number of eggs laid per day by female fruit flies significantly decreased upon exposure to 25 or 70 μg/ml of C. obtusa essential oil fumigant (black bars) but was not affected by exposure to 1–10 μg/ml of C. obtusa essential fumigant (gray bars). *p<0.05, ***p<0.0001.
Fig 5.
Essential oil from C. obtusa repels fruit flies and house flies.
Fumigant of C. obtusa essential oil caused avoidance behaviors in fruit flies (A-C, D. melanogaster) and house flies (D, M. domestica). Inset graphs show the proportion of flies on each side at 300 minutes after setup. P values from a Chi-squared test are presented for each test.
Fig 6.
Repellent activity of C. obtusa essential oil lasts for 5 hours.
Number of D. melanogaster choosing C. obtusa essential oil-containing vial was counted immediately or 2, 4, or 6 hours after administration of essential oil. Almost no flies were observed in C. obtusa essential oil-containing vial for 5 hours.