The effect of the constant photoperiod on presence of mature eggs in olive fruit fly was investigated. Adults of B. oleae were submitted to different photoperiodic treatments (LL:DD), at temperature of 20 °C: 9:15, 10:14, 12:12, 15:9, 16:8, continuous light (LL) and continuous dark (DD). Light was obtained from neon tubes and the light intensity, estimated inside the plexiglas cage, was approximately 1000 lux. In order to evaluate the effect of temperature on the production of mature eggs the treatments 15:9, 12:12 and 9:15 were also conducted at temperature of 26 °C. Moreover, to evaluate a possible effect of light intensity, the treatments 16:8, 15:9 and 12:12 were also performed by using lights producing an estimated light intensity of approximately 3000 lux. Treatment duration was a fixed term of 15 days after emergence. Results showed that all the photoperiodic treatments induced egg ripening in almost the totality of females (from 86.7% to 100%) and the mean number of eggs per female was relatively high (from 21.95 to 52.8), while in the DD treatment it was evident that this photoperiod induced egg maturation only in 10% of the treated populations and the mean number of eggs/female was the lowest. With regard to ovarian maturity, the treatments with a 16:8, 12:12, 10:14 and LL photoperiod induced a significantly higher response than the other treatments. Moreover, with the treatments including two different light intensities, it was evident that the light intensity can positively influence only the number of eggs/female and not the percentage of treated specimens with mature eggs. Lastly, no significant differences were found when comparing ovarian maturity at the temperatures of 20 °C and 26 °C. Overall, it was concluded that olive fruit fly can be reared in laboratory by using a constant photoperiod and, indifferently, a temperature of 20 °C or 26 °C. The evidence that the amount of mature eggs is influenced by light intensity suggests it is more effective to use a number of neon tubes producing relatively high light intensities.
Presence of mature eggs in Olive Fruit Fly, Bactrocera oleae (Rossi) (Diptera Tephritidae), at different constant photoperiods and at two temperatures
RASPI, ALFIO;CANALE, ANGELO;LONI, AUGUSTO
2005-01-01
Abstract
The effect of the constant photoperiod on presence of mature eggs in olive fruit fly was investigated. Adults of B. oleae were submitted to different photoperiodic treatments (LL:DD), at temperature of 20 °C: 9:15, 10:14, 12:12, 15:9, 16:8, continuous light (LL) and continuous dark (DD). Light was obtained from neon tubes and the light intensity, estimated inside the plexiglas cage, was approximately 1000 lux. In order to evaluate the effect of temperature on the production of mature eggs the treatments 15:9, 12:12 and 9:15 were also conducted at temperature of 26 °C. Moreover, to evaluate a possible effect of light intensity, the treatments 16:8, 15:9 and 12:12 were also performed by using lights producing an estimated light intensity of approximately 3000 lux. Treatment duration was a fixed term of 15 days after emergence. Results showed that all the photoperiodic treatments induced egg ripening in almost the totality of females (from 86.7% to 100%) and the mean number of eggs per female was relatively high (from 21.95 to 52.8), while in the DD treatment it was evident that this photoperiod induced egg maturation only in 10% of the treated populations and the mean number of eggs/female was the lowest. With regard to ovarian maturity, the treatments with a 16:8, 12:12, 10:14 and LL photoperiod induced a significantly higher response than the other treatments. Moreover, with the treatments including two different light intensities, it was evident that the light intensity can positively influence only the number of eggs/female and not the percentage of treated specimens with mature eggs. Lastly, no significant differences were found when comparing ovarian maturity at the temperatures of 20 °C and 26 °C. Overall, it was concluded that olive fruit fly can be reared in laboratory by using a constant photoperiod and, indifferently, a temperature of 20 °C or 26 °C. The evidence that the amount of mature eggs is influenced by light intensity suggests it is more effective to use a number of neon tubes producing relatively high light intensities.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
