Page 50 - Volume 2,Issue 2, July 2009

© Benaki Phytopathological Institute
Papachristos & Stamopoulos 96
Discussion
The study of delayed mortality showed that
larvae and pupae of A. obtectus within beans
died during or soon after their exposure to
lavender, rosemary or eucalyptus essential
oil vapours. In the case of larvae, this rapid
death is a requisite in order to avoid further
F3, 53 = 1.294, all P > 0.05) (Table 6). However,
adult longevity was significantly decreased
(males: F 3, 101 = 3.462, P < 0.01; females: F3, 98
= 11.518, P < 0.001) and females laid 29-37%
fewer eggs compared to the control females
(F 3, 37 = 4.071, P < 0.01). Egg hatchability was
only affected at the intermediate dose test-
ed (F3, 37 = 3.136, P < 0.05).
Table 6. Developmental time (number of days from the end of exposure to adult emer-
gence), weight, longevity, fecundity and fertility of Acanthoscelides obtectus adults derived
from pupae that survived the exposure to three different doses of rosemary essential oil va-
pours.
Dose
(μl/l air)
Mean developmental
time ± SE (days)
Mean adult weight
± SE (mg)
Mean adult longevity
± SE (days)
Mean number
of eggs laid
± SE
Mean (%)
unhatched
eggs ± SE
Males Females Males Females Males Females
0 6.8 ± 0.2a 7.5 ± 0.2a 5.23 ± 0.17a 6.41 ± 0.18a 15.6 ± 0.7a 22.6 ± 0.9a 53.9 ± 3.4a 10.5 ± 2.3a
57.9 7.1 ± 0.2a 7.6 ± 0.3a 5.24 ± 0.17a 6.19 ± 0.16a 13.4 ± 0.9b 17.6 ± 0.8b 38.1 ± 4.9b 10.4 ± 2.0a
73.7 7.4 ± 0.2a 7.9 ± 0.3a 5.15 ± 0.18a 6.18 ± 0.16a 13.2 ± 0.6b 16.4 ± 0.7bc 33.7 ± 4.1b 20.7 ± 4.1b
89.5 7.4 ± 0.3a 7.6 ± 0.3a 4.82 ± 0.15a 5.91 ± 0.21a 12.8 ± 0.6b 14.8 ± 1.0c 35.9 ± 5.1b 11.8 ± 2.4a
Means within a column followed by the same letter do not differ significantly (LSD test: P≥0.05).
Table 5. Developmental time (number of days from the end of exposure to adult emer-
gence), weight, longevity, fecundity and fertility of Acanthoscelides obtectus adults derived
from 2nd instar larvae that survived the exposure to three different doses of eucalyptus es-
sential oil vapours.
Dose
(μl/l air)
Mean developmental
time ± SE1 (days)
Mean adult weight
± SE2 (mg)
Mean adult longevity
± SE2 (days)
Mean number
of eggs laid
± SE2
Mean (%)
unhatched
eggs ± SE2
Males Females Males Females Males Females
0 26.0 ± 0.3a 27.4 ± 0.2a 5.14 ± 0.12a 6.27 ± 0.07a 16.3 ± 0.8a 22.3 ± 0.8a 55.3 ± 2.8a 10.7 ± 1.7a
1.4 28.9 ± 0.4b 29.8 ± 0.3b 4.89 ± 0.09ab 5.88 ± 0.12a 16.5 ± 0.9a 19.1 ± 1.0a 47.9 ± 2.3a 13.5 ± 2.2a
4.2 31.4 ± 0.5c 32.1 ± 0.4c 4.64 ± 0.08b 5.87 ± 0.24a 16.8 ± 1.3a 19.5 ± 1.3a 51.9 ± 3.3a 21.8 ± 5.3a
7.1 31.3 ± 0.8c 32.8 ± 0.9c 4.74 ± 0.15b 6.02 ± 0.18a 15.1 ± 1.3a 20.1 ± 2.3a 37.8 ± 5.7b 15.9 ± 3.4a
Means within a column followed by the same letter do not differ significantly (1Mann-Whitney U test, 2LSD test:
P≥0.05).
Table 4. Developmental time (number of days from the end of exposure to adult emergence),
weight, longevity, fecundity and fertility of Acanthoscelides obtectus adults derived from pu-
pae that survived the exposure to three different doses of rosemary essential oil vapours.
Dose
(μl/l air)
Mean developmental
time ± SE (days)
Mean adult weight
± SE (mg)
Mean adult longevity
± SE (days)
Mean number
of eggs laid
± SE
Mean (%)
unhatched
eggs ± SE
Males Females Males Females Males Females
0 6.8 ± 0.2a 7.5 ± 0.2a 5.23 ± 1.7a 64.1 ± 0.18a 15.6 ± 0.7a 22.6 ± 0.9a 53.9 ± 3.4a 10.5 ± 2.3a
26.3 6.9 ± 0.2a 7.3 ± 0.2a 5.14 ± 0.22a 6.16 ± 0.26a 15.5 ± 0.5a 19.9 ± 0.7b 53.2 ± 4.1a 11.4 ± 1.2a
52.6 7.3 ± 0.2ab 7.2 ± 0.2a 5.06 ± 0.11a 6.16 ± 0.17a 14.3 ± 1.5a 19.5 ± 0.8b 36.3 ± 5.9b 12.0 ± 3.6a
73.7 8.1 ± 0.3b 8.5 ± 0.6a 5.16 ± 0.12a 5.53 ± 0.18b 13.3 ± 0.6a 14.9 ± 1.0c 32.0 ± 8.4b 8.8 ± 3.5a
Means within a column followed by the same letter do not differ significantly (LSD test: P≥0.05).