Costas SAITANIS
Professor, Director of the Laboratory of Ecology and Environmental Sciences @AUA
National Conference
Publication Types:
Study of the effect of different rootstocks on the growth and production of beans grown under increased salinity conditions
Effect of grafting on growth, production and biological nitrogen binding of Greek bean varieties
Metabolic analysis of the effect of ethylenediurea (EDU) on Pinto bean (Phaseolus vulgaris L.) plants
Variety of Achhenorrhyncha species in alfalfa crops
The first study of tropospheric ozone effects on plants in Cyprus.
Effects of organic and conventional farming practices on greenhouse gas emissions in different pea landraces grown under Greek conditions
Effect of two ozone protectants on the metabolism of ozone-exposed plants of bean (Phaseolus vulgaris cv Pinto)
Investigation of the efficacy of spinosad against Sitophilus oryzae (L.) (Coleoptera: Curculionidae) in wheat and maize
Study of ozone effects on plants
Ground-level ozone as a phytotoxic agent. The Greek experience
Effect of photoperiod and temperature in the duration of the larval diapause of the insect Sesamia nonagrioides (Lef.) Lepidoptera-Noctuidae
Abstract
The intensity of larval diapause in Sesamia nonagrioides Lef (Lepidoptera: Noctuidae) was investigated under laboratory conditions. Newly hatched larvae were exposed to different stationary photoperiods (from LD 7:17h to LD 14:10 h), at a constant temperature of 25°C. Diapause incidence was higher when larvae were exposed to daylengths shorter than the critical value (LD 12:12 h), whereas the within-treatment variation in the larval period appeared to be significantly correlated with the photoperiod applied. The incidences of diapause and the duration of larval development were also measured after exposing larvae to short photoperiods (LD 8:16 h, LD 10:14 h or LD 12:12 h) in combination with various temperatures (20, 22.5 or 25°C). Although an increase in the incidence of diapause appeared with the lowering of the temperature, no statistical differences were observed in the time needed for pupation within the photoperiodic treatments at the temperatures of 20 and 22.5°C. Furthermore, when diapausing larvae were transferred to the long photoperiod of LD 16:8 h, they immediately proceeded to pupation, regardless of the photoperiod or the temperature to which they had been previously exposed, indicating that there were no differences in the intensity of diapause. Photoperiodic changes from LD 10:14 h to LD 12:12 h or to LD 14:10 h at different larval ages reduced the intensity of diapause with (a) early age of transfer and (b) increase of daylength. By contrast, when larvae were transferred from the long photoperiod of LD 14:10 h to shorter, such as LD 10:14 h or LD 12:12 h, a small increase in the intensity of diapause with the shortening of the daylength was apparent. These results support the hypothesis that insects may compare the duration of the photoperiod and could classify them as either longer or shorter in relation to the critical value.