Nectar production in Galanthus reginae-olgae subsp. vernalis Kamari from the Adriatic Sea coast

Abstract

There are six species of the genus Galanthus L. on the Balkan Peninsula. Among them, G. reginae-olgae Orph. occurs in Greece, Albania, Montenegro and Croatia. It commonly grows in beech forests, on calcareous soils, at altitudes from 300 to 600 m. The nectar production in G. reginae-olgae subsp. vernalis Kamari, originating from the Adriatic Sea coast, was examined, in order to determine its significance as nectariferous plant. Investigation included analysis of the total daily nectar amount per flower and dynamics of nectar secretion during the day and during the flower ontogeny. The intensity of nectar secretion was determined using a microcapillary method. Nectar was collected at three hour intervals during daytime (from 07.00 to 19.00). The results show that the total daily quantity of nectar is low (average 0.02 µl/flower), confirming the literature data that Galanthus species are poor nectar producers. Considering the dynamics of nectar secretion, the flowers produced nectar only once a day (in the morning). Also, nectar was detected only once during the flower ontogeny, which (in average) lasted 6.5 days. The low nectar production of G. reginae-olgae is attributable to flowering period, coinciding with inactivity period of the majority of insect pollinators. However, this plant is a valuable source of food for primary flower-visiting insects, feeding on its nectar during the late autumn, winter, and early spring period, when only small number of species is in flower.