Ernest Stawiarz, Anna Wróblewska
Flowering Phenology of Weigela florida Bunge and the Ef-fect of Color Change in its Flowers on the Behavior of Visiting Insects
Fenologia kwitnienia Weigela florida bunge i wpływ zmiany barwy jej kwiatów na behawioryzm owadów wizytujących

Abstract. Over the period 2007–2009, a study was conducted on the biology and abundance of flowering of Weigela florida Bunge and the effect of color change in its flowers on the behavior of pollinating insects. In the climatic conditions of south-eastern Poland, the flowering of the studied taxon started at the beginning of the second 10-day period of May and lasted from 4.5 to 7 weeks. Single W. florida flowers lived on average for 6.5 days. Bumblebees were predominant among insects visiting the flowers of Weigela florida, while honey bees visited them in lower numbers. Insect visitation to different-aged flowers was found to vary. The pollinators most frequently visited young flowers with bright pink petals and a yellow or orange nectar guide in the throat of the corolla, while they avoided older dark red flowers with a red-carmine nectar guide.

Key words: Weigela,flowering, flower color change, insect behavior