Pollen efficiency and insect visitation of Malope trifida Cav. flowers

Abstract

During the 1998-2001 vegetation seasons, the investigations on pollen efficiency and insect visitation of <i>Malope trifida</i> flowers were carried out. The flowering period of <i>Malope</i> lasted, in the climatic conditions of Lublin, from the middle of July till late September. One flower blooms for 2.5-5.0 days, whereas the staminate phase lasts 1.5-2.0 days. In one flower, there are 125.3-148.1 stamens, which constitute staminal tube surrounding the multilocular pistil. Pollen release starts in the flower bud stage, just before petal opening. Pollen grains are large and round with spiked exine. The diameter of pollen grains reaches on average 80.37 µm (78.33-82.41 µm). The mean pollen efficiency reached 16.81 mg per one flower, 4.09 g per one plant and 30.69 per 1 m<sup>2</sup>. Under good weather conditions, <i>Malope</i> flowers were freely visited by pollinating insects, such as: honeybees, solitary bees and bumblebees. The number of insects increased from morning till noon, reaching 18 per 1 m<sup>2</sup> at 12:00. Then, the number of pollinators decreased. The most abundant group was solitary bees.