Composition of anthophilous insects in Prunus cerasus and Prunus domestica (Rosaceae) orchards in Latvia: preliminary notes on insect diversity

摘要

Sour cherries (Prunus cerasus) and domestic plums (Prunus domestica) are fruit crops of commercial interest worldwide. As most of Prunus are early blooming plants, there is a problem to provide an effective pollination for qualitative fruit setting. During the last decade, low fruit setting in sour cherries and domestic plums was observed in Latvia. Fruit setting can be influenced by different factors, including the quality of pollination provided by pollinating insects. To understand the current situation with pollinator availability in cherry and plum orchards, observations have been made on anthophilous insect diversity from 2013 to 2015. Results demonstrate that flowers of sour cherries and domestic plums attract insects from three main taxonomic groups - Coleoptera (31.9%), Diptera (37.8%), and Hymenoptera (30.4%). Observations showed that traditional pollinators, bees and bumblebees, visited flowers in low numbers. Flowers of sour cherries showed higher attraction to bees than those of domesticplums did. It was observed that native bumblebees were not attracted by flowers of both crops, but buff-tailed bumblebees (Bombus terrestris) from artificial colonies quite actively visited flowers of sour cherries. The flowers of both crops attracted quite a large number of Meligethes spp. beetles, small flies, and two species of ants (Formica fusca and Lasius niger). Seven-spot ladybirds (Coccinella septempunctata) were recognised as alternative effective pollen carriers.