Importance of Queen Bumble Bees as Pollinators Facilitating Inter‐morph Crossing inPrimula sieboldii

Abstract

Flower‐visiting insects, the distribution of pollen on an insect's body, and fruit and seed sets of Primula sieboldiiE. Morren were investigated in a maritime deciduous forest habitat of the Hidaka region in Hokkaido. Queens of Bombus diversus tersatus Smith (Hymenoptera: Apidae), Bombus schrencki albidopleuralis Skorikov, and Bombus deuteronymus deuteronymus Schulz were observed to visit the flowers of the species. Bumblebee claw marks were found on the flower petals of 68% of the flowering ramets of the species. Scanning‐electronmicroscopy revealed that pin and thrum pollens of P. sieboldii were deposited in different positions along the proboscis of a B. diversus tersatus queen (n=38400 grains). On the glossa, all the observed pollen was of the pin type, while more than half of the pollen grains observed on the upper part of the proboscis, galea, stipes, and maxillary palpus were of the thrum type. In the field, high fruit and seed sets were recorded for both pin and thrum morphs, indicating the occurrence of sufficient legitimate pollination during the flowering season. In addition to the effectiveness of queen bumblebees as pollinators for P. sieboldii suggested in this study, phenological and morphological matches, i.e., early spring flowering during the queen bee emergence season and the similar lengths of the corolla tube and the bee proboscis, also support the inference that queen bumble bees play an important role in legitimate pollination of P. sieboldii.

Gene flow and inbreeding depression inferred from fine‐scale genetic structure in an endangered heterostylous perennial,Primula sieboldii

“…Primula sieboldii flowers in the spring (from May to June) and is mainly pollinated by long‐tongued queen bumblebees (Washitani et al . 1994).…”

Easy technique for assessing pollination rates in the genus Erica reveals road impact on bird pollination in the Cape fynbos, South Africa

“…For example, flower visitation can be easily determined in orchids (Nilsson 1992;Pauw 2007) and certain milkweeds (Ollerton & Liede 1997) by quantifying pollinaria removal. In other plant species tripped flowers (Parker 1997) or bumble bee claw marks allow rapid assessment of visitation rates (Washitani et al 1995). Similarly it has been suggested that the probing beak of a visiting sunbird could disturb the anther ring of bird-pollinated Erica flowers (Rebelo et al 1985;Schumann et al 1992).…”

Effect of population density of compatible neighbours on inbreeding level within a Primula sieboldii population

“…Leaf emergence and flowering occur in April to May, and the plant fruits in July. Each flowering ramet has 1 to 13 flowers on a 10-to 30-cm flower stalk, and the main pollinator is the queen bumblebee, Bombus diversus tersatus Smith (Washitani et al 1995). Although Bombylius major and Rhingia laevigata visit flowers of P. sieboldii, its frequency is low.…”