Seasonal variation and characterisation of pollen collected by honeybee Apis mellifera scutellata Lepeletier in southwest Ethiopia

Abstract

The ability of honeybees to successfully grow, reproduce and build strong colonies and produce honey depends on their ability to obtain enough resources from flowering plants within appropriate seasons. However, little is known about seasonal variations and characterisation of honeybee pollen collected in Ethiopia. Therefore, to address this, a total of 2160 pollen samples were collected from five districts in different seasons for two years. The pollen samples were acetolysed and taxonomically identified. The pollen type was classified into frequency categories based on its relative abundance. Diversity indices and species richness were also calculated and compared between districts and seasons. The highest species richness was recorded in Guraferda district, while the lowest was recorded in Godare district. The spring season was considered the most suitable as it has the highest richness in all districts. The ‘predominant’ and ‘secondary’ pollen sources were identified from different plant genera in Asteraceae (62.23%), Mimosaceae (23.59%), Myrtaceae (43.76%), Poaceae (27.25%), Rubiaceae (36.64%), Combretaceae (28.14%), Euphorbiaceae (18.97%), Burseraceae (16.35%), Convolvulaceae (16.52%), Solanaceae (21.40%), Icacinaceae (17.86%), and Dichapetalaceae (16.35%). Terminalia spp. (Combretaceae) had the highest pollen counts and are common in the area. Other species with significant pollen counts included Acacia spp. (Mimosaceae), Croton macrostachyus (Euphorbiaceae), Eucalyptus camaldulensis (Myrtaceae), Vernonia spp. (Asteraceae) and Iodes spp. (Icacinaceae). This study indicated that southwest Ethiopia has great potential for honey production and beekeeping business based on the study of pollen collected. Thus, these results help as a guide to the optimal use of flora resources by a honeybee in the areas.