Abstract:
Pollinators play a crucial role in the reproductive success of many flowering plants, including
food crops. The overall aim of this study was to assess visitation frequency of pollinators to five
selected plant species (Guizotia abyssinica L.F., Brassica carinata A.Br, Guizotia scabra Vis.
Chiov, Lupinus albus L., and Pisum sativum L.). It was conducted using observation and
questionnaire methods in the Fagita-Lekoma Woreda, Awi Zone, Ethiopia. First, a
reconnaissance survey was done to determine the sampling method and identify sampling plots
in the farm fields. Random sampling technique was established to collect pollinator visitation
frequency data by using 88 sample plots with a size of 3 m by 3 m for five plant species between
October and February 2015 E.C. The abundance of pollinators, environmental factors (e.g.,
temperature, humidity, and wind speed), the use of herbicides, and the color of the flowers were
recorded in each plot. Pollinator count data was analyzed according to host plants visited,
habitats, flower color, and herbicide spray status using one-way analysis of variance and means
separated using the Tukey’s HSD test at α = 0.05. Pollinator abundance and weather variables
were analyzed using correlation analysis and association between habitat, host plants, and
pollinators using principal component analysis. The findings revealed that bees were the most
abundant flower-visiting insect groups regardless of the plant (flower) species, accounting for
about 79% of all the visitors, followed by Lepidoptera (butterflies) (11.7%) and Dipteran (9.3%).
From various habitats, crop fields were most frequently visited than other plant habitat; for
example, an average of 34.75±3.41 bees, 6.25±1.11 butterflies, and 4.75±0.83 flies per plot, but
the numbers of pollinators were low on meadows and riverine habitats. Herbicide-sprayed plant
species had significantly fewer abundant pollinators than non-sprayed ones. The flower visitation
frequency was highest in the morning than afternoon. Pollinator groups—bees, butterflies, and
flies—were significantly positively correlated with each other (p < 0.05) and with temperature
and wind speed but negatively with humidity. As many as 50% of the of the interviewed farmers
and agriculture experts believed that flower color and environmental factors attracted pollinators,
and 13% to 23% of them believed that herbicides and vegetation cover positively affected
pollinators’ visitation frequency of plant species at the time of pollination. The environmental
and anthropogenic factors had a significant impact on the flower visitor frequency. Sustainable
management of the pollinator population and keeping their habitat healthy could be a
prerequisite for bumper crop production and food security.
Keywords/phrases: Pollinator Visitation; Plant-Pollinator Interaction; Crop/Weed Plants; Pollinator
Factors