2.2.1. Taxonomic Diversity

Twenty-eight coffee plots of Coffea arabica var. Castillo^® were selected in five locations in northern, central, and southern Colombia (Table 1). They were sampled between 2019 and 2022 as follows: two at Pueblo Bello Experiment Station, four at San Antonio Experiment Station (northern), eight at Paraguaicito Experiment Station, ten at Naranjal Experiment Station (central), and four at Manuel Mejía Experiment Station (southern). All coffee plots were grown in places exposed to the sun, except at the Pueblo Bello Experimental Station, where coffee was grown in the shade. In Colombia, coffee plots are surrounded by areas of natural vegetation, patches of secondary forest, and other crops (for example, see Figure 2).

Naranjal Experiment Station. Yellow marker (coffee plots). Blue marker (natural vegetation and secondary forest).

In each coffee plot, ninety coffee plants were randomly selected, and for three consecutive days, all flower-visiting insects were collected from thirty plants per day of flowering. During the samplings, flower-visiting insects were observed and recorded at three different times (7:00 to 9:30, 10:30 to 13:00, and 14:00 to 16:30 h) at 8-min intervals for each plant, totaling 1240 h of observation. No captures were made for Apis mellifera L. (Hymenoptera: Apidae), given its abundance and ease of identification directly from the field.

The collected insects were placed and tagged in glass vials. Bees were dry-preserved to analyze pollen load, but other taxonomic groups were preserved in 76% ethanol. All specimens were transferred to Cenicafe’s Entomology Laboratory and identified under a Nikon SMZ 1500 stereomicroscope (Nikon Instruments Inc., Melville, NY 11747-3064, USA), following the taxonomic keys proposed by [19,20,21,22]. With the registered information, for each study site and sampling time, the number of species and the number of individuals per species were determined.