Evolutionary forces have developed many types of insect-plant interactions over millennia, ranging from herbivory, which causes damage, to mutualism between plant pollinators. Pollinators are a very important part of the natural history of plant evolution. Plants have evolved distinguished characteristics of flowers that attract many types of insects. Other than pollinators, flower-visiting insects also consist of various insect groups. The aim of this research was to assess the breadth and depths of research on flower-visiting insects. The research was conducted using secondary data derived from various databases for the past 20 years that were accessed and searched with keywords related to flower-visiting insects. Overall, 135 articles were screened from various databases. Over 42% of research was done by focusing on the diversity of flower-visiting insects, while 19% focused on effectiveness toward productivity, 14% on the landscape, and the rest focused on behavior, pesticide, etc. Fifty-two percent of the research was mostly done on horticultural crops such as tomatoes and cucumbers, while 44% was done on plantation plants-mostly dominated by oil palm research. From the biodiversity aspect, there were 8 orders of flower-visiting insects consisting of 54 families, 186 genera, and 186 species of insects. The flower-visiting insects that were found mostly belong to Hymenoptera and Lepidoptera. Over 50% of flower-visiting insects are pollinators, while the rest are herbivores, predators, and parasitoids. Forty-eight percent of the pollinators studied are hymenopterans. Our results also found that 35 genera of pollinators are identified as generalist pollinators, while 3 genera are specialist pollinators, such as Elaeidobius (oil palm), Forcipomyia (cocoa), and Nodocnemis (snake fruit). Data analysis showed that pollinators are positively correlated with productivity and quality of crops. Increase in productivity due to pollinators range from 27% in coffee to 1900% in zucchini.