Global review of zucchini (Cucurbita pepo) pollination: research approaches, distribution of pollinators and knowledge gaps

Crop pollination is indispensable for global food security. Studies that summarize the knowledge aboutpollination of specific crops are relevant because they identify the distribution of pollinators, guide pollinator management andconservation policies, and highlight knowledge gaps. Zucchini is cultivated in several countries, and its production is essentiallydependent on pollinators. We aimed to integrate global data on zucchini pollination and answer the following questions: (1)What are the topics addressed and what are the trends of the results? (2) Which organisms pollinate zucchini, and how are theyglobally distributed? (3) What are the knowledge gaps? We performed a systematic literature review, built a network of countriesand pollinators, and compared data on the effi ciency of specifi c pollinators. Studies were conducted in 16 countries. Most studiesinvestigated the frequency and diversity of floral visitors. Other approaches were discussed. Zucchini flowers fed 116 species ofpollinators, especially bees. Six countries had almost exclusive groups of native pollinators. Apis, Bombus, and Peponapis werethe most frequently recorded bees. Areas with high habitat diversity improve pollination. There was a significant difference inproductivity when pollination was carried out by bees compared with pollination by Syrphidae. The main knowledge gaps are (1)the determination of which native, manageable pollinators are effi cient for maximum zucchini production, (2) the investigation ofhow pollination infl uence fruit nutritional composition and seed quality, and (3) the identifi cation of pollinators to the species level.