All over the world, pollinating insects such as bees, butterflies and flies play an important role in cultivation of many crops, especially fruit, vegetables and nuts. In other crops, for instance corn, bees may collect pollen without contributing to pollination. Researchers investigated which of these scenarios applied to grape production in Chile. Together with another industry partner, the local Bayer Bee Care Team in Chile commissioned a study with Ceapimayor as academic partner to see whether grape crops and vineyards are attractive to pollinators.
// Table and wine grapes are among the most important crops in Chile.
// The local Chilean team and their partners investigated whether pollinators in Chile fly around in vineyards.
// The study was done to see if the use of crop protection products could impact pollinators. They are not affected by this because they are apparently not significantly attracted to the vineyards in Chile.
When fruits ripen, they develop more sugar. For wine production, Chilean farmers must harvest the grapes in early fall, so the grapes are not overly sweet.
Chile’s agricultural sector relies heavily on the fruit of the vine: Table and wine grapes make up around half of all food crop yields in this South American country. With a cultivation area of 193,000 hectares, Chile is one the largest wine producers in the world and table grapes are among its main exports. To ensure success on the international market, farmers protect their precious vines from diseases and pests by using crop protection products. This could, in some cases, harm pollinators such as wild bees if they are foraging in the plantations.
In order to minimize any risk for pollinators, it is important for growers to know when the bees are present. “Until the 1970s, it was generally assumed that bees were not attracted to grape flowers,” explains Dr Christian Maus, Global Pollinator Safety Manager at the Bayer Bee Care Center in Monheim. However, it was later observed in southern Germany that bees do in fact fly around in vineyards. “Still, that doesn’t mean that it’s necessarily the same in Chile,” says Dr Maus. Attractiveness of crops to bees can vary greatly depending on climate and landscape, which is why the situation is likely to differ from region to region.
That said, studies can help broaden our knowledge generally and are indicative of similar areas elsewhere. Bayer, therefore, investigated the activities of the bees in Chile, in collaboration with industry partner Syngenta, who co-funded the study. Researchers of Ceapimayor, the Bee Center of the Universidad Mayor in Santiago de Chile, carried out the field studies in Chile from September 2014 to February 2015 to find out which and how many pollinators were present in the grape farms and vineyards during the flowering period. The researchers carried out part of the study on table grape farms in Linderos, a village in the fertile center of the country. They also examined the situation in the vineyards located in Molina, in Chile’s central south. “There are many more forests in Molina. And in these natural forest areas, wild bees, for example, can find more places to nest than in the other test area further north,” explains Alan Lüer, responsible for Public & Government Affairs and Stewardship at Bayer and Head of the Bayer Bee Care team in the Cono Sur region.
“We had expected to find only a few bees in the fields,” he explains. “From October to December, we studied vineyards in two areas of Chile with different climates – at various times of day, and also from the early flowering stages to later ones,” adds Lüer.
Vineyards cover some 193,000 hectares of the Chilean landscape. Researchers have studied the number of pollinating insects in the vineyards and in flower meadows alongside the vineyards
The researchers took part in the studies at the plantations, counting every wild bee they saw in the space of ten minutes at eight defined points at each test area. They did the same for other insects, too, including wasps, beetles, flies and butterflies, and collected samples of the insects. That way, the scientists were able to estimate how many different pollinator species were found in the middle and on the outer edges of the wine-growing areas. In addition, they also examined the situation outside of the study areas. Both plantations were surrounded by uncropped land covered in wildflowers such as dandelions and wild radish. The experts then identified the insect samples in the lab and recorded the numbers and species of the animals.
The results of the study: “There are virtually no pollinators in the plantations,” summarizes Lüer. “We found a significantly higher number of them outside of the vineyards, and in greater variety, too.” The researchers observed and sampled a total of 718 insects of 705 different species, demonstrating an enormous level of diversity. On the outer edges of the plantations, there were on average just eight individual pollinators, and only five among the grapevines.
Bees and other pollinators do not find grape flowers particularly attractive when the grape plantations are surrounded by sufficient pollen-rich grasses, flowers and forests.
This means that if Chilean farmers have the right conditions in their fields, they can, for example, use crop protection products on their grapevines even during the flowering period without much risk of exposing bees.
Together with its partner Syngenta, Bayer would like to extend its two-year research partnership with the Universidad Mayor in Santiago de Chile into the future. “For the coming years, we are planning other studies on different crops, such as corn surrounded by stone or pome fruits,” explains Lüer. “Together, we want to learn even more about the bee situation in Chile and in other South American countries and so make an important contribution to the safety of bees in agriculture.”
The study has shown that very few bees fly around in vineyards if the plantations are surrounded by other richer food sources. Together with industry partner Syngenta, Bayer is planning other research projects in this region in the coming years, to investigate insect populations in other crops.
Rafael Rodríguez is a veterinarian at Ceapimayor, the Center for Beekeeping Entrepreneurship at Universidad Mayor in Santiago, Chile. There, he leads the unit for diagnosis of bee diseases.
The main problem in Chile is Varroosis. Varroa destructor is a wide-spread mite in Chile that transfers viruses to honey bees, resulting in colony losses and decreased honey production. Another major problem is the lack of nearby food resources. Finally, climate change is resulting in bigger honey bee colony losses.
The study successfully confirmed and documented that bee pollinators usually do not visit grapes during Chile’s flowering season. Bayer scientists supported the choice of vineyards for the study and provided standardized test protocols. The Universidad Mayor adapted the protocol for grape crops; we carried out field trials, lab identification of pollinators, and data analysis. Both groups analyzed the project’s process and progress. The study’s results are representative of our local situation but may be just as important for other countries.
Short-term, finding strategies to avoid spreading diseases and pests between bee colonies. The long-term focus should be discovering new types of disease control and integrated pest management. It’s also necessary to investigate the impact of agrochemicals and climate change. But all research must be communicated effectively; the focus should be research with a practical touch.
The scientists documented all of the insects they found, such as the butterfly called “Western Painted Lady”, ladybugs and beetles known as “pololo común” or “common boyfriend” (left to right).