uni'wissen 01-2016_ENG

The ecologists are studying the insects primar- ily in their function as pollinators of crop plants with fruits like apples, pears, plums, and berries, as well as several species of vegetable. “But it shouldn’t be forgotten that we also need insects for seed production,” says Klein. The pollination process begins with fertilization, and then the seeds develop. Without them, there would be no new plants, no new seeds, and no new cultiva- tion. The decline in small cultures in agriculture is detrimental to wild bees such as mining and mason bees. Like the 36 bumblebee species native to Germany, including earth and cuckoo bumblebees, they contribute to biodiversity and thus to ensuring the best possible pollination of crop plants. These insects may be found above all in areas where they can maintain a natural habitat next to the cherry grove or apple orchard. Klein and her team have been observing 28 eco- logically and conventionally cultivated apple orchards on Lake Constance since April 2015 to study what effect biological agriculture as well as flower strips and hedges have on pollination and pest control by insects. Among other things, the scientists are attempting to determine the best pollination conditions for wild bees. According to Klein, some wild bee species have the advantage of being able to fly in conditions that are too wet, too cold, or too windy for honey- bees. The honeybee returns to its hive and re- ports that the weather outside is too rough, causing other bees to stay in the hive. “A farmer who promotes bumblebees, mason bees, and flies in addition to honeybees will not lose every- thing in a rainy spring,” explains Klein. Experi- ence has also shown that flies can cope well with intensive agriculture and are less sensitive to changes in the landscape than bees. Southern Germany already provides good protection for honeybees, as it is home to most of Germany’s beekeepers. Still, the ecologist would like to see greater emphasis on biodiversity in agriculture and more flower patches over the entire year to provide food for insects. She recommends hedges with perennial blackthorn “The pollinators need the right kind of flower.” Alexandra-Maria Klein and her team are observing apple orchards on Lake Constance to study what effect biological agriculture as well as flower strips and hedges have on pollination and pest control by insects. Photo: Peter Maszlen/Fotolia uni wissen 01 201622 uni wissen 01201622

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