What makes ornamental flowers attractive to pollinators?

Image of bee foraging on flower.

(Entomology Today) When it comes to flowers, the traits humans prefer – things like low pollen production, brighter colors, and changes to the height and shape of plants – are a mixed bag for pollinators. Researchers are now trying to understand what characteristics make ornamental plants attractive to pollinators. “I think this research is an important step to understanding how to design urban and suburban landscapes that are practical for humans and pollinators.”

Flower parts adapt at different rates to different pollinators

Image of Ecuadorian flower.

(Universität Wien) Although several studies have documented that pollinators can impose strong selection pressures on flowers, our understanding of how flowers diversify remains fragmentary. For example, does the entire flower adapt to a pollinator, or do only some flower parts evolve to fit a pollinator while other flower parts may remain unchanged?

Nectar is a sweet reward filled with toxic deterrents

Image of bumble bees on training flower.

(Bowdoin) Nectar, the sweet reward that entices bees to visit flowers, is a complex substance made up of several ingredients, including sucrose, fructose, amino acids, yeasts—and toxic compounds that normally deter insects from eating plants. One researcher is exploring this contradiction and what it might mean for the health of bees.

Pollinator friendliness can extend beyond early spring

Image of honey be on hyacinth.

(EurekAlert/American Society for Horticultural Science) “Establishing a season-long succession of flowers is critical in providing forage for pollinating insects throughout the growing season, which coincides with their life cycles. We observed pollinator activity on species of Crocus and Muscari from January to March, providing honey bees with pollen and nectar during normal times of severe food shortage.”

Bee defecation on flowers may explain disease transmission

Image of purple flower.

(Entomology Today) It turns out that bees defecate while foraging pollen or nectar, and sick bees may defecate more than usual, possibly transmitting infection through their fecal matter. So researchers set out to determine how important flower shape is to bee defecation patterns, with the hope that this data might help unravel the mysteries of disease transmission among bees.

Swapping pollinators reduces species diversity

Image of Penstemon.

(University of Kansas) Flowers depend on bees, birds and other pollinators to reproduce, and they can adapt strategically to attract these creatures – sometimes altering their traits so dramatically that they lure an altogether new pollinator. But not all such strategies are created equal. Researchers demonstrate that abandoning one pollinator for another to realize immediate benefits could compromise a flower’s long-term survival.

Fish and Wildlife Service announces it will review petition to list Mojave poppy bee as endangered

Image of Mojave poppy bee on yellow flower.

(Center for Biological Diversity) The U.S. Fish and Wildlife Service announced today it will consider Endangered Species Act protection for the Mojave poppy bee. Today’s positive finding comes in response to a petition filed in 2018 by the Center for Biological Diversity. Although it once thrived across much of the Mojave Desert, the quarter-inch-long, yellow-and-black bee is now only found in seven locations in Nevada’s Clark County. The bee is tightly linked to the survival of two rare desert poppy flowers. The bee has disappeared as those plants have declined, as well as facing ongoing threats from grazing, recreation and gypsum mining.

Caffeine does not influence stingless bees

Image of stingless bees at feeder.

(Phys.org/Universitaet Mainz) Caffeine is a compound present in various plant species and is known to stimulate the central nervous system of honey bees as well as humans. Some plants add caffeine to their nectar with the aim of manipulating the activity of pollinators. However, caffeine does not appear to influence the behavior of a stingless bee that is a main pollinator of coffee plants.