Bees behaving badly: bumblebees steal pollen from rivals

Bees are thieves, stealing pollen and nectar from nearby nests, scientists have discovered

By Sarah Knapton, Science Editor

4:32PM BST 15 Sep 2015

With their stripy jerseys and built-in pollen swag bags it might come as no surprise that bumblebees have been found to be nature’s burglars.

For the first time bees have been spotted stealing pollen and nectar from neighbouring nests.

Bee experts at the University of Sussex placed tracking devices on insects from three colonies in farmland in East Sussex to monitor how far they travelled in search of pollen-rich flowers.

But they were amazed to find that for one in eight bees the prospect of a hard day flitting from flower to flower was clearly too much effort. Instead they simply flew to nearby nests and pilfered the pollen and nectar that was already stored there.

Continued ...

Just What Makes That Little Old Ant… Change a Flower's Nectar Content?

Apr. 24, 2013 — Ants play a variety of important roles in many ecosystems. As frequent visitors to flowers, they can benefit plants in their role as pollinators when they forage on sugar-rich nectar. However, a new study reveals that this mutualistic relationship may actually have some hidden costs. By transmitting sugar-eating yeasts to the nectar on which they feed, ants may be indirectly altering the nectar-chemistry and thus affecting subsequent pollinator visitations. 

Many species of plants benefit from interacting with ants, and some even secrete special sugary substances to attract ants. Plants produce sugar, in the form of nectar, and in exchange ants provide services such as pollination or protection from herbivores. 

The main components of nectar that attract pollinators include three dominant sugars -- sucrose, fructose, and glucose -- and amino acids (or proteins). The chemical composition of nectar differs among plant species and has been thought to be a conservative trait linked to pollinator type. For example, plants pollinated by hummingbirds tend to have nectar with high amounts of sucrose. In addition, nectar composition is thought to be regulated by the plant. 

"When people think about how flowers are pollinated, they probably think about bees," notes Clara de Vega, a postdoctoral researcher at the Estación Biológica de Doñana, Spain. "But ants also pollinate flowers, and I am interested in the role ants play in pollination since it is still poorly understood." 

Continued: http://www.sciencedaily.com/releases/2013/04/130424185232.htm

Insect-Eating Bat Outperforms Nectar Specialist as Pollinator of Cactus Flowers

Dec. 6, 2012 — Of the two bat species known to visit the flowers of the cardon cactus in Baja California, one depends entirely on nectar and is highly specialized to feed from the flowers, which are adapted for pollination by bats. The other is an insect-eating bat best known for its ability to hear the footsteps of large insects and scorpions and capture them on the ground.

In a surprising result, scientists at the University of California, Santa Cruz, have found that the insect-eating pallid bat is a more effective pollinator of the cactus flowers than the nectar-feeding specialist, the lesser long-nosed bat.

"The lesser long-nosed bat is highly specialized for nectar-feeding and was thought to be the primary pollinator of the cardon cactus. But when we measured their effectiveness, we found that the pallid bat actually delivers about 13 times as much pollen per visit," said Winifred Frick, a research scientist at UC Santa Cruz. Frick is first author of a paper on the new findings published online in American Naturalist.

The study highlights the complex nature of the mutually beneficial relationships between plants and their pollinators, which in most cases have evolved together over long periods of time. There are often conflicts of interest between the partners, according to coauthor Kathleen Kay, assistant professor of ecology and evolutionary biology at UC Santa Cruz.

Continued:  http://www.sciencedaily.com/releases/2012/12/121206131827.htm