Fuel Exhaust Disrupts Scent Signals for Honeybees

Originally published on National Geographic Daily News, 3 October 2013.

A honeybee foraging. Source: Tracey Newman/University of Southampton.
A honeybee foraging. Source: Tracey Newman/University of Southampton.

To a bee, no two flowers smell quite the same. When honeybees forage for flowers, they search for, learn, and memorize distinctive floral scents and return to the hive to tell other bees what they’ve found through their famous waggle dance.

It is an important ritual that is being disrupted by one of the most pervasive forms of air pollution—diesel exhaust—according to a new study published Thursday in Scientific Reports. The research pinpoints the mechanism by which the fuel-combustion pollutants degrade certain chemicals in floral odors. The absence of those chemicals affects honeybees’ ability to recognize the scent.

Engine exhaust is hardly the only threat facing the honeybee. It is well recognized that exposure to multiple pesticides can impair bees’ olfactory skills, while ground-level ozone, or smog, and ultraviolet (UV) radiation can also degrade floral odor compounds that bees pick up on. Authorities around the globe are grappling with how to address the little-understood cyclical diseases that are causing colonies to dwindle.

The new study offers insight into the specific hazard for pollinators from the fumes from cars, trucks, trains, ships, and heavy machinery. Significantly, the study indicates that honeybees haven’t been helped by the “cleaner” diesel now used in Europe and the United States due to regulations that over the past decade removed sulfur from the fuel. The researchers used ultra-low-sulfur diesel fuel in their experiment…

Read more here.

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Flamboyant shrimp communication

California Mantis Shrimp, water color by Erica Staaterman
Mantis Shrimp watercolor by Erica Staaterman

Mantis Shrimp #1: “Bbbbrrrnanndndndggghhhh” (MARCO!)

Mantis Shrimp #2: “Grrryyyyybbbbbghhhhhhhh” (POLO!)

Communication can be difficult even for us humans – otherwise how on earth would fashion magazines make their money off of columns like “Male Body Language Decoded – how to tell if he’s the one.” But, that’s perhaps why we spend a lot of time and effort analyzing how animals say “Heyyyy how you doin’?” This can be especially difficult in environments – like the bottom of the ocean – where it’s so dark that organisms can’t even see, let alone pick up the intricacies of body language.

In this pitch-black world, California mantis shrimp (Hemisquilla californiensis, a vibrantly colored benthic dwelling crustacean that lives in muddy holes along the ocean floor of the west coast) use sound. Or more specifically, they ‘rumble’.  A study by six scientists from the University of Miami, UMass Amherst, Cornell, and Berkeley looks at how deep sea dwelling mantis shrimp flirt, scare off rivals, escape predators, and say hey get off my porch.

The research graces the August cover of Aquatic Biology and shows that not only do mantis shrimp communicate through low frequency muscle vibrations or rumbles, they each have a unique “voice”, too. It’s hard to study this in a lab because the shrimp vary their rumbles acoustically and temporally to a much higher degree in the wild. So, in addition to recording shrimp in lab tanks, the researchers strapped on their scuba gear and placed high tech audio-visual equipment – an autonomous recording unit (audio) and a hydrophone array (visual/location calculator) – near mantis shrimp burrows on the ocean floor near Catalina Island in California.

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