Friday, June 10, 2016

A Wild Success - Pollinators

Text, photos and videos by Nancy Partlow ©  All photos and videos taken at the Capitol Lake Interpretive Center, unless otherwise noted. 

Renowned biologist E. O. Wilson calls invertebrates "the little things that run the world".   My interest in insects, particularly pollinators, has always been in observing and learning about  their world, especially in a natural context.
 Pollinator bee on a starburst spray of Red-osier Dogwood blossoms

One of my favorite places to do this is at the Capitol Lake Interpretive Center when the native shrubs are in bloom.  Each spring, nootka rose, thimbleberry, twinberry, ninebark, mock orange, serviceberry, vine maple, snowberry and red-osier dogwood offer pollinators what they really need - pollen and nectar.  In return, these plants receive fertilization, which result in the fruits and seeds that wildlife  eat.     

Bombus mixtus worker buzz-pollinating Nootka Rose

It's really fun to watch bumble bees buzz-pollinate Nootka rose and thimbleberry blossoms.  These worker bees (all female) sound like teensy kazoos as they scramble over flower stamens while vibrating their wing muscles at a frequency that dislodges the closely-held pollen. 

Bombus melanopygus pollen-gathering  
from Thimbleberry
Bombus sitkensis on Nootka Rose

Their male counterparts, unburdened by the requirement to gather pollen to feed larvae back at the nest, go straight for the sugar nectaries on flowers like ninebark and twinberry.   This sweet syrup fuels their sole purpose in life - to find a queen to mate with.    

Bombus melanopygus male on Pacific Ninebark
Male Bombus flavifrons nectaring on Twinberry

I'd always wanted to see a pair of bumble bees mating,  so I felt lucky when I  happened upon two bumble bees coupling at the CLIC.  

I spied what looked like a very large Bombus queen stumbling oddly about on a thimbleberry leaf.  As I watched in puzzlement,  she dropped heavily to the ground and continued to stagger around in the leaf litter.  It wasn't until I had  observed her for about a minute (an eon in insect time) that I realized that it was actually two bumble bees together - a Bombus mixtus queen with a much smaller male clinging to her back.

The queen did not seem particularly receptive to his advances.  In fact, she appeared to be vigorously trying to give him the brush off.  It's unclear from  this video  whether the male eventually successfully mated with her or not. 

Bombus mixtus male attempting to mate with B. mixtus queen

Most people don't know that beetles can also be pollinators, but according to the Xerces Guide to Attracting Native Pollinators

Beetles (order Coleoptera) represent the greatest diversity of pollinators.  There are more than 340,000 identified species of beetles worldwide, including nearly 30,000 species in North America alone.  Fossil records suggest that beetles, along with flies, were probably the first insect pollinators of prehistoric flowering plants in the late Jurassic era, around 150 million years ago. 

Its not uncommon to see beetles hanging about on rose stamens at the CLIC, attracted by the edible pollen.

Long-horned beetle on Nootka Rose

Another species of Long-horned beetle

Flies provide incidental pollinator services at the CLIC.  In their larval form, some bee-mimic flies are are voracious aphid predators.  As gem-like adults, however,  they are content to sop up nectar with their spongy tongues, receiving a light dusting of pollen in the process. 

Bee mimic fly on blackberry blossom

Syrphid fly on Mock Orange

Bumble bees are our most familiar native pollinators, yet a  host of other indigenous bees imbibe nectar and collect pollen to feed their young. 
An unidentified mining bee gathers pollen from Nootka Rose

Adrena bee on Snowberry

A Halictid (?) bee gleans larval food from
 Ninebark flowers

A newly released book, The Bee-friendly Garden, says this about native plants and pollinators:

While many plants provide resources for bees, native plants are especially beneficial.  These are the plants that have evolved with the local pollinators and evolved in the local habitats.  They are likely to support specialist species and be easier to grow without the aid of pesticides and herbicides.

I would like to add that native plants are drought-tolerant.  The Interpretive Center's  trees and shrubs endured extreme stress during last year's record heat and aridity, but nearly all survived until autumn rains arrived to slake them.  

The CLIC's diverse ecosystem is like a symphony composed daily by the plants and animals that live there.  Working in concert, they create a beautiful and exuberant Song of Life.  Pollinators supply the buzz,  and their irreplaceable services help ensure that the Song never ends. 

A pollen-flecked ground-nesting bee on Red-osier Dogwood flowers

Online Resources:

Video of a long-horned beetle eating rose pollen: