Pollination and pollinators

Pollination and pollinators

Many types of pollinators

Pollinators

• Free ecosystem service• Links wild ecosystems

with farming• Ag chemicals kill many

pollinators• Not all crops have

honeybee pollinators

Basic Flower Structures

Pollination is not an accident• Plants manipulate animal pollination

at the cost of pollen, nectar, oils and waxes offered

• Adult bees drink nectar for sugar• Pollen is high in protein which bees feed to larvae

Skunk cabbage is a native wetland plant

with beetle pollinators

Weevils Pollinate Oil Palms

red palm weevil larvae are eaten as a delicacy in New Guinea and

Southeast Asia; Photo by Hegariz

Palm Weevil + Coconut Palm disease

•Its not a simple story though.

•Red ring fungus disease has already killed up to 80% of coconut palms in parts of the Colombia.

• The disease, on a nematode brought by the palm weevil causes the trees to wither and die.

Eggplants in Africa• Eggplants in Kenya are bumblebee “buzz”

pollinated (honeybees can’t do it!)• Two species of solitary forest bees do pollinate

the eggplants.• As forests are cleared for farming, these

pollinators are lost.Hand pollination in Africa

Watermelons in California• Native bees on organic farms provide 100%

pollination for organic watermelon crops.• “Conventional” farms had greatly reduced native

bee populations + needed additional pollination.• Conservation and restoration of native bee

habitats can be a successful strategy

Wild bees + Honeybees affect each other

The wild bumble bee + a honey bee collecting pollen on a sunflower.

Honey bees that interact with wild, native bees are up to five times more efficient in pollinating sunflowers. (Sarah Greenleaf photos)

Seeds grow next years crop!• Amaranthus greens are a traditional food

in Africa, and must be grown from seed (hence) must be pollinated !

Valuing Pollination in $• Foods high in vitamins and minerals like fruits

and vegetables are mostly animal pollinated• Estimates of the value of pollination range from

$120 - $200 billion / year• The wide range in estimated values results from

the limited tools and focus appreciating the “free” service of pollination

• Many honeybee pollinated crops benefit greatly from the addition of native pollinators

Estimates of crop pollination• Bees pollinated 71 – 103 of 107 crops

worldwide (Prescott-Allan 1990)• Bees pollinate 75% of 1330 cultivated crops

(Roubik 1995)• Bees, birds + bats pollinate 35% world crops +

increase outputs of 87 foodcrops (Klein 2006)

Apple PollinationApple varieties used as good

cross - pollinators.

Hedgerows are barriers + boundaries made up of trees, shrubs and herbs

Wind breaks, any small areas and idle fields on farms can be critical habitat for pollinators

Honeybee Monocultures

• Corporate agriculture depends on only a few species and varieties of pollinators – mostly european honeybees

• Trucking honeybees nationwide spreads pests + disease to native pollinators, and reduces genetic diversity

• Many crops are better pollinated by non-honeybees

Pyrethrum insecticide• The Pyrethrum, an insecticide from

Chrysanthemum flowers, is stronger if insect pollinate the flower

Research Studies are Needed on the Diversity of Native Pollinators

• To understand what is missing or declining, you need to know what species exist and what the interactions are!

• Most information on taxonomy is in museums …• A single database to share information needed• Native crops usually havelocal native pollinators – but little is know about them

The Pollinator Matrix• Native flowers may have different pollinators over

time (years)• As each species flowering is limited to a specific

part of a season, pollinators need many different species of flowers (and hence different species of plants) to survive over the year/season.

• Pollinator populations may vary due to many environmental variables – parasites, habitat changes, climate

• So, pollinator diversity depends on plant diversity

Human Ecosystem Disturbance • So, a variety of flowers and pollinator types help

to keep ecosystems functioning… until…• Humans disturb habitats with large monocultures

and chemicals impacting native pollinators… so pollination service is lost

• So….Humans turned to European + Asian honeybees to fill the loss