Ent 222: Pollinator Conservation in Agriculture Landscapes

What is pollination? where does it take place?

Bringing male gametophyte (pollen grain) to a female gametophyte (embryo sac)

Union of their gametes (sperm + egg) = fertilization

This takes place within the ovary, with development of seeds following pollination

What is the difference between bisexual flowers and unisexual flowers?

Bisexual flowers (perfect) = has both stamens and carpels

Unisexual flowers (imperfect) = only has stamens or carpels

What is the difference between monoecious and dioecious?

Monoecious = plant has both M and F flowers

Dioecious = plant has M and F flowers on separate plants

What are the three pollination systems?

Self pollination from the same flower= autogamy

Self pollination from the same plant = geitonogamy

Cross pollination = xenogamy

What makes a great pollinator?

Can fly

Hairy body

Pollen carrying structures

→ some insects have pollen baskets on their back two legs (corbicula)

→ some bees have dense mats of long hairs somewhere on their bodies

What are the different kinds of insect pollinators?

785 bee species as crop pollinators

More flies than bees in colder regions

Butterflies and moths

Beetles

Wasps

Thrips

Ants

and more ….

What floral resouces are flower visiting insects looking for?

Nectar = sugar source for energy

Pollen = protein source for larval development

Oils = fats used for provisions

Fragrances = used for attraction

Resins = used in nest construction

Vitamins, fatty acids and minerals

How dependent are flowering plants on animal pollination?

~ >300,000 (85%) species of the world's flowering plants are pollinated by animals

Animal mediated pollination is responsible for 33% of global food production

>¾ of leading types of global food crops rely on to some extent animal pollination

Which is better,

One abundant pollinator or

A diverse pollinator community ?

Diverse communities of pollinators pollinates better than a single abundant species

Is using only honeybees for crop production stable?

No by relying on only honeybees for crop production we make ourselves vulnerable to population crashes

→ We get better fruitset when pollinated by native pollinators than honeybees across all crops tested!!

What is the trend for pollinator pops worldwide?

(-) Wild pollinators have declined in occurrence and diversity at local and regional scales for NW Europe and North America … Lack of data for other places

(+) Number of managed western honey bee hives has increased globally over the last 50 years

(++)Volume of production of pollinator dependent crops has increased by 300% over the past 50 years

… Crops dependent on pollinators have experienced lower growth and stability of yield than pollinator independent crops

What are some components of biodiversity?

Species richness

Abundance of individuals

Evenness in species abundance

Species composition

Genetic diversity

Trait diversity

Interaction diversity

What are the four main threats to pollinator biodiversity?

Land use changed (intensive agriculture management)

Environmental pollution (widespread pesticide use)

Invasive species = pathogens

Climate change

What happens when we control all weeds in a field?

There is no food for insects that depend on floral resouces

What 4 things do pollinators need to persist on the landscape?

• Food resources throughout the year

• Undisturbed overwintering sites

• Refuges from heavy pesticide use

• Natural areas !!

Do all natural areas have to be large?

Sometimes just the small area of non-crop vegetation that makes up the field border on the road verge

How many acres of farmland are present in Canada?

In 2016 there were 270,000 farm operators and almost 200,000 farms with a total area of 159 million acres across Canada, mostly in Western Canada

This is huge compared to other countries

Do treed field borders or herbaceous field borders better support pollinators?

Treed field borders export over 82,000 more hoverflies per km per week into crop fields than herbaceous field borders

→ important pollinators as adults

What is the importance in having both treed field borders and herbaceous?

They both support different flower visiting insect species; having both types maximises insect diversity around a crop field

Does the composition of road berg vegetation impact bee floight direction?

No