Bees: How Important Are They and What Would Happen If They Were Extinct?

The Conversation - I Need to Know August 19, 2019

How important are bees and what will happen when they go extinct? Is there research into what is killing them? I’ve been told it’s weed killers… – Tink, aged 18, Cornwall, UK.

Bees – including honey bees, bumble bees and solitary bees – are very important because they pollinate food crops. Pollination is where insects move pollen from one plant to another, fertilising the plants so that they can produce fruit, vegetables, seeds and so on. If all the bees went extinct, it would destroy the delicate balance of the Earth’s ecosystem and affect global food supplies.

There are more than 800 wild bee species within Europe, seven of which are classified by the International Union for Conservation of Nature (IUCN) as critically endangered. A further 46 are endangered, 24 are vulnerable and 101 are near threatened. While it’s unlikely that all bee species will be wiped out anytime soon, losing these threatened species would still have a big impact on pollination around the world, wiping out plant species, some of which we rely on for our food.


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But the problem goes far beyond bees. In fact, honeybees are responsible for only one third of crop pollination and a very small proportion of the wild plant pollination. There are a diverse range of other insects including butterflies, bumblebees and small flies that do the rest of the work – and it looks like these insects are in trouble too.

A bumblebee, pulling it’s weight. Emily L Brown, Author provided

A bumblebee, pulling it’s weight. Emily L Brown, Author provided

A recent study suggests that as many as 40% of the world’s insect species are in decline. Insects are facing extinction rates that are eight times higher than vertebrates. In Germany, scientists have recorded losses of up to 75% of the total mass of insects in protected areas.

These trends lead scientists to believe that about a third of all insect species – that’s nearly 2m – may be threatened with extinction. And that figure is growing by over 100,000 species every year. Yet hard data on threatened insect species is lacking, with only 8,000 records actually assessed by the IUCN.

Here’s a rundown of what scientists believe to be the top causes of declines in insect diversity and abundance.

Invasive species

Invasive predators, parasites and disease-causing bacteria called “pathogens” have been blamed for the collapse of honeybee colonies around the world.

Recently, the spread of the Asian Hornet in Europe has caused great concern. This species preys on honey bees, and a single hornet is capable of killing an entire hive.

There is some evidence that wild bees in North America have declined in the face of fungal and bacterial diseases.



Of course, in the past bees have coexisted with these pathogens. The fact that scientists have seen more bees lost to these diseases in recent times is probably linked with the bees’ increased exposure to pesticides, which can damage their immune systems.

Pesticides

Pollution – particularly from exposure to pesticides – is a key cause of pollinator decline. There are three types of chemical pesticide widely used in the UK: insecticides targeting insect pests, fungicides targeting fungal pathogens of crops and herbicides targeting weeds.

Insecticides contain chemicals that can kill pollinators, so they’re clearly a threat. But they may not be the greatest problem pollinators experience. Herbicides are actually used five times as much in farming as insecticides. These weed killers target a huge variety of the wild plants that bees need to forage.

Environmentally-friendly farming schemes recommend planting wildflower strips on the edge of crops, to provide safe refuge and food sources for pollinators. Yet drifting clouds of herbicide from growing fields can contaminate these wildflower strips.

Wildflowers border farmland in Sussex, UK.  Shutterstock.

Wildflowers border farmland in Sussex, UK. Shutterstock.

The most cutting-edge research suggests glyphosate (the most commonly used weed killer) can impact the gut microbes of bees, which can have devastating implications for their health.

Although exposure to herbicides and pesticides used by farmers is likely to be one of the main causes of pollinator decline, the chemicals used by city authorities and civilian gardeners might also be harming bees and other insects. So, for the bees’ sake, it’s best to avoid using them where possible.

Climate change

Global warming is believed to be a major driver of wild bee declines. Some wild bees can only survive in a narrow range of temperatures. As their habitats get warmer, the places where they can live grow smaller. For example, some might be forced to live at higher altitudes, where it’s cooler, reducing the space they have to live in.

Habitat destruction

The way land is farmed has been associated with declines in biodiversity and pollination. Farming destroys the kinds of spaces that bees use to nest, it takes away the diversity of food that bees use to forage on and it even has wider impacts on other animals like wild birds, mammals and amphibians.

While countless insect species are currently going extinct, those that remain are taking their place, so it’s unlikely that crops will stop being pollinated any time soon. Generalist species such as the buff-tailed bumblebee, the European honey bee and common small black flies, which can survive in a huge range of temperatures and conditions, will become the main species pollinating our food sources, while rarer, more specialist species will decline.

But as generalist species move in to take the place space left by the losses of specialists, and complex ecosystems become dominated by a couple of generalists, the whole system becomes far more susceptible to a single sudden change. Insects form the base of many intricate food webs, their decline will result in a complex cascade of impacts on vertebrates, threatening ecological stability.

https://theconversation.com/bees-how-important-are-they-and-what-would-happen-if-they-went-extinct-121272

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How Do Bees Make Honey? (Not Just Bee-Barf)

NC State University By Matt Shipman  6/19/13

honey bee

Last weekend, my daughter asked me how bees made honey, and I realized that I didn’t know the answer. How do bees make honey? I did some homework, and can now explain it to her – and to you.

Different honey bees have different jobs. Some of these bees are “forager” bees, which collect nectar from flowering plants. The foragers drink the nectar, and store it in their crop, which is also called the honey stomach. The crop is used solely for storage, and the bee does not digest the nectar at all.

The forager bee then takes the nectar back to the hive, regurgitating the nectar directly into the crop of a “processor” bee at or near the entrance to the hive.

While the forager heads back to the flowers for more nectar, the processor bee takes the nectar to the honeycomb, which tends to be near the top of the hive, and regurgitates it into a hexagonal wax cell. But now the nectar needs to ripen.

The processor bees add an enzyme called invertase every time they regurgitate their nectar (and it takes many loads of nectar to fill a cell). The nectar consists largely of sucrose (table sugar) and water. The invertase breaks the sucrose down into two simpler sugars: glucose (blood sugar) and fructose (fruit sugar).

By definition, honey contains less than 18.6 percent water, but water usually makes up approximately 70 percent of nectar. During the ripening process, the bees “dry out” the nectar. One of the ways they do this is by fanning their wings, which creates airflow around the honeycomb and helps water evaporate from the nectar.

Once the nectar has ripened into honey, it contains so little water that no microbes can grow in it. That keeps it from becoming contaminated by bacteria or fungi. At this stage, the processor bees “cap” the cell with an airtight wax seal. If the cap is not airtight, the honey will absorb moisture from the air, making it susceptible to bacterial or fungal growth. (This is also why it’s important to screw the lid back on your jar of honey.)

Here are a few more honey-related questions and answers.

If microbes can’t grow in honey, why can’t babies have honey?

Children under the age of one shouldn’t eat honey because the honey can still containbotulinum spores. The spores can’t germinate inside the honey (it’s too dry), but they may become viable after the honey has been consumed – and infant immune systems may not be capable of warding them off.

Why do some types of honey crystallize more easily than others?

In addition to sucrose and water, nectars from different plants can hold varying amounts of other sugars and chemicals. (That’s why honeys from different plant sources have different flavors.) Nectars that have higher levels of glucose tend to crystallize more readily. Sourwood and tupelo honeys have lower levels of glucose, and so almost never crystallize.

How can I turn honey that’s crystallized back into a liquid?

If your honey has crystallized, put the jar of honey into a pot filled with hot (but not boiling!) water. This is better than microwaving it, because over-heating the honey can make it taste unpleasant.

Sweet, right?

Note: Many thanks to David Tarpy, associate professor of entomology at NC State and director of the Beekeeper Education & Engagement System, for taking the time to talk with me about bees and honey. Any errors in the above post are mine alone.

http://web.ncsu.edu/abstract/science/how-do-bees-make-honey/