When the bees are gone

Asian Geographic - - Environment - Pes­ti­cide use, habi­tat loss, dis­eases, par­a­sites and global warm­ing are plung­ing the hon­ey­bee pop­u­la­tion into de­cline, so much so that fruit farm­ers in China and else­where are do­ing the work of bees. Why? Be­cause you have a bee to thank for ev­ery one in t

above The long-term vi­a­bil­ity of hand pol­li­na­tion is be­ing challenged by ris­ing labour costs and de­clin­ing fruit yields right Heavy pes­ti­cide use on fruit trees in the area has caused a se­vere de­cline in wild bee pop­u­la­tions

Do­ing the work of bees

In China’s moun­tain­ous Maox­ian re­gion in Sichuan Prov­ince, there are al­most 6,500 hectares of pear and ap­ple or­chards. Ev­ery year, vil­lagers de­scend on the farm­lands to be­gin the mon­u­men­tal task of pol­li­nat­ing ev­ery sin­gle fruit blos­som – by hand.

Ap­ple pro­duc­tion in the Maox­ian Val­ley be­gan in 1946 with 400 trees. By the 1980s, the re­gion had over 200,000 trees, with ap­ples be­ing the county’s lead­ing crop yield. By the late 1990s, Maox­ian was pro­duc­ing over 30,000 tonnes a year to the value of USD6.4 mil­lion. With this bur­geon­ing com­mer­cial suc­cess came the in­creased use of pes­ti­cides, over­tak­ing the more tra­di­tional or­ganic fer­til­i­sa­tion meth­ods. The 1990s saw over­all ap­ple pro­duc­tiv­ity de­cline by half, at­trib­uted to the mys­te­ri­ous dis­ap­pear­ance of bees.

The pol­li­na­tion of ap­ples in Maox­ian has to be com­pleted within five days in or­der for the trees to bear fruit. When the trees blos­som, the vil­lagers go out en masse, armed with small paint brushes. They use home­made pol­li­na­tion sticks made from chicken feathers and ci­garette fil­ters and dip them into a pot full of pur­chased pollen, and then rub the end of the stick to the pis­tils of the tree flow­ers. Chil­dren clam­ber up to pol­li­nate the higher parts of the tree. One per­son can pol­li­nate be­tween five to 10 trees in a day.

In a vil­lage in Nanxin, farm­ers have been us­ing hand-pol­li­na­tion – also called “me­chan­i­cal pol­li­na­tion” – for the past two decades to en­sure their trees yield fruit. How­ever, the long-term vi­a­bil­ity of hand pol­li­na­tion is be­ing challenged by ris­ing labour costs and con­tin­u­ously de­clin­ing fruit yields.

Hu­man im­pact

Bio­profit con­ducted an in­ves­ti­ga­tion into the de­clin­ing bee is­sue in the Sichuan Val­ley in 2001. Un­able to iden­tify one ex­act cause of their dis­ap­pear­ance, sci­en­tists put it down to sev­eral fac­tors. Pes­ti­cide was one sig­nif­i­cant in­flu­ence, as was over-farm­ing, re­sult­ing in the de­struc­tion of the bees’ nat­u­ral habi­tat. They also found that com­mer­cial bees had been in­tro­duced to the area to coun­ter­act the deficit in the num­bers of indigenous bees, but, ac­cord­ing to Bio­profit, the overuse of pes­ti­cides sub­se­quently killed them all.

Surely, then, there should be some form of pes­ti­cide reg­u­la­tion in place? As it turns out, there is. China’s Min­istry of Agri­cul­ture has set out stan­dards for use, but im­ple­ment­ing them is an­other story. While there are nat­u­ral pes­ti­cides avail­able, they cost far more than the chem­i­cal equiv­a­lents, and so, the bud­get-con­scious farmer will go for the cheaper, al­beit more en­vi­ron­men­tally harm­ful, op­tion.

The 1990s saw over­all ap­ple pro­duc­tiv­ity de­cline by half, at­trib­uted to the mys­te­ri­ous dis­ap­pear­ance of bees

The plant­ing of polliniser trees, such as the crabap­ple tree – which are in­tro­duced to the or­chard to pro­vide pollen for the bees to fer­tilise with – may have been an­other con­tribut­ing fac­tor. The Maoxin farm­ers were plant­ing less than 10 per­cent polliniser trees, think­ing that it would not be com­mer­cially vi­able to have more.

Cli­mate change is the other ma­jor con­trib­u­tor to the prob­lem. The Maoxin farm­ers re­ported un­usual changes in weather pat­terns, such as rain and hail­storms un­char­ac­ter­is­tic for the blos­som­ing sea­son. Rapid tem­per­a­ture changes were re­ported, too. And then there is the huge pol­lu­tion prob­lem in China.

In 2011, Bio­profit re­turned to the re­gion. They found that many farm­ers had sub­sti­tuted their ap­ple plan­ta­tions with other crop va­ri­eties that didn’t re­quire bees for pol­li­na­tion. The once lu­cra­tive Maowen ap­ple in­dus­try op­er­ates at a frac­tion of its pre­vi­ous pro­duc­tiv­ity.

The big­ger pic­ture

For most of us, the buzzing of bees amongst the flow­ers is a quin­tes­sen­tial part of a sum­mer at­mos­phere, the sound of lazy pic­nics in a sun-drenched meadow or of re­lax­ing af­ter­noons sip­ping cold drinks loung­ing in a deckchair in the gar­den. We should not take this sound for granted, for there are now places in the world, such as the Sichuan Val­ley, where this hum can no longer be heard – where the bees are gone.

Bees are per­haps the most im­por­tant in­sects on the planet, for they pol­li­nate our crops; about three quar­ters of all the types of crops we grow to eat need pol­li­na­tion by in­sects to give a full crop yield. With­out bees, we would not have rasp­ber­ries, run­ner beans, cour­gettes, to­ma­toes, chilli pep­pers or cof­fee, to name just a few. About a third of all the food we con­sume by weight de­pends upon pol­li­na­tors. With­out bees, our diet would con­sist largely of pro­duce from wind­pol­li­nated plants: rice, maize, wheat and bar­ley. In short, with­out bees our di­ets would be more than a lit­tle dull.

It is a com­mon mis­con­cep­tion that more or less all pol­li­na­tion is done by hon­ey­bees, the fa­mil­iar bees kept by bee­keep­ers from which we get honey. This is, how­ever, a very long way from the truth. There are some 20,000 known species of bee in the world, plus other in­sects such as hov­er­flies, but­ter­flies and bee­tles that also pol­li­nate.

About three quar­ters of all the types of crops we grow to eat need pol­li­na­tion by in­sects

Dif­fer­ent in­sects tend to visit dif­fer­ent flow­ers, and are bet­ter suited to pol­li­nat­ing some than oth­ers. To­ma­toes and blue­ber­ries, for ex­am­ple, are best pol­li­nated by bum­ble­bees, while ma­son bees are ex­cel­lent at pol­li­nat­ing ap­ples. We have tiny flies to thank for giv­ing us cho­co­late, for it is they that pol­li­nate the ca­cao tree.

Dis­turbingly, how­ever, many of these pol­li­na­tors are in de­cline. Some species, such as Franklin’s bum­ble­bee ( Bom­bus franklini), once found in the western US, are now ex­tinct. Oth­ers cling on to ex­is­tence, but are far less com­mon than they once were. Pop­u­la­tions of in­sects such as the Monarch but­ter­fly ( Danaus plex­i­pus) in North Amer­ica, or the great yel­low bum­ble­bee ( Bom­bus dis­tinguen­dus) in Europe have dropped by about 90 per­cent.

This is a mat­ter of the ut­most con­cern, for we can­not feed a grow­ing global hu­man pop­u­la­tion with­out our in­sect al­lies.

Col­lat­eral Dam­age

What has hap­pened to our pol­li­na­tors? The an­swer is com­plex, and there is no one vil­lain to blame; hu­mans have cre­ated a hive of prob­lems for pol­li­na­tors.

The big­gest driver of pol­li­na­tor de­clines is a lack of wild flow­ers. Farm­ing has changed enor­mously in the last 100 years, from an age of low-in­ten­sity farm­ing of small fields to an era of vast crop mono­cul­tures, fields that stretch to the hori­zon, with not a weed or wild­flower to be seen. Some crops, such as oilseed rape or sun­flow­ers, pro­vide food for bees, but only for a week or two, and for the rest of the year there is noth­ing for them to eat. Main­tain­ing these fields free from weeds is greatly aided by mod­ern her­bi­cides such as glyphosate, which al­low farm­ers to grow per­fect mono­cul­tures of crops.

To make mat­ters worse, hu­mans have in­ad­ver­tently spread bee dis­eases and par­a­sites around the globe with do­mes­tic hon­ey­bees, and also with com­mer­cially-reared bum­ble­bees that are used for tomato pol­li­na­tion. For ex­am­ple, the care­less move­ment of bees has spread the Var­roa mite – a tiny blood­suck­ing par­a­site which at­tacks hon­ey­bees – to al­most ev­ery coun­try in the world. Sim­i­larly, wild Ja­panese bum­ble­bees now have to cope with at­tacks of Euro­pean tra­cheal mites, which in­fest their breath­ing air­ways.

To add to these prob­lems, the mod­ern world is full of in­sec­ti­cides that are di­rectly toxic to bees. Farm­ers spray their crops with organophos­phates, pyrethroids and neon­i­coti­noids, all chem­i­cals in­tended to kill pests, but which in­evitably cause col­lat­eral dam­age. The neon­i­coti­noids are par­tic­u­larly in­sid­i­ous, for they are per­sis­tent and sys­temic, get­ting into plant tis­sues and then into their nec­tar and pollen. In gar­dens and towns, a sim­i­lar bar­rage of chem­i­cals is used to kill gar­den pests, mos­qui­toes, flies, ants, or fleas on do­mes­tic an­i­mals.

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