tag:theconversation.com,2011:/id/topics/mite-10512/articlesMite – The Conversation2021-07-22T14:56:21Ztag:theconversation.com,2011:article/1629452021-07-22T14:56:21Z2021-07-22T14:56:21ZBees, mites and viruses: assessing the risk to South African crop pollinators<figure><img src="https://images.theconversation.com/files/411685/original/file-20210716-22-r99ejf.jpg?ixlib=rb-1.1.0&rect=19%2C127%2C2567%2C1997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mite on a bee.</span> <span class="attribution"><span class="source">E. Villalobos</span></span></figcaption></figure><p>The world’s bees face a major threat from <a href="https://www.sciencedirect.com/science/article/abs/pii/S0022201109001839">deformed wing virus</a>, a pathogen transmitted by the parasitic varroa mite. It is responsible for causing the death of <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0004071">millions of colonies</a> in the US, Europe and Asia. The major losses started in the early 1990s with at least 30% of colonies <a href="https://www.tandfonline.com/doi/abs/10.3896/IBRA.1.49.1.02">dying each year</a>. </p>
<p>The virus has been seen in 18 species of bees so far, as well as 64 other insect species, where it is typically benign.</p>
<p>Honeybees are very important for the pollination of crops, contributing between US$235 billion and $577 billion to <a href="http://www.fao.org/3/I9527EN/i9527en.pdf">global agricultural production</a> every year. Any disease that causes colony deaths is therefore a major problem, though the cost of the damage caused by deformed wing virus is still unknown.</p>
<p>The continents of South America and Africa have not recorded major honeybee colony losses associated with the varroa mite, the number one pest of honeybees in the northern hemisphere. We <a href="https://link.springer.com/article/10.1007/s00705-020-04863-5">investigated</a> why varroa was not a problem in South Africa. One factor may be the presence or absence of the deformed wing virus, since it is this pathogen – when transmitted by varroa – that kills the infested colony. </p>
<h2>Mutating virus</h2>
<p>Two subspecies of indigenous bees in South Africa (<em>Apis mellifera capensis</em> and <em>Apis mellifera scutellata</em>) make up a well-developed bee industry. They produce honey, wax and other related products, and also provide pollination services in crops such as oil seeds, deciduous fruits, subtropicals and nuts. In South Africa a <a href="https://scholar.sun.ac.za/handle/10019.1/100915">total</a> of 1,069 beekeepers are registered, managing 60,351 colonies. </p>
<p>Bees are the main pollinators of both natural flora and commercial crops and, therefore, of great economic importance. It’s important to track the deformed wing virus, following its evolution and the impacts that each variant has on the various host insects.</p>
<p>The varroa mite is an external parasite of the honeybee which feeds on the bee’s fat cells. The fat cells are nutrient rich and located near the surface of both adult and immature honey bees. The parasite’s mouth-parts inadvertently transfer deformed wing virus into the bee’s body where it multiplies rapidly. This reduces the bee’s life expectancy, leading to the death of the colony. </p>
<p>The virus consists of three closely related variants (genotypes A, B and C). It is constantly mutating, like all other RNA (ibonucleic acid) viruses whose genetic material is encoded in RNA. The most commonly detected type is the A variant, which has been associated with widespread <a href="https://www.mdpi.com/1999-4915/9/11/314">colony decline</a>. The more recent B variant is starting to dominate colonies across the world but the danger it poses is <a href="https://www.mdpi.com/1999-4915/13/6/969">not clear yet</a>. The effects of type C are still unknown, as it is the most recently described variant and <a href="https://www.nature.com/articles/s41598-017-17802-3">is very rare</a>.</p>
<h2>Dominant variant</h2>
<p>We used honeybee samples of both South African subspecies collected between 2004 and 2018 across the south of the country to compare the virus variant distribution and viral load. Pools of 10 adult bees or one infested pupa from each colony were analysed to access the RNA viral load within the bee’s body and thus allowing us to identify which variant of deformed wing virus existed in South Africa.</p>
<p>Our <a href="https://link.springer.com/article/10.1007/s00705-020-04863-5">study</a> found that the B type variant was dominant in South Africa. Since the country has not had serious colony losses, this might suggest that type B is not so lethal. But in Brazil – another country which has not recorded major losses – type A dominates, so the relationship must be more complex than first thought.</p>
<p>The most important finding was that the viral loads in both South Africa and Brazil were much lower than what has been found in the <a href="https://www.microbiologyresearch.org/content/journal/jgv/10.1099/jgv.0.001206">northern hemisphere</a>. This may be why the colonies did not die, since high viral loads are required to kill a colony. </p>
<p>A lower mite population would help explain the lower viral loads in South Africa and Brazil. The lower population may be achieved by the bees themselves: <a href="https://www.nature.com/articles/s41598-018-26001-7">a recent study</a> indicated that honeybees in South Africa and Brazil have learnt to detect and remove mite infested cells. This prevents mite reproduction. And this “hygienic” behaviour appears to be <a href="https://academic.oup.com/gbe/article/11/3/937/5318327">gentically heritable</a>. </p>
<p>Our studies confirmed the low levels of the virus and the low infestation by the mite. More research is needed, however, to prove if there is a link between the hygienic bee behaviour and lower viral loads in colonies. </p>
<p>The only way to prevent colonies dying is to control the varroa mite. In the northern hemisphere this is typically done by using pesticides. Understanding how low viral loads are achieved would help beekeepers to use other control methods. They could selectively breed colonies that have hereditary traits of resisting the mite, or collect swarms from naturally surviving colonies that have already developed varroa resistance.</p><img src="https://counter.theconversation.com/content/162945/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen John Martin receives funding from BBKA and BDI. </span></em></p><p class="fine-print"><em><span>Flaviane Santos Souza does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Bees are the main pollinators of many crops. It’s important to track the deformed wing virus and its impacts.Flaviane Santos Souza, PhD abroad School of Environment and Life Sciences, University of SalfordStephen John Martin, Chair in Social Entomology, University of SalfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/548012016-03-02T02:03:54Z2016-03-02T02:03:54ZHidden housemates: we live with a zoo of harmless mini-beasts<figure><img src="https://images.theconversation.com/files/113487/original/image-20160302-25881-1ks9mx8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fungus gnats are one the many arthropods that find their way into our homes. </span> <span class="attribution"><span class="source">Gnat image from www.shutterstock.com</span></span></figcaption></figure><p>Do you take pride in a clean house? They may not be obvious, but a <a href="http://news.nationalgeographic.com/2016/01/160119-insects-spiders-bugs-homes-science-animals/">recent US survey</a> has shown that each of our homes harbours a fauna of perhaps hundreds of species of insect and other terrestrial arthropods such as mites, millipedes and centipedes. </p>
<p>The survey, conducted in free-standing houses in Raleigh, North Carolina, sampled every arthropod, both known pests and others. Almost 75% of the diversity consisted of just four main groups, true flies (Diptera), spiders (Araneae), beetles (Coleoptera), and wasps and ants (Hymenoptera). </p>
<p>Most of the species are not the ones you might traditionally associate with houses, such as German cockroaches (<em>Blattella germanica</em>) and house flies (<em>Musca domestica</em>), but rather tended to be local arthropods filtered from the surrounding landscape. </p>
<p>More than 500 rooms were surveyed in total, and a staggering 99% of them contained arthropods. Insects were overwhelmingly common, with over 90% of kitchens, bedrooms and bathrooms harbouring them. The bigger the house, the more species it contained, and the human inhabitants were generally unaware of their uninvited guests. </p>
<p>How do these insects enter homes? As in Australia, most US homes have fly screens installed on windows, but many of these arthropods are small and can enter through the gaps around doors and windows, chimneys, drains, basements, attics and ceiling spaces. </p>
<p>Although no similar study has been done in Australia, it would probably uncover similar results. So what are all these mini-beasts doing in our homes?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/113470/original/image-20160301-12114-v84caq.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/113470/original/image-20160301-12114-v84caq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/113470/original/image-20160301-12114-v84caq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=513&fit=crop&dpr=1 600w, https://images.theconversation.com/files/113470/original/image-20160301-12114-v84caq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=513&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/113470/original/image-20160301-12114-v84caq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=513&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/113470/original/image-20160301-12114-v84caq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=645&fit=crop&dpr=1 754w, https://images.theconversation.com/files/113470/original/image-20160301-12114-v84caq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=645&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/113470/original/image-20160301-12114-v84caq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=645&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Proportion of different arthropods found in homes: there are a lot of flies and spiders.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.7717/peerj.1582">Bertone et al</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Meet the arthropods</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/113474/original/image-20160302-12131-1qtvroo.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/113474/original/image-20160302-12131-1qtvroo.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/113474/original/image-20160302-12131-1qtvroo.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1314&fit=crop&dpr=1 600w, https://images.theconversation.com/files/113474/original/image-20160302-12131-1qtvroo.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1314&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/113474/original/image-20160302-12131-1qtvroo.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1314&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/113474/original/image-20160302-12131-1qtvroo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1651&fit=crop&dpr=1 754w, https://images.theconversation.com/files/113474/original/image-20160302-12131-1qtvroo.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1651&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/113474/original/image-20160302-12131-1qtvroo.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1651&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The most common mini-beasts in homes: (A) cobweb spiders (B) carpet beetles (C) gall midges (D) ants (E) book lice (F) dark-winged fungus gnats (G) cellar spiders (H) weevils (I) mosquitoes (J) scuttle flies (K) leafhoppers (L) non-biting midges.</span>
<span class="attribution"><a class="source" href="https://peerj.com/articles/1582/">Bertone et al</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Arthropods have been living in our homes ever since we moved out of caves and built houses. For example, the remains of a variety of <a href="http://www.sciencedirect.com/science/article/pii/S0305440301906971">beetles that consume grains are common in Egyptian archaeological sites more than 3,000 years old</a>. </p>
<p>Animal domestication and food storage brought many different opportunities for arthropods to make a living where we live. Some, such as bed bugs, may have <a href="http://link.springer.com/article/10.1007%2Fs00436-012-2862-5">followed us out of the caves</a>. </p>
<p>Most studies have focused on known pests, with particular emphasis on medically and economically important species such as mosquitoes, termites, fleas and dust mites. </p>
<p>The US study was the first to uncover the multitude of other non-pest species in our homes. Their true interactions with humans remain largely unknown. None is known to cause us any direct harm.</p>
<p>Common groups found in almost all houses included cobweb spiders (Theridiidae), carpet beetles (Dermestidae), gall midges (Cecidomyiidae), ants, book lice (Liposcelididae), and fungus gnats (Sciaridae). Dust mites and American cockroaches were found in 75% of the houses sampled. Flies were found in over 80% of homes, but the commonest ones (non-biting midges, Chironomidae; and gall midges, Cecidomyiidae) are harmless and form part of the aerial plankton outside homes.</p>
<p>Interestingly, none of the homes surveyed had any bed bugs. This suggests these insects may thrive best in motels, hotels and hostels rather than in permanent residences.</p>
<p><a href="http://jee.oxfordjournals.org/content/107/2/867">Book lice have a broad diet</a>, including grain, fungi, paper products and organic waste, and have a long history of living in close association with birds and mammals and their nests. They can survive for long periods without food and females can reproduce without sex (parthenogenesis). Both these attributes contribute to their success. </p>
<h2>A whole ecosystem in your living room</h2>
<p>The insects found have a range of different relationships with people, from species that have a very strong association (for example, carpet beetles, cobweb spiders), to others that seek shelter and resources only occasionally (ants, hunting spiders), to others that blunder into our homes and are trapped to their detriment (plant-feeding bugs and gall midges).</p>
<p>Many of the insects found were plant feeders. The were probably attracted into the home by lights at night, or introduced via cut flowers, and cannot complete their life cycle in the home. </p>
<p>Some, such as the fungus gnats (Sciaridae), may be able to complete their life cycle in the soil associated with indoor plants. Some predators, such as spiders, are able to feed on other arthropods in the home, and others are tiny parasitic wasps, which may be able to complete their life cycle on other arthropods in the home. </p>
<p>In these cases our homes may contain very simple, but self-sustaining, ecosystems. </p>
<p>Many of the insects found in the US homes are a sample of the local arthropod fauna that are not known to cause us any direct harm. All the pest groups in the US homes are also present in Australia and elsewhere. </p>
<p>These results suggests that if a similar survey was conducted in an Australian city, a minority of the insects would be the cosmopolitan pests found in human houses all over the world, whereas the majority would be a sample of the local Australian arthropod fauna. </p>
<p>Should we be worried? Probably not - other recent research has shown <a href="http://link.springer.com/article/10.1007%2Fs11252-007-0045-4">how diverse the arthropod fauna is in urban areas</a> as well. If your home harbours a healthy arthropod fauna, it is safe for you as well. Whether we like it or not, we have evolved with a zoo of arthropod mini-beasts in our dwellings and suburbs for millions of years. </p>
<p><em>This article is part of a <a href="https://theconversation.com/au/topics/hidden-housemates">series profiling our “hidden housemates”</a>. Are you a researcher with an idea for a “hidden housemates” story? <a href="mailto:james.whitmore@theconversation.edu.au">Get in touch</a>.</em></p><img src="https://counter.theconversation.com/content/54801/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Yeates does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Our homes harbour hundreds of species of insects and their relatives.David Yeates, Director of the Australian National Insect Collection, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/539162016-02-04T22:05:56Z2016-02-04T22:05:56ZRevealed: honeybees are being killed off by a manmade pandemic<p>We live in a world where large numbers of people are connected by just a few degrees of separation. But while having friends of friends all over the globe can be great for holidays, trade and networking, travel also allows viruses to move like never before.</p>
<p>Zika is the latest “<a href="http://www.nejm.org/doi/full/10.1056/NEJMp1600297?af=R&rss=currentIssue&&">explosive pandemic</a>” to be declared a <a href="http://www.bbc.co.uk/news/health-35459797">global emergency</a> by the World Health Organisation. But viruses don’t just target humans – they can infect all forms of life from bacteria to <a href="https://theconversation.com/why-disease-may-wipe-out-worlds-bananas-and-how-we-might-just-save-them-54082">bananas</a>, horses to honeybees. </p>
<p>A lethal combination of the Varroa mite and the <a href="http://www.honeybeesuite.com/deformed-wing-virus/">deformed wing virus</a> has resulted in the death of billions of bees over the past half century. In a study published in the journal <a href="http://www.sciencemag.org/cgi/doi/10.1126/science.aac9976">Science</a>, colleagues from the Universities of Exeter, Sheffield and I report how the virus has spread across the globe. </p>
<h2>Bee boundaries</h2>
<p>Honeybees are geographically separated into two distinct groups, a single species from Africa, confusingly known as the European honeybee, and six other species, all from Asia. The European honeybee is the main species managed by humans, purely because of its ability to make the most honey per colony.</p>
<p>In the 1950s these European bees were taken to Asia to improve honey production, and at some point the Varroa mite jumped the species barrier from its native Asian honeybee across to the Western one. Over the next 50 years, the mites spread around the world with the global trade in European honeybees. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/110019/original/image-20160202-32222-1r4a144.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/110019/original/image-20160202-32222-1r4a144.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=553&fit=crop&dpr=1 600w, https://images.theconversation.com/files/110019/original/image-20160202-32222-1r4a144.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=553&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/110019/original/image-20160202-32222-1r4a144.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=553&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/110019/original/image-20160202-32222-1r4a144.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=695&fit=crop&dpr=1 754w, https://images.theconversation.com/files/110019/original/image-20160202-32222-1r4a144.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=695&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/110019/original/image-20160202-32222-1r4a144.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=695&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Eaten alive?</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/129427023@N06/15771312916">Monika Fischer</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Within three to five years of the mites’ arrival, bee colonies started to collapse on a massive scale. Natural wild populations were soon wiped out, as were millions of managed colonies.</p>
<h2>A crippling death</h2>
<p>For decades it was thought that bees were being sucked to death by the mites, as the mites feed exclusively on the bees’ blood. This idea was supported by the appearance of bees in heavily-infested colonies with dry, crippled wings.</p>
<p>But <a href="http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2664.2001.00662.x/full">more recent research</a> showed that the Varroa mite was, in fact, a carrier rather than a killer, transmitting deformed wing virus directly into the bloodstream. Though bees suffer from various viruses, these are usually found at very low levels and move between bees via food or during mating. The Varroa mite’s totally new transmission route <a href="http://science.sciencemag.org/content/336/6086/1304">changed the game</a>.</p>
<p>Some infected honeybees had crippled wings so could not fly and died quickly, but although most infected bees had normal wings their lifespan was shortened by up to 50% by the virus – causing inevitable colony collapse. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/110022/original/image-20160202-32227-4ohh4r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/110022/original/image-20160202-32227-4ohh4r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/110022/original/image-20160202-32227-4ohh4r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/110022/original/image-20160202-32227-4ohh4r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/110022/original/image-20160202-32227-4ohh4r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/110022/original/image-20160202-32227-4ohh4r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=506&fit=crop&dpr=1 754w, https://images.theconversation.com/files/110022/original/image-20160202-32227-4ohh4r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=506&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/110022/original/image-20160202-32227-4ohh4r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=506&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Trying to spread those wings.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/klaasdegelder/5137860060">klaas de gelder</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Over time, the virus evolved into a single killer form, now known as the A-type, and it is this which has since spread to bee colonies globally. By analysing data from bees and mites collected around the world, the evolutionary history of this pathogen was reconstructed to reflect how it was spreading.</p>
<h2>Future flight</h2>
<p>We learned that the deformed wing virus originated within European honeybees themselves, and not their Asian relatives or the mites. The Varroa mite just happened to be particularly effective at spreading the virus.</p>
<p>The current pandemic started in the mid-20th century and its spread mirrors that of the Varroa mite. European and North American honeybee colonies were found to be the main transmission hubs, which is to be expected since they are key areas in the global bee trade. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/110214/original/image-20160203-5865-2n6t9a.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/110214/original/image-20160203-5865-2n6t9a.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/110214/original/image-20160203-5865-2n6t9a.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=332&fit=crop&dpr=1 600w, https://images.theconversation.com/files/110214/original/image-20160203-5865-2n6t9a.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=332&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/110214/original/image-20160203-5865-2n6t9a.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=332&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/110214/original/image-20160203-5865-2n6t9a.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=417&fit=crop&dpr=1 754w, https://images.theconversation.com/files/110214/original/image-20160203-5865-2n6t9a.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=417&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/110214/original/image-20160203-5865-2n6t9a.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=417&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The mites will inherit the Earth: how Varroa went global.</span>
<span class="attribution"><a class="source" href="http://www.science.sciencemag.org/cgi/doi/10.1126/science.aac9976">Wilfert et al; Science</a></span>
</figcaption>
</figure>
<p>Honeybees and other pollinators are all interconnected via trade, which creates an ideal situation for the rapid spread of pathogens and parasites worldwide and between species – including bumblebees.</p>
<p>There are many parallels between the global spread of deformed wing virus and other insect-borne human pathogens such as the Zika virus. And as international trade and travel continues to increase we can expect to see many more emerging viruses impacting both human and animal health.</p>
<p>But our genetic history indicates we are well adapted to survive these emerging pathogens, and there are a number of Varroa infested honeybee populations around the world that can now survive without any form of mite control. Natural selection wins again it would seem.</p><img src="https://counter.theconversation.com/content/53916/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Martin has received funding from NERC, BBSRC & OECD. </span></em></p>New study maps the spread of ‘deformed wing virus’ – and it follows patterns of human trade.Stephen John Martin, Chair in Social Entomology, University of SalfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/486842015-10-20T03:35:40Z2015-10-20T03:35:40ZPoor nutrition may be another reason for the declining honey bee population<figure><img src="https://images.theconversation.com/files/98260/original/image-20151013-31126-3mupea.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sunflowers contain less protein than aloe plants and bees need more of this. </span> <span class="attribution"><span class="source">Chamanti Laing</span></span></figcaption></figure><p>Honey bees are essential for pollination of wild and cultivated plants, and honey production. As a result honeybee colonies are managed all over the world. Bees and other pollinators are in the <a href="http://news.nationalgeographic.com/news/2013/13/130510-honeybee-bee-science-european-union-pesticides-colony-collapse-epa-science/">news</a> a lot more recently because they are declining in numbers, while the demand for crop production increases.</p>
<p><a href="http://www.economist.com/node/21551451">Pesticides</a> and bee <a href="http://www.dpi.nsw.gov.au/agriculture/livestock/honey-bees/pests-diseases">diseases</a> seem to draw the most attention as the cause of declining bee numbers. But nutritional stress could be another. Habitat loss and intensified agriculture lead to diminishing food resources for bees. This additional stress lowers their resistance to pesticides and diseases.</p>
<h2>Nutritional requirements of bees</h2>
<p>Adult bees need mainly carbohydrates, and sugars in nectar provide energy for foraging and thermoregulation. Their larvae need protein, fats, vitamins and minerals for growth. These nutrients come from <a href="http://health.howstuffworks.com/diseases-conditions/allergies/outdoor-allergies/what-is-pollen.htm">pollen</a>. Among solitary bees, larvae are the main pollen consumers. Honey bees differ in that the main consumers are nurse bees, young workers who digest pollen and produce jelly that they feed to the larvae, also known as brood.</p>
<p>We need to distinguish between the quality and quantity of bee food. Mass-flowering crops such as sunflower or canola provide superabundant food. But this has disadvantages: it’s for a limited period only, it increases exposure to pesticides and it is unlikely to be nutritionally balanced. Sunflower pollen for example, contains much less protein than <a href="http://www.honeybadger.co.za/sabj_7401.html">aloe pollen</a>.</p>
<p>In addition to the total amount of protein, amino acids are important. Some pollen lacks essential amino acids, or the proportions may be wrong for developing larvae. A mixed pollen diet is much better than a single pollen source.</p>
<p>In a recent <a href="https://honeymedic.files.wordpress.com/2015/03/science-2015-goulson.pdf">review</a> of bee problems, bees feeding on monoculture crops were likened to humans eating only sardines, chocolate or parsnips for a month!</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/98664/original/image-20151016-25152-1wgvn7d.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/98664/original/image-20151016-25152-1wgvn7d.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/98664/original/image-20151016-25152-1wgvn7d.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/98664/original/image-20151016-25152-1wgvn7d.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/98664/original/image-20151016-25152-1wgvn7d.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/98664/original/image-20151016-25152-1wgvn7d.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/98664/original/image-20151016-25152-1wgvn7d.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/98664/original/image-20151016-25152-1wgvn7d.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bee on an aloe plant.</span>
<span class="attribution"><span class="source">Massimo Nepi</span></span>
</figcaption>
</figure>
<h2>Nectar and pollen</h2>
<p>Nectar is mainly a solution of simple sugars; sucrose, glucose and fructose in varying proportions. It also contains amino acids but in much smaller amounts. Water has to be removed from the nectar before storage as honey. This is achieved by repeated regurgitation and evaporation in the hive.</p>
<p>Pollen is much more complex. Much of its nutritional value is in the protein - this can be more than half the dry mass. When bees collect pollen they add nectar to stick the grains together for transport on their legs, so pollen brought into the hive contains extra sugar.</p>
<p>This stored pollen is known as bee bread. It’s been assumed that microbes in stored pollen improve its nutritional value through fermentation, but recent <a href="http://www.nzbees.net/threads/pollen-nutrition-research.6009/">research</a> has shown that microbes are essentially absent. In fact the added nectar has a preservative function. This confirms our analyses of sunflower and aloe pollens, which do not change in composition during storage.</p>
<p>Social existence makes nutrient regulation more complex. Does a bee forage for herself or the colony? Foraging bees tend to specialise in either nectar or pollen collection, but they forage for the whole colony. Its protein requirements depend on the worker/brood ratio. More brood means a greater need for pollen protein. Storage of food resources as honey or bee bread can buffer nutritional imbalances to some extent.</p>
<h2>Interacting effects of disease, pesticides and nutrition</h2>
<p>Honey bees are plagued by many parasites and pathogens that can affect their health. Multiple pathogen infections are common, often associated with the parasitic mite <a href="http://entnemdept.ufl.edu/creatures/misc/bees/varroa_mite.htm">Varroa destructor</a>. This infects most managed colonies world-wide and also transmits viral diseases. </p>
<p>Some pathogens have a direct influence on nutrition. The gut parasite Nosema competes with host bees for carbohydrates, placing them under energetic stress, and interferes with digestion. Poor nutrition in honey bees, as when consuming a single pollen type compared to a mixture, reduces their immunity to infection.</p>
<p>Malnourished honey bees may also be less efficient at detoxifying pesticides. The widely used neonicotinoids are systemic pesticides that spread throughout plant tissues and into <a href="http://www.npr.org/sections/thesalt/2013/03/27/175278607/are-agricultures-most-popular-insecticides-killing-our-bees">nectar and pollen</a>. Apart from direct toxicity, they have been shown to have subtle, sublethal effects on flight, navigation and learning in bees. This behaviour is important for food collection. A recent study showing that bees can’t taste neonicotinoid pesticides is especially <a href="http://www.bbc.com/news/science-environment-32399907">worrying</a>.</p>
<p>Even without going out to forage, honey bees are exposed to multiple pesticides at home. Many toxic chemicals end up in stored pollen in the <a href="http://www.honeycolony.com/article/honeybee-pollen-contaminated-cocktail-pesticides/">hive</a>, including the miticides that are used by beekeepers to combat Varroa.</p>
<p>These complex interactions between poor nutrition and other stress factors contribute to poor health of both wild and managed honey bees. But there are ways to improve bee nutrition. An obvious one is preserving semi-natural habitat in farmland, so that wild flowers sustain the bees and add variety to their diet.</p><img src="https://counter.theconversation.com/content/48684/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sue Nicolson receives funding from the National Research Foundation of South Africa.</span></em></p>Nutrition is another factor - in addition to pesticides and bee disease - that has led to the dwindling of the global bee population.Sue Nicolson, Professor of Zoology, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/479542015-10-08T03:39:27Z2015-10-08T03:39:27ZHow African honey bees can help mitigate global colony losses<figure><img src="https://images.theconversation.com/files/97397/original/image-20151006-7349-1d1ub7l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The African honeybee is more resistant to pests and pathogens than its European counterparts.</span> <span class="attribution"><span class="source">Jon Hrusa/EPA</span></span></figcaption></figure><p>Managed honeybee population stocks are declining in many <a href="http://www.ibra.org.uk/articles/Guest-Editorial-Honey-bee-colony-losses">countries</a>, worrying scientists, the public and politicians. This decline affects us all, as it poses a risk to food security. </p>
<p>Honeybees can be moved where needed and are not picky about the flower they visit to collect pollen and nectar which they feed on. Thanks to these qualities, they are the major crop pollinators relied on by humans. The honeybee equals and sometimes surpasses all other wild pollinators for this task. </p>
<p>In the last decade, many studies focused on honeybee health to identify the causes of unusually high colony losses. Most of this work has been performed in <a href="http://www.ibrabee.org.uk/index.php/component/k2/item/3131">Europe</a> and <a href="http://www.ibra.org.uk/articles/US-honey-bee-colony-mortality-2012-13">North America</a> where bees are exploited in large scale commercial operations. Scientists observe interactions of many factors affecting honeybee <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0043562">health</a>. </p>
<p>But these results are so far not sufficiently clear to understand the causes of the declines and implement adapted mitigation measures. Scientists and beekeepers will first need to understand the reasons for deaths amongst bees before they can adjust their practices to ensure the stocks’ survival.</p>
<p>Honeybee health status or even basic data of population sizes in the wild before the modern beekeeping area is unknown. We lack important information to evaluate the severity of the current problem. Understanding how bees deal with pests, pathogens and other environmental factors in Africa, where beekeeping has not been as intrusive, could help scientists understand more about why the bees of Europe and North America struggle. </p>
<h2>How can African honeybees help?</h2>
<p>The honeybee, <em>Apis mellifera</em>, is also present in <a href="http://entnemdept.ufl.edu/creatures/misc/bees/ahb.htm">Africa</a>. In contrast to the docile European honeybees, African honeybees are more <a href="http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Apis_mellifera_scutellata.htm">aggressive</a> to beekeepers and are rarely confined to man-made hives. The majority of their estimated 310 million colonies strong <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2009.01331.x/suppinfo">population</a> is <a href="http://edis.ifas.ufl.edu/mg113">wild</a> and lives in natural cavities in trees or ground. </p>
<p>A lack of data on the health status of African honeybees has prompted several international teams to investigate this issue in recent years. In attempting to deal with the problem of colony losses, beekeepers and scientists throughout the world posed the following questions:</p>
<ol>
<li><p>Is it possible that by developing beekeeping to the current industrial level, we pushed the honeybees to their biological limits? When managing these pollinators, do we place them in such unnatural situations that they are weakened?</p></li>
<li><p>Was the selective breeding used to improve desirable traits such as honey production or docility done at the expense of their defence mechanisms? </p></li>
<li><p>Does the wide scale honeybee trade result in the spread of damaging pathogens to which the honeybees are not adapted? </p></li>
</ol>
<p>By studying African honeybees in their unique <a href="http://www.apidologie.org/articles/apido/abs/2009/03/m08180/m08180.html">context</a>, we could obtain the answers.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/97425/original/image-20151006-7375-1akj0fi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/97425/original/image-20151006-7375-1akj0fi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/97425/original/image-20151006-7375-1akj0fi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/97425/original/image-20151006-7375-1akj0fi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/97425/original/image-20151006-7375-1akj0fi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/97425/original/image-20151006-7375-1akj0fi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/97425/original/image-20151006-7375-1akj0fi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/97425/original/image-20151006-7375-1akj0fi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bee with deformed wings caused by a virus transmitted by the varroa mite.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Increased knowledge on African honey bee health</h2>
<p>Recent health surveys indicated that honeybee populations in <a href="http://www.sciencedirect.com/science/article/pii/S0022201113000748">South Africa</a>, <a href="http://www.sciencedirect.com/science/article/pii/S0022201110000571">Uganda</a>, <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0094459">Kenya</a> and <a href="http://link.springer.com/article/10.1007%2Fs13592-015-0372-z">Benin</a> are indeed healthy. Pathogens, either endemic or imported, are present but do not at this time seem to generate unusual and widespread mortality. A notable exception is the damage done by a certain <a href="http://www.ibra.org.uk/articles/Colony-losses-in-South-Africa-2009-11">honeybee</a>. A particular honeybee lineage originating in the Cape region in South Africa functions as a social <a href="http://www.americanscientist.org/issues/pub/2002/9/attack-of-the-pseudo-clones">parasite</a>.</p>
<p>To promote its own reproduction, this parasitic honeybee invades colonies of other subspecies and exhausts their resources until they dwindle to death. Tens of thousands of managed colonies in the hands of the beekeepers have been lost to this parasite, while the wild populations still living in natural nests fortunately seem spared. This means that beekeepers are seen as the vectors of the parasitic bee as it largely affects managed <a href="http://www.apidologie.org/articles/apido/abs/2006/04/M6021/M6021.html">honeybees</a>. </p>
<p>This phenomenon is one example of an unexpected and negative consequence of trade involving the displacement of a subspecies of bees from their natural distribution range. The huge numbers of bees being traded all over the word exposes them to numerous <a href="http://web.oie.int/boutique/index.php?page=ficprod&id_prec=945&id_produit=1062&lang=en&fichrech=1">diseases</a>.</p>
<p>In contrast, the invasion by the most damaging honeybee parasite, the well named mite <em>Varroa destructor</em>, does not show the same long term devastating effect on some African honeybee <a href="http://link.springer.com/article/10.1007%2Fs10493-014-9842-7">populations</a>. </p>
<p>Researchers are very interested in identifying the tolerance mechanisms of the honeybee populations able to survive infestation without treatments. Selective breeding of the responsible behavioural or physiological traits could help the currently susceptible populations survive in presence of the parasite. Control efforts of the past decades have not resulted in parasite eradication and new methods are required. Honeybees that can live in the presence of this mite without human intervention are the Holy Grail for many scientists and beekeepers.</p>
<h2>Learning from past mistakes</h2>
<p>The African honeybee populations have so far largely coped with the arrival of new parasites and <a href="http://www.apidologie.org/articles/apido/abs/2009/03/m08180/m08180.html">pathogens</a>. But measures should be put in place to maintain their apparently healthy status. Beekeepers should work with local honeybee populations and refrain from importing colonies from distant places. </p>
<p>Despite the general positive situation, worrying signs of declining populations have recently been <a href="http://www.bioone.org/doi/abs/10.4001/003.022.0313?journalCode=afen">reported</a> in Madagascar, Kenya and South Africa. This is where colonies succumb to the newly arrived varroa mite or where beekeepers have increasing difficulty trapping wild swarms to build their stocks.</p>
<p>Africa would benefit from the mistakes made elsewhere by preventing such problems through the protection of honeybee populations. Before the states establish rules and restrictions, better information for the primary stakeholders are needed. Beekeepers play a vital role. They can help keep African honeybees healthy. The African honeybee could be a major tool for researchers and beekeepers if they want to learn about conserving the western honeybee.</p><img src="https://counter.theconversation.com/content/47954/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vincent Dietemann receives funding from the government and other foundations for his research. He is also part of part of the COLOSS (Preventing Honeybee Colony Losses) network.</span></em></p>The way the Africa honeybee’s deal with parasites and pathogens can teach western beekeepers and researchers how to adapt their bees to fight diseases.Vincent Dietemann, Extraordinary lecturer in Zoology and Entomology, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/257102014-05-19T04:34:57Z2014-05-19T04:34:57ZExplainer: Varroa mite, the tiny killer threatening Australia’s bees<figure><img src="https://images.theconversation.com/files/48551/original/6nwp4rcb-1400116742.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A busy bee, giving free horticultural help by collecting pollen. But a tiny mite has devastated bee populations around the world – and it's now on Australia's doorstep.</span> <span class="attribution"><span class="source">David McClenaghan/CSIRO</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>A tiny mite has been killing honey bees all around the world, and will inevitably reach Australian shores. So what is this destructive mite, and what we can do to protect Australian honey bees?</p>
<p>The Varroa mite, also known as <em>Varroa destructor</em>, is only the size of a pin head but it is the most serious threat to the viability of the Australian honey bee industry. </p>
<p>The mite is parasitic and feeds on the blood of adult and larval honey bees. It also transmits viral and other pathogens, which kill entire bee colonies. Varroa mite is part of the syndrome leading to honey bee declines in many places around the world.</p>
<h2>The global invasion heading our way</h2>
<p>Varroa mite has been highly invasive. It originated in north Asia in the 1950s and spread to Europe in the 1970s. It then spread to the USA, southeast Asia, South America and Africa. In 2000 it turned up in New Zealand.</p>
<p>Varroa kills honey bees that are managed by beekeepers as well as honey bees living in the wild (known as “feral” bees). Beekeepers need to use chemicals to protect their bees, which increases their costs and yet offers only a partial solution.</p>
<p>Honey bees living in the wild are even more vulnerable, and widespread declines occur. Within four years of the invasion of New Zealand’s North Island, feral bee populations plummeted to about 10% of what they had been. </p>
<p>Australia is <a href="https://theconversation.com/honeybee-decline-warrants-concern-but-not-panic-5707">one of the last remaining regions</a> in the world still free of Varroa. But it is closer to coming here than ever, having now spread to our neighbours in New Zealand and Indonesia.</p>
<p>Just to complicate matters further, a new Varroa mite has emerged in Papua New Guinea, where a near relative of <em>Varroa destructor</em> has made a similar behavioural jump from the Asian Honey Bee, and now also attacks the European Honey Bee. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Nfn4jwqUqvI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A camera inside a hive shows a varroa mite on a bee, which is unable to shake it off.</span></figcaption>
</figure>
<h2>Why bees are so crucial to farming</h2>
<p>Varroa mite threatens one of our key crop pollinators, just as we have begun to realise that improved pollination is part of the secret to raising agricultural productivity.</p>
<p>Australian agriculture is vulnerable to honey bee declines because a number of our most significant horticultural crops rely on honey bee pollination, and many growers have been accustomed to a high level of free service from feral honey bees.</p>
<p>When free pollination from feral bees declines, horticultural industries will look to managed bees to fill the gap. Unfortunately, beekeepers and their managed bees will be dealing with the same crisis.</p>
<p>Nowhere is this shown better than in the USA, where the mite entered in 1987. After its arrival, the feral honey bee population crashed, managed hives were reduced by about 30% and many beekeepers left the industry.</p>
<p>The decline in managed hives, along with increasing demand from crop growers, has seen a four-fold increase in the cost of hives. Each year, there has been a growing gap between demand for hives and the capacity to supply them.</p>
<h2>Better border protection and beyond</h2>
<p>Here in Australia, that gap between the supply and demand – the number of bees that beekeepers could supply and how many bees are needed – is where we are most vulnerable.</p>
<p>Our heavy reliance on feral honey bees means there has been a relatively low demand for managed hives. As a consequence, our managed pollination industry is only in the early stages of development.</p>
<p>Given that beekeepers in the USA and NZ have failed to keep pace with demand for crop pollination, Australia may experience an even greater shock to our horticultural industries in future.</p>
<p>The threat of Varroa mite incursion into Australia is real. Any European honey bee swarm arriving on a vessel at an Australian port could be carrying Varroa.</p>
<p>The arrival of Asian honey bees by ship at Australian ports, as occurred at Cairns in North Queensland, provides another pathway for the mite’s incursion.</p>
<p>And it should be noted that the mite managed to slip through New Zealand’s quarantine defences, which are similar to Australia. </p>
<p>In 2007, bio-economic modelling by CSIRO examined the risk to Australian plant industries. It was estimated that the economic risk from Varroa incursion was great enough to justify spending between A$21 million and A$50 million annually over the next thirty years to delay incursion. </p>
<p>Reducing the risk of incursion is sensible, but there must also be a strategy to combat the pest in the likely event that it eventually establishes. This conclusion was reported in the 2008 House of Representatives <a href="http://www.aph.gov.au/parliamentary_business/committees/house_of_representatives_committees?url=/pir/honeybee/report.htm">“More than Honey” inquiry</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/48550/original/y9xhh7f4-1400116685.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/48550/original/y9xhh7f4-1400116685.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/48550/original/y9xhh7f4-1400116685.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=393&fit=crop&dpr=1 600w, https://images.theconversation.com/files/48550/original/y9xhh7f4-1400116685.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=393&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/48550/original/y9xhh7f4-1400116685.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=393&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/48550/original/y9xhh7f4-1400116685.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=494&fit=crop&dpr=1 754w, https://images.theconversation.com/files/48550/original/y9xhh7f4-1400116685.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=494&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/48550/original/y9xhh7f4-1400116685.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=494&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A Varroa mite on a bee pupae.</span>
<span class="attribution"><span class="source">CSIRO</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Finding local solutions to help the world</h2>
<p>Threats to the European honey bee should remind us that reliance on a single species for crop pollination is a risky strategy. There are thousands of other insect species that contribute to crop pollination, and there are strategies available to better support them, and keep them in our production landscapes.</p>
<p>Nevertheless, we still need managed pollinators that can be supplied on demand to supplement wild pollinators. And the European honey bee will continue to be the most important managed pollinator. </p>
<p>Australia is uniquely placed to contribute to the global effort to deal with Varroa mite impacts on honey bees. As long as we keep Varroa out, we can provide the “Varroa free” comparison needed to understand management options for honey bee health.</p>
<p>Further, because the Varroa mite-honey bee relationship evolved in our region (Asia), we are well placed to contribute to the genetic and evolutionary studies that will underpin options for Varroa control.</p>
<p>The Varroa mite has caused problems worldwide, and there is worldwide interest in finding solutions. We need to mobilise the Australian scientists to collaborate globally, in the interests of healthy bees and productive crops.</p>
<p><em>* This article is based on the <a href="https://drive.google.com/file/d/0B0vOSyC-9daBY1BGX19SaHppU00/edit?usp=sharing">CSIRO submission</a> to a Senate inquiry into the <a href="http://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Rural_and_Regional_Affairs_and_Transport/Beekeeping">Future of the beekeeping and pollination service industries in Australia</a>. The Senate committee is holding a <a href="http://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Rural_and_Regional_Affairs_and_Transport/Beekeeping/Public_Hearings">public hearing in Brisbane</a> tomorrow (May 20), and is due to complete its report by June 19.</em></p><img src="https://counter.theconversation.com/content/25710/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Saul Cunningham receives funding from Horticulture Australia Limited, the Grains Research and Development Corporation and the Commonwealth Government's Caring for Our Country program. He provides advice to the Commonwealth Government on strategies for dealing with Varroa mite impacts on agriculture.</span></em></p><p class="fine-print"><em><span>Paul De Barro leads the Reducing Likelihood theme in the CSIRO Biosecurity Flagship. Researchers in this theme receive funding from a number of agricultural industries that benefit from pollination and would be directly impacted by an incursion of Varroa mite and honey bee pathogens.</span></em></p>A tiny mite has been killing honey bees all around the world, and will inevitably reach Australian shores. So what is this destructive mite, and what we can do to protect Australian honey bees? The Varroa…Saul Cunningham, Researcher, CSIROPaul De Barro, Senior Principal Research Scientist, Ecosystem Sciences, CSIROLicensed as Creative Commons – attribution, no derivatives.