Gardeners have been urged to work with their neighbours to support moths and hover flies after research found them to be particularly sensitive to urban landscapes.<\/p>\n
While bees get most of the attention when it comes to supporting pollinators in our cities, researchers found that their less glamorous \u2013 but no less important \u2013 counterparts from other orders are even more acutely affected by urbanisation.<\/p>\n
Three researchers from Sheffield\u2019s school of biosciences investigated the impact that urbanisation in the UK was having on pollinators and found that urban landscapes support 43% fewer pollinator species, with the biggest declines evident the further into the heart of the city they went.<\/p>\n
Emilie Ellis, the lead author of the study who carried out the work as part of her PhD, said: \u201cThe original focus was going to be on bees as they\u2019re the most charismatic species.<\/p>\n
\u201cBut then my interest in moths added this on to it, and then [co-author Stuart Campbell]\u2019s interest in flies included hover flies. That\u2019s the kind of cool novelty of this manuscript, that we included three different pollinating groups that are very diverse.\u201d<\/p>\n
The research, carried out over the summer of 2019, involved Ellis visiting allotments in Leeds, Leicester and Sheffield, in varying urban densities, to sample the number of pollinating insects from all three groups. \u201cWe just collected insects every month for six months in eight sites in each city \u2013 so it was a lot of driving.\u201d<\/p>\n
Their findings were sobering. They found that for every 10% increase in impervious surfaces \u2013 such as roads and building cover \u2013 there was a reduction of up to 7.5% in the variety of pollinating species. But the number of moths and hover flies of any species took a far greater hit compared with the number of bees.<\/p>\n
\u201cWe hypothesise that this could be due to the fact that they\u2019ve got more complex life cycles because they need those different kind of resources other than flowers to become adults,\u201d Ellis said. But that crucial vulnerability also contains a potential answer. If gardeners and urban planners bear in mind the needs of other pollinators, then there are straightforward ways to cater to them.<\/p>\n
\u201cWe\u2019re so good now planting flowers for pollinators like bees and that could be the reason why we\u2019re not seeing them decline,\u201d Ellis added. \u201cIt\u2019s just a matter of taking these guys into account and maybe having some more shrubs or a pond or something like that to also benefit those insects.<\/p>\n
\u201cThe diversity of habitat is the most important \u2013 so you need your flower patch, you need a tree, you need some shrubs, you need an untouched bit of grass \u2013 and kind of just keeping the patches that you have diverse and catering for all different types of insects and animals.<\/p>\n
\u201cA huge thing that\u2019s important is collaborating and talking to your neighbours and families and friends and encouraging them to do it too. Because an individual allotment or flower garden is pretty small and almost useless, but when you create a whole network of people that are interested and engaged these small little patches can become these huge habitat networks in cities.\u201d<\/p>\n