It’s time to watch out for our nectar lovers

One of the good days brought a swallow and a hoverfly into the same frame of my delight, the first zooming past the gable just to let me know they were back, the second frozen in the air like a jewelled Higgs boson before changing co-ordinates in the usual quantum instant. Goodness knows what the swallows have been eating, arriving to such chilled and empty Irish air, but hoverflies, with their gifts of bilocation, up, down or sideways, have never made it easy for birds.

We need all the insects this spring and all the springs – our 180 different hoverflies, 101 native bumble and solitary bees, our countless moths and wasps. Never mind the ban on neonicotinoid sprays – though the EU has had the right idea – we need to watch out for all our pollinating insects, not just the honeybees that do the media-appearances side of the job.

To excite public interest in the whereabouts and wellbeing of our nectar-loving insects, the Irish Pollinator Initiative website of the National Biodiversity Data Centre offers 10 insects to look out for as the weather warms up – an encouragement to get your eye in, as it were.

At the top of the list is a colourful rarity, the tawny mining bee ( Andrena fulva ), rediscovered in Kilkenny and Wicklow last summer after more than 80 years of seeming extinction. Look for the female, clothed in bright red hairs, as she burrows into the lawn, raising a little volcano of excavated spoil.

The hairy-footed flower bee – isn't that lovely? – or Anthrophora plumipes hasn't been confirmed in Ireland yet but is probably heading this way from the warmer gardens of England. A lover of flowers in the mint family, it can nest by the hundred in south-facing cliffs.

Among other imminent immigrants, given climate change, is the tree bumblebee ( Bombus hypnorum ), already building up its numbers on the Welsh coast, sometimes in the comfort of garden nesting boxes.

Hanging on in Ireland, just about, is the great yellow bumblebee ( Bombus distinguendus ) that once thrived in the hay meadows of the west, its long tongue tailored to the deep florets of red clover and knapweed. Since hay gave way to early-mown silage and flowery meadows were resown with ryegrass, this bee is on the verge of extinction, thriving only in a few pockets of north Mayo's Mullet peninsula.

Records of the small heath bumblebee ( Bombus jonellus ), once common on our coastal dunes and moorlands, seem also to have fallen off drastically, and learning the sequence of its football-jersey stripes is good practice for sorting the more common bumblebees of our gardens.

Another speciality of dunes on our east and southeast coasts is the ginger-haired solitary bee Osmia aurulenta – "fantastic to watch in action" promises the Pollinator Initiative website, presumably as it exits from its nests in empty snail shells.

The four hoverflies, or Syrphidae, "to look for" are plucked from the formidable database of Dr Martin Speight, long the leading entomologist with the National Parks and Wildlife Service. (He notably named his website Syrph t he Net .)

First hoverfly choice for beginners (and remains among them, for all my pleasure in the insects' brilliance and variety) is one prettily banded with gold. Episyrphus balteatus is also anthropophilic, meaning that it's happy almost anywhere, even around people, and helps by eating aphids on growing cereals as well as by visiting, and thus pollinating, a wide range of white and yellow flowers.

E balteatus not only lives in Ireland, and is seen on the wing as early as February, but its numbers are often overtaken by vast swarms of migrants from southern Europe.

The migration of flies in any self-directed way is an idea that takes some getting used to. Indeed, the swarms of E balteatus arriving – on the same wind as red admiral butterflies – from the sea at Courtmacsherry Bay, in Co Cork, in July 1995 were the first such event on Irish record. But this and a few other European species are regular migrants – E balteatus has even arrived alive (if rather pointlessly) on Arctic ice floes.

It also figures in one of my favourite accounts of migration, that of the British ornithologist David Lack in his Enjoying Ornithology (1965). Almost disbelievingly, he and his wife watched flocks of finches, linnets and other small birds flying southwards through one of the highest and narrowest passes of the Pyrenees, often only inches above the ground. With them were unending processions of clouded yellow butterflies, red admirals and dragonflies. But outnumbering them all were swarms of gold-and-black hoverflies, later identified as Episyrphus balteatus . "The whole surface of the pass," he wrote, "was a shimmer of iridescent light, due to the reflections of the autumn sun on myriad tiny wings."