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May butterflies and insects

Other May pages: Woodland, meadow and field flowersWayside flowersDownland and seaside flowersTrees and shrubsBirdsWeather

Put your cursor over any photo on this page to see its caption, or click here to see more May butterfly and insect photos. For more information on butterflies and moths see the Butterfly Conservation website.

May sees the overwintering butterflies - those that hibernated over the winter - giving way to others that are newly emerged. As a result the number of species on the wing increases but some of them are quite hard to spot.

Of the overwintering butterflies, small tortoiseshells can still be quite common at the start of May but they tend to be gone by mid month: the same is true of peacocks, though you can see the occasional one (looking rather worn out by now) right till the end of May. Both look almost black in flight due to their dark underwing, but have a handy habit of landing for a rest on paths, making their colourful upperwings easy to see.

The striking yellow brimstone can last longer, appearing throughout May and into June. Note that the female brimstone is a very pale yellow and can be mistaken for a large white butterfly: the key is its lack of black wingtips and the shape of its wing if you see it at rest. Another overwintering butterfly is the comma, though it rarely seems to survive into May. You may just see it early in the month near bramble bushes and hedgerows, however.

Also early in the month (all month in 2015 and 2016) you can see the lovely orange tip. It usually lasts as long as the flowers of garlic mustard, one of its favourite plants for laying eggs on. Again, the female can be mistaken for a small white butterfly as it does not have the orange tips to its wings: the key to identification is a mottled green pattern on its lower underwing.

You can only make this identification if the butterfly comes to rest, however, and that is a problem for all the white butterflies, which seem to be especially restless. They are popularly grouped together as "cabbage whites" but there are in fact three different species - large white, small white and green-veined white. All are usually about in May, but it is almost impossible to tell them apart as they flutter past. If you do get a look, then large whites have more extensive black wing tips, extending down the edge of the wing, while small whites have smaller grey tips. Green-veined whites are most easily identified by the green veins on the underside of their hindwing: their upperwings also have grey tips, but descending down edge in a series of blobs. All three overwinter as pupae, though large and small whites also migrate from the continent in May.

Another butterfly that can overwinter as a pupa is the speckled wood, though some also spend the winter as caterpillars. This means they have less of a pronounced season than other butterflies and are reasonably well spread throughout May. If you see a brown butterfly in a wood or on a shady verge then it is almost certainly a speckled wood. They are relatively placid and happy to settle on a leaf, so are not hard to identify.

You may also see a red admiral or painted lady during May. The red admirals are migrant females who have already mated on the continent and lay eggs here immediately on arrival, while the painted ladies mate once they arrive in the UK. In both cases, their offspring go on to make up a much more numerous summer generation, boosted by further migrants. Both species then travel back southwards in the autumn. Some red admirals also overwinter and survive into early spring but there is as yet no evidence that they go on to breed.

Rarer butterflies include the wall, which has brown on orange markings somewhat similar to those of the comma. Once a common farmland butterfly, it is now only found on coasts (for example near Dover or on Portland Bill). It likes to sunbathe on paths (and also supposedly walls, hence its name) but is quite flighty when disturbed.

Look out also for tiny blue butterflies during the month. Near brambles, ivy bushes or hedgerows early in the month these might be holly blues, which have a pale blue underside and look a bit like a silver flash as they fly past. Later in the month and on grassland you may well be seeing the common blue, which can be distinguished by its brown underside with black spots.

Also later in the month, on south-facing downland slopes with horseshoe vetch growing, there is a possibility that you may be seeing an adonis blue - a fairly remote one as these are rare and localised butterflies, but one colony lives on the southern slopes of Ranmore Common near Dorking. Telling them apart from the common blue is a big challenge. The adonis is a lighter blue, but the common blue looks fairly light in flight too; the adonis has black lines through the tiny white borders on its wings, but the common blue has the beginnings of lines; the adonis blue male's underwing is darker than the male common blue's and with only the faintest of blue blushes near its body: and there are also slight differences in the arrangement of the black underwing spots between the two species. But unless you manage to take a good quality photograph you are unlikely to see these details. To make matters worse, when their markings fade adonis blues look a lot more like common blues.

The female of both these two species are brown with orange chevrons around the outside of the wing (practically invisible on the forewing of the adonis, but its female is also very rarely seen). However if you see a very small butterfly with these markings, the brown argus is also possible. Its male is smaller than the female common blue but its female looks pretty identical. Again, the minute details of the black spots on the underwing are the guide to identification. Just to make life extra confusing, you sometimes you also get common blue females which are substantially blue in colour.

Also brown and very tiny - the smallest UK butterfly in fact - is the small blue, yet another butterfly of downland grassland (and yes, despite its name it is brown not blue). You really have to go to a site where they are known to be found in order to see them, but when you do their beige grey underwings are the key to identification. One colony is on the slopes of Pewley Down near Guildford.

Once you start looking for butterflies this small, all sorts of wonders open up. May is the best month to see both dingy skippers and grizzled skippers, but you might easily mistake these tiny brown-patterned butterflies for day-flying moths, so small and inconspicuous are they. Both are found in downland or short, rough grassland but they are quite localised - that is to say, only found in a few places (the slopes of Pitstone Hill near Tring is one location).

Still small, but more brightly coloured, are the small copper, with its bright orange markings, and the small heath, which looks orange in flight but always closes its wings when at rest. The small heath likes grassland - it is only ever found very close to the ground. The small copper is more adventurous and tends to crop up when one least expects it - on grassland, but also on flowery hillsides, even woodland rides. Much harder to spot is the green hairstreak, whose green underwing means it blends in with its downland habitat. (Try Aldbury Nowers near Tring.)

It is easy to mix all these small butterflies up with various tiny day-flying moths that also appear around this time. These include grass veneer moths, which look like tiny white butterflies as they flit around grassland but then close their wings tight to almost completely disappear when at rest on a blade of grass. On a slightly larger scale are brown moths such as the burnet companion (easily confused with the dingy skipper butterfly, as noted above). Some day flying moths look for all the world like small butterflies - for example the speckled yellow, the various species of white carpet moth, and - at the end of the month - the black chimney sweeper moth in meadows.


April has already seen quite a lot of tiny insects emerge (it is one reason those summer visiting birds come to our shores) and this continues into May.

One that used to be found in large swarms early in the month, but which sadly seems to have become rare in the south east in recent years, is the St Mark's fly. Its legs trail below it as it flies, making it look rather sinister. But it is in fact quite harmless. Its name refers to the 25th of April, the feast of St Mark, when it traditionally appeared.

Otherwise, there are plenty of bees around - honeybees, solitary bees and also bumble bees. The latter may still be queens earlier in the month. Having mated in the late summer, they emerge from hibernation in March and fly around feeding up while they look for nest sites. But by mid May nests have been established and the slightly smaller workers start to emerge.

Other insects have evolved to look like bees for protection from predators - this is true of several species of hoverfly, which are by now to be seen everywhere (they can easily be distinguished from bees by their charming capacity to hover absolutely immobile in mid air). Notice also the bee fly, a fly that looks like a bee, and is found more in the early part of the month. You almost never see wasps yet, however, and house flies (aka bluebottles) are not a nuisance until later in the month, if then.

Instead, the kind of insect common in May are the tiny ones that fly into your mouth when you are running or cycling, or swarm at dusk, or produce mysterious insect bites on your arms and legs. Certain flowers attract them particular - look in buttercups or on the big white flowerheads of hogweed. Later in the month you also see crane flies in grassy fields.

As the month goes on you can also see dragonflies and damselflies, including the beautiful banded demoiselle with its hypnotically patterned double wings. Look for the latter jockeying for the best position on fronds of vegetation on river banks. The most often seen damselfly is the common blue damselfly but it is only the males of the species that have this colouring: the females are green, while newly emerged males have black and beige markings. To see the two clutched in their rather brutal mating clasp is not unusual: they even fly through the air in this posture. There is also a blue-tailed damselfly with black body with a blue tip, and a green emerald damselfly. Banded demoiselle females are green too, becoming more bronze with age, while the males are metallic blue.

By a river towards dusk, look out for swarms of mayflies, which dance up and down in the air. A clue to idenfication are the three long tail filaments, easily visible as they float downwards in their dance, and the striped black and white tips to their abdomens. They actually metamorphose twice when they emerge from the water - once into a dull brown sub-adult and then into a more highly decorated full adult. They live in this form for just one night - long enough to mate. You can see them even in early May and indeed later in the summer, but late May or early June is supposedly the peak time.

This is also the month that you see cuckoo spit - the saliva-like liquid on plants that is actually produced by the froghopper.

More May pages:

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