How To Identify White Butterflies
One of the hardest common butterfly species to identify accurately are white butterflies, especially when first starting out. It can be awkward to compare distinguishing features of butterflies using guide books, where each butterfly species usually has its own separate dedicated section. This article uses side-by-side “real-life” comparison photos of “confusion” species taken from similar angles, including images of faded individuals, to help “get your eye in” and identify which white butterfly you saw.
In the UK, the “Whites” family Pieridae actually encompasses 5 white and 2 yellow butterflies. They can be tricky to identify because from a distance many of the white butterfly species look very similar, often fly at the same time, in the same habitat and even in some cases use the same caterpillar host plants. I’ve omitted the Wood White here as its extremely rare. Being the smallest and flimsiest of the Pieridae family, it’s very local and not resident in Norfolk.
Its All About The Closed Hindwing
Probably the best method for identifying Pieridae butterflies is to start with the underneath of the hindwings. First, use any patterns to eliminate or identify Green-veined Whites, Orange-tips, and Brimstones and then look at the upper side of the forewing to differentiate between the Large White and Small White. Of course, this relies on getting a good look or photo from both angles and butterflies don’t always oblige!
On closer inspection, the underside of the hindwings of “white” butterflies are anything but! The Green-veined White butterfly has a beautiful powdery green-grey veining (when viewed close up, these are actually a combination of black and yellow scales) set on a milky background whereas the Orange-tip butterfy sports a bold, mottled dark green-yellow wing underside pattern against a crisp white base.
The greenish-white leaf shape of the Brimstone female is also uniquely distinctive, the lemon yellow of the male Brimstone even more so, not to mention their vivid reddish maroon-coloured antennae and shoulder rim.
The Green-veined White butterfly has green-grey powdery markings along its closed underwing veins on a cream coloured background
The female Brimstone is greenish white, with a leaf-like appearance, an overall “boxier” shape and bright maroon antennae and shoulder.
The Orange-tip butterfly has dark green-yellow mottling on its underwings against a cool white.
Both Large and Small White butterflies have largely plain, creamy coloured underwing and a similar wingshape.
Identifying Small White And Large White Butterflies Using The Underside Of Their Wings
Despite their names, size is often a poor differentiator between Large White and Small White butterflies. Even though the average wingspan of a Large White is, at c60mm, markedly larger than the circa 45mm wingspan of the Small White, Green-veined White and Orange-tip butterflies, this can be difficult to gauge in the field. To add complexity, the sizes of the two genders can differ significantly.
At first glance, the underneath of the hindwing of both Large White and Small White butterflies appears a plain, warm cream or ivory tone. The veins are pronounced but lack differentiating features. However, though care needs to be taken when attempting to distinguish the Large White and Small White from the underside of their hindwings, it is often possible.
Usually, the butterfly’s dark upperside wingtip marking bleeds through to the underside of the rear wing, appearing as a darker yellowish-grey or ochre colour than the rest of the underside of the forewing, so its shape and size can be used as a differentiator (in a nutshell “Larger black wing tip = Large White”). In the Large White I often think of the marking shape as looking like a shark’s fin or a boomerang. Caution is required because this bleed-through can sometimes be difficult to see from certain light angles and may be faint in aged specimens where the dark markings have faded.
In female Large Whites sometimes you can also sometimes see the distinguishing larger dark wing spots on the underside of the forewing, particularly in the second brood where these become even more marked. But again, caution is necessary because the angle of the closed wing position at rest does not always leave these fully visible and spots on a second brood Small White female can also be somewhat pronounced.
The good news is that a butterfly single small spot showing through and a plain cream hind wing underside is almost certainly a male Small White butterfly, since male Large Whites lack a spot and females of both species have double spots.
The Large White has a darker “shark fin” bleed through of its black corner marking that runs in an arc halfway down the far edge of its wing. Here Its black forewing spot is almost entirely obscured by the hind wing position. .
The Small White has a fainter bleed through of its grey wingtip that here appears buttery yellow and is restricted to the very tip. The male's single spot is smaller and less pronounced.
"Tips" To Identify White Butterflies From Their Upper Forewing Markings
From above, male Orange-tips are of course immediately identifiable due to their unmistakeable bright orange wing band. Female Green-veined Whites are also evident due to their powdery-grey veining.
From this perspective, identifying the Large White is usually straight forward because it has a comparatively larger and much blacker upper wingtip edging that is clearly visible from this viewpoint. This runs in an arc down to about midway along the far end of the forewing in a boomerang-like shape.
By contrast, the Small White’s dark wingtip mark is fainter and more of a brown-grey than black. It runs further up the side of the wing than along, reaching only about a third of the way along the far edge of the wing, with the corner points forming an isosceles triangle rather than an equilateral one. A little care may be needed in identifying aged Large White specimens as the wingtip markings may have also faded to more of a brown-grey - the shape and size is the key differentiator.
In female Large Whites you can also use their double black postdiscal forewing spots as an extra identification aid. Again these are much blacker and significantly larger than the fainter brown-grey ones of the Small White female, bear in mind that in the second brood these can sometimes be quite pronounced so a little caution needs to be taken with this feature.
The Orange-tip male is unmistakeable seen from above due to its vivid orange banding on the upperside of the forewings.
The Large White male has a larger blacker wingtip that arcs halfway across its upper forewing rear edge in a ”boomerang” shape and lacks forewing spots.
The Small White has a narrower wing tip marking that does not extend far along the far edge of the wing. The male has a small spot that is brownish-grey.
The Green-veined white female can be readily identified by clearly visible grey-green powdery vein dusting along its upperside forewing veins.
The Small White female has a pair of brown-grey upper forewing spots, these can be more pronounced in second brood individuals.
The Large White female has twin very large black spots as well as the bigger stronger black wing tip marking than the Small White.
Use Wing Shape To Identify Or Eliminate A Suspect
There is the greatest potential for confusion between Small White males, Green-veined White males and Orange-tip females, which are all of a similar size and have more subtle wing markings.
The easiest suspect of these to eliminate is usually the Orange-tip female. The rounded rear wingshape creates a letter “B” when basking which can be a distinctive feature even when seen in flight.
“Spot” The Butterfly’s Forewing Markings
The overall wing colour of the female Orange-tip is a cooler white hue than the Small White. The wing tip marking is also a cooler grey colour and the rim has a checkered / feathered appearance on both wings. This is particularly evident on the forewing tip set against the grey area.
The position of the spots on the upperside of the butterfly’s forewing can also help. In an Orange-tip the spot is positioned much closer to the side edge of the forewing than in the other white butterflies. Lastly, you can sometimes also even see bleed-through of the Orange'-tips striking underside mottling on the top side of the underwing.
Green-veined Whites are one of the more variable of UK butterflies. It can range from being almost pure white with no black spots at all and a barely visible vein dusting, right through to being a dusky cream or beige with strong and wide dusty green-grey vein markings and heavy double spotting in females. As in other butterflies, markings tend to be paler in the spring brood and heavier in later summer broods.
A pitfall to watch out for is that faintly marked Green-veined White males can be problematic to distinguish from a male Small White, particularly early in the season. However, even when barely visible, the veining usually breaks up the upperside grey forewing tip marking to give it a lined or broken apppearance.
The female Orange-tip also has grey wing tips but these have a checkered edging. It is a cooler white and has a rounded wingshape with a feathered appearance.
The Green-veined White also has a pointed forewing shape. Its upperside wing markings are highly variable and can be very faint.
This male Green-veined White has a very plain upperside and superficially looks like a Small White with a single spot. Close inspection reveals the green-grey dusting along the underside of its underwing veins and a broken appearance to its grey forewing tip mark.
Male Small White has more pointed forewing shape and flattened off rear wing shape than the female Orange-tip. It also has a warmer hue.
Male Small White nectaring on Lavender showing its narrower wing tip markings which are smoother than a male Green-veined White.
Female Orange-tip butterfly at an angle showing cool-grey coloured forewing. Also the dot position close to the wing edge, checkered wingtip edging and rounded wing shape as identifiers.
Behaviour and Habitat
Behavior can also sometimes aid differentation - the Orange-tip female is a relatively weak and wafty flier generally staying close to the ground and resting frequently on plants. It is often found near ponds and along hedgrow-lined lanes where host plants Cuckoo Flower and Hedge garlic are to be found. The Green-veined White is widespread. Although, according to Lewington it too prefers damper habitats and woodland rides it is frequently seen in gardens where it has a fondness for nasturtiums as a host plant, much to gardeners dismay. The Small White, and especially the Large White by contrast are more vigorous fliers and generally wider ranging.
Identifying White Butterflies in Context
Below are some side-by-side contextual photos of the three main confusion species: Small White male, Orange-tip female and a Green-veined White male, to help get a feel for the gist or “jizz”, that is the character of a butterfly when viewed from a distance. Ultimately it’s best to get record shots of both the top and underwings for a confident identification.
Large White vs Small White Butterfly In Context
Large White female in context. It has bold black or dark grey wing tips. The female also has two large black spots on the wings.
Small White in context. It has fainter, browner grey wing tip markings that cover less area than the Large White.
Small White vs Male Green-veined White Butterfly In Context
Male Green-veined White in context. Though faint, you can still see some vein dusting on the upper wing running through the grey wingtip.
Small White in context. From a distance Small Whites can look similar to a male Green-veined White. They are creamier in colour and the dark wing tips are more even and consistent, and no vein markings.
Female Orange-tip vs Green-veined White Butterfly In Context
Orange-tip female basking. The checkered wing rim and rounded wingshape aid identification.
Green-veined White female with faded grey powdery veining and wing-tip markings still apparent.
Side on Views
Usually from this angle there is enough of both the underside underwing marking and the upperside forewing tip shape and shading to distinguish all of the whites. Here are some photographic examples.
Orange-tip female butterfly on grass flowerhead tip. Even with a faded grey wingtip the spot placement, rounded wingshape and a hint of the underside all contribute to a confident ID.
Although this male Green-veined white lacks any upper wing spots or veining the underwing underside is strongly veined and a marked cream hue.
The female’s black spot is misleadingly suggestive of a Large white but the narrow isosceles triangle shape of the dark wingtip indicates a Small White. The black would need to extend along the wing edge as far as the spot to be a Large White.
As well as the clearly greenish-veined underwing underside, you can also see faint darker veining and the white gaps breaking up the upper forewing tip grey marking of this female Green-veined white.
Both the “shark fin” bleed through extending well across the far wing edge and black spots are evident on this female Large White due to the light and wing angle.
This similarly lit view of a Large White female shows how much further along the wing the “boomerang” black wingtip edging goes.
Identifying Yellow Butterflies
Two of our “White” or Pieridae family butterflies are actually yellow and one doesn’t even live here permanently! The Clouded Yellow is a frequent summer migrant whereas the Brimstone butterfly is a long-lived, single-brooded resident butterfly. It is often among the first butterflies seen in spring when it emerges from hibernation as an adult. The different yellow hues and wingshapes should allow for straightforward differentiation between the two butterflies.
The Clouded Yellow is pretty much unmistakeable, with a distinctive custard or canary yellow colouring, and a contrasting wide, deep black band running along the upper side of both wings which is a distinctive and characteristic in flight. In profile, look for the black spot on the upper forewing underside and a white spot on the underside of the hindwing and especially its unique, wonderful emerald-green eyes.
Male Brimstones are instead a largely uniform vivid lemon yellow, while the females are a muted pale mint green hue. Brimstones are best identified by their scalloped wingshape, which lends them a chunky appearance in flight. The front of the forewing tapers to a hook, while the rear wing is teardrop shaped, enabling them to camouflage themselves as leaves when hanging upside down. Both females and males have distinctive maroon-coloured antennae and shoulders.
The Clouded Yellow is a custard colour has rounded wingshape with a black spot on the underwing
The male Brimstone butterfly is a bright lemon yellow hue, has scalloped wings and maroon antennae.
Female Brimstone is a muted mint-white colour and has scalloped, deeply veined wings that resemble a leaf.
And One Interloper…
Despite its appearance, the Marbled White butterfly isn’t technically speaking in the “Whites” family of butterflies at all. Instead it’s classed in the “Browns” or Satyrinae family, a sub family of the “Nymph” or Nymphalidae family. It also isn’t officially resident in Norfolk…yet.
Recently, one or two individuals have been sighted on grassland and chalky areas in the county so it could well be gradually following the same North Easterly pattern of expansion into the county seen among some other butterfly species, perhaps aided by the odd accidental, or even illicit, release. Marbled Whites are readily distinguished from other true “Whites” by its black-brown and white checkered pattern, which is clearlyy visible from above and underneath.
Marbled White butterfly - top view
Marbled White butterfly - three quarter view
Non Visual Characteristics Can Also Eliminate A Suspect
Distribution
The Wood White is very local, remains nationally very rare, is not resident in Norfolk so is not addressed here. Due to its small size and wing shape it would only likely be mistaken for a female Orange-tip butterfly but it lacks any spots on the upper side of its wings.
The Marbled White remains very unlikely to be seen in Norfolk as the county is, for now, tantalisingly just beyond its home range. The other native White butterflies are widespread across the county.
Being a migrant, the Clouded Yellow can pop up anywhere but is seen less often, except in years when weather conditions are exceptionally favourable, which can lead to an influx. Sightings are frequently made later on in summer near fields of Lucerne or legumes which are its host plants.
Flight Times / Phenology
Below are tables showing the first, mean and last sightings of each White species over the five years to 2019. (At time of writing more recent data was not available). Phenology is of somewhat less help than in some other families, but there are a couple of exceptions.
Brimstones are reliably the early bird of the family, emerging from hibernation as early as the end of January, fading by July before their offspring emerge in late July or August. This generation are then on the wing until entering hibernation in late autumn, occasionally emerging in winter on very mild days.
The Small White, Large White and Orange-tip appear next in a cluster, all typically flying from mid March, usually followed a week or two later by the Green-veined White. The migrant Clouded Yellow butterflies are usally brought to us by favourable windstreams later in Spring these individuals then breed to produce a second generation which emerges from the end of June. There is however some speculation that it may be starting to breed in the more southern counties of the UK.
The Small White and Large White and Green-veined White are all double-brooded, with a second generation typically flying from July through into Autumn. According to Lewington, in warm years a third brood of the Green-veined White can be seen.
By contrast, the single-brooded Orange-tip has the narrowest flight period, being seen on the wing from the end of June usually no later than mid July, although occasionally the odd individual has been spotted in August and September. The Clouded Yellow is a robust butterfly and the homegrown adult generation can usually be seen into mid to late Autumn in clement years.
Table of First Sightings of Pieridae Butterflies in Norfolk. Averages are a five year arithmetic mean to 2019.
Table of Last Sightings of Pieridae Butterflies in Norfolk. Averages are a five year arithmetic mean to 2019.
Host Plants
The White butterfly family predominantly use plants in the Crucifer or Cabbage family, Cruciferaea. Although individual preferences do vary, there is considerable overlap so other than perhaps for the Brimstone butterfly, plants don’t really serve as clues for identification.
The Large White is notorious among gardeners for its taste for cultivated Brassicas as a caterpillar host plant, however it will also use Nasturtiums, Tropaeolum majus, Wild Mignonette, Reseda lutea, Wild Cabbage, Brassica oleracea, Oil Seed Rape, Brassica napus and Sea Kale, Crambe maritima as well, many of which make good diversionary or sacrificial plants on an allotment bed.
The Small White is something of a crossover, it shares its larger cousin’s taste for Wild Mignonette, Wild Cabbage and Nasturtiums and has an individual preference for Hoary Cress, Lepidium draba. But it also uses Charlock, Sinapis arvensis, Garlic Mustard, Alliaria petiolata and Hedge Mustard, Sisymbrium officinale, which are all eagerly utilised by the Green-veined White and Orange-tip butterflies.
Meanwhite the latter pair also share a preference for Cuckoo Flower, Cardamine pratensis, Water-cress, Roripa nasturtium-aquaticum, Large Bittercress, Crucifer amara. The Green-veined White has also been known to use Wild Cabbage, Wild Radish, Raphanus raphanistrum and, in gardens, even Nasturtiums and Alyssum, Alyssum maritimum.
Lastly, the Orange-tip’s secondary preferences tend to be Turnip, Brassica rapa, Hairy Rock-cress, Arabis hirsuta and at a pinch ornamental garden flowers Honesty, Lunaria annua and Dame’s Violet, Hesperis matronalis, although according to Butterfly Conservation survival is thought to be poorer on these.
Although the Brimstone butterfly is a wanderer and often seen nectaring in gardens, it actually relies on Buckthorn (Rhamnus cathartica) and Alder Buckthorn (Frangula alnus) as its caterpillar host plants, so the loss of traditional native hedgerows can negatively impact it.
Clouded Yellow butterflies by contrast rely on Legumes as their host plants, favouring Clover, Trifolium spp. and Lucerne, Medicago sativa but also sometimes using common Bird’s Foot Trefoil, Lotus corniculatus.
Resources
My own photographs and in-the-field observations
Butterfly Conservation Society - Species information and factsheets:
R. Lewington - Pocket Guide to the Butterflies of Great Britain and Ireland
A. M. Riley - British and Irish Butterflies
All images taken by and © Kiri Stuart-Clarke. All rights reserved