LEPIDOPTERA (Butterflies & Moths) > PAPILIONOIDEA (Butterflies) > Pieridae >

Dismorphiinae (mimic-whites), Pierinae (whites) and Coliadinae (sulphurs or yellows)

Collectively known as Pierids, this group includes eight British species that can effectively be classed as 'whites' or 'sulphurs'. I say effectively, as the two rare Wood White species that I mentioned earlier are actually regarded as 'mimic-whites'.

Classified with the true 'whites', the Orange-tip [Anthocharis cardamines] is a distinctive and unmistakable species. Well, the male certainly is with his bright orange wing tips and beautiful green mottled underside and so is the female when resting with closed wings but, if seen with the wings spread open, she could be possibly confused with any of the other 'whites'.

Separation of the two species commonly referred to by gardeners as 'Cabbage Whites' seems straightforward, but with variations between individuals and more pronounced markings in later generations, mistakes can be made. The main distinguishing features are that the Small White [Pieris rapae] typically has far weaker and less extensive black wing-tip markings than those found on the Large White [Pieris brassicae] - more of a small dark smudge compared with the distinct black edge normally seen on the Large White that wraps around the end of the forewing. It's also relevant to note that female Small Whites are more heavily marked than the males and have two distinct spots on the upper side of each forewing, whereas the males only have one spot or, in the case of first-brood males, maybe none at all. Similar differences apply to the Large White although in that species the male is noticeably smaller than the female and always with a plain un-spotted upperside lacking the pale-yellowish wash on the hindwings that the females often have.

The Green-veined White [Pieris napi] actually has black rather than green veins as its common name implies, but they do appear green against the pale-yellow background when viewed from beneath or when the insect is resting with closed wings. When viewed from above you can see they're black, but both the veins and markings differ between sexes and generations. Typically, the veins are more evident in the first brood of the year and usually females have more black markings than the males.

The 'sulphurs' are represented in Britain by just one native species, the Brimstone [Gonepteryx rhamni], plus the migrant Clouded Yellow [Colias croceus]. They're both pretty distinctive, but there are some differences between the sexes that are worth noting. Whereas the sulphur-yellow male Brimstone is easy to identify, the much paler female could be confused with a Large White, particularly when seen at distance. The pale lemon or greenish-yellow colour is the problem, but there are no black markings and, when viewed closer, the wings are a different shape often likened to a leaf due to the pointed ends. With the Clouded Yellow, the sexes are not dissimilar when resting with their wings closed except that the female is normally slightly darker, although just to confuse matters, there is a pale form that occurs in about 10% of females. The real difference is when you see the wings open, or partially open, as the chrome-yellow wings are heavily edged in black, and darker in the females with yellow spots or blotches. Unfortunately, the upper side of the wings is usually only seen in flight, or momentarily when landing or adjusting position on a flower head. At the time of writing, I've only seen one Clouded Yellow so it's definitely a species that I need to keep a lookout for. Although they can turn up almost anywhere, they do favour chalk grassland areas such as Martin Down, which is my top butterfly location.