Large White Larvae during Winter

 The Large White (Pieris brassicae) is mainly a double brooded butterfly in Britain but in good years, it can produce a third brood, with larvae found late in the season. The latest example that I had previously found was on 12th November 2008, when I came across a colony of 5th instar larvae on Rye Levels.

On 19th December 2025 (as reported in an earlier post) I happened upon a colony of 4th and 5th instar brassicae larvae, numbering about 40 caterpillars, feeding on Rape (Brassica napus) on Pevensey Levels. I decided to observe their progress over the following weeks.

With a warming climate in south-east England, our winters are generally damp and mild and freezing overnight temperatures are less frequent than they used to be. During early January, I noted just three consecutive nights with sub-zero temperatures (down to minus 2 degrees) but this had little effect on the larvae, with only two dead caterpillars found limp in the foliage.

During my vigil, there was no evidence of parasitic attack and by 2nd February 2026 (my last visit) there were only eight fully mature larvae still feeding. I am confident that the vast majority of the larvae completed their development unmolested by predators.

The main predator of P. brassicae is the parasitic wasp Cotesia glomerata, the adults of which inject their eggs into the larval host. The development of the parasitic larvae within the living caterpillar is rapid and their emergence from the dying host is made obvious by the presence of their yellow cocoons around the dead caterpillar.

The life cycle of Cotesia glomerata is currently synchronised with the spring and summer broods of Pieris brassicae. Unless glomerata is able to extend its season by taking advantage of our warming climate, then it appears that any third brood larvae of P. brassicae has every chance of avoiding such parasitic attack. 

Larval skin-shedding stem (1st January 2026)

The following images are all of mature 5th instar larvae showing evidence of feeding.

(14th January)

(18th January)

(28th January)

Pierids in Sussex

 The white and yellow butterflies in Britain all belong to the Pieridae family. 

Of those species that occur in Sussex, most are common and widespread and found in a range of habitats.

 However, one is a rare resident, only to be found in a few small colonies in the north-west of the county.

Wood White (Leptidea sinapis)

This species is our rarest Pierid in the county and only occurs in a few areas in north-west Sussex.

(males)

(females)

(courtship)

Clouded Yellow (Colias croceus)

This species is a migrant to Britain, occurring annually in varying numbers. Some years it can arrive in huge numbers and produce summer and autumn broods. In other years it can be a rare sight.

(female)

(female, form helice)

This pale form accounts for about 10% of the female population.

(male)

(mating)

Brimstone (Gonepteryx rhamni)

The Brimstone hibernates as an adult butterfly and is one of our first species to be seen on the wing during late winter and early spring sunshine.

(males)

(female)

(mating)

Large White (Pieris brassicae)

This is a common and widespread species. Together with the next species, it can cause serious damage to garden cabbage crops.

(females)

(male)

(mating)

Small White (Pieris rapae)

This common and widespread butterfly is also a cabbage crop pest.

(females)

(male)

(mating)

Green-veined White (Pieris napi)

This cousin of the previous two species is certainly not a garden pest. It is more akin to the next species in its choice of habitat, preferring to wander along field margins, verges and woodland edges, looking for foodplants such as garlic mustard and lady's smock.

(males)

(females)

(mating)

Orange-tip (Anthocharis cardamines)

This pretty little butterfly is a true harbinger of spring, emerging from its overwintering pupa from late March to late May.

(males)

(females)

(mating)

Satyrids in Sussex

 The Satyrinae are a sub-family within the Nyphalidae family. Of those that occur in Sussex, one is a rarity but the others are common and widespread within the county. They all use various grasses as a food-plant on which to lay or scatter their eggs and the commoner species can be found in a range of habitats.

The males and females are similarly marked but there are sufficient differences between them to tell them apart, particularly where males of some species show a notable sex-brand in the centre of the forewings.

Speckled Wood (Pararge aegeria)

This is a species of dappled woodland edges, where males battle each other for territories. 

(males)

(female)

(courtship)

Wall (Lasiommata megera)

In Sussex, megera is predominantly a downland species but also occurs on coastal flats and along woodland rides.

(males)

(male) (ab. mediolugens)

(female)

(mating)

Marbled White (Melanargia galathea)

This is a very common downland species but small colonies can also be found in wealden glades and field edges.

(female)

(males)

Grayling (Hipparchia semele)

This is the rarest of our Satyrids in Sussex. I am not very up-to-date with its status in West Sussex but in East Sussex, semele is more-or-less restricted to one south facing hillside on the South Downs. 

(male)

(female)

(mating)

The Grayling only shows its upperwing surface during courtship or, as in the following image, when a mating male is fending off another male.

Gatekeeper (Pyronia tithonus)

This is a common and widespread species in Sussex.

(male)

(male) (ab. obscurior)

(female)

(female) (ab. anticrasipuncta)

(mating)

Meadow Brown (Maniola jurtina)

This is a common and widespread species in Sussex.

(male)

(male) (ab. pallidus)

Not to be confused with age related bleaching that often occurs in this species.

(female)

(mating)

Small Heath (Coenonympha pamphilus)

This common and widespread butterfly rarely displays its upperwings.

(mating)

Ringlet (Aphantopus hyperantus)

This is a common and widespread butterfly of  damp woodland rides and glades.

(males)

(female)

(female) (ab. arete)

(mating)