This is another of my infrequent reports concerning the life-cycle of one of our common species. This time it relates to the Large White, which is the most notorious and prominent of the "Cabbage Whites" (The other being the Small White). Both are well known to gardeners and vegetable growers, but it is the Large White which causes most of the damage to Brassica crops. Garden Nasturtium is also a favoured foodplant for this species. Most people have encountered the conspicuous eggs or larvae, so given this familiarity, I have tried to approach this report from a slightly different angle. This principally involves looking at a wild habitat involving a non-cultivated host plant as well as aiming to obtain new and detailed images that add to existing information. The majority of the early photos were taken in the wild, but several eggs and larvae were collected and taken home in order to continue to monitor and record their development to the pupal and adult stages.
EDIT: This report was updated to include a full pupation sequence and some other fresh images in September 2013 and an emergence sequence in 2014. Additional images of larvae were included in November 2017.
Having failed to attract an egg-laying female to the larval host plants in my home garden, I was very pleased to find lots of Sea-kale (
Crambe maritima) growing on a beach whilst holidaying on the Suffolk coast in early September 2011.
- Sea-kale - Dunwich, Suffolk 5-Sept-2011
- Sea-kale - Dunwich, Suffolk 5-Sept-2011
This wild Brassica was found growing in abundance along the coast at Dunwich Cliffs, occupying a band of shingle from the base of the sandy cliff to within a few metres of the high water mark. Several Large whites were seen to be investigating these plants. These individuals could either have been migrants or locally hatched. Soon one settled down to lay a batch of eggs. The eggs are usually laid on the underside of a leaf, but also on the upperside if it has a sheltered aspect. The average size of a batch is known to be 40-100 eggs, but those that I found ranged in size from a minimum of 23 to a maximum of 141. On some leaves were also the smaller, single eggs of the Small White. The Large White eggs are initially pale yellow, but gradually darken to orange and then to pale grey just before hatching. Vegetable growers and allotment holders should look away now.................
- Large White eggs - Dunwich, Suffolk 5-Sept-2011
- Large White eggs (batch of 141) hours before hatching - Dunwich, Suffolk 8-Sept-2011
- Large White eggs and larvae - Dunwich, Suffolk 5-Sept-2011
Upon hatching the larvae consume their eggshells. In most instances all that remains is the circular imprint made by the base of the egg. In the last photo above you can see the imprint left by the bases of the eggs and also a solitary Small White egg. Between 4th and 9th September 2011 I found over 1000 eggs in just a small area together with approximately 800 larvae in all stages of their development.
- Large White larvae hatching - Dunwich, Suffolk 8-Sept-2011
- Large White larvae hatching - Dunwich, Suffolk 7-Sept-2011
In this last photo you can clearly see the egg imprints.
- Large White larvae - Dunwich, Suffolk 5-Sept-2011
For the first day the larvae feed on the surface of the leaf close to the hatching site, before moving as a group to a more secluded area of the plant.
Sometimes it may appear that one new hatchling has wandered away from the group. If it has a pale or orange-coloured head it is actually a Small White larva.
- Small White larva (1st instar) - Caterham, Surrey 27-July-2013
Freshly emerged Large White larvae have black heads. They feed and rest together and sometimes build a loose communal shelter within the plant using silken strands. It is not until much later in their development that they gradually disperse and become solitary.
- Large White 1st instar larvae (6 days old) - Caterham, Surrey 21-Sept-2011
- Large White larvae (1st instars) - Crawley, Sussex 31-July-2017
- Large White larvae 1st instars (pre moult) - Crawley, Sussex 13-Aug-2017
- Large White larvae (2nd instars) - Crawley, Sussex 2-Aug-2017
- Large White 2nd instar larvae (12 days old) - Caterham, Surrey 27-Sept-2011
- Large White larvae 2nd instars (pre moult) - Crawley, Sussex 5-Aug-2017
- Large White 3rd instar larva (14 days old) - Caterham, Surrey 29-Sept-2011
- Large White larvae (3rd instars) - Crawley, Sussex 5-Aug-2017
- Large White larva (3rd instar) - Crawley, Sussex 7-Aug-2017
- Large White larvae 3rd instars (pre moult) - Crawley, Sussex 8-Aug-2017
- Large White larvae (4th instars) - Crawley, Sussex 9-Aug-2017
- Large white larva (4th instar) - Crawley, Sussex 8-Aug-2017
- Large White larva 4th instar (pre moult) - Crawley, Sussex 11-Aug-2017
- Large White larva 5th instar (post moult) - Crawley, Sussex 12-Aug-2017
The striking colouration of the late-instar stage is a warning to birds and other preditors that they are distasteful, because of the mustard oils they have absorbed from the plant while feeding. This colouration appeared at the 3rd instar stage (around the 14th day of their development). Fifth instar larvae can be distinguished by the two blue/grey lobes on the sides of their head and a whitish or yellow triangular plate above the mouth. The time between egg hatch and pupation took approximately 6 weeks.
- Large White larva (5th instar) - Caterham, Surrey 15-Aug-2013
- Large White larva (5th instar) - Caterham, Surrey 15-Aug-2013
- Large White larva (5th instar) - Crawley, Sussex 15-Aug-2017
- Large White larva (5th instar) - Crawley, Sussex 17-Aug-2017
- Large White larvae (5th instar) - Lancing, Sussex 11-Oct-2018
When ready to pupate the larvae leave the plant and may travel some distance to seek out the undersides of solid structures such as building ledges, fences and branches, as well as tree trunks. They will also pupate head-up in a vertical position if there are no horizontal surfaces available.
All the following images of pupae have been rotated for presentation purposes.
- Large White larva preparing to pupate - Caterham, Surrey 24-Aug-2013
- Large White larva commencing pupation - Caterham, Surrey 24-Aug-2013
- Large White larva pupating - Caterham, Surrey 24-Aug-2013
- Large White larva pupating - Caterham, Surrey 24-Aug-2013
- Large White larva pupating - Caterham, Surrey 24-Aug-2013
- Large White larva pupating - Caterham, Surrey 24-Aug-2013
- Large White larva pupating - Caterham, Surrey 24-Aug-2013
- Large White larva pupating - Caterham, Surrey 24-Aug-2013
- Large White pupa discarding larval skin - Caterham, Surrey 24-Aug-2013
- Large White pupa discarding larval skin - Caterham, Surrey 24-Aug-2013
- Large White pupa (freshly emerged) - Caterham, Surrey 24-Aug-2013
- Large White pupa (20 mins old) - Caterham, Surrey 24-Aug-2013
- Large White pupa (1 hour old) - Caterham, Surrey 24-Aug-2013
- Large White pupa (3 hours old) - Caterham, Surrey 24-Aug-2013
- Large White pupa (6 days old) - Caterham, Surrey 30-Aug-2013
The colour patten of the pupa varies according to such factors as light levels at the pupation site and the nature of the background.
- Large White larva preparing to pupate on bark - Caterham, Surrey 23-Oct-2011
- Large White pupa (grey form) on bark - Caterham, Surrey 4-Nov-2011
- Large White pupa (grey form) on bark - Caterham, Surrey 4-Nov-2011
Pupae range in colour between pale cream to pale green, through grey/green to grey, usually with speckling.
- Large White pupa (cream form) - Caterham, Surrey 7-Oct-2011
- Large White pupa (pale green form) - Caterham, Surrey 6-Sept-2013
- Large White pupa (grey/green form) - Caterham, Surrey 19-Sept-2011
- Large White pupa (grey form) - Caterham, Surrey 4-April-2012
- Large White pupa (grey/yellow form) - Crawley, Sussex 26-Feb-2019
In the days before the adult emerges, the pupa darkens and the wing colours begin to show strongly through the pupal case. The head and abdominal areas then suddenly darken and the abdominal segments distend indicating that emergence is only a few hours away.
- Large White pupa (40 days before emergence) - Caterham, Surrey 3-April-2012
- Large White pupa (36 hours before emergence) - Caterham, Surrey 12-May-2012
- Large White pupa (female - 20 hours before emergence) - Crawley, Sussex 6-May-2019
- Large White pupa (female - 12 hours before emergence) - Caterham, Surrey 13-May-2012
- Large White pupa (female - 9 hours before emergence) - Caterham, Surrey 13-May-2012
- Large White pupa (female - 6 hours before emergence) - Caterham, Surrey 13-May-2012
- Female pupa 30 minutes before emergance 27-April-2014
- Adult emerging - Caterham, Surrey 27-April-2014
- Adult emerging - Caterham, Surrey 27-April-2014
- Adult emerging - Caterham, Surrey 27-April-2014
- Adult emerging - Caterham, Surrey 27-April-2014
- Adult emerging - Caterham, Surrey 27-April-2014
- Adult emerging - Caterham, Surrey 27-April-2014
- Adult emerging - Caterham, Surrey 27-April-2014
- Freshly emerged female - Caterham, Surrey 27-April-2014
If the temperature was right, most emergences took place between 2am and 8am.
The pupae that were strongly speckled tended to mask the identity of the sex until the very last moment. The previous one was female, and this is clearly a male.
- Large White pupa (male - 6 hours before emergence) - Caterham, Surrey 9-May-2012
Not unexpectedly there were some losses along the way, mainly at the larval stage, but I was surprised to lose 5 pupae during one night due to predation by a rodent (most likely a mouse or shrew). They were just cleanly plucked from their sites, leaving no trace. Even more of a shock was finding a large spider guarding its latest meal...................
- Spider with Large White pupa - Caterham, Surrey 2-Oct-2011
- Spider with Large White pupa - Caterham, Surrey 2-Oct-2011
I believe this to be
Drassodes lapidotus (Stone Spider or Mouse Spider). Another possibility is
Drassodes cupreus (Blackwall Spider). You can see the point where it has injected digestive enzymes into the pupa. These have the effect of liquifying the contents of the pupa, enabling the spider to subsequently suck them up.
- Large White pupa (result of spider predation) - Caterham, Surrey 4-Oct-2011
The outcome is quite dramatic, but I would not have guessed it was the work of a spider unless I had seen it for myself. This turned out not to be an isolated incident, because I lost another pupa to a similar spider in September 2103. Slugs and snails also predate huge numbers of eggs and many larvae are taken by wasps. Parasitism of eggs and larvae also affects countless individuals, however in 2018 it was unusual to see a Harlequin ladybird also taking an interest in some eggs. It did not eat all of the eggs and I suspect that it was just scavenging from those that had been damaged by previous predators.
- Harlequin ladybird with Large White eggs - Crawley, Sussex 14-Aug-2018
However on a happier note........................
- Large Whites (female and male) upon release - Caterham, Surrey 8-May-2012
My pupae were overwintered in an outbuilding located on the north side of the house which has good light, ventilation and humidity levels. It does not significantly insulate the pupae from low temperatures in winter nor does it warm up readily in the spring. In all cases, overwintered pupae of all species kept in this environment, have hatched after those in the wild. All adults were released at a suitable site as soon as weather conditions would allow.
* NO SPIDERS WERE HARMED DURING THE PRODUCTION OF THIS REPORT
Reading References:
The Butterflies of Britain and Ireland (Thomas and Lewington 2014)
UK Butterflies Website
)
Goldie 
