Sussex Butterfly Conservation : Species

Butterfly Species in Sussex

Female Large White nectaring on Verbena Bonariensis – photo by Martin Kalaher

Large White

Pieris brassicae

Description

This is a fairly common resident, widely distributed across the county, and it is also an annual immigrant in late summer/early autumn. For the years 2006-2024 the “average first sighting” was April 5th (range March 8th to April 15th) and this first brood is on-the-wing until mid-June. The flight period for the more numerous second brood is between mid-July and mid-September and the variable third brood generally flies from mid-September until late October/early November. For the years 2006-2024 the “average last sighting” was October 30th (range October 9th to December 17th).

In flight, a Large White could be confused with both Small White and female Brimstone. When perched, the distinctive, curved rear edge of a Brimstone readily separates it from the other two species. Large Whites are usually bigger than Small Whites but not invariably so, and therefore the size of a white butterfly is not an infallible guide to ID. To separate these species, we need to check the upperside forewings for grey and black markings. Female Large Whites have two large black patches in the centre of the forewings and extensive black markings on the tip of the forewings. Males also have extensive black on the wing tip but no black dots on the wing itself. Small Whites are very poorly marked compared to Large Whites (see species account for Small Whites for a further description). Basically, if the butterfly in front of us has lots of black on the forewings we can be confident it is a Large White and not a Small White.

The eggs are laid on a wide variety of brassicas and crucifers, including cabbage, sprout, broccoli, kale, turnip, Garlic Mustard, Dames Violet and also Wild Mignonette. The broad spectrum of larval foodplants helps to explain why this species is so widely-distributed and so successful.

There is an annual immigration of Large Whites in late summer and early autumn, but the numbers have been fairly modest in the past 35 years, or so. There was a very significant landfall, in 1992, between Rye and Worthing, with “thousands flying over a field of layed-over oil seed rape” at Rye Harbour. More recently there were 100s at Peacehaven on 26/09/2018 and 100s at The Gallops inside Friston Forest in July 2019. In Sussex, the large numbers recorded are for coastal locations, or on downland a few kilometres from the sea. Should these butterflies disperse inland they will soon mix with local, home-grown individuals and then deciding which-is-which is difficult, but not impossible. If there has been a significant influx on the coast and four days later 5-6 Large Whites suddenly appear in my Storrington garden, then more-than-likely these will be fresh immigrants.

Where to find

This species can be seen anywhere in Sussex. It is a common visitor to vegetable gardens and allotments, anywhere Brassicas are grown. These butterflies also visit gardens to nectar on flowerheads and they are especially fond of Field Scabious and Devilsbit Scabious.