UPDATE: My report of Orange Tip on 2024-03-17 may well have been the first reported nationally this year, according to our County Butterfly Recorder.
I saw my first Orange Tip (Anthocharis cardamines) of 2024 on 17th March in Cottenham patrolling a roadside verge (Broad Lane).
This was the first report for Cambridgeshire and Essex butterflies this year, apparently. I have to admit I’ve not kept a personal record of first sightings of this species, but the Cambs & Essex page does, so I can give you a list of previous years.
4 Apr 23, 24 Mar 22, 30 Mar 21, 26 Mar 20, 28 Mar 19, 17 Apr 18, 28 Mar 17, 8 Apr 16, 8 Apr 15, 24 Mar 14, 25 Apr 13, 26 Mar 12, 24 Mar 11, 11 Apr 10, 5 Apr 09, 21 Apr 08, 12 Apr 07.
So, it looks like my sighting is the earliest Orange Tip of the year in our Butterfly Conservation sector since they started recording public records on those pages. Previous earliest was three years where it appeared on 24 March, i.e. a week later. I posted on Twitter about the sighting and the tweet garnered a lot of interest.
Someone asked if there were wild brassicas, such as Cuckoo Flower (Cardamine pratensis) or Garlic Mustard (Alliaria petiolata) plants in bloom in our area. As far as I know, there aren’t. Indeed, the wildest it gets on that roadside verge is probably with the presence of Common Dandelion (Taraxacum officinale) and Common Daisy (Bellis perennis) unless someone has shaved it to the ground to make it all neat and tidy.
The lack of blooming wildflower brassicas (formerly known as crucifers) species, Cuckoo Flower or Garlic Mustard, could be a problem for early mating Orange Tips as the females are very choosy about the host plants on which they lay their eggs. They need large flowerheads from those wild brassicas and then generally plants that are growing in full sunlight. They don’t even like to fly through shade to find the plants, it seems.
Then there is the issue of egg colour and pheromones. When first laid, Orange Tip eggs are white but change to orange and then brown within days perhaps making their presence obvious to other females arriving at the flower. The female also covers her eggs with a pheromone that dissuades other females from laying eggs in the same bloom. This will benefit the larvae of both females as the original ones will not have competitors for food (the host plant’s seed pods), but also, the more recent eggs, and so younger larvae, will not be cannibalised by the older ones.
The weather patterns have been weird at this time of year for several years now. Think back to the warm days of March during lockdown. I’ve not seen any more Orange Tips yet, so this may have simply been a precocious male who may miss his chance of spreading his seed if no females appear soon. The main emergence may happen at the end of the month and into April, as is more usual.