As far as I can remember, I first encountered the larvae of the Cinnabar (Tyria Jacobaeae) in 1988 when I was 14 years old growing up in Salford. Somewhere I noticed an advert for volunteers to help with conservation projects during the summer holidays from school. The advert was probably in the local free press or even a poster at school. This was on offer from the Salford and Trafford Groundwork Trust a charitable organisation specialising in urban conservation projects and encouraging young people to consider the natural environment and the benefits of connecting with nature. As a reward for participating in the conservation work, we went on days out to other local sites, I remember one trip over to Delamere Forest in Cheshire. They are still going strong and now called Groundwork (www.groundwork.org.uk) and people from all walks of life can join in with the projects. Arrangements were made, for my younger brother and I, to be picked up from outside the Town Hall in Swinton where we would be taken by minibus to help with a project, all I needed to take was a decent packed lunch and old clothes and be ready for a bit of hard graft, all equipment was to be provided. One of the first projects was to do some work at the new Irlam Linear Park which followed an old, derelict railway line from Irlam to Cadishead (https://irlamandcadishead.net/locations/irlam-linear-park/). Along the old railway cutting there was a yellow plant about half a metre tall in large clumps. This turned out to be Common Ragwort (Senecio jacobaea). On closer inspection we could see lots of small, about one inch in length, black and yellow/orange striped caterpillars (larvae) crawling around the plants, eating the flowers, leaves and stems. There were hundreds of these larvae and they were found on most of the Common Ragwort plants along the cutting.

Larvae of Cinnabar on Common Ragwort

As it turns out, the Cinnabar larvae have voracious appetites and can quickly strip a plant of its leaves and flowers. As they feed, the larvae absorb toxic alkaloids from the plant rendering them, the larvae, unpalatable to predators such as birds. Common ragwort is renowned to be harmful to livestock if eaten by them so the plants are often cleared from farmland, but it is very common to see it growing on roadside verges and areas of waste ground. Common ragwort is an excellent food source for butterflies and moths and over 200 invertebrates have been found feeding on it, making it quite an important link in the food chain. Since first observing them in my youth, I quite often inspect swathes of ragwort to see if the larvae are present and quite often see them. Up until recently I had never observed the adult moth. My first official sighting of the adult moth was in May 2016 when a beautiful red and black specimen alighted on my daughters shoulder in the back garden.

Adult Cinnabar moth on the shoulder of my daughter, Erin.

We have seen the adults quite often since then, usually in the garden flying during the day after being disturbed by play time.

A few years ago, my children got a butterfly rearing kit as a gift at Christmas. We successfully raised the supplied Painted Lady butterflies from eggs to adults and released them locally. We found some recently hatched Cinnabar larvae on some local Common Ragwort so decided to use the butterfly rearing kit to see if we could get the larvae to pupate (where the larva undergo the transformation into adults in a cocoon) with a view to storing the cocoons over the winter and watch them emerge in the Spring as adults. We collected four larvae and a selection of healthy plants and put them safely in the butterfly rearing net.

Cinnabar larva feeding on Common Ragwort inside the rearing kit
Cinnabar larva

It was interesting to see how much the larvae ate over the next week or so, it was quite a lot of plant. Judging by the amount of frass (the excrement of the larvae) in the bottom of the cage, they must have been eating plenty. We had to clean the cage out regularly and replace the old plants with fresh from the nearby roadside verge. We were careful not to take plants with larvae on and collected from different areas locally. It wasn’t long before we could see the larvae moving around slowly and eating less so we knew a change was afoot and watched them more intently. The larvae eventually made their way to the base of the cage and clearly started the process of pupating.

The larvae pupating
Cinnabar cocoon

After a couple of days, the cocoons hardened and darkened in colour. They are very delicate so careful handling was required. in the wild, the pupa overwinter just under the ground so we placed the cocoons carefully into a plant pot with a light covering of soil and popped them in the shed with a net over the top so we can view the emerging adults in the Spring.

One of the cocoons

In terms of trapping, I had Cinnabar adults come to the actinic light trap in the garden, in low numbers, at the end of May and into early June.

We have also raised a White Ermine (Spilosoma lubricipeda) larvae and watched it pupate. Following this we have raised three larvae of the Large White butterfly (Pieris brassicae) which we found feeding on our nasturtium (Tropaeolum majus) in the garden, they have just pupated over this last weekend so they will be stored until Spring ready for emergence.

I hope you have enjoyed this latest installment and it would be awesome if you would share it.

Cheers.

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