Monday, 25 May 2015

Butterfly rearing and releasing

For the second year, I decided to buy in some painted lady butterfly caterpillars to rear in my lab on my nature table at work. Last year, the pupils loved watching them develop and emerge as butterflies, so I thought I would try it again. Little did I know that this year, they would get 'lost' in the post, arriving a week late and looking like monsters already! We did still watch them grow and develop for a week before they became chrysalises though. When they reach this stage, they have to be transferred to their 'hatching habitat' to stop their wings getting trapped. I had forgotten how much these seemingly motionless hanging brown blobs could wriggle when threatened!

My STEM Club of three found them fascinating and wrote some observations of the caterpillars on a few different days. For the first time ever, I actually saw one emerge from its chrysalis; the process took much less time than I imagined - a wriggle, a tear, then out within 30 seconds! A little bit longer to pump up the wings using meconium, which is then expelled from the abdomen, but still completed within no more than 20 minutes or so.

The bit my pupils enjoyed most though was releasing them. This year, the butterflies hung around for longer, fueling up on nectar before disappearing for good. We got to watch them fly, then float towards the dandelions and daisies on the school field. The pupils watched them unfurl their proboscis' and sip nectar, like drinking through a straw. Eventually, we decided to leave them be and hope that the sun continued to shine so they could finish fueling, warm up, disperse and continue the battle for survival.

Still inside the hatching habitat before being released

Sitting on the hand of a year 7 member of STEM Club

Sipping nectar using its very visible proboscis!

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