Despite the lock-down I got a bit of a treat over the Easter weekend. Two years ago the excellent Martin of Martin’s moths gave me 5 emperor caterpillars. These had hatched from eggs laid in his moth trap. Martin did a very good job rearing the caterpillars and ended up with quite a few, so he very kindly gave me some:
Martin had been feeding them Hawthorn (they can also eat heather, meadowsweet, alder buckthorn, bramble, blackthorn, willows and birches) despite the prickles sustained collecting it I carried with the Hawthorn from a bush down the road. They grew fast and eventually pupated.
Despite the fact I didn’t have to feed them anymore the pupae still needed looking after. I put the tank into the shed to avoid the pupae being predated but that meant trying to mimic the outside conditions and temperature within the tank and ensuring that the pupae didn’t dry out by spraying them with water,
Unlike most species that only stay as pupae for a year, emperors can take up to 4 years to emerge! Its also really important that the caterpillars eat as much as possible before they pupate as the adults don’t have any mouth parts so have to use the energy from the food they ate while they were caterpillars to hopefully meet a mate and breed.
The first of my emperors emerged in 2019 and I was lucky enough to get both a male and female
I think they had already mated and the male didn’t stick about but the female was very calm so I put her on a safe spot in the trellis to see if the male would come back or if she could attract another mate (Emperors don’t usually come to light traps, so if you want to record them you use a pheromone lure which mimics a female).
I had three pupae left in the tank, but I wasn’t sure if any were still alive however this year at Easter another female hatched.
I left the female in the tank until the evening started to draw in in case her pheramones encouraged one of the other pupae (a male) to emerge. She didn’t gain a mate so again I put her on the trelis at the bottom of the garden.
The next morning at 6am when emptying my weekly moth trap (its a light trap, the moths aren’t harmed they sleep in the bottom of the trap and then I empty, identify, release and finally record what came to the light).
Sat where I had left the female the previous evening…. Gentleman caller!
A very happy Easter indeed 🙂