I’ve photographed puss moth caterpillars (Cerura vinula) before, but this summer I wanted to follow them through all 5 stages, or ‘instars’, of their larval development.
Luckily I discovered a batch of recently laid puss moth eggs by searching the exact same aspen sapling chosen by another adult female the previous year.
6 June: Unhatched Ova

12 June: Hatched Ova

12 June: 1st Instar
The ‘puss’ moths look a lot more cat-like at this early stage in their development I reckon.


15 June: 2nd Instar
I’d received a shock on my visit the previous day when I found the caterpillars frozen rigid in position, with their backs arched and tails in the air. They looked decidedly dead and I thought they must have been parasitised. Today, however, they were re-animated once more.



24 June: 3rd Instar
9 days later, after vanishing for several days, the two siblings had relocated further up the branch they originally hatched on. Neither was particularly active in the midday heat.


28 June: 4th Instar
It lashed with rain on my next visit and the only visible puss moth was trying its hardest not to get pummeled off the leaf. Its silk pad lashed to the surface provides a firm anchor for feet to grasp.


9 July: 5th Instar
A further 11 days later I returned to find only one of the original 4 puss moth siblings remaining, now in its magnificent mature larval form.


To be continued…
Soon after reaching this mature larval stage the puss moth stops eating and leaves in search of a safe place to pupate. Its transformation into the furry white adult moth can then begin. Despite much searching I couldn’t locate any pupae. Next time maybe!