Monday, September 12, 2011

3rd Instar

Larvae in captivity and in the wild are now almost all in the 3rd instar. This stage lasts some 8 months, including ca 5 months in hibernation. After skin changing into the 3rd instar larvae move to a new leaf, and usually to a new spray. In the wild this may involve a journey of >1m, sometimes as far as 2.5m, usually upwards within the tree. These movements can be mistaken for instances of mortality / predation.

The number of larvae I'm finding in Wilts remains horribly low - currently averaging out at one larvae per 80 mins of actual searching time at present, though the task isn't finished yet and this figure will change. In the annus mirabilis of 2009 I was finding one every 20 mins in these woods...

I'm going to spend a weekend searching for 3rd instar larvae in the Northants woods soon. I strongly suspect that the egg lay will have been considerably better there, for the population's significantly bigger and females were laying well there several days before the weather fell apart on July 6th.

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