Wednesday, 15 April 2015

Emperor success

I was also donated an Emperor cocoon by Martin, from which a female emerged this morning 15th. I put her outside at 13.00 in a cage. The males usually fly in the second half of the afternoon so I wasn't expecting anything to happen straight away. I checked at regular intervals for arrivals and just after 6 two males arrived, followed shortly after by a third. Bearing in mind this is the middle of East Oxford with very little habitat other than gardens.

They seem to get confused at close range presumably by the high concentration of pheromone (and perhaps the way the wind swirls around the patio) and blundered around quite a bit, even getting lost on the other side of the fence, and they failed completely to find their way into the open cage (although one settled on the wrong side of the netting), so I put her on the fence. This proved a little awkward for the only male who succeeded in finding her, but she obligingly lifted her wings to give him a bit more room before flattening them out again. Any other records of assembled males from VC 23 gratefully received - most of the records are of females at light. 
Martin Townsend


  1. Hi Martin - this is great news following Steve's success. I'll try to follow your technique if and when my cocoons hatch, assuming one of them is a female. Fascinating! All warm wishes, Martin

  2. I'm sure you already have my records from when I lived in Oxford - I had males at Shotover and in my garden in Headington + at Crowmarsh Gifford (CEH Wallingford). I have always assumed, despite still recording them in the place I attract them, that given the long distance from which males can detect the pheremones, unless the males come within a short amount of time they have probably come from much further afield. Talking of which there was an interesting talk at the moth recorders meeting on the use of pheremone lures and some of the potential issues. There should be a paper coming out of the work soon and it really was a bit of an eye opener. Not only can you generate spurious distribution records, but it can have a knock-on effect to the success of local breeding populations by altering male behaviour - for example, (if I remember correctly which is always a danger) some males of certain Zygaenid species were no longer as attracted to genuine virgin females following exposure to pheremone lures, I think as a result of the overpowering concentration of synthetic pheremone still lingering long after use. Also, males attracted to lures would pick up the pheremone chemicals on their bodies and then be attractive to other males. The problem is, how else do you survey some of these species and how different is a light trap in respect of attraction versus genuine residency? Recent work on the effects of light pollution is showing some pretty amazing, if not wholly unexpected, negative impacts on moths. All interesting stuff and so much more to learn.

    With respect to the bumbling males around assembled females, in my experience that is always the case - I use a lobster pot style net cage so that eventually a male can get in if persistent, but interestingly, I have found that the males do give in if not successful in finding the female after a certain amount of time. I have never experience a female calling after being mated though - that is bizarre.

  3. Yesterday afternoon (Saturday 18th) I took my virgin females on a tour and added four more 10km square records for VC24. Like almost all of the others in Bucks from which there are as yet no records, they are around the periphery and shared with other counties. SP60 & SP51 (both mostly in Oxon) and SP53 & SP64 (both mostly in Northants) all produced males very promptly and the longest I had to wait anywhere was 15 minutes. Choosing one's spot carefully, with due regard to the wind direction, pays dividends.


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