I had a reasonably good night's trapping in Wolvercote, Oxfordshire last night; 17 individuals of nine species, several (Muslin Moth, Early Thorn, Pale Prominent) new for the year. Also my second Emperor Moth of the year - a rather battered female, who turned out to have laid eggs on one of the egg boxes. I've released her, but have cut out the bit of the egg box with her eggs - I'd like, ideally, to try to raise them to caterpillars, but have little idea how to do it. I think of the food plants listed in the Bible, bramble is the obviously easiest to acquire; but any suggestions as to where/at what temperature to keep the eggs, and what to do when they hatch, would be very welcome.
Female Emperor Moth, 16th April 2022
Steve Goddard
Hi Steve,
ReplyDeleteI keep Emperors each year. I use the females to lure wild males. I'd keep your eggs indoors as they'll hatch quicker. Maybe 3 weeks as eggs. I have used bramble, hawthorn, blackthorn and damson as foodplant. The latter I prefer as less prickles. Keep the container clean and dry. They are prone to damp off and die if humid otherwise easy to rear. After pupation I remove the pupae and keep in the garage outside over Winter piled up in a container, watching for hatching in Spring and making sure males are immediately separated and start the process again.
I agree with Peter's comments. Timescale-wise, I'd keep checking the eggs daily after two weeks and if you rear the larvae indoors they should have spun up their cocoons to pupate by the end of June/beginning of July. Once they've all properly pupated it is safe to handle the cocoons, which are very tough. I try to divide them up into male and female at this stage, which is normally quite easy to do based on the size of the cocoon (the larger ones being female). They then get transferred to the garage in a mice-proof container to sit out the winter. Our garage has no windows so by the end of February the cocoons get transferred to the garden shed so that they can get used to day length/temperature. Emergences can sometimes start any time during the second half of March, as they did this year, but more likely after a "normal" winter is from mid-April onwards.
ReplyDeleteThanks, Peter and Dave for these detailed suggestions: this is a whole area of mothing about which I knew nothing at all. I'll have a go, and see what happens.
ReplyDeleteHi Steve
ReplyDeleteYou will have a great time. I've reared five generations here from a magnificent female which came in 2014 and have run updates from time to time on my own blog. The arrival is here: http://martinsmoths.blogspot.com/2014/05/empress-of-sun.html and there's more here: http://martinsmoths.blogspot.com/2020/04/emperors-are-go.html and here: http://martinsmoths.blogspot.com/2017/04/an-assembly-of-emperors.html - the last one a no-holds-barred account of assembling. Good luck!
Thank you, Martin! -- they hatched a few days ago, and are now feasting on bramble leaves and producing quite a lot of frass...
ReplyDelete