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Index of Subjects There has been an interesting discussion on just this subject on the NEOdes listserv over the past week or so. I've pasted a relevant posting below. I have occasionally seen Stream Cruisers (Didymops transversa) and Illinois River Cruisers (Macromia illinoiensis) emerge 40-50 feet back from the shore and 30 feet up in a tree along the Saint John River here in NB. Even when looking for exuviae in that kind of situation, it is almost a chance encounter to find one at that height and distance from water (so many trees!), so it doesn't surprise me to hear of them travelling 80 feet before emergence. Dwayne ************************************************************************************************************************************************* From: NEodes@yahoogroups.com [mailto:NEodes@yahoogroups.com] On Behalf Of Thomas W Donnelly Sent: Tuesday, July 30, 2013 12:15 PM To: Northeast Odes Subject: Re: [NEodes] Dragonhunter exuvia On the subject as to how far a larva will go before emerging, I would like to speculate a bit. I have had Didymops larva walking around my basement for hours before being induced to cling to a hardware cloth, and then emerge (at 3 AM). I noticed that they finally became less mobile, and walked stifffer, before finally splitting their skin. I think that it is necessary for larvae to dry out a bit before splitting their skin. This is so their legs more or less lock, holding them to the substrate. Daytime emergers essentially dry out in the sun almost immediately and generally do not go far from water. Also, the further you go, the more chance a hungry predator will get you. But nighttime emergers are relatively safe from predators. The problem is that they dry slowly in the humid night air, and their leg joints remain fairly loose. Therefore, they have to walk further and climb also (the humidity is less the higher you climb) in order that their leg joints stiffen up. You wouldn't want to split your skin if you are in danger of falling off your perch! Their are lots of accounts of nighttime emergers going as much as 100 feet horizontally, and then climbing trees (e.g. Macromia). It may be that they have to do this so that they become stiff enough not to fall from their perch. Nick Donnelly ************************************************************************************************************************************************* -----Original Message----- From: naturens-owner@chebucto.ns.ca [mailto:naturens-owner@chebucto.ns.ca] On Behalf Of nancy dowd Sent: Friday, August 02, 2013 9:38 AM To: naturens Subject: [NatureNS] do dragonfly nymphs crawl long distances This shed dragonfly nymphal skin is on the side of the shed at the camp. I did not notice it until now but it could be several weeks old. If anyone knows the family or further ID (Libellulidae, possibly) please let me know. The extremely long legs seem characteristic. http://www.flickr.com/photos/92981528@N08/9420049895/ The strange thing is the shed is 80' from the lake, the only water anywhere nearby. I usually find these on the rocks along the lakeshore (although I seem to find fewer now than I did when young). Everything I read says the nymphs crawl out of the water a short distance before the adult emerges. But would one crawl 80 feet? Nancy
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