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Coenagrion larver med hjälp av borsten på framben och fötter?
Dragonflies are fascinating. The larvae stays larvae from a couple of weeks up to 5 years, it depends on the species (Hansen, 1981). The temperature, nourishment and time of the year also play a role for the growing factor for the larvae. Both Sahlén (1985) and Begon a.o (1990) say so. My report contains information about the branched setae on the front legs from the family damselflies (Zygoptera) and the species Coenagrion. I have examined the larvae from Coenagrion puella/pulchellum to find out what they use their branched setae for. The branched setae on these larvae look like forks and feathers. I caught larvae from a pond, outside Halmstad, Sweden and I brought them back to Halmstad University to define the species. I used copper paste and put it on the larvae on different spots to see if they used their front legs and front feet to clean themselves from the substance. If they do I can see the copper paste on the branched setae. I used a microscope called SEM to be able to see the small particles on the different body parts. I separated the head and the right front leg from the rest of the body. When I was using the SEM I also took photos on the different body parts. My conclusion is that the larvae from Coenagrion puella/pulchellum use their front legs and front feet to clean themselves from particles that get stuck on their body. It seems like they find it very important to clean the eyes because I could not find any particles from the paste on the eye but I found a lot of them on their legs and feet. Maybe the ancestors of the larvae of Coenagrion puella/pulchellum have been living in tree-holes like their distant relatives in Costa Rica, Megaloprepus, Pseudostigma and Mecistogaster which Hedström & Sahlén (2003) and Sahlén & Hedström (2005) writes about. Or like the the African Coryphagrion (Clausnitzer & Lindeboom, 2002). The tropical larvae have the same structures as Coenagrion puella/pulchellum have. Maybe Coenagrion puella/pulchellum have these structures left from the past.