I have a big population of Sitobion avenae. But I am unable to identify which one is nymph and which one is adult. So kindly tell me how I can differentiate them?
Isa Schön, Koen Martens, Peter van Dijk.2009.Lost Sex: The Evolutionary Biology of Parthenogenesis Springer Science & Business Media, Pp.615. ISBN904812770X, 9789048127702
I think that the adult has a caudal process. I am not sure if that is an easy character to use in S. avenae.
If you have to develop your own key, then try number of antennal segments, and number of setae on the caudal process.
You could also take a good guess by simply measuring size. There will be some overlap between the different instars, but on average they should fall into five size classes.
It has been about 20 years since I worked with aphids. Hopefully, someone else will have some better ideas.
Dear Houda Kawas and Timothy A Ebert thank you very much for your help. Actually I am confused about apterous adults because they are almost similar to their nymphal ones. So on which basis we can differentiate them?
What is the difference between winged and wingless adult aphids? If no difference then why they adopt this behavior?