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Hi all,

I'm fairly new to keying Diptera. It's clear that costal breaks are both important and difficult to see at times. Can someone give me tips on how to best see costal breaks? I have a scope with a rather weak transmitted light at the base, do I need to get a more powerful light source underneath the specimen? And do I need to see a complete break in the vein, or just lack of pigment, or...?

Thanks!
Ken