Yesterday was about 55 degrees and workers started to fly; I noticed quite a few brown streaks on hive body/top;however, I watched for about 10 minutes and no new streaks -- could spots be from earlier cleansing flights or are they sick(nosema?).
Your bees are on a cleansing flight. Nothing to worry about, completely normal. If you had nosema, there would be much more of a mess, especially your combs inside. And your hive would be greatly stresses, mabey pushing dead.
It could be nosema, but if I had to put money on it I would say T-Mites (tracheal mites) One way that you can tell is from K-wing. That's where one or both sets of wings are kicked out to the side....if you see it it almost looks like the bee/s would be uncomfortable the way the wings are being held.
The only 100% sure fire way of telling if it is T-mites is to inspect the trachea under a microscope.
Some give grease patties every spring and fall for T-mites, but that's up to you. I had a problem with it last spring but haven't seen any sign of it so far this spring.
Brown or yellow streaks on the hive don't mean much other than they were taking a lot of cleansing flights because of the nice weather.
What does the inside of the hive look like? feces in the hive would be an indication of dysentary. Dysentary may or may not be nosema but it is one symptom. If you have bees with dysentary, try field stripping a bee. Take a live worker and pull it apart to spread out the guts. A normal gut will be gray and you can see ribs in it. An infected gut will usually be white and swollen.
The white swollen gut is usually nosema. This is not foolproof, but is the most common method of field detection. If you have a microscope you can look for the nosema protozoans.
The "conventional" treatment, is Fumidil or as it's now being billed Fumigilan(?sp).
I personally have never used it.
Thanks -- it was too cold to do an inspection so I haven't looked inside yet, but it sounds like the streaks are normal and they are OK. Thanks for you prompt replies.