Sellhorn requested info on dissecting microscopes for tracheal mite
    (TM) analysis.  Several responses came forward including Allen dick's
    comprehensive one.
 
    As BusyKnight correctly pointed out, if your are frequently involved in
    TM analysis where you would examine large samples sizes (= looking
    through a microscope for many hours), buy good quality in optics.  Any
    of the 'big' names such as Zeiss, Leitz, Wild-Heereburg would do
    (including used ones), but you also pay for the name.  Excellent scopes
    also include various Japanese makes such as Meiji, Olympus, etc.  If
    you plan to use the scope almost exclusively for this purpose, buy
    simplicity without "bells & whistles".  Only consider a stereo
    microscope, not a mono-ocular models.
 
    I recommend magnification of up to about 40x.  Don't bother with those
    up to 70 or 80x because you will never use such magnification while you
    pay for it.  Zoom is desirable (but you pay) while pre-fixed mag.
    settings do fine also.
 
    If you really want to get fancy, make sure to have an excellent light
    source.  Too many focus (no pun intended!) on the scopes without paying
    much attention to the light source.  The best are the fibre-optic,
    halogen lateral light sources where the specimen is illuminated from
    all sides with cool light (so you don't fry or shrivel your specimen)
    while the background remains black. The result is superb contrast.
 
    Do you need all this stuff for your incidental examination?  Absolutely
    not.  These are expensive toys which I would only consider to purchase
    if your profession requires it, you have an irrespressible urge to
    examine your bees (and other small things, I presume), and you have
    plenty of money to burn!
 
    To elaborate on BusyKnight's comments, for less than $100, you can buy
    a first-rate illuminated magnifier with elbow mount, where you can
    carry out the "rough" examination as he described.  Discoloration of
    the tracheae will be a good sign and you will learn quickly to gauge a
    light from a heavy infestation.  As beekeeper, do you really need much
    more than that?  I don't think so.
 
    Paul van Westendorp                         [log in to unmask]
    Provincial Apiarist
    British Columbia