Microscopy for Nosema Diagnosis

[mdotb]

Looking for evidence of Nosema through a microscope, and despite various resources, uncertain whether any of what I'm seeing is nosema, or whether the colony was not (significantly) affected.

I've been looking for the symptoms described as "classic" - oval items around 5 micron x 2 micron in size, which "glow" when slightly off focus and then as the focus comes in have a distinct dark outline. What I'm unsure about is whether any of the objects I've seen which are near to but not quite that (in particular those which seem too small) are therefore something else, or are within the normal variation.

One image has a calibrated 5 micron scale shown - all were taken to the same scale.

Any diagnoses from those with an experienced eye at this would be much appreciated.

 

[masterBK]

Nosema apis spores look like this

 

[pargyle]

It doesn't look like Nosema to me ... see MBK slide above ... classic nosema spores ... but what magnification were you using on your microscope ?

 

[jenkinsbrynmair]

It doesn't look like Nosema to me

depends whether you're looking for apis or ceranae

 

[mdotb]

It doesn't look like Nosema to me ... see MBK slide above ... classic nosema spores ... but what magnification were you using on your microscope ?

Magnification was 400x however being a digital image it will of course scale depending how you're looking at it; the 5um scale taken from a scale calibration slide of 10um gradation on under microscope, which has been used to calibrate the relevant lens.

 

[pargyle]

depends whether you're looking for apis or ceranae

Yes ... Difficult to see from the slides ... it still doesn't look like Nosema to me. Randy Oliver has some good illustrations to compare the two:

http://scientificbeekeeping.com/the-nosema-twins-part-1-2/

 

[jenkinsbrynmair]

 

[jenkinsbrynmair]

Yes ... Difficult to see from the slides ... it still doesn't look like Nosema to me. Randy Oliver has some good illustrations to compare the two:

Snap!! went to a good talk on N ceranae given by professor Nanetti a few years ago at the spring convention, he had some reaaly good and clear images - I always use rice as a comparison when asked , Ceranae is akin to long grain rice whilst Apis is more rounded, more like pudding or rissotto rice

 

[drex]

Not the best of images. One or two could possibly be N spores, however even then there are not enough to worry about. Nosema is present in all hives. At the spore density shown in Master BK's image I might be worried, but one gets accustomed to one's own preparation of the slide and ones own scope.