Boyd sent me a nifty light transmission base (LTB) to try out for dissecting flies. I’ve used it several times now and have found it to be a wonderful improvement over my usual approach of placing a watchmaker’s glass on a small box under the microscope, using an LED ring light to top light the subject.
Boyd’s LTB is fitted with an LED bottom light that projects through a specific diffusion acrylic material designed for LED lighting that dissipates the bright light. This light can be used alone or in combination with a top light. A range of neutral density filters are used in conjunction with a built in iris diaphragm to provide light control.
Fine movement, essential when dissecting genitalia of small flies such as Pipunculidae and Chloropidae, is delivered using an x-y axis mechanical stage (see photos). This proved extremely useful. Using the fine adjustment made centering and re-centering the subject at high magnifications very easy. By contrast, my usual approach of trying to move the watchmaker’s glass gently with my hands is bordering on disastrous, as the slight jarring frequently causes the subject to be propelled well out of the field of view, so one has to search for it and centre it again; A real pain!
My last dissection was a Pipunculid in the genus Cephalops. To identify the specimen I needed to dissect out the phallic duct and get a clear view of the Phallic guide. This was proving difficult to achieve at x65 magnification under my stereo microscope, until I remembered I had not switched the bottom lighting on, so I had been relying on top lighting. When I switched the bottom lighting on the improvement was immediately obvious and I could clearly make out the position of the phallic duct and guide. I needed more magnification, which is where another piece of Boyd’s kit came to the rescue – adapters that allow me to insert 20 x eyepieces (from my compound microscope) into my stereo microscope, doubling the magnification and retaining the vital working space that this microscope provides.
An essential component of the LTB is two “bat wing” hand rests” that slot one to each side of the unit. These provide a steady rest point for hands when holding dissecting needles and performing very delicate dissecting operations (photos show the unit with the rests fitted). I have found that this arrangement is a great assistance for keeping a steady hand whist dissecting. Indeed, I doubt I would have been able to maintain a steady enough hand to dissect out the phallic guide from the tiny Cephalops genital capsule without the hand rests.
