• Moth fly (Psychodidae)

    Date:17 July 2012 Tags:, ,

    Kevin Mackenzie, University Of Aberdeen

    This false-coloured scanning electron micrograph shows a moth fly (Psychodidae), also known as a drain fly. As its name suggests, the fly’s larvae commonly live and grow in domestic drains; the adult fly emerges near sinks, baths and lavatories. The moth flies’ bodies and wings are covered in hairs, which gives them a ‘fuzzy’, moth-like appearance. The fly is 4-5 mm long, and each eye is approximately 100 microns wide.

    Why was the creator looking at this fly?
    Kevin Mackenzie explains: “This small fly was resting on the interior kitchen wall at home. Even to the naked eye, it was unusual in appearance – like a tiny moth, holding large wings across the top of a distinctly fuzzy body. I’d seen nothing like it before, so it definitely warranted a closer look under the scanning electron microscope.”

    How was the sample prepared for imaging?
    The fly was placed directly into a tube containing ice-cold 100 per cent methanol that had been cooled to -20°C, and it was then placed back in the freezer for 24 hours. After this time, it was removed and allowed to thaw out at room temperature. The specimen was then placed into 100 per cent ethanol and transferred to hexamethyldisilazane and air dried. This method minimised possible damage to the fine hairs and scale of the fly. The dried sample was attached to an SEM mounting stub and lightly coated with a thin layer of gold before being imaged using the backscatter detector.

    The 12th Wellcome Image Awards were announced on 20 June 2012, recognising the creators of the most informative, striking and technically excellent images among recent acquisitions to Wellcome Images, as chosen by a panel of judges.