This coloured scanning electron microscopic image depicts the compound eye of Drosophila sp. The eye of Drosophila is composed of 760 individual ommatidia (single compound eye) containing photoreceptor cells. The reddish pigment cells protect the single eyes from blue light, which would blind the fly during normal daylight. Within the photoreceptor cells millions of rhodopsin molecules are situated, activated by light and triggering nervous pathways generating the visional information. The processing of the highly developed vision uses around two thirds of the fly`s brain. Ommatidia cannot focus nor can they move. Thus insect eyes have adopted a spherical shape allowing for a field of vision of 360°. The temporal resolution of insect eyes is around 4-10 times better than the human eye. Each single ommatidium gathers information and fires upon perceived movement, this flicker effect allows them to interpret movement much quicker than we can.
Samples are a kind gift of a rotten fruit from the authors kitchen.
Fruit flies are – as the name says – attracted by fruit and their acids. To build a fruit fly trap add a bit of orange juice and vinegar to concentrated soap water. The soap will lower the surface tension so that the flies, who try to feed, cannot escape (and slowly die.)
