Light pulse on a dying mosquito

Featured is a dying mosquito from northern California, as seen through our digital microscope. The area in question is in the upper right, where there is a pulsing movement with small flashes of light (I'm guessing biochemical)--it is the underside of the mosquito, where the thorax (above) meets the abdomen/tail (below). Before it died, the abdomen was larger and pulsed in a wave-like manner. Please comment if you know what causes the little flashes of light.