The invention relates to a novel counter, and belongs to the field of agricultural technology. The novel counter comprises a light emitting device, a photoelectric conversion device, an electric signal receiving and amplifying circuit, an information receiving device, an information transmission system, an information display device and a power part, and is applicable for sensing and monitoring of harmful organisms such as insects, spiders, mites and the like. By rationally selecting the type and the number of the photoelectric conversion device, the novel counter expands the monitoring range, prevents missed inspection occurred when the harmful organisms with small sizes such as the insects, the spiders, the mites and the like pass through the counter, has high sensitivity to the harmful organisms with small sizes such as the insects, the spiders, the mites and the like and provides better choice for the monitoring of the harmful organisms.