Effects Of Light On The Phototaxis Of Several Important Agricultural Pests

Insect phototaxis is an important biological characteristics of many nocturnal insects. In this research, the trend frequency of insect populations was used as statistical indicators and recorded the tend difference for different wavelengths combination of light source in9kinds of common agricultural pests. The results are summarized as follows:(1)Among21different wavelengths of fluorescent light source,2#(313.11nm-371.08nm) light on Helicoverpa armigera (Hiibner) trapping the highest rate (40%); During the process of using seven kinds of fluorescent light of different wavelengths to trap the two kinds of insects, it is found thatCK (335.09nm-359.95nm;408.66nm-432.83nm) light on Prodenia litura(Fabricius) trapping the highest rate (37.91%),11#(443.84nm-475.72nm) light on Adoretus sinicus(Burmeister) trapping the highest rate (25.27%). Different combinations of plurality of peak light wave from different sources impact on insects’phototaxis obviously.The wavelength of the light source is a major factor affecting the rate of Helicoverpa armigera(Hubner) phototaxis,310nm-370nmlight on Helicoverpa armigera(Hubner) trapping the highest rate; Second, in the light intensity within a certain range, light intensity impacts on insects’phototaxis obviously.Of the five peak wavelengths from the21kinds of different light source (365.82nm、404.99nm、436.13nm、546.18nm、577.93nm), Only365nm light impacts on Helicoverpa armigera(Hubner) phototaxis obviously.(2) Under CK light, light trap distance of lm, Phototaxis rate of a variety of insects is Helicoverpa armigera(Hubner)> Prodenia litura(Fabricius)> Leucania/oreyi(Duponchel)> Axylia putris> Adoretus sinicus(Burmeister)> Agrotis ypsilon(Rottemberg)> Cnaphalocrocis medinalis(Guenee)> Holitrichia lata(Brenske)>Spodoptera exigua (Hiibner).(3)Under conditions of CK light and three kinds of different light intensity (1.181x,0.61x,0.241x), Helicoverpa armigera(Hubner), Prodenia litura(Fabricius) and Holitrichia lata(Brenske) exhibited the trend that phototaxis rate increased with light intensity enhancement. And in the condition of different level light intensity (0.02lx、0.05lx、0.11lx、0.16lx、0.24lx、0.45lx、0.6lx、1.81lx), the phototaxis rate under high light intensity of Adoretus sinicus(Burmeister) is bigger than the one in the low light intensity.(4)Helicoverpa armigera(Hubner), Prodenia litura(Fabricius) and Holotrichia lata(Brenske) all have the highest phototaxis during the two periods:19:30～20:30and22:45-7:00.(5)Among the outdoor light trap lepidopteran insects by the CK light (335.09nm-359.95nm;408.66nm-432.83nm), the number of males was significantly higher than females, and females carrying eggs have a higher rate.