光谱和光强度对棕榈蓟马雌成虫行为反应的影响

Effect of spectral sensitivity and intensity on the behavioral response of the Thrips palmi female adult

室内研究了光谱、光强度对棕榈蓟马雌成虫的趋、避光行为的影响。结果显示:在340—605 nm波谱内棕榈蓟马雌成虫对14个单色光刺激的趋光行为反应为多峰型。其中蓝光483 nm处峰最高,趋光反应率达34.96%,其次为绿光498—524 nm、562—582 nm、紫外光340 nm处;其避光行为反应共有3个峰,其中紫外光380 nm处最高,避光率18.08%,另外2个峰分别在橙光605 nm、紫光420 nm处。在趋光率较高的单色光(340、483、524、582 nm)和避光率较高的单色光(380、605 nm)以及白光刺激下,棕榈蓟马雌成虫的趋光率随光强增强的增强而提高,而避光率则随着光强的增强而降低;光强最弱时仍均有一定趋光率,最强时均未出现高端平台。因此:棕榈蓟马雌成虫对不同单色光具有明显的选择性,光谱和光强度对其趋光行为和避光行为有较大影响,光强度的影响作用与波长因素有关。

Thrips palmi is one of the most serious insect pests,causing adverse effects on vegetable production. In China,the insect pest was first discovered in Guangdong Province in the 1970 s and has gradually become a major insect pest of vegetables,especially solar greenhouse vegetables. For example,in 1993 solanaceous fruit vegetables such as eggplant,green pepper and potato were damaged seriously by T. palmi,and the damage rate was about 90% in the Hangzhou district. In recent years,with the development of solar greenhouse vegetables in northern China,T. palmi has survived through the winter in solar greenhouses and damaged vegetables throughout the year,so controlling these insect pests has become more difficult. Physical control is an important control technique within integrated pest management（ IPM）,and the color plate trap is one of the most important methods of physical control. The color plate trap can not only reduce the number of T. palmi insects effectively,but can also forecast the occurrence of the insect pests in the field,so this method plays an important role in the IPM of T. palmi. The selectivity of T. palmi to colors in the field has been reported to show significant variation. To discover the photosensitivity of the insect pest,we studied the phototactic and photophobic behavior of T. palmi female adults in response to spectral sensitivity and light intensity by behavior method in the laboratory. The results showed that the phototactic response of T. palmi female adults to monochromatic light at 14 different wavelengths within a 340—605 nm range occurred in a curve with multiple peaks. The primary peak,representing the highestphototactic response（ 34. 96%）,occurred at a wavelength of 483 nm（ blue）,the secondary peak at 498—524 nm（green）,and the remainder at 562—582 nm（green） and 340 nm（ultra-violet）. The photophobic response occurred in a curve with three peaks： one peak at 380 nm（ ultra-violet） represented the highest photophobic response rate（18. 08%）,and the other two peaks at 605 nm（ orange） and 420 nm（ violet）. Under the stimulus of monochromatic light—at which the T. palmi showed high phototactic response rates（340 nm,483 nm,524 nm,582 nm,380 nm,605 nm） and high photophobic response rates（380 nm,605 nm） —and white light,the phototactic response rate of T. palmi female adults increased with increasing light intensity,while the photophobic response rate decreased. The response rate of T. palmi female adults could be detected at the lowest intensity but not at the height of the strongest intensity. Therefore,in T. palmi female adults,both the spectrum and intensity of light stimulus resulted in phototactic and photophobic responses under monochromatic light conditions,and the level of response was proportional to the wavelength. The results obtained provided a theoretical basis for further investigation and applications as well as for the evaluation of scientific light traps used to monitor and control T. palmi.