长头谷盗对6种寄主谷粉及其挥发物的行为反应

Behavioral responses of Latheticus oryzae (Waterhouse) to six host grains and their volatiles

利用Y型嗅觉仪和四臂嗅觉仪,测定了长头谷盗Latheticus oryzae(Waterhouse)对6种寄主谷粉的行为趋性反应,采用固相微萃取和气质联用(GC-MS)分析了其中3种寄主挥发物组分和含量,并测定长头谷盗对其中7种挥发物单体标样在5个浓度下的行为学反应,以期明确谷物挥发物在长头谷盗寄主定向行为中所起的作用。结果显示,6种寄主挥发物对长头谷盗雌雄成虫均具有显著的引诱作用,且雌雄个体间差异不显著;6种寄主之间分组比较时,长头谷盗的引诱强弱均显著的表现为全麦粉>黄豆粉>玉米粉>荞麦粉>小米粉>高粱粉。选择全麦粉、黄豆粉和玉米粉进行分析时,3种寄主挥发物具有不同的化学图谱,且挥发物的相对含量差异较大,黄豆粉挥发物总量大于全麦粉和玉米粉;从组分来看,全麦粉挥发物中主要为烯醛类(37.46%),黄豆粉挥发物中主要为醇类(45.24%)和醛类(27.06%),玉米粉挥发物种主要为烷烃类(39.58%)。7种寄主挥发物标样(100～1600μL/mL)中,除甲酸正己酯、二十烷和正十四烷对长头谷盗始终具有引诱作用外,正己醇、正己醛和反式-2,4-癸二烯醛分别在200～800、400～800和400～800μL/mL时,才具有引诱作用;而反式-2-癸烯醛在高浓度(1600μL/mL)下对长头谷盗具有趋避作用。综合分析表明,挥发性物质在长头谷盗对不同寄主谷粉的选择时具有重要的行为导向作用,且挥发性化合物的组成及浓度影响其引诱效果。

Using Y-type and Four-type olfactometer, behavior response of Latheticus oryzae （Waterhouse） to six kinds of host grains were studied. The volatiles of three hosts were qualitative and quantitative analyzed, coupled with solid-phase microextraction and gas chromatograph-mass spectrometry （GC - MS ）. And the attraction of 7 single volatiles of three hosts to L. oryzae was analyzed at five different concentration respectively. The results indicated that, six host volatiles had strong behavior selection to the female and male longhead flour beetles, and no significant difference between female and male individual; When host from different groups were eomparatively tested, the attraction of longhead flour beetles showed significantly the strongest host preference to whole wheat flour, followed by soybean flour, corn flour, buckwheat flour, millet flour and then sorghum flour in turns. When analyzed, there were significant difference in volatile profile, components and relative contents among whole wheat flour,soybean flour and corn flour. Volatile quantity of soybean flour is a little more than that of whole wheat flour and corn flour. From components, the main components of whole wheat flour volatile extract were dienenal （37.46 % ）, while alcohole （45.24 % ） and aldehydes （27.06 % ） in soybean flour, the volatile extract of corn flour were hydrocarbon （39.58 % ）. When seven kinds of reference sample volatile compounds were tested, Formic acid-hexylester, Eicosane and Tetradecane always showed strong attraction to L. oryzae at five difference concentrations. Hexyl alcohol, Hexanal and Trans, trans - 2, 4 -Decadien - 1 - al showed trapping response just at appropriate concentrations; however, Trans - 2 - Decenal showed repellent effect to L. oryzae at high concentration （ 1600 μL/mL）. The results suggest that volatile semiochemicals from different host grains play important roles in orientating behavior of L. oryzae and their co^ipound composition and relative concentration affected attraction effect.