D.S.I.R. Plant Protection, Private Bag, Palmerston North, New Zealand.
J Chem Ecol. 1992 Nov;18(11):1965-80. doi: 10.1007/BF00981920.
More than twice the number of mated female Hessian flies,Mayetiola destructor (Say) entered a zone within 1 cm of a paper strip treated with one plant equivalent (PE) of a chloroform extract of wheat foliar waxes compared to a strip treated with solvent only; females also stayed six times longer and laid 10 times more eggs on the strip treated with the wheat extract. Column chromatographic fractionation of the wheat extract and application of these fractions onto filter paper strips showed four fractions elicited significant numbers of eggs to be laid. Single, binary, and tertiary combinations of three of these fractions (two of the four fractions apparently contained similar compounds) were tested. The greatest numbers of eggs were laid on strips treated with the tertiary combination or the binary combination conaining the two most active fractions (3 and 6); three times the number of eggs were laid on strips treated with this binary combination than the sum of eggs laid on strips treated with these two fractions separately. A comparison of grasses and their extracts showed female Hessian flies laid greater numbers of eggs on wheat or rye than on barley or oat. Fractionated barley and oat extracts were tested for activity as for wheat, and a similar pattern was observed, i.e., the greatest numbers of eggs were laid on fractions 3 and 6. Dose-response tests, using these two fractions of wheat, barley, or oat showed the same threshold of activity for fraction 3 for all three extracts, i.e., 2 PE. In contrast, fraction 6 of wheat was active at the lowest dosage tested, 0.25 PE, while the same fraction of either barley or oat was not active until tested at a dosage of 2 PE. It appears that (at least) two chemicals in the foliar waxes of these grasses influence ovipositional behavior of female Hessian flies. Furthermore, given the similar foliar chemistry of these grasses and the strong synergistic interaction between fractions 3 and 6 shown for wheat extract, it is likely that the ovipositional preferences exhibited by female Hessian flies towards these grasses may be explained by quantitative differences in the amount(s) of the active chemical(s) in their respective fraction 6 (most polar fraction tested).
与仅用溶剂处理的纸条相比，进入距涂有 1 个植物当量（PE）的氯仿提取的麦类叶片蜡纸条 1cm 范围内的交配雌性麦长蝽数量增加了一倍多；这些雌性还停留的时间延长了六倍，在涂有麦类提取物的纸条上产卵量增加了 10 倍。对麦类提取物进行柱色谱分离，并将这些级分应用于滤纸条上，结果显示有四个级分可显著诱使产卵。测试了这四个级分中的三个的单一、二元和三元组合（这四个级分中的两个显然含有类似的化合物）。在处理过的纸条上产卵最多的是用三元组合或包含两个最活跃级分（3 和 6）的二元组合处理的纸条；用这个二元组合处理的纸条上产卵数是用这两个级分分别处理的纸条上产卵数的三倍。对草类及其提取物的比较表明，雌性麦长蝽在麦类或黑麦上产卵数多于在大麦或燕麦上产卵数。对大麦和燕麦的分级提取物进行了活性测试，结果与麦类提取物相似，即产卵最多的是 3 级分和 6 级分。使用这两种麦类、大麦或燕麦的分级提取物进行剂量反应测试，结果表明，所有三种提取物的 3 级分的活性阈值相同，即 2PE。相比之下，麦类 6 级分在测试的最低剂量 0.25PE 时就具有活性，而大麦或燕麦的相同级分在测试剂量达到 2PE 时才具有活性。似乎这些草类叶片蜡中的（至少）两种化学物质影响雌性麦长蝽的产卵行为。此外，鉴于这些草类具有相似的叶片化学性质，并且在麦类提取物中 3 级分和 6 级分之间表现出很强的协同作用，雌性麦长蝽对这些草类的产卵偏好可能可以用它们各自的 6 级分（测试的最极性级分）中活性化学物质的数量差异来解释。
