Germinara Giacinto S, De Cristofaro Antonio, Rotundo Giuseppe
Department of Animal, Plant and Environmental Sciences, University of Molise, Via De Sanctis, 86100 Campobasso, Italy.
J Chem Ecol. 2008 Apr;34(4):523-9. doi: 10.1007/s10886-008-9454-y. Epub 2008 Mar 14.
The antennae of Sitophilus granarius (L.) (Coleoptera: Curculionidae) adults detect a wide variety of compounds in the odor blend of various cereal grains (Germinara et al., Tec. Molit., 53:27-34, 2002). In the present study, we looked at the behavioral responses of the granary weevil to 20 of these individual volatiles (aliphatic alcohols, aldehydes, ketones, and aromatics) in a two-choice pitfall olfactometer, using the aggregation pheromone and propionic acid as the attractant and repellent controls, respectively. Five doses, ranging from 1 microg to 1 mg, of each compound were tested. At least one concentration of eight compounds attracted beetles but required doses 1,000- to 5,000-fold higher than the concentration of aggregation pheromone to elicit a response. Three compounds, while attractive at lower concentrations, acted as repellents at higher doses. Twelve compounds were repellent at concentrations similar to the quantity of propionic acid that significantly repelled beetles. The data show that granary weevil adults have the ability to respond behaviorally to a wide range of cereal volatiles and that responses may change as a function of concentration. The results suggest that host finding behavior of weevils will depend on the balance of positive and negative volatile stimuli from grain as the relative concentrations of volatiles may change during storage. An understanding of how the weevils respond to such changes could be useful for the development of effective integrated pest management strategies.
谷象（Sitophilus granarius (L.)，鞘翅目：象甲科）成虫的触角能检测到各种谷物气味混合物中的多种化合物（Germinara等人，《Tec. Molit.》，53:27 - 34，2002）。在本研究中，我们在双选陷阱嗅觉仪中观察了谷象对其中20种单一挥发性物质（脂肪醇、醛、酮和芳烃）的行为反应，分别使用聚集信息素和丙酸作为引诱剂和驱避剂对照。对每种化合物测试了5种剂量，范围从1微克到1毫克。至少有一种浓度的8种化合物吸引了甲虫，但引发反应所需的剂量比聚集信息素的浓度高1000至5000倍。3种化合物在较低浓度下具有吸引力，但在较高剂量时起到驱避作用。12种化合物在与能显著驱避甲虫的丙酸量相似的浓度下具有驱避作用。数据表明，谷象成虫有能力对多种谷物挥发性物质做出行为反应，且反应可能随浓度变化。结果表明，象甲的寄主寻找行为将取决于谷物中正负挥发性刺激的平衡，因为挥发性物质的相对浓度在储存过程中可能会发生变化。了解象甲如何对这种变化做出反应可能有助于制定有效的综合虫害管理策略。
