Stockton Dara G, Martini Xavier, Patt Joseph M, Stelinski Lukasz L
Department of Entomology and Nematology, University of Florida, Citrus Research and Education Center, Lake Alfred, Florida, United States of America.
United States Department of Agriculture, Agricultural Research Services, U.S. Horticultural Research Laboratory, Ft. Pierce, Florida, United States of America.
PLoS One. 2016 Mar 1;11(3):e0149815. doi: 10.1371/journal.pone.0149815. eCollection 2016.
Although specialist herbivorous insects are guided by innate responses to host plant cues, host plant preference may be influenced by experience and is not dictated by instinct alone. The effect of learning on host plant preference was examined in the Asian citrus psyllid, Diaphorina citri; vector of the causal agent of citrus greening disease or huanglongbing. We investigated: a) whether development on specific host plant species influenced host plant preference in mature D. citri; and b) the extent of associative learning in D. citri in the form of simple and compound conditioning. Learning was measured by cue selection in a 2-choice behavioral assay and compared to naïve controls. Our results showed that learned responses in D. citri are complex and diverse. The developmental host plant species influenced adult host plant preference, with female psyllids preferring the species on which they were reared. However, such preferences were subject to change with the introduction of an alternative host plant within 24-48 hrs, indicating a large degree of experience-dependent response plasticity. Additionally, learning occurred for multiple sensory modalities where novel olfactory and visual environmental cues were associated with the host plant. However, males and females displayed differing discriminatory abilities. In compound conditioning tasks, males exhibited recognition of a compound stimulus alone while females were capable of learning the individual components. These findings suggest D. citri are dynamic animals that demonstrate host plant preference based on developmental and adult experience and can learn to recognize olfactory and visual host plant stimuli in ways that may be sex specific. These experience-based associations are likely used by adults to locate and select suitable host plants for feeding and reproduction and may suggest the need for more tailored lures and traps, which reflect region-specific cultivars or predominate Rutaceae in the area being monitored.
尽管专食性食草昆虫受对寄主植物线索的先天反应所引导，但寄主植物偏好可能会受到经验的影响，并非仅由本能决定。我们在亚洲柑橘木虱（Diaphorina citri）——柑橘黄龙病病原体的传播媒介——中研究了学习对寄主植物偏好的影响。我们调查了：a）在特定寄主植物物种上发育是否会影响成熟亚洲柑橘木虱的寄主植物偏好；b）亚洲柑橘木虱以简单和复合条件作用形式进行的联想学习程度。通过在二选一行为测定中对线索的选择来衡量学习情况，并与未经处理的对照进行比较。我们的结果表明，亚洲柑橘木虱的学习反应复杂多样。发育期间的寄主植物物种会影响成虫的寄主植物偏好，雌虫更喜欢它们所取食的植物物种。然而，在24至48小时内引入替代寄主植物后，这种偏好会发生变化，这表明存在很大程度的经验依赖性反应可塑性。此外，在多种感官模式下都会发生学习，其中新的嗅觉和视觉环境线索与寄主植物相关联。然而，雄虫和雌虫表现出不同的辨别能力。在复合条件作用任务中，雄虫单独表现出对复合刺激的识别，而雌虫能够学习各个组成部分。这些发现表明，亚洲柑橘木虱是动态变化的动物，它们基于发育和成虫期的经验表现出寄主植物偏好，并且能够以可能具有性别特异性的方式学习识别嗅觉和视觉寄主植物刺激。成虫可能利用这些基于经验的关联来定位和选择适合取食和繁殖的寄主植物，这可能意味着需要更具针对性的诱捕器，以反映特定区域的栽培品种或监测区域中占主导地位的芸香科植物。
