Bellota E, Dávila-Flores A, Bernal J S
Dept of Entomology, Texas A&M Univ, College Station, TX, 77845, USA.
Dept of Entomology, Texas A&M Univ, College Station, TX, 77843-2475, USA.
Neotrop Entomol. 2018 Apr;47(2):171-180. doi: 10.1007/s13744-017-0516-0. Epub 2017 Apr 10.
The corn leafhopper [Dalbulus maidis (DeLong & Wolcott)] is a specialist on Zea (Poaceae) that coevolved with maize (Zea mays mays) and its teosinte (Zea spp.) relatives. This study tested the hypothesis that host acceptance by females varies among Zea hosts, and is correlated with variation in defensive levels across those hosts. Prior studies revealed differences in plant defenses among Zea hosts and corresponding differences in corn leafhopper performance. Thus, host acceptance was expected to be correlated with defensive levels and offspring performance across Zea hosts, following the hypothesis that offspring performance mediates host preference. In parallel, host acceptance was expected to be correlated with transitions in life history strategy (perennial to annual life cycle), domestication status (wild to domesticated), and breeding intensity (landrace to hybrid variety) in Zea because variation in defensive levels and corn leafhopper performance were shown in prior studies to be correlated with those transitions. The study's hypotheses were tested by comparing, under no-choice conditions, host acceptance by corn leafhopper of a suite of Zea hosts encompassing those transitions: perennial teosinte (Zea diploperennis), Balsas teosinte (Zea mays parviglumis), and landrace and commercial hybrid maize. The results did not show differences in host acceptance for oviposition or feeding among the hosts. Thus, under no-choice conditions, all Zea hosts may be similarly acceptable for feeding and oviposition, despite marked ovipositional preferences under choice conditions and poorer offspring performance on teosintes relative to maize shown previously. The results suggested also that oviposition frequency per plant by females was not correlated with their offspring's performance.
玉米叶蝉[Dalbulus maidis（德隆和沃尔科特）]是一种专食玉米（禾本科）的昆虫，它与玉米（Zea mays mays）及其大刍草（玉蜀黍属物种）近缘种共同进化。本研究检验了以下假设：雌性叶蝉对寄主的接受程度在不同的玉米寄主间存在差异，且与这些寄主的防御水平变化相关。先前的研究揭示了不同玉米寄主间植物防御的差异以及玉米叶蝉表现的相应差异。因此，按照后代表现介导寄主偏好这一假设，预计寄主接受程度与不同玉米寄主的防御水平及后代表现相关。同时，预计寄主接受程度与玉米的生活史策略转变（多年生到一年生生命周期）、驯化状态（野生到驯化）以及育种强度（地方品种到杂交品种）相关，因为先前的研究表明防御水平和玉米叶蝉表现的变化与这些转变相关。本研究的假设通过在无选择条件下比较玉米叶蝉对一系列涵盖这些转变的玉米寄主的接受程度来进行检验：多年生大刍草（Zea diploperennis）、巴尔萨斯大刍草（Zea mays parviglumis）以及地方品种和商业杂交玉米。结果并未显示寄主在产卵或取食的接受程度上存在差异。因此，在无选择条件下，尽管先前显示在选择条件下有明显的产卵偏好且相对于玉米，叶蝉在大刍草上的后代表现较差，但所有玉米寄主在取食和产卵方面可能同样可被接受。结果还表明，雌性叶蝉每株植物的产卵频率与其后代的表现无关。
