Cooper W Rodney, Spurgeon Dale W
USDA-ARS Shafter Cotton Research Station, Shafter, CA 93263, USA.
Environ Entomol. 2012 Apr;41(2):342-8. doi: 10.1603/EN11236.
Lygus hesperus Knight (Hemiptera: Miridae) is a key pest of cotton (Gossypium spp.) in the western United States that injures floral buds (squares) and developing fruit (bolls). However, no clear relationship between Lygus population level and plant injury has been established. Age-dependent feeding activity by L. hesperus is a possible source of variation that has not been examined for its influence in studies of the impact of Lygus on cotton. Recent video-based laboratory studies indicated that feeding behaviors and trivial movement varied among L. hesperus adults of different gender and reproductive states (prereproductive; reproductive and unmated; and reproductive and mated). We compared within-plant distributions and accumulations of feeding injury to intact cotton plants corresponding to adult L. hesperus of different gender and reproductive states. Adult females, regardless of reproductive state, were observed on squares and axillary buds more often than were males. Additionally, prereproductive adults were observed on squares and axillary buds more often than were mated or unmated reproductive adults, regardless of gender. Plants that were exposed to prereproductive adults exhibited more abscised squares and more squares with injured anthers compared with plants exposed to reproductive adults. However, feeding injury did not differ by insect mating status or gender. These results are consistent with results of our previous video-based assays, and indicate adult reproductive state represents a source of variation that should be controlled in studies to evaluate Lygus-induced injury to cotton and other crop plants.
西方盲蝽（Lygus hesperus Knight，半翅目：盲蝽科）是美国西部棉花（棉属）的一种关键害虫，会损害花芽（棉蕾）和发育中的果实（棉铃）。然而，西方盲蝽的种群水平与植株损伤之间尚未建立明确的关系。西方盲蝽的年龄依赖性取食活动可能是造成差异的一个原因，但在关于西方盲蝽对棉花影响的研究中，尚未对其影响进行检验。最近基于视频的实验室研究表明，不同性别和生殖状态（生殖前期；生殖但未交配；生殖且已交配）的西方盲蝽成虫的取食行为和微小移动存在差异。我们比较了完整棉花植株上对应不同性别和生殖状态的西方盲蝽成虫的取食损伤在植株内的分布和累积情况。无论生殖状态如何，成年雌虫出现在棉蕾和腋芽上的频率都高于雄虫。此外，无论性别如何，生殖前期成虫出现在棉蕾和腋芽上的频率都高于已交配或未交配的生殖期成虫。与接触生殖期成虫的植株相比，接触生殖前期成虫的植株有更多脱落的棉蕾和更多花药受损的棉蕾。然而，取食损伤在昆虫交配状态或性别上并无差异。这些结果与我们之前基于视频的测定结果一致，表明成年生殖状态是一个差异来源，在评估西方盲蝽对棉花和其他作物造成的损伤的研究中应加以控制。
