USDA-ARS, Western Integrated Cropping Systems Research Unit, 17053 North Shatter Ave, Shatter, CA 93263, USA.
J Insect Sci. 2012;12:36. doi: 10.1673/031.012.3601.
The western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae) is a key pest of fruit, vegetable, and field crops in the western United States, but many aspects of L. hesperus ecology are poorly documented. A sound understanding of oviposition behavior and characterization of the phases of embryonic development would be useful in studies of interactions between L. hesperus and its hosts, and in efforts to better understand the developmental consequences of low temperatures. Because L. hesperus insert their eggs into the host, most of the egg is obscured from view, and some aspects of oviposition and subsequent egg development cannot be observed directly. A novel observational method which took advantage of the propensity for L. hesperus to oviposit in semi-transparent sheets of agarose was used to observe oviposition and subsequent embryonic development. Lygus hesperus females stylet-probed prospective oviposition sites and during oviposition the ovipositor followed the path of the final probe. Oviposition, from insertion to withdrawal of the ovipositor, required ∼30 seconds. Identifiable phases of embryo development included egg swelling, katatrepsis, appearance of body segments and appendages, development of red pigmentation in the eyes and terminal antennal segments, and formation of the 3(rd) embryonic cuticle. These phases were observed at about 0.3, 0.4, 0.5, 0.6, and 0.8 of the total duration between oviposition and hatch, respectively. Infertile eggs did not exhibit any of these phases. Our descriptions of embryonic development will facilitate the study of L. hesperus egg biology and ecology, and permit estimates of egg population age structure and prediction of egg hatch.
西方玷污叶蝉，Lygus hesperus Knight（半翅目：Miridae）是美国西部水果、蔬菜和大田作物的主要害虫，但 L. hesperus 生态学的许多方面记录甚少。对产卵行为的深入了解和胚胎发育阶段的特征描述，将有助于研究 L. hesperus 与其宿主之间的相互作用，并更好地理解低温对其发育的影响。由于 L. hesperus 将卵插入宿主，因此大部分卵都被遮挡，无法直接观察到产卵和随后的卵发育的某些方面。一种新的观察方法利用了 L. hesperus 倾向于在半透明琼脂糖薄片中产卵的特性，用于观察产卵和随后的胚胎发育。Lygus hesperus 雌性用口针刺探预期的产卵部位，在产卵过程中，产卵器沿着最后一次探针的路径移动。产卵从插入到抽出产卵器大约需要 30 秒。可识别的胚胎发育阶段包括卵肿胀、翻缩、体节和附肢出现、眼睛和末端触角节的红色色素沉着发育以及第三层胚胎角质层的形成。这些阶段分别在产卵后至孵化前的总时间的 0.3、0.4、0.5、0.6 和 0.8 左右观察到。不育卵则没有出现这些阶段。我们对胚胎发育的描述将有助于研究 L. hesperus 卵生物学和生态学，并能够估计卵种群的年龄结构和预测卵孵化。
