Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS, USA.
Delta Research and Extension Center, Mississippi State University, Stoneville, MS, USA.
Pest Manag Sci. 2020 Dec;76(12):4057-4063. doi: 10.1002/ps.5960. Epub 2020 Jul 13.
The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), has emerged as a major pest of cotton, Gossypium hirsutum L, in the mid-southern USA. In the early 1990s L. lineolaris populations developed resistance to several classes of conventional insecticides, increasing the need for insecticides with alternative modes of action such as insect growth regulators (IGRs) for integrated pest management (IPM). The benzoylphenyl urea (BPU) class of IGRs acts by disrupting the growth and development of immature stages of insects, but little is known about its impact on adult stages.
The effect of novaluron (Diamond™ 0.83EC), a BPU with known chitin synthesis inhibitor activity, was investigated on adult females of L. lineolaris. Treatment of 1-day-old adults with 600 ppm of novaluron in the diet prevented oviposition, while treatment of older females had no impact on oviposition. Oral novaluron exposure of adults of all ages reduced the viability of eggs laid. Novaluron treatment caused ultrastructural changes in the ovaries of 1-day-old adults (48 h post exposure), distorting the follicular epithelial cell architecture of developing oocytes. Additionally, novaluron treatment decreased the chitin content in ovarian tissue.
Our results suggest that chitin or chitin-like components in the developing ovaries of adult L. lineolaris are a target of IGRs such as novaluron, but its activity is specific to a critical time during development. This enhances our understanding of the effects of BPUs on adult insects and could lead to incorporation of IGRs in IPM for controlling adult insect pest populations in the field. © 2020 Society of Chemical Industry.
玷污叶蝉，Lygus lineolaris（Palisot de Beauvois），已成为美国中南部棉花，Gossypium hirsutum L 的主要害虫。在 20 世纪 90 年代初，L. lineolaris 种群对几类常规杀虫剂产生了抗性，这增加了对具有替代作用模式的杀虫剂（如昆虫生长调节剂（IGRs））的需求，以用于病虫害综合管理（IPM）。苯甲酰基脲（BPU）类 IGR 通过破坏昆虫的生长和发育来发挥作用，但对其成虫阶段的影响知之甚少。
研究了 novaluron（Diamond™ 0.83EC）对玷污叶蝉成虫雌虫的影响。novaluron 对 1 日龄成虫进行饮食处理，浓度为 600 ppm，可防止产卵，而对大龄雌虫的产卵则无影响。novaluron 对所有年龄成虫的口服暴露均降低了产卵的活力。novaluron 处理会导致 1 日龄成虫的卵巢超微结构发生变化（暴露后 48 小时），破坏正在发育的卵母细胞滤泡上皮细胞结构。此外，novaluron 处理降低了卵巢组织中的几丁质含量。
我们的结果表明，正在发育的卵巢中的几丁质或几丁质样成分是 IGR（如 novaluron）的靶标，但它的活性是针对发育过程中的关键时间的。这增加了我们对 BPU 对成年昆虫的影响的理解，并可能导致将 IGR 纳入 IPM 中，以控制田间成年昆虫害虫种群。 © 2020 英国化学学会。
