Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC.
J Econ Entomol. 2019 Mar 21;112(2):827-834. doi: 10.1093/jee/toy393.
Frankliniella fusca (Hinds) (Thysanoptera: Thripidae) is an early-season cotton pest. Seedlings are injured by larvae, which hatch from eggs oviposited into seedlings and feed on developing plant tissue. Better understanding F. fusca oviposition in cotton may improve their management and address new challenges such as resistance to neonicotinoid seed treatments (NSTs). Cotton seedlings exposed to F. fusca were either cleared and stained to determine egg density and location, or dissected and washed to determine larval distribution. Experiments were conducted in the greenhouse with a susceptible population and field with a NST-resistant population. Eggs of both populations were recovered predominantly in cotyledons. Larvae were more uniformly distributed on seedlings. On NST seedlings, oviposition by the susceptible population was reduced and preference shifted to true leaves. NSTs did not alter egg placement by the resistant population. These findings suggest that injury to cotton seedlings is primarily caused by F. fusca emerging on the cotyledons, and then moving to developing leaves. The oviposition shift in NST plants correlates with how systemic NSTs have been reported to concentrate in cotyledons. This can better inform management tactics in cotton, such as well-timed foliar sprays, which, given the current resistance issue, are needed to maintain effective thrips management.
烟粉虱（Hinds）（缨翅目：蓟马科）是棉花的早期害虫。幼虫从卵中孵化出来，然后钻入幼苗并以发育中的植物组织为食，从而导致幼苗受伤。更好地了解烟粉虱在棉花上的产卵情况可能有助于改善其管理，并解决新的挑战，例如对新烟碱类种子处理剂（NSTs）的抗性。暴露于烟粉虱的棉花幼苗要么被清除和染色以确定卵密度和位置，要么被解剖和冲洗以确定幼虫的分布。实验在温室中用敏感种群和田间用 NST 抗性种群进行。两个种群的卵主要在子叶中回收。幼虫在幼苗上的分布更加均匀。在 NST 幼苗上，敏感种群的产卵减少，而对真叶的偏好增加。NST 不会改变抗性种群的产卵位置。这些发现表明，棉花幼苗的伤害主要是由在子叶上出现的烟粉虱引起的，然后移动到发育中的叶子。在 NST 植物上的产卵转移与系统 NST 如何集中在子叶中的报道有关。这可以更好地为棉花管理策略提供信息，例如及时的叶面喷雾，鉴于目前的抗性问题，这是维持有效蓟马管理所必需的。
