Paula-Moraes S V, Hunt T E, Wright R J, Hein G L, Blankenship E E
Department of Entomology, University of Nebraska-Lincoln, NEREC Haskell Agricultural Laboratory, 57905 866 Rd., Concord, NE 68728, USA.
Environ Entomol. 2012 Dec;41(6):1494-500. doi: 10.1603/EN12149.
Western bean cutworm, Striacosta albicosta (Smith), has undergone a recent eastward expansion from the western U.S. Corn Belt to Pennsylvania and parts of Canada. Little is known about its ecology and behavior, particularly during the early instars, on corn (Zea mays L.). There is a narrow treatment window for larvae, and early detection of the pest in the field is essential. An understanding of western bean cutworm larval feeding and early-instar dispersal is essential to understand larval survival and establishment in corn. Studies were conducted in 2009 through 2011 in Nebraska to determine the feeding and dispersal of early-instar western bean cutworm on corn. The treatment design was a factorial with three corn stages (pretassel, tassel, and posttassel) and five corn plant zones (tassel, above ear, primary ear, secondary ear, and below ear) in a randomized complete block design. The effects of different corn tissues on larval survival and development were investigated in laboratory studies in a randomized complete block design during 2009 and 2011. Treatments were different corn tissues (leaf alone, leaf with developing tassel, pollen, pollen plus silk, and silk alone). Results demonstrated that neonate larvae move to the upper part of the plant, independent of corn stage. Larval growth was optimal when fed on tassel tissue. Overall results indicated a selective benefit for movement of the early instar to upper part of the plant.
西部玉米螟，学名Striacosta albicosta (Smith)，近期已从美国西部玉米带向东扩张至宾夕法尼亚州及加拿大部分地区。人们对其生态和行为了解甚少，尤其是在玉米（Zea mays L.）上的低龄幼虫阶段。幼虫的防治窗口期很窄，因此在田间早期发现这种害虫至关重要。了解西部玉米螟幼虫的取食和低龄幼虫的扩散情况对于理解其在玉米中的存活和定殖至关重要。2009年至2011年在 Nebraska 开展了研究，以确定西部玉米螟低龄幼虫在玉米上的取食和扩散情况。试验设计为析因试验，有三个玉米生长阶段（抽雄前、抽雄期和抽雄后）和五个玉米植株区域（雄穗、穗上、主穗、次穗和穗下），采用随机完全区组设计。2009年和2011年在实验室研究中采用随机完全区组设计，研究了不同玉米组织对幼虫存活和发育的影响。处理为不同的玉米组织（仅叶片、带发育中雄穗的叶片、花粉、花粉加花丝和仅花丝）。结果表明，初孵幼虫会向植株上部移动，与玉米生长阶段无关。以雄穗组织为食时幼虫生长最佳。总体结果表明，低龄幼虫向植株上部移动具有选择性优势。
