Roza-Gomes Margarida F, Salvadori José R, Schons Jurema
Rua Pedro Roso, 42, Centro, 99600-000, Nonoai, RS.
Neotrop Entomol. 2008 Sep-Oct;37(5):577-81. doi: 10.1590/s1519-566x2008000500013.
Aphids are considered relevant pests on wheat either by direct damage through sap sucking or by indirect damage vectoring BYDV (Barley yellow dwarf virus). Rhopalosiphum padi L. has been observed infesting wheat fields with an increasing frequency. The knowledge and the available technology, besides being more related to other aphids species already recognized as pests, they are insufficient to control the specific problem of R. padi. Thus, this work evaluated the effects of feeding duration and infestation densities of R. padi on seedlings of wheat cv. Embrapa 16. Grain yield, yield components and the extent of symptoms were recorded. The experiment was carried out in the field under a completely randomized split-plot experimental design with four replications. The main plot was feeding duration (two and seven days) and the sub-plots were infestation densities (zero, two and 10 aphids per plant). Independent on feeding duration, 10 aphids per plant resulted in significant yield losses, reduction of number of heads and tillers per plant. Canopy dry matter was also reduced. Infestations of two and 10 aphids per plant resulted in continuous yellowing of wheat plants from tillering to the end of flowering stage. When aphids fed for seven days on wheat, more yellowing symptoms were observed at the flower stage in comparison with two days feeding.
蚜虫被认为是小麦上的相关害虫，其通过吸食汁液造成直接损害，或通过传播大麦黄矮病毒（BYDV）造成间接损害。已观察到麦长管蚜侵染麦田的频率不断增加。现有的知识和技术，除了更多地与已被确认为害虫的其他蚜虫种类相关外，不足以解决麦长管蚜的特定问题。因此，本研究评估了麦长管蚜的取食持续时间和侵染密度对小麦品种Embrapa 16幼苗的影响。记录了籽粒产量、产量构成因素和症状程度。试验在田间采用完全随机裂区试验设计，重复四次。主区为取食持续时间（两天和七天），副区为侵染密度（每株零、两只和十只蚜虫）。无论取食持续时间如何，每株十只蚜虫都会导致显著的产量损失、每株穗数和分蘖数减少。冠层干物质也减少。每株两只和十只蚜虫的侵染导致小麦植株从分蘖期到开花期末持续发黄。当蚜虫在小麦上取食七天时，与取食两天相比，在花期观察到更多的发黄症状。
