Neotropical Entomology (2008) 37, 577-581

Margarida F. Roza-Gomes, José R. Salvadori and Jurema Schons (2008)
Danos de Rhopalosiphum padi (L.) (Hemiptera: Aphididae) no trigo em função da duração e da densidade de infestação
[Damage of Rhopalosiphum padi (L.) (Hemiptera: Aphididae) on wheat plants related to duration time and density of infestation]
Neotropical Entomology 37 (5), 577-581
Abstract: 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.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Research topic(s) for pests/diseases/weeds:
damage/losses/economics

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhopalosiphum padi	Wheat (Triticum)	Brazil (south)