Resende Tiago Teixeira, Auad Alexander Machado, Fonseca Marcy das Graças, Santos Thiago Henrique dos, Vieira Tamiris Moreira
Federal University of Juiz de Fora, Juiz de Fora, Brazil.
ScientificWorldJournal. 2012;2012:926715. doi: 10.1100/2012/926715. Epub 2012 Aug 13.
The aim of this study was to determine the damage in Brachiaria ruziziensis (Germain & Edvard) according to the density of and exposure time to adults of Mahanarva spectabilis (Distant, 1909) (Hemiptera:Cercopidae). Each plant was kept with 0, 12, 18, or 24 adults of M. spectabilis for five or ten days. Then, the insects were removed from the plant, and the following parameters were evaluated: content and loss of chlorophyll, visual damage score, shoot dry mass, and the capability for regrowth. In fact, plants exposed to the highest level of infestation for 10 days showed an 80.97% loss of chlorophyll, which is 25% higher than that shown by the plants exposed for five days. The damage score also increased with infestation levels. In the levels of 12 and 18 adults per plant, the damage score increased with increasing time of exposure. The dry mass content was higher in plants exposed to 24 insects for 10 days, suggesting that the attack of spittlebugs caused premature drying of the plant. These effects caused significant reduction in the number of tillers of infested plants. Our results indicate that exposure to adults of M. spectabilis causes significant damage and affects the development and persistence of B. ruziziensis plants.
本研究的目的是根据壮观沫蝉（Mahanarva spectabilis (Distant, 1909)，半翅目：沫蝉科）成虫的密度和暴露时间，确定鲁齐紫黍（Brachiaria ruziziensis (Germain & Edvard)）的损伤情况。每株植物分别与0、12、18或24只壮观沫蝉成虫放置5天或10天。然后，将昆虫从植物上移除，并评估以下参数：叶绿素含量和损失、视觉损伤评分、地上部干质量以及再生能力。事实上，暴露于最高虫害水平10天的植物叶绿素损失达80.97%，比暴露5天的植物高出25%。损伤评分也随虫害水平增加而升高。在每株12只和18只成虫的水平下，损伤评分随暴露时间的增加而增加。暴露于24只昆虫10天的植物干质量含量较高，这表明沫蝉的侵害导致植物过早干枯。这些影响导致受侵染植物的分蘖数显著减少。我们的结果表明，暴露于壮观沫蝉成虫会造成显著损伤，并影响鲁齐紫黍植物的发育和存活。
