Telhado Cristina, Esteves Daniela, Cornelissen Tatiana, Fernandes G Wilson, Carneiro Marco Antonio A
Ecologia Evolutiva and Biodiversidade/DBG, ICB/Universidade Federal de Minas Gerais, Belo Horizonte MG, Brazil.
Environ Entomol. 2010 Jun;39(3):849-55. doi: 10.1603/EN09179.
Fluctuating asymmetry (FA) represents small, random variations from the symmetric bilateral pattern, and it is a frequently used measurement of plant and animal stresses. Some studies have shown a relationship between FA and herbivory, suggesting that FA might be a reliable indicator of plant quality and plant susceptibility to herbivore attack. In this study, we investigated the relationship between leaf FA of Coccoloba cereifera Schwacke (Polygonaceae) and the pattern of attack by the scale insect Abgrallaspis cyanophylly Signoret (Hemiptera: Diaspididae). Thirty individuals of C. cereifera were marked and followed during 2007 in southeastern Brazil, and all leaves of three shoots per plant were sampled, numbered, and categorized as young, mature, or senescent. We measured right and left widths of all leaves after digitizing the images to determine levels of FA for each leaf sampled per plant. Individuals of A. cyanophylli were counted using a stereoscope in the laboratory to determine infestation levels. Leaves of C. cereifera exhibited true patterns of FA, as shown by the normal distribution of asymmetry values. We observed high variation in attack rates by A. cyanophylly among C. cereifera individuals, with 43.3% of plants with no insects, whereas others exhibited up to 23,000 insects. No statistically significant relationship was observed between variation in FA and variation in A. cyanophylli among plants. These results suggest that FA cannot be used as an indicator of plant quality and susceptibility to herbivore attack but suggest that herbivores themselves might act as plant stressors.
波动不对称性（FA）代表了与对称双侧模式的微小随机变化，它是植物和动物应激常用的测量指标。一些研究表明FA与食草作用之间存在关联，这表明FA可能是植物质量和植物对食草动物攻击易感性的可靠指标。在本研究中，我们调查了巴西东南部Cerifera（蓼科）叶片的FA与盾蚧Abgrallaspis cyanophylly Signoret（半翅目：盾蚧科）的攻击模式之间的关系。2007年对巴西东南部30株Cerifera进行了标记并跟踪观察，对每株植物的三个枝条上的所有叶片进行采样、编号，并分类为嫩叶、成熟叶或衰老叶。在对图像进行数字化处理后，我们测量了所有叶片的左右宽度，以确定每株植物所采叶片的FA水平。在实验室中使用体视显微镜对cyanophylly的个体进行计数，以确定感染水平。Cerifera的叶片呈现出真正的FA模式，不对称值呈正态分布表明了这一点。我们观察到cyanophylly对Cerifera个体的攻击率差异很大，43.3%的植株没有昆虫，而其他植株上的昆虫数量高达23000只。在植物中，未观察到FA的变化与cyanophylly的变化之间存在统计学上的显著关系。这些结果表明，FA不能用作植物质量和对食草动物攻击易感性的指标，但表明食草动物本身可能是植物应激源。
