Insect Herbivores ofCoccoloba cereiferaDo Not Select Asymmetric Plants

Abstract

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.

Fluctuating asymmetry and herbivory in two ontogenetical stages ofChamaecrista semaphorain restored and natural environments

“…However, the relationship between FA and herbivory is not clear in the literature. While some studies show positive relationships (Møller 1995(Møller , 1996 2003; Stiling 2011, 2005), others show no relationship (Ban˜uelos et al 2004;Dı´az et al 2004;Telhado et al 2010). Differences in plant chemistry, plant age, environmental conditions, and enemy free-space have been suggested as possible causes for these differences (Lempa et al 2000;Cornelissen et al 2003;Ban˜uelos et al 2004;Cornelissen and Stiling 2005;Cuevas-Reyes et al 2011a, 2011b.…”

“…Therefore, FA reflects developmental instability during ontogenetic stages as a result of environmental disturbances and hence has been considered a reliable indicator of environmentally induced stress in different taxa (Wauters et al 1996;Anciles and Marini 2000;Leamy and Klingenberg 2005;Hagen et al 2008;Cornelissen and Stiling 2011). In plants, some studies indicated higher levels of FA in disturbed habitats, pollution, urbanization, climate changes, parasitism, and herbivore pressure (Chistyakova and Kryazheva 2001;Stiling 2005, 2011;Cuevas-Reyes et al 2011a, 2011b; but see Telhado et al 2010). Plants respond to herbivore damage in different ways (Cuevas-Reyes et al 2004), one is altering the developmental instability of leaves during ontogenetic stages (Dı´az et al 2004).…”

“…In some studies, leaf FA is positively related with the levels of herbivory suggesting that leaf FA serves as an indicator of plant stress as result of herbivore attack (e.g. Lempa et al 2000;Cuevas-Reyes et al 2011a), while in other studies no relationship has been found (Ban˜uelos et al 2004;Dı´az et al 2004;Telhado et al 2010). Differences in environmental conditions, enemy-free space, plant chemistry, and plant age have been suggested as possible causes for these differences (Ban˜uelos et al 2004;Cornelissen and Stiling 2005;Cornelissen et al 2003;Lempa et al 2000).…”

Relationship between gall-midge parasitism, plant vigor, and developmental instability in Ouratea polygyna Engl (Ochnaceae) in a patch of a Brazilian Atlantic Forest

“…Once established in leaves, galls can alter leaf development (Souza et al 2000) and cause asymmetries and distortions (Santos et al 2013). Studies focusing on the influence of galls on leaf bilateral symmetry show unclear relationships between leaf asymmetry and galls (see Telhado et al 2010;Alves-Silva 2012). Differences in leaf morphometry between galled and ungalled leaves may indicate that besides causing changes in leaf development (Santos et al 2013), galls also affect leaf symmetry, which may compromise plant fitness (Venâncio et al 2014).…”

“…Nonetheless, DA is presumed to occur in populations that experience high levels of stress; Lens & Dongen (2000) showed that FA was common under low levels of habitat disturbance, but DA prevailed under elevated perturbation levels. The consideration of how galls stimulate or elicit changes in leaf shape is a cornerstone of gall-host interactions (Cornelissen & Stiling 2005;Telhado et al 2010), since changes in leaf shape because of parasitism are usually associated with low fitness of the host (Fay et al 1996). Furthermore, since galls are leaf parasites, their presence and abundance are assumed to decrease plant vigor and fitness (Sacchi et al 1988;Hartley 1998).…”