The objective of this study was to determine the effects of gall induction on leaf phenolic compounds and their indirect effects on the subsequent attack of folivorous insects inAchatocarpus gracilis,Cordia alliodora,Guapira macrocarpa,Guettarda ellipticaandRuprechtia fuscathat occur in both hillside and riparian sites at Chamela-Cuixmala tropical dry forest in western Mexico. There are differences in soil water content between riparian and hillside sites where trees in the first are mainly evergreen and deciduous in the second. A few tree species occur in both sites and their intraspecific phenological response is also different between sites. In this case, trees of a given species that occur in riparian sites will be evergreen whereas trees on hillsides of the same species will be deciduous. Four plant species had significantly greater total phenol concentrations in galled than ungalled leaves in both deciduous hillside and riparian sites. In three plant species associated with galls, host total phenol concentrations were significantly greater in short than in tall plants. The frequency and amount of folivore damage were greater in leaves without galls than leaves with galls in these four plant species. These results indicate that galling insect species may directly affect leaf phenolic concentrations and indirectly may affect the incidence and consumption of folivorous insects in tropical plant species. This may have important consequences on the preference of leaves by folivorous insects that might be excluded by galling insect species in this dry tropical system.

Leaf fluctuating asymmetry (FA) is considered an important indicator of environmentally induced stress in plants, but the relationship between herbivory and FA levels is not clear. In this study we compared leaf size and shape, leaf area consumed by herbivorous insects, and FA levels between individuals of Heliocarpus pallidus (Tiliaceae) from two adjacent and contrasting habitat types (deciduous and riparian) in the Chamela–Cuixmala tropical dry-forest biosphere reserve. Ten individuals of H. pallidus were collected in each habitat type. Leaf shape was assessed using geometric morphometric techniques. Results indicated statistically significant differences in leaf shape between individuals from the two habitat types. In individuals from the riparian habitat leaf area (mean = 42.3 ± 1.2 cm2), herbivory levels (mean = 25.5% ± 1.8%) and FA levels (mean = 0.38 ± 0.04 cm) were significantly higher than in individuals from the deciduous habitat (17.2 ± 3.5 cm2; 9.6% ± 1.0% and 0.18 ± 0.04 cm, respectively). Within habitats, significant correlations were found between total leaf area and percentage leaf area removed by insects (R2 = 0.92 in riparian habitats, R2 = 0.9 in deciduous habitats), and between percentage leaf area removed and FA (R2 = 0.70 in riparian habitats, R2 = 0.79 in deciduous habitats). As has been suggested for other plant species, it is possible that the more favourable conditions in the riparian habitat enhance leaf growth, resulting in higher FA. Also, individuals in this habitat might be characterized by lower chemical defence and/or higher nutritional quality, which would explain the higher herbivory levels.