The extent of Chilades pandava Horsfield herbivory among 85 Cycadaceae species was determined by three evaluators in a common garden setting in Thailand to identify patterns that may improve horticultural and conservation management practices. The significant differences in herbivory damage from this invasive lepidopteran pest ranged 8.7-fold among the species. Phylogenetic sections of this monogeneric cycad family did not correspond to the relative differences among the species, and country of nativity was also not informative for this purpose. We suggest the Cycas L. species that share native habitat with this butterfly or the closely related Theclinesthes onycha Hewitson are among the least damaged taxa when they are comingled with other Cycas species in a common landscape. Grouping the most damaged Cycas species together in a managed landscape may reduce costs associated with plant protection. The inclusion of non-native Cycas plants in gardens nearby native Cycas habitats carries the potential of disrupting the delicate specialist relationship that native butterfly populations have with host Cycas species.
Thomas E. Marler, Anders J. Lindström and L. Irene Terry
Benjamin E. Deloso, Anders J. Lindström, Frank A. Camacho and Thomas E. Marler
The influences of indole-3-butyric acid (IBA) concentrations of 0–30 mg·g−1 on the success and speed of adventitious root development of Zamia furfuracea L.f. and Zamia integrifolia L.f. stem cuttings were determined. Root formation success for both species was greater than 95%. The IBA concentrations did not influence the speed of root development for Z. furfuracea, but the Z. integrifolia cuttings that received IBA concentration of 3 mg·g−1 generated adventitious roots more slowly than the cuttings in the control group. The ending dry weights of the stems, leaves, and roots were not influenced by IBA concentration for either species. Our results indicated that adventitious root formation on stem cuttings of these two Zamia species is successful without horticultural application of IBA. Additional IBA studies are needed on the other 300+ cycad species, especially those that are in a threatened category.