In order to further our understanding of the habitat requirements an endangered butterfly, I undertook a study to determine the spatial patterning of a Rutaceous tree with a neotropical distribution. Torchwood, Amyris elemifera L., is considered to be the primary larval food plant of an endangered butterfly subspecies with an Antillean distribution, the Schaus swallowtail, Heraclides (=Papilio) aristodemus ponceanus . Patchiness in plant communities can provide the underlying habitat structure for a specialist herbivore on both a landscape and population level. Determining the scale of the spatial patterning for torchwood can aid us in determining the minimum scale at which models of the butterfly's habitat must be based, as well as providing a cell size for multivariate models of both butterfly and host plant habitat. Two term local quadrat variance (TTLQV) as described by Dale (1999) in Spatial Pattern Analysis in Plant Ecology was used to address the question, at what scale(s) is torchwood aggregated in the tropical hardwood hammocks of south Florida? The unit measured was contiguous 5 meter square quadrats. The data recorded is mapped locations of stems at each of two life stages, seedlings (< breast height) and reproductive individuals (>breast height). In TTLQV, the average squared difference between a block and the adjacent block is calculated for a range of block sizes, b . Peaks in the plot of the variance, V3 (b) against block size are indicative of scales at which the species is aggregated. Preliminary results collected in Crocodile Lakes National Wildlife Refuge, North Key Largo Florida, indicate that Amyris elemifera is strongly aggregated at distances between 20 and 25 meters.

Key words: Amyris elemifera , spatial pattern analysis, specialist herbivore, Torchwood, tropical dry forest, two term local quadrat variance