Gall-inducing insects have long been known to exhibit a high degree of host-plant specificity. Data was collected from six oak species at the Archbold Biological Station on the lake Wales Ridge of central Florida. The results indicate that the host-plant associations of cynipid gall-inducing insects are highly specific, host-plant chemistries that vary significantly across oak species, and host-plant chemistry is correlated with the distribution of cynipid species.
The isolation of this compound from Lindera was shown to be identical with those previously isolated from the fern Pityogramma and from Pinus clausa.
The allelopathic effect of Calamintha ashei’s above ground biomass (i.e., stems and litter) on native scrub species was tested in the field. Above ground biomass was removed from plots and replaced with activated carbon to neutralize allelochemicals. The C. ashei removal treatments did not yield any significant increases in the germination of other species from native or disturbed sites. A field and laboratory study involving direct application of leachates and the manipulation of water and other resources may be useful to determine if the affect on other species is via competition for resources or allelopathic chemicals.
Analyses of leaf extracts from Dicerandra frutescens, (a highly aromatic mint plant from scrub community in Central Florida), revealed presence of 12 closely related monoterpenes. The terpenes produced serve for defense against insects, and are also released when the leaf is injured.
Soil physical and chemical properties, plus foliar elemental concentrations, are reported for surface and subsurface soil and foliar tissue samples from 20 sand pine populations, 9 from the Choctwhatchee variety in the Florida panhandle and 11 from the Ocala variety. Foliar elemental concentrations did not reflect soil elemental patterns.
The hypothesis was tested that allelopathic agents released from fire-sensitive plants of the Florida scrub community deter the invasion of fire-prone sandhill grasses.
The hypothesis that allelochemicals released from members of the Florida scrub community deter the invasion of fire-prone sandhill grasses was investigated. Constituents of the endemic scrub members, Ceratiola ericoides, Conradina canescens and Calamintha ashei, were examined for their phytotoxic activity. Effects of the plant natural products on the germination and radicle growth of lettuce (Lactuca sativa), as well as little bluestem (Schizachyrium scoparium) and green sprangletop (Leptochloa dubia), two native grasses of the Florida sandhill community, were tested.
The hypothesis that allelochemicals released from members of the Florida scrub community deter the invasion of fire-prone sandhill grasses was investigated. The germination and growth of grasses is reduced in soils from beneath the scrub perennial, Polygonella myriophylla (Small) Horton, supporting the hypothesis that this shrub chemically interferes with the growth of other species.
A review of the allelopathic properties of several shrub species from the scrub and how the delivery and activation mechanisms of phytotoxins may be useful for herbicide applications.
Discusses the phytotoxic properties of chemicals from Ceratiola and several mint species found in the sand pine scrub.