Lantana camara Linn. (Verbenaceae)

Lantana is a serious problem in several tropical and sub-tropical areas around the world. It is a Weed of National Significance in Australia where it costs the grazing industry alone over $104 million per annum. The chapter summarises current knowledge about the taxonomy, biology, distribution, ecology, impacts and biological control of the weed worldwide. Attempts to achieve biological control of lantana date back to 1902 making this weed one of our oldest targets. Although control has been achieved in some areas of the world, in many other areas control is still sub-optimum. Factors thought to contribute to the difficulty of achieving biocontrol include the plant's biology, the wide genetic variation associated with hundreds of varieties or biotypes and the wide range of climatic habitats associated with the weed. This chapter provides a good summary of the present day position.

Biology and host range of Ophiomyia camarae Spencer (Diptera: Agromyzidae), a potential biocontrol agent for Lantana spp. (Verbenaceae) in Australia

The life history and host range of the herringbone leaf-mining fly Ophiomyia camarae, a potential biological control agent for Lantana spp., were investigated. Eggs were deposited singly on the underside of leaves. Although several eggs can be laid on a single leaf and a maximum of three individual mines were seen on a single leaf, only one pupa per leaf ever developed. The generation time (egg to adult) was about 38 days. Females (mean 14 days) lived longer than males (mean 9 days) and produced about 61 mines. Oviposition and larval development occurred on all five lantana phenotypes tested. Eleven plant species representing six families were tested to determine the host range. Oviposition and larval development occurred on only lantana and another nonnative plant Lippia alba (Verbenaceae), with both species supporting populations over several generations. A CLIMEX model showed that most of the coastal areas of eastern Australia south to 30°16' S (Coffs Harbour) would be suitable for O. camarae. O. camarae was approved for release in Australia in October 2007 and mines have been observed on plants at numerous field sites along the coast following releases.

Prospects for the biological control of Lantana camara (Verbenaceae) in New Zealand

Lantana camara is an environmental weed in the northern North Island of New Zealand. It is an increasingly observed problem in forest margins, coastal scrublands, dunes, plantations and island habitats, and its rapid, uncontrolled growth can create dense impenetrable thickets, suppressing vegetation and bush regeneration. Biological control options are being considered for its management. A strain of the Brazilian rust Prospodium tuberculatum was released against lantana in Australia in 2001. This rust was screened against invasive forms of the weed that occur in New Zealand and was found to be pathogenic under glasshouse conditions. A survey found no evidence that the rust occurs in New Zealand. It is concluded that P. tuberculatum is potentially a suitable agent for the biocontrol of lantana in New Zealand and further research should be carried out prior to importation of the organism.

Lantana camara L. (Verbenaceae) invasion effects on soil physicochemical properties

Lantana camara is a recognized weed of worldwide significance due to its extensive distribution and its impacts on primary industries and nature conservation. However, quantitative data on the impact of the weed on soil ecosystem properties are scanty, especially in SE Australia, despite the pervasive presence of the weed along its coastal and inland regions. Consequently, mineral soils for physicochemical analyses were collected beneath and away from L. camara infestations in four sites west of Brisbane, SE Australia. These sites (hoop pine plantation, cattle farm, and two eucalyptus forests with occasional grazing and a fire regime, respectively) vary in landscape and land-use types. Significant site effect was more frequently observed than effect due to invasion status. Nonetheless, after controlling for site differences, ~50% of the 23 soil traits examined differed significantly between infested and non-infested soils. Moisture, pH, Ca, total and organic C, and total N (but not exchangeable N in form of NO3-) were significantly elevated, while sodium, chloride, copper, iron, sulfur, and manganese, many of which can be toxic to plant growth if present in excess levels, were present at lower levels in soils supporting L. camara compared to soils lacking the weed. These results indicate that L. camara can improve soil fertility and influence nutrient cycling, making the substratum ideal for its own growth and might explain the ability of the weed to outcompete other species, especially native ones.

Life history and host range of Alagoasa extrema (Coleoptera: Chrysomelidae: Alticinae), a potential biological control agent of Lantana spp. (Verbenaceae) in Australia

The life history and host range of the lantana beetle, Alagoasa extrema, a potential biocontrol agent for Lantana spp. were investigated in a quarantine unit at the Alan Fletcher Research Station, Brisbane, Australia. Adults feed on leaves and females lay batches of about 17 eggs on the soil surface around the stems of plants. The eggs take 16 days to hatch and newly emerged larvae move up the stem to feed on young leaves. Larvae feed for about 23 days and there are three instars. There is a prepupal non-feeding stage that lasts about 12 days and the pupal stage, which occurs in a cocoon in the soil, lasts 16 days. Teneral adults remain in the cocoon for 3 days to harden prior to emergence. Males live for about 151 days while females live for about 127 days. The pre-oviposition period is 19 days. In no-choice larval feeding trials, nine plant species, representing three families, supported development to adult. Three species, Aloysia triphylla, Citharexylum spinosum and Pandorea pandorana were able to support at least two successive generations. These results confirm those reported in South Africa and suggest that A. extrema is not sufficiently specific for release in Australia. Furthermore, it is not recommended for release in any other country which is considering biological control of lantana.

Modeling population growth and site specific control of the invasive Lantana camara L. (Verbenaceae) under differing fire regimes

It is at the population level that an invasion either fails or succeeds. Lantana camara L. (Verbenaceae) is a weed of great significance in Queensland Australia and globally but its whole life-history ecology is poorly known. Here we used 3 years of field data across four land use types (farm, hoop pine plantation and two open eucalyptus forests, including one with a triennial fire regime) to parameterise the weed’s vital rates and develop size-structured matrix models. Lantana camara in its re-colonization phase, as observed in the recently cleared hoop pine plantation, was projected to increase more rapidly (annual growth rate, λ = 3.80) than at the other three sites (λ 1.88–2.71). Elasticity analyses indicated that growth contributed more (64.6 %) to λ than fecundity (18.5 %) or survival (15.5 %), while across size groups, the contribution was of the order: juvenile (19–27 %) ≥ seed (17–28 %) ≥ seedling (16–25 %) > small adult (4–26 %) ≥ medium adult (7–20 %) > large adult (0–20 %). From a control perspective it is difficult to determine a single weak point in the life cycle of lantana that might be exploited to reduce growth below a sustaining rate. The triennial fire regime applied did not alter the population elasticity structure nor resulted in local control of the weed. However, simulations showed that, except for the farm population, periodic burning could work within 4–10 years for control of the weed, but fire frequency should increase to at least once every 2 years. For the farm, site-specific control may be achieved by 15 years if the biennial fire frequency is tempered with increased burning intensity.

Patterns of seed bank and size asymmetry of plant growth across varying sites in the invasive Lantana camara L. (Verbenaceae)

Lantana camara L. (Verbenaceae) is a weed of great significance in Australia and worldwide, but little is known about connections among components of its life history. We document over a 3-year period, the links between L. camara seed-bank dynamics and its above-ground growth, including size asymmetry in four land-use types (a farm, a hoop pine plantation and two open eucalypt forests) invaded by the weed near Brisbane, Queensland Australia. Seed-bank populations varied appreciably across sites and in response to rainfall and control measures, and they were higher (~1,000 seeds/m2) when annual rainfall was 15-30 % below the long-term yearly average. Fire reduced seed-bank populations but not the proportion germinating (6-8 %). Nearly a quarter of fresh seeds remain germinable after 3 years of soil burial. For small seedlings (<10 cm high), the expected trade-offs in two life-history traits-survival and growth-did not apply; rather the observed positive association between these two traits, coupled with a persistent seed-bank population could contribute to the invasiveness of the plant. Relationships between absolute growth rate and initial plant size (crown volume) were positively linear, suggesting that most populations are still at varying stages of the exponential phase of the sigmoid growth; this trend also suggests that at most sites and despite increasing stand density and limiting environmental resources of light and soil moisture, lantana growth is inversely size asymmetric. From the observed changes in measures of plant size inequality, asymmetric competition appeared limited in all the infestations surveyed. © 2013 Crown Copyright as represented by: Department of Agriculture, Fisheries and Forestry, Australia.

Long-Term Environmental Correlates of Invasion by Lantana camara (Verbenaceae) in a Seasonally Dry Tropical Forest

Invasive species, local plant communities and invaded ecosystems change over space and time. Quantifying this change may lead to a better understanding of the ecology and the effective management of invasive species. We used data on density of the highly invasive shrub Lantana camara (lantana) for the period 1990-2008 from a 50 ha permanent plot in a seasonally dry tropical forest of Mudumalai in southern India. We used a cumulative link mixed-effects regression approach to model the transition of lantana from one qualitative density state to another as a function of biotic factors such as indicators of competition from local species (lantana itself, perennial grasses, invasive Chromolaena odorata, the native shrub Helicteres isora and basal area of native trees) and abiotic factors such as fire frequency, inter-annual variability of rainfall and relative soil moisture. The density of lantana increased substantially during the study period. Lantana density was negatively associated with the density of H. isora, positively associated with basal area of native trees, but not affected by the presence of grasses or other invasive species. In the absence of fire, lantana density increased with increasing rainfall. When fires occurred, transitions to higher densities occurred at low rainfall values. In drier regions, lantana changed from low to high density as rainfall increased while in wetter regions of the plot, lantana persisted in the dense category irrespective of rainfall. Lantana seems to effectively utilize resources distributed in space and time to its advantage, thus outcompeting local species and maintaining a population that is not yet self-limiting. High-risk areas and years could potentially be identified based on inferences from this study for facilitating management of lantana in tropical dry forests.

Lantana camara L. (Verbenaceae) invasion along streams in a heterogeneous landscape

Streams are periodically disturbed due to flooding, act as edges between habitats and also facilitate the dispersal of propagules, thus being potentially more vulnerable to invasions than adjoining regions. We used a landscape-wide transect-based sampling strategy and a mixed effects modelling approach to understand the effects of distance from stream, a rainfall gradient, light availability and fire history on the distribution of the invasive shrub Lantana camara L.(lantana) in the tropical dry forests of Mudumalai in southern India. The area occupied by lantana thickets and lantana stem abundance were both found to be highest closest to streams across this landscape with a rainfall gradient. There was no advantage in terms of increased abundance or area occupied by lantana when it grew closer to streams in drier areas as compared to moister areas. On an average, the area covered by lantana increased with increasing annual rainfall. Areas that experienced greater number of fires during 1989-2010 had lower lantana stem abundance irrespective of distance from streams. In this landscape, total light availability did not affect lantana abundance. Understanding the spatially variable environmental factors in a heterogeneous landscape influencing the distribution of lantana would aid in making informed management decisions at this scale.

Anatomia comparada do lenho em raiz e caule de Lippia salviifolia Cham. (Verbenaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Zinc iodide-osmium tetroxide (ZIO) reactive sites in the extrafloral nectary of Citharexylum mirianthum Cham. (Verbenaceae)

This paper reports on a study of the zinc iodide-osmium tetroxide method (ZIO) applicability to formaldehyde-glutaraldehyde prefixed extrafloral nectary tissues of Citharexylum mirianthum Cham. (Verbenaceae). The ZIO solution impregnates the dictyosome stacks and adjacent vesicles, smooth endoplasmic reticulum, nuclear envelope, multivesicular bodies, and peroxisomes. The use of this method greatly facilitates the observation and recognition of organelles in each nectary region. it also allows the correlation between structure and function in nectariferous cells. (C) 2001 Harcourt Publishers Ltd.

Chemical and antifungal investigations of six Lippia species (Verbenaceae) from Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Composição química de Aegiphila sellowiana Cham. (Verbenaceae)

Este trabalho contribui para a caracterização química de Aegiphila sellowiana Cham. (Verbenaceae). As partes aéreas da planta foram extraídas corn solventes orgânicos e fracionadas cromatograficamente. As frações resultantes foram analisadas por rnétodos espectrométricos, fornecendo hidrocarbonetos alifáticos lineares, estigmasterol, α-amirina e o verbascosideo.