Success and safety in the biological control of environmental weeds in New Zealand

Biological control, using specialist insect herbivores and plant pathogens, can be a self‐sustaining, cost‐effective and low‐risk tool for the management of environmental weeds. Agents have been recorded attacking non‐target plants in New Zealand and elsewhere, but the effects are usually minor and/or transitory. It seems probable that only two cases, worldwide, will result in significant damage to non‐target plants (representing 0.5% of the nearly 400 insect, mite, or fungal species used in classical weed biocontrol). Both of these cases were predictable from host range testing. Negative indirect, or ‘downstream’, ecological effects from specific weed biocontrol agents are difficult to predict and measure. They are probably insignificant compared to the impacts of the invasive plants that the agents are introduced to control. However, it is necessary to balance the risks associated with any introduction against the environmental benefits from controlling a weed to a predicted level. Recent analyses suggest that success rates are better than generally perceived. For New Zealand programmes, where enough time has lapsed to allow assessment, we calculate a full/partial success rate of 83%. Many of the costs associated with environmental weeds are difficult to quantify. Detailed risk assessment will make biological control programmes more expensive and time‐consuming, so that reliance on non‐biological management methods for environmental weeds may actually increase. The costs of biocontrol programmes against some New Zealand weeds can be kept down by using research already carried out in Australia and other countries, and the process is reciprocal. Developing international consortia of sponsors is also a potential way to fund programmes against weeds shared by several countries.     

Micell-mediated extraction for the spectrophotometric determination of nitrite in water and biological samples based on its reaction with p-nitroaniline in the presence of diphenylamine

A cloud point extraction process using the nonionic surfactant Triton X-100 to extract nitrite from aqueous solution was investigated. The method is based on the color reaction of nitrite with p-nitroaniline in the presence of diphenylamine in acid media and micell-mediated extraction of an azo product. The optimal extraction and reaction conditions (e.g., acid concentration, reagent concentration, effect of time) were studied, and the analytical characteristics of the method (e.g., limit of detection, linear range, molar absorptivity, preconcentration, and improvement factors) were obtained. Linearity was obeyed in the range of 2-40 ng ml(-1) of nitrite ion. The detection limit of the method is 0.87 ng ml(-1) of nitrite ion. The interference effect of some anions and cations was also tested. The method was applied to the determination of nitrite in tap water, waste water, and human urine samples.     

A comparison of attack rates in a native and an introduced population of the parasitoid Cotesia glomerata

The attack rate of a population of the braconid parasitoid Cotesia glomerata, introduced into the USA over 100 years ago as a parasitoid of Pieris rapae, was compared with that of a native British population, which normally attacks P. brassicae, and with that of a P. rapae specialist, Cotesia rubecula. British C. glomerata attacked P. brassicae at a much higher rate than it attacked P. rapae. In comparison with British C. glomerata, C. rubecula showed a higher attack rate with P. rapae. American C. glomerata attacked P. rapae at a slightly higher rate than did British C. glomerata, but not at as high a rate as that achieved by C. rubecula. The differences in each comparison were statistically significant. The possible causes of the differences between British and American C. glomerata attacking P. rapae are discussed. They may be due to genetic or environmental effects. Egg load did not appear to be a factor limiting the number of hosts parasitized under the conditions of the experiments.     

A comparison of two methods for prediction of response and rates of inbreeding in selected populations with the results obtained in two selection experiments

Selection programmes are mainly concerned with increasing genetic gain. However, short-term progress should not be obtained at the expense of the within-population genetic variability. Different prediction models for the evolution within a small population of the genetic mean of a selected trait, its genetic variance and its inbreeding have been developed but have mainly been validated through Monte Carlo simulation studies. The purpose of this study was to compare theoretical predictions to experimental results. Two deterministic methods were considered, both grounded on a polygenic additive model. Differences between theoretical predictions and experimental results arise from differences between the true and the assumed genetic model, and from mathematical simplifications applied in the prediction methods. Two sets of experimental lines of chickens were used in this study: the Dutch lines undergoing true truncation mass selection, the other lines (French) undergoing mass selection with a restriction on the representation of the different families. This study confirmed, on an experimental basis, that modelling is an efficient approach to make useful predictions of the evolution of selected populations although the basic assumptions considered in the models (polygenic additive model, normality of the distribution, base population at the equilibrium, etc.) are not met in reality. The two deterministic methods compared yielded results that were close to those observed in real data, especially when the selection scheme followed the rules of strict mass selection: for instance, both predictions overestimated the genetic gain in the French experiment, whereas both predictions were close to the observed values in the Dutch experiment.     

Development of a validated HPLC method for the determination of iodotyrosines and iodothyronines in pharmaceuticals and biological samples using solid phase extraction

Identification, separation and quantitation of iodoaminoacids, is essential for the biological research and the clinical diagnosis of thyroid gland disease. Under this aspect a reversed-phase high-performance liquid chromatographic method was developed for the determination of thyroid gland hormones and some of their primary metabolites, 3,3',5,5'-tetra-iodo-L-thyronine (L-thyroxine), 3,3',5-tri-iodo-L-thyronine, 3,5-di-iodo-L-thyronine, L-thyronine, 3,5-di-iodo-L-tyrosine, 3-iodo-L-tyrosine and l-tyrosine. Analysis was performed on an Inertsil C(18) column with photodiode-array detection, using a 25 min gradient scale program of a binary mobile phase consisted of 0.1% aqueous solution of trifluoroacetic acid at pH 3 as solvent A and acetonitrile as solvent B, at a flow rate of 1 mL/min. Quantitation was performed using were obtained using theophylline as internal standard. The method was applied to commercial pharmaceuticals and biological samples (serum, urine and tissue). Drug-free urine and serum samples were spiked with known concentrations of the analytes standards and pretreated by solid phase extraction to remove matrix interferences. C(18) cartridges were used, yielding recoveries ranging from 87.1% to 107.6% for serum samples and from 92.1% to 98.7% for urine samples. With regard to total-T(4) concentrations in serum samples, results are cross-validated with RIA and found to agree well.     

Cloud point formation based on mixed micelle in the presence of electrolyte for extraction, preconcentration, and spectrophotometric determination of trace amounts of hydrazine in water and biological samples

A cloud point extraction process using mixed micelle of the anionic surfactant sodium dodecyl sulfate and the nonionic surfactant Triton X-114 to extract hydrazine from aqueous solutions was investigated. The method is based on the condensation reaction of hydrazine with p-(dimethylamino)benzaldehyde, azine formation, and mixed micelle-mediated extraction of azine in the presence of NaCl electrolyte as an inducing phase separation. An azine product was concentrated in surfactant-rich phase after separation. The optimal extraction and reaction conditions (e.g., surfactant, reagent and electrolyte concentrations, and centrifuge time) were studied and the analytical characteristics of the method (e.g., limit of detection, linear range, preconcentration, and improvement factors) were obtained. Linearity was obeyed in the range of 0.50-110ngml(-1) of hydrazine and the detection limit of the method is 0.08ngml(-1). The interference effect of some cations, anions, and organic compounds was also tested. The method was successfully applied to the determination of hydrazine in water and biological samples.     

A call for more transparent reporting of error rates: the quality of AFLP data in ecological and evolutionary research

Despite much discussion of the importance of quantifying and reporting genotyping error in molecular studies, it is still not standard practice in the literature. This is particularly a concern for amplified fragment length polymorphism (AFLP) studies, where differences in laboratory, peak‐calling and locus‐selection protocols can generate data sets varying widely in genotyping error rate, the number of loci used and potentially estimates of genetic diversity or differentiation. In our experience, papers rarely provide adequate information on AFLP reproducibility, making meaningful comparisons among studies difficult. To quantify the extent of this problem, we reviewed the current molecular ecology literature (470 recent AFLP articles) to determine the proportion of studies that report an error rate and follow established guidelines for assessing error. Fifty‐four per cent of recent articles do not report any assessment of data set reproducibility. Of those studies that do claim to have assessed reproducibility, the majority (~90%) either do not report a specific error rate or do not provide sufficient details to allow the reader to judge whether error was assessed correctly. Even of the papers that do report an error rate and provide details, many (≥23%) do not follow recommended standards for quantifying error. These issues also exist for other marker types such as microsatellites, and next‐generation sequencing techniques, particularly those which use restriction enzymes for fragment generation. Therefore, we urge all researchers conducting genotyping studies to estimate and more transparently report genotyping error using existing guidelines and encourage journals to enforce stricter standards for the publication of genotyping studies.     

Analysis of importations for biological control of insect pests and weeds in New Zealand

Importations of biological control agents for insect pests and weeds in New Zealand are summarized and factors contributing to the relative success of the programmes are examined. The establishment rate of 30.9% is similar to that achieved worldwide, but is significantly lower than the rate achieved in the island habitat of Hawaii. The pioneering role of New Zealand in biological control is shown by the high proportion of programmes first attempted in this country. Although this novelty has not reduced the establishment rate, introductions against endemic species have not succeeded. Size of release was not a dominant feature in the establishment of agents. Complete or substantial success is recorded for 17 of the 70 target pests, with a relatively high success rate in forestry programmes. Examples of the influence of climate matching and competitive exclusion are also discussed. Changing practices and attitudes to the introduction of biological control agents are documented to show the increasing emphasis on specialists. No adverse effects of introductions are reported. The challenge to practitioners and regulators is to develop systems to evaluate conflicts of interest and develop workable mechanisms to determine which biological control agents are suitable for release.     

Implications of collection patterns of botanical specimens on their usefulness for conservation planning: an example of two neotropical plant families (Moraceae and Myristicaceae) in Peru

We evaluated the usefulness of herbarium collection databases for assessing patterns of species diversity and distribution based on a dataset from the flowering plant families Moraceae and Myristicaceae from the Peruvian Amazon. For Moraceae, a total of 3523 collections were used representing 134 species. The Myristicaceae were represented by 2113 collections of 46 species. We evaluated the distribution of collections based on 252 grid cells (0.5° size) covering all lowland rainforest in the Peruvian Amazon. We found that collections were concentrated in a few cells and that species diversity clearly increases in relation to collection density. Moraceae were collected in only 45% and Myristicaceae in only 31% of the 252 grid cells. Fifty percent of the collections came from just six and three cells, respectively. Most species were represented by only a small number of collections and collected only in a few grid cells, meaning a few widespread common species tend to dominate the collection records. Not surprisingly, most collections were made close to towns and transport routes. We evaluated the usefulness of rarefaction curves and diversity estimators for comparing diversity between regions. These techniques seem to be of little use for botanical collections due to violations of underlying assumptions. Problems such as accuracy of geographic and taxonomic data and strong bias in the spatial representation of the whole dataset are important to consider when basing conservation analysis, planning, and decision-making on seemingly large databases of biodiversity collections and are discussed in detail.     

Evolution of natural history information in the 21st century – developing an integrated framework for biological and geographical data

Threats to marine and estuarine species operate over many spatial scales, from nutrient enrichment at the watershed/estuarine scale to invasive species and climate change at regional and global scales. To help address research questions across these scales, we provide here a standardized framework for a biogeographical information system containing queriable biological data that allows extraction of information on multiple species, across a variety of spatial scales based on species distributions, natural history attributes and habitat requirements. As scientists shift from research on localized impacts on individual species to regional and global scale threats, macroecological approaches of studying multiple species over broad geographical areas are becoming increasingly important. The standardized framework described here for capturing and integrating biological and geographical data is a critical first step towards addressing these macroecological questions and we urge organizations capturing biogeoinformatics data to consider adopting this framework.     

Host range testing and life history of the defoliator Hymenomima nr. memor: an unsuitable biological control agent for Schinus terebinthifolia in the U.S.A.

Host range of larvae of Hymenomima nr. memor (Lepidoptera: Geometridae) was examined in quarantine to evaluate its suitability as a biological control of Brazilian peppertree, Schinus terebinthifolia. Brazilian peppertree, S. terebinthifolia is an environmental and agricultural weed from South America that had invaded many subtropical and tropical areas of the world including Florida and Hawaii, USA. Laboratory life history and quarantine host range studies of H. memor were conducted with no-choice feeding tests. These tests included eight species of the Anacardiaceae and one species of Sapindaceae. Larvae of H. memor had five to six instars with each head capsule width increasing by 1.68-X. Development time from neonate to adult was 46.7?±?2.2 days. In host range tests, neonates completed development to the adult stage on all non-target species, except Toxicodendron radicans. Moreover, developmental times were delayed and pupal weights were reduced for larvae fed Spondias purpurea leaves. Due to the broad host range exhibited by H. memor larvae, this species will not be considered as a biological control agent of S. terebinthifolia in the continental U.S.A.     

Implications of the UNCLOS Marine Scientific Research Regime for the Current Negotiations on Access and Benefit Sharing of Marine Genetic Resources in Areas Beyond National Jurisdiction

Abstract

Access to marine genetic resources (MGRs) in areas beyond national jurisdiction (ABNJ) and the sharing of benefits arising out of the utilization of these resources are among the most contentious at the UN Intergovernmental Conference on Marine Biodiversity of Areas Beyond National Jurisdiction. This article examines the applicability of the marine scientific research (MSR) regime of the UN Convention on the Law of the Sea (UNCLOS) to the access and benefit-sharing issues. It concludes that the MSR regime of UNCLOS provides the legal basis for setting up nonmonetary-benefit sharing obligations, including the dissemination of information, data, and research results concerning MGRs at the UN negotiations on marine biodiversity in the ABNJ.     

Short-distance dispersal behavior and establishment of the parasitoid Gonatocerus ashmeadi (Hymenoptera: Mymaridae) in Tahiti: Implications for its use as a biological control agent against Homalodisca vitripennis (Hemiptera: Cicadellidae)

The egg parasitoid Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae), was introduced into French Polynesia as a biological control agent to control the invasive plant feeding pest Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae). The short-distance dispersal of G. ashmeadi was monitored as part of the biological control program. G. ashmeadi showed exponential dispersal capacity with 47 m/day being a minimum estimate of its natural rate of spread at high host densities (>150 nymphs per minute of sweep net sampling) in urbanized areas at sea level, which were characterized by a high diversity of exotic ornamental plants. This rate of spread contrasted starkly with almost nonexistent establishment and dispersal where host densities were very low (<2 nymphs per minute of sweep net sampling) at high elevation (800 m) with relatively undisturbed native vegetation. Survey results across different altitudes revealed an effect of vegetative diversity and host density on the measurable mobility and establishment of G. ashmeadi. In contrast, no significant influence of wind direction was found on G. ashmeadi dispersal rate or direction. Survey results for G. ashmeadi from French Polynesia suggest that the best release establishment strategies for classical biological control of H. vitripennis are: (1) many small releases where host density is high, or (2) larger and fewer releases where host densities are low.