The paper presents a model for quantifying quarantine-related trade barriers by combining the two basiccomponents of pest risk assessment, probability of establishment and economic effects, into a singlemanagement framework, Iso-Risk. The model provides a systematic and objective basis for defining andmeasuring acceptable risk and for justifying quarantine actions relative to acceptable risk.

A survey of the floors of 3001 empty sea cargo containers in storage was undertaken to estimate the quarantine risk of importing exotic insect pests into Australia, with special reference to pests of timber. More than 7400 live and dead insects were collected from 1174 containers. No live infestations of timber-feeding insects were recorded, but feeding damage detected in one floor indicates a low risk of importing colonies of timber pests in containers. The survey collection of dead insects demonstrates that containers are regularly exposed to economically important quarantinable insects, including timber pests (bostrichids, curculionids, cerambycids, siricids and termites), agricultural pests (including Adoretus sinicus, Adoretus sp., Carpophilus obsoletus and Philaenus spumarius), and nuisance pests (vespids and Solenopsis sp.). Stored product pests were found in more than 10% of containers. The assessment of pest risk associated with shipping containers is discussed in terms of the quantity and quality of opportunities for exotic insects to establish via this pathway.

In the context of the ongoing expansion of forest plantations of exotic tree species in the tropics, a critical assessment was made of the risk of insect pest outbreaks in exotics. To date, there have been two opposing views: that plantations of exotic species are at greater risk compared to indigenous species and conversely, that exotics are at lesser risk. Both views rest on theoretical arguments. In this study, an empirical approach was used to address the issue. For nine most commonly planted species in the tropics, the pest problems in natural forest stands, in countries in which the species are indigenous (native plantations), and in exotic plantations were compared. The species chosen were Acacia mangium, Eucalyptus spp., Gmelina arborea, Hevea brasiliensis, Leucaena leucocephala, Paraserianthes falcataria, Pinus caribaea, Swietenia macrophylla and Tectona grandis. The results showed that: (1) monoculture itself caused an increase in the pest problems; and (2) the pest risk of exotics was variable, for some species similar to that of native plantations, while greater or lesser for others. The risk of pest outbreak is therefore not solely dependent on the exotic or indigenous status of a species. Empirical results also showed that pest outbreaks occurred in native plantations. The theory relating to insect population dynamics and causes of pest outbreaks is discussed and based on a mix of empirical evidence and theory. It is concluded that the following factors determine the risk of pest outbreak in exotic monoculture plantations: (1) presence or absence of plant species closely related to the exotic; (2) extent of area under the exotic species; (3) genetic base of the planted stock; (4) distance from the native habitat of the exotic; (5) existence of serious pests in the native habitat of the exotic; (6) time elapsed since introduction; (7) chemical profile of the exotic species; and (8) innate biological attributes of the insects associated with a tree species. The overall conclusion from this study is that while all monoculture plantations are at greater risk of pest outbreaks than natural forests, plantations of exotics are at no greater risk than plantations of indigenous species. It should be possible to develop a pest risk rating system for different tree species for different locations, based on these criteria.

In this report, we assess the unmitigated pest risk potential of importing Eucalyptus logs and chips from South America into the United States. To do this, we estimated the likelihood and consequences of introducing representative insects and pathogens of concern. Nineteen individual pest risk assessments were prepared, eleven dealing with insects and eight with pathogens. The selected organisms were representative examples of insects and pathogens found on the foliage, on the bark, in the bark, and in the wood of Eucalyptus spp. Among the insects and pathogens assessed, eight were rated a high risk potential: purple moth (Sarsina violescens), scolytid bark and ambrosia beetles (Scolytopsis brasiliensis, Xyleborus retusus, Xyleborus biconicus, Xyleborus spp.), carpenterworm (Chilecomadia valdiviana) on Eucalyptus nitens, round-headed wood borers (Chydarteres striatus, Retrachyderes thoracicus, Trachyderes spp., Steirastoma breve, Stenodontes spinibarbis), eucalyptus longhorned borer (Phoracantha semipunctata), Botryosphaeria cankers (Botryosphaeria dothidea, Botryosphaeria obtusa, Botryosphaeria ribi), Ceratocystis canker (Ceratocystis fimbriata), and pink disease (Erythricium salmonicolor). A moderate pest risk potential was assigned to eleven other organisms or groups of organisms: eucalypt weevils (Gonipterus spp.), carpenterworm (Chilecomadia valdiviana) on two Eucalyptus species other than E. nitens, platypodid ambrosia beetle (Megaplatypus parasulcatus), yellow phorancantha borer (Phoracantha recurva), subterranean termites (Coptotermes spp., Heterotermes spp.), foliar diseases (Aulographina eucalypti, Cryptosporiopsis eucalypti, Cylindrocladium spp., Phaeophleospora spp., Mycosphaerella spp.), eucalyptus rust (Puccinia psidii), Cryphonectria canker (Cryphonectria cubensis), Cytospora cankers (Cytospora eucalypticola, Cytospora eucalyptina), Coniothyrium canker (Coniothyrium zuluense), and root and stem rots (Armillaria spp., Phellinus spp., Ganoderma sp., Gymnopilus spectabilis). For those organisms of concern that are associated with logs and chips of South American Eucalyptus spp., specific phytosanitary measures may be required to ensure the quarantine safety of proposed importations.

Poplars (genus Populus) have emerged as a model organism for forest biotechnology and genetic modification (GM: asexual gene transfer) is more advanced for this genus than for any other tree. The goal of this paper is to consider the benefits expected from the use of GM poplar trees, and the most significant claims made for environmental harm, by comparing them to impacts and uncertainties that are generally accepted as part of intensive tree culture. We focus on the four traits with greatest commercialization potential in the near term: wood modification, herbicide tolerance, insect resistance, and flowering control. After field trials and selection of the top performing trees, similar to that during conventional poplar breeding, GM poplars appear vigorous and express their new traits reliably. The ecological issues expected from use of GM poplars appear similar in scope to those managed routinely during conventional plantation culture, which includes the use of exotic and hybrid genotypes, short rotations, intensive weed control, fertilization, and density control. The single-gene traits under consideration for commercial use are unlikely to cause a significant expansion in ecological niche, and thus to substantially alter poplar's ability to "invade" wild population. We conclude that the ecological risks posed by GM poplars are similar in magnitude, though not in detail, to those of routine poplar culture. We also argue that the tangible economic and environmental benefits of GM poplars for some uses warrant their near-term adoption-if coupled with adaptive research and monitoring-so that their economic and ecological benefits, and safety, can be studied on commercially and ecologically relevant scales. We believe that the growing demand for both wood products and ecological services of forests justifies vigorous efforts to increase wood production on land socially zoned for tree agriculture, plantations, or horticulture. This is the key reason for poplar biotechnology: the combination of economic efficiency with reduction of farm and forestry impact on the landscape.

Hohe Qualitätsansprüche und äußerst geringe Schädlingstoleranz bedingen im Zierpflanzenbau einen vergleichsweise hohen Einsatz von Pflanzenschutzmitteln. Um gesundheitliche Probleme der Beschäftigten bei Pflege- und Erntearbeiten zu vermeiden, erfolgt im Zulassungsverfahren für Pflanzenschutzmittel eine Risikoabschätzung nach einer Ergänzung der BBA-Richtlinie Teil I 3-3. Um deren Annahmen zur dermalen Belastung zu überprüfen, wurde in Gewächshäusern die Exposition der Beschäftigten bei verschiedenen Arbeiten in behandelten Chrysanthemen- und Pelargonienbeständen ermittelt. Bei abstreifbaren Rückständen (dislodgeable foliar residues - DFR) von 0,03 bis 0,13 µg Wirkstoff /cm2 war die Exposition bei der Chrysanthemenemte wesentlich höher als bei Pflegearbeiten. Im Rechenmodell des Zulassungsverfahrens wird die Exposition aus den abstreifbaren Rückständen, einem generellen Transferfaktor, der täglichen Arbeitszeit und der Aufwandmenge berechnet. Der Vergleich der gemessenen mit den berechneten Daten zeigt, dass die Worst-case-Annahmen des theoretischen Modells auf der sicheren Seite liegen, da die Exposition bei allen unter" suchten Arbeiten stark überschätzt wird. Für das Ernten von Chrysanthemen wurde ein Transferfaktor von 3500 cm2 Person-1 h-1 abgeleitet. Die Durchführung von Feldversuchen zur Bestimmung spezifischer Transferfaktoren und abstreifbarer Rückstände wird empfohlen. | High expectations in quality and extremely negligible pest tolerance call for comparatively greater amounts of plant protection products in ornamentals. In order to avoid health problems for those employed in cultivating and harvesting ornamentals, a risk assessment is carried out within the framework of the authorisation procedure for plant protection products in accordance with a supplement to the BBA guideline I 3-3. In order to examine its assumptions concerning dermal impact, the exposure of workers was tested in greenhouses containing treated chrysanthemums and pelargoniums whilst performing various jobs. Exposure to dislodgeable foliar residues (DFR) of 0.03 to 0.13 a.i. ~tg/cm2 from the chrysanthemum harvest was considerably higher than when performing other cultivation work. In the authorisation procedure's calculation model, exposure is calculated from the dislodgeable residues, a general transfer factor, daily working hours and the application rate. The comparison of the measured with the calculated data shows that the worst-case assumptions of the theoretical model are on the safe side, since exposure is overestimated for all the jobs examined. A transfer factor of 3500 cm2 Person-1 h-1 was derived for harvesting chrysanthemums. lt is recommended to perform field trials to determine specific transfer factors and dislodgeable residues.

The preplant soil fumigant 1,3-dichloropropene (1,3-D) is effective for nematode control and is expected to further replace methyl bromide (MeBr) as MeBr use is phased out. Acute human exposure to soil fumigants is managed in part by using buffer zones between treated fields and occupied structures. The required buffer zone for 1,3-D in California is 91.4 m (300 ft) for all uses. However, a 30.5-m (100-ft) buffer setback is desired for 1,3-D to be an important replacement for MeBr in the orchard and vineyard markets. The Industrial Source Complex Short-Term model, Version 3 (ISCST3) was used to simulate township-wide long-term average and short-term air concentration distributions of 1,3-D. The Gaussian plume model ISCST3 can be used to assess dispersion of air pollutants and pollutant concentrations on receptors from a variety of sources and in diverse airsheds. Long-term and daily-average air concentrations can be compared with the California permitted chronic or acute toxicity endpoints, respectively, to assess the potential risk for individuals living within the township at the proposed buffer setback. Modifications to ISCST3 were made for specific nonpoint-source agricultural constraints and management practices. Chronic and acute air concentration distributions of 1,3-D with a 30.5-m buffer constraint around treated fields are similar to currently permitted air concentration distributions in California. Refinement of exposure as a function of buffer distance, application rate, and field size is possible due to the resolution of the simulation and external post-processing capabilities. Simulated examples of 1,3-D acute and chronic exposure cumulative distributions are presented.

Cowpea trypsin inhibitor (CpTI) was shown to have a deleterious effect on the growth and development of larvae of the tomato moth, Lacanobia oleracea, when incorporated in artificial diet (2.0% of soluble protein) and expressed in transgenic potato leaf (up to 1.0% of soluble protein). The effect of CpTI on parasitism of L oleracea by the ectoparasitoid Eulophus pennicornis was investigated. The parasitic success of the wasp was reduced by the presence of CpTI in the diet of the host and, in the case of transgenic potato leaves expressing the transgene protein, was collated with the length of time the host fed on the diet prior to parasitism. In all cases the proportion of hosts parasitised when fed CpTI-containing diets was reduced when compared with controls, although these differences were only significant when hosts were fed from the third instar on the transgenic potato leaves. Parasitoid progeny that developed on L oleracea reared on CpTI-containing diets, however, were not adversely affected. These results show that, whilst expression of CpTI in transgenic potato plants confers resistance to the lepidopterous pest L oleracea, adverse effects on the ability of the ectoparasitoid E pennicornis to parasitise this moth species successfully may also occur. These results are discussed in relation to the potential impact of transgenic crops on beneficial biological control agents.

Myrothecium verrucaria was found to be an effective pathogen against kudzu grown in the greenhouse and the field. M. verrucaria produced large amounts of macrocyclic trichothecenes when cultured on solid rice medium, including epiroridin E (16.8 mg/g crude extract), epiisororidin E (1 mg/g), roridin E (8.7 mg/g), roridin H (31.3 mg/g), trichoverrin A (0.6 mg/g), trichoverrin B (0.1 mg/g), verrucarin A (37.4 mg/g), and verrucarin J (2.2 mg/g). Most of these toxins were also isolated from M. verrucaria spores and mycelia grown on potato dextrose agar medium, including epiroridin E (32.3 mg/g), epiisororidin E (28.6 mg/g), roridin E (0 mg/g), roridin H (60 mg/g), trichoverrin A (1.3 mg/g), trichoverrin B (1.8 mg/g), verrucarin A (13.8 mg/g), and verrucarin J (131 mg/g). When M. verrucaria was cultured on liquid media, the numbers but not the amounts of toxins decreased. Only epiroridin E (28.3 mg/g), epiisororidin E (29.6 mg/g), verrucarin B (195 mg/g) and verrucarin J (52.6 mg/g) were measured when the fungus was cultured on cornsteep medium. On soyflour-cornmeal broth M. verrucaria produced several toxins, including epiroridin E (58.1 mg/g), epiisororidin E (5.8 mg/g), verrucarin B (29.9 mg/g) and verrucarin J (32 mg/g). In contrast, no macrocyclic trichothecenes were detected by HPLC analysis of plant tissues of kudzu, sicklepod, and soybean treated with aqueous suspensions of M. verrucaria spores formulated with a surfactant. Chloroform-methanol extracts of kudzu leaves and stems treated with M. verrucaria spores were less cytotoxic to four cultured mammalian cell lines than the corresponding extracts from control plants. Purified macrocyclic trichothecenes (verrucarin A and T-2 toxin) were very cytotoxic to the same cell lines (less than or equal to 2 ng/ml). These results show that neither intact macrocyclic trichothecenes nor toxic metabolites could be detected in plant tissues after treatment with M. verrucaria spores. These results argue for both safety and efficacy for the use of M. verrucaria in biological control of kudzu and other noxious weeds, and support proceeding to animal feeding trials for further evaluation of safety.

Significantly more occlusion bodies (OB) of DuPont viral construct HzSNPV-LqhIT2, expressing a scorpion toxin, were transported by artificial rainfall to cotton plants from sandy soil (70:15:15 sand-silt-clay) than from silt (15:70:15) and significantly more from silt than from clay (15:15:70). The amounts transported by 5 versus 50 mm of precipitation were the same, and transport was zero when there was no precipitation. In treatments that included precipitation, the mean number of viable OB transported to entire, 25- to 35-cm-tall cotton plants ranged from 56 (clay soil, 5 mm of rain) to 226 (sandy soil, 50 mm of rain) OB/plant. In a second experiment, viral transport increased with increasing wind velocity (0, 16, and 31 km/h) and was greater in dry (-1.0 bar of matric potential) than in moist (-0.5 bar) soil. Wind transport was greater for virus in a clay soil than in silt or sand. Only 3.3 x 10(-7) (clay soil, 5 mm rain) to 1.3 x 10(-6) (sandy soil, 50 mm rain) of the OB in surrounding soil in experiment 1 or 1.1 x 10(-7) (-0.5 bar sandy soil, 16-km/h wind) to 1.3 x 10(-6) (-1.0 bar clay soil, 31-km/h wind) in experiment 2 were transported by rainfall or wind to cotton plants. This reduces the risk of environmental release of a recombinant nucleopolyhedrovirus (NPV), because only a very small proportion of recombinant virus in the soil reservoir is transported to vegetation, where it can be ingested by and replicate in new host insects.