Search

In an Environmental Risk Analysis (ERA) benefits and risks of a biocontrol agent (BCA) or other beneficial organisms are assessed using criteria based on ecological determinants such as the potential and impact of establishment and dispersal, on known and new hosts (host range vs. specificity) and direct and indirect non-target effects. There is a wide variety of natural enemies used for biocontrol, each of which has its specific biological and ecological requirements. In regulatory requirements for regulation and registration of non-native agents, assessment of host specificity is one of the main criteria in evaluating risks. Establishing a generalist’s potential host range in a new area is one of the most challenging issues to be assessed prior to its introduction and release. Thus, generalist predators and parasitoids are often excluded a priori from being licensed. Here we will discuss several examples of different taxa with a generalist host range and show that each of them has specific requirements and as a result require a specific risk assessment of their own.

Environmental risk assessments (ERAs) are required before utilizing exotic arthropods for biological control (BC). Present ERAs focus on exposure analysis (host/prey range) and have resulted in approval of many specialist exotic biological control agents (BCA). In comparison to specialists, generalist arthropod BCAs (GABCAs) have been considered inherently risky and less used in classical biological control. To safely consider exotic GABCAs, an ERA must include methods for the analysis of potential effects. A panel of 47 experts from 14 countries discussed, in six online forums over 12 months, scientific criteria for an ERA for exotic GABCAs. Using four case studies, a three-tiered ERA comprising Scoping, Screening and Definitive Assessments was developed. The ERA is primarily based on expert consultation, with decision processes in each tier that lead to the approval of the petition or the subsequent tier. In the Scoping Assessment, likelihood of establishment (for augmentative BC), and potential effect(s) are qualitatively assessed. If risks are identified, the Screening Assessment is conducted, in which 19 categories of effects (adverse and beneficial) are quantified. If a risk exceeds the proposed risk threshold in any of these categories, the analysis moves to the Definitive Assessment to identify potential non-target species in the respective category(ies). When at least one potential non-target species is at significant risk, long-term and indirect ecosystem risks must be quantified with actual data or the petition for release can be dismissed or withdrawn. The proposed ERA should contribute to the development of safe pathways for the use of low risk GABCAs.

Due to typesetting errors, Table 5 was not displayed correctly in the initial online publication. The original online article has been corrected.

International audience; The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is native to Asia but has been intentionally introduced to many countries as a biological control agent of pest insects. In numerous countries, however, it has been introduced unintentionally. The dramatic spread of H. axyridis within many countries has been met with considerable trepidation. It is a generalist top predator, able to thrive in many habitats and across wide climatic conditions. It poses a threat to biodiversity, particularly aphidophagous insects, through competition and predation, and in many countries adverse effects have been reported on other species, particularly coccinellids. However, the patterns are not consistent around the world and seem to be affected by many factors including landscape and climate. Research on H. axyridis has provided detailed insights into invasion biology from broad patterns and processes to approaches in surveillance and monitoring. An impressive number of studies on this alien species have provided mechanistic evidence alongside models explaining large-scale patterns and processes. The involvement of citizens in monitoring this species in a number of countries around the world is inspiring and has provided data on scales that would be otherwise unachievable. Harmonia axyridis has successfully been used as a model invasive alien species and has been the inspiration for global collaborations at various scales. There is considerable scope to expand the research and associated collaborations, particularly to increase the breadth of parallel studies conducted in the native and invaded regions. Indeed a qualitative comparison of biological traits across the native and invaded range suggests that there are differences which ultimately could influence the population dynamics of this invader. Here we provide an overview of the invasion history and ecology of H. axyridis globally with consideration of future research perspectives. We reflect broadly on the contributions of such research to our understanding of invasion biology while also informing policy and people.

Hyperparasitism by virgin female Encarsia tricolor was studied by direct observation of its behaviour when contacting two secondary host species (Encarsia formosa and E. tricolor) at different host stages (first and second larval stage, third larval stage, and pupal stage). The searching and hyperparasitism behavioural sequence of E. tricolor was independent of the host stage of the whitefly (Aleyrodes proletella), and was similar to several related primary parasitoid species. In experiments with equal numbers of secondary hosts, encounter frequencies were equal for both secondary host species in all developmental stages observed. However, rates of hyperparastism were different according to host stage and host species. Hosts in the late larval stages were most preferred for hyperparasitization and the heterospecific E. formosa was more preferred as a secondary host than the conspecific, E. tricolor, in particular from the prepupal stage onwards. The window of vulnerability, i.e., the duration of the period in which a secondary host is susceptible to hyperparasitism, was largely determined by the occurrence and rate of melanization after the onset of pupation. The duration of a successful hyperparasitization event was longer than one that failed. Superparasitism occurred only once in all cases. The potential effect of autoparasitoids on biological control programs and the consequences for selection and release of an effective, yet ecologically safe agent are discussed.

In the past 100 years many exotic naturalenemies have been imported, mass reared andreleased as biological control agents. Negativeenvironmental effects of these releases haverarely been reported. The current popularity ofinundative biological control may, however,result in problems, as an increasing number ofactivities will be executed by persons nottrained in identification, evaluation andrelease of biological control agents.Therefore, a methodology for risk assessmenthas been developed within the EU-financedproject `Evaluating Environmental Risks ofBiological Control Introductions into Europe[ERBIC]' as a basis for regulation of importand release of exotic natural enemies used ininundative forms of biological control (i.e.not in `classical biological control' thoughsome of the same principles and approachesapply). This paper proposes a general frameworkof a risk assessment methodology for biologicalcontrol agents, integrating information on thepotential of an agent to establish, itsabilities to disperse, its host range, and itsdirect and indirect effects on non-targets. Ofthese parameters, estimating indirect effectson non-targets will be most difficult, asmyriads of indirect effects may occur whengeneralist natural enemies are introduced. Theparameter `host range' forms a central elementin the whole risk evaluation process, becauselack of host specificity might lead tounacceptable risk if the agent establishes anddisperses widely, whereas, in contrast, amonophagous biological control agent is notexpected to create serious risk even when itestablishes and disperses well. Drawing onpublished information and expert opinion, theproposed risk assessment methodology is appliedto a number of biological control agentscurrently in use. These illustrative casehistories indicate that the risk assessmentmethodology can discriminate between agents,with some species attaining low `risk indices'and others scoring moderate or high. Riskindices should, however, not be seen asabsolute values, but as indicators to which ajudgement can be connected by biologicalcontrol experts for granting permission torelease or not.

Improved laboratory methods are described in detail for mass rearing of various thrips species, such as Frankliniella occidentalis, Frankliniella intonsa, Thrips palmi, Thrips tabaci (Thysanoptera: Thripidae) and a thrips parasitoid, Ceranisus menes (Hymenoptera: Eulophidae), using various foods. In one method, plant pollen and honey solution are used as food sources. In a second method, germinated broad bean seeds are used. Eggs, produced in large numbers in water, are collected by a suction funnel onto a filter paper and incubated in a Petri dish. Large numbers of larvae that hatch are collected by using food traps (plant pollen). Larvae can be reared on pollen or on germinated broad bean seeds until adult emergence without additional water and food. This method has been found useful for producing even-aged thrips at different densities (up to 500 larvae in a cage of 80 mm diameter) with relatively low mortality rates. Evaluation of this rearing method for F. intonsa, shows that during 2 weeks at 20 ◦ Cp er 100 females more than 4000 females could be produced in the next generation. About 5 min per day is required to achieve this productivity of mass production. The method is also suitable for producing large numbers of the solitary endoparasitoid of thrips larvae, C. menes.

Times Cited: 0 0; International audience; Inferences about introduction histories of invasive species remain challenging because of the stochastic demographic processes involved. Approximate Bayesian computation (ABC) can help to overcome these problems, but such method requires a prior understanding of population structure over the study area, necessitating the use of alternative methods and an intense sampling design. In this study, we made inferences about the worldwide invasion history of the ladybird Harmonia axyridis by various population genetics statistical methods, using a large set of sampling sites distributed over most of the species' native and invaded areas. We evaluated the complementarity of the statistical methods and the consequences of using different sets of site samples for ABC inferences. We found that the H.axyridis invasion has involved two bridgehead invasive populations in North America, which have served as the source populations for at least six independent introductions into other continents. We also identified several situations of genetic admixture between differentiated sources. Our results highlight the importance of coupling ABC methods with more traditional statistical approaches. We found that the choice of site samples could affect the conclusions of ABC analyses comparing possible scenarios. Approaches involving independent ABC analyses on several sample sets constitute a sensible solution, complementary to standard quality controls based on the analysis of pseudo-observed data sets, to minimize erroneous conclusions. This study provides biologists without expertise in this area with detailed methodological and conceptual guidelines for making inferences about invasion routes when dealing with a large number of sampling sites and complex population genetic structures.

Native to Asia, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is considered an invasive alien ladybird in Europe and North America, where it was widely introduced as a biological control agent of aphids and coccids. In Europe, H. axyridis was sold by various biological control companies from 1995 in France, Belgium and the Netherlands, and was also intentionally released in at least nine other countries. It has spread very rapidly, particularly since 2002, and is now regarded as established in thirteen European countries. The established range extends from Denmark in the north to southern France in the south, and from Czech Republic in the east to Great Britain in the west. In this paper we map the spread and distribution of H. axyridis in Europe, and examine the situation on a country-by-country basis. We report first records of the species in five countries; Spain, Sweden, Denmark, Czech Republic and Italy; and first evidence of H. axyridis establishment in the latter three countries. Despite releases of H. axyridis in Portugal, Spain and Greece, there is little evidence of establishment in southern Europe. It is predicted that the spread and increase within Europe will continue and that H. axyridis will become one of the most widely distributed coccinellids in the continent.

In this paper, we summarize the international situation with respect to environmental risk assessment for biological control agents. Next, we apply a recently designed, comprehensive risk evaluation method consisting of a stepwise procedure to evaluate the environmental risks of Harmonia axyridis in Northwest Europe. This resulted in the very clear conclusion that H. axyridis is a potentially risky species for Northwest Europe, because it is able to establish, it has a very wide host range including species from other insect orders and even beyond the class of Insecta, it may feed on plant materials, it can cover large distances (>50 km per year), it does move into non-target areas, it may attack many non-target species including beneficial insects and insects of conservation concern, its activities have resulted in the reduction of populations of native predators in North America, it is known as a nuisance in North America and recently also in Northwest Europe, and it may develop as a pest of fruit in North America. Considering the H. axyridis case, current knowledge would lead to the conclusion that, although the predator is capable to effectively control several pest species, its risks are manifold and it should, thus, not have been released in Northwest Europe. At the time of the first releases in Nortwest Europe in 1995, the available scientific literature made clear that H. axyridis is a large sized polyphagous predator and has a great reproductive capacity in comparison with other ladybird beetles, and that there was a need to study non-target effects because of its polyphagous behaviour. In retrospect, this information should have been sufficient to reject import and release of this species, but it was apparently ignored by those who considered release of this predator in Northwest Europe. The case of Harmonia releases in Northwest Europe underlines that there is an urgent need for harmonized, world-wide regulation of biological control agents, including an information system on risky natural enemy species.

▪ Abstract More than 5000 introductions of about 2000 species of exotic arthropod agents for control of arthropod pests in 196 countries or islands during the past 120 years rarely have resulted in negative environmental effects. Yet, risks of environmental effects caused by releases of exotics are of growing concern. Twenty countries have implemented regulations for release of biological control agents. Soon, the International Standard for Phytosanitary Measures (ISPM3) will become the standard for all biological control introductions worldwide, but this standard does not provide methods by which to assess environmental risks. This review summarizes documented nontarget effects and discusses the development and application of comprehensive and quick-scan environmental risk assessment methods.

In this chapter, we first summarize the international situation with respect to environmental risk assessment for biological control agents. Next, we present the risk assessment procedure previously developed in the OECD and EU-ERBIC projects. Then, we propose anew, comprehensive risk evaluation method consisting of a stepwise procedure, which can be used for all types of biological control agents, used in augmentative and classical biological control programmes, for species or biotypes, and for native, established exotics or as yet unestablished exotics. This new comprehensive method solves weaknesses that we encountered when using the previous assessment methods: decision criteria are more clear and the decision to advise a release is taken at relevant steps in the process, thus preventing unnecessary research.We applied the new procedure to the 92 species of natural enemies mentioned inthe EPPO list of commercially available biological control agents. The elimination of obviously risky species early in the process, and the acceptance of other species that previously scored a high index, clearly show the improvements achieved the new procedure.For those natural enemies that have been in use for many years in certain ecoregions of the world we propose that environmental risks are evaluated by using a quick scan method, based on available information only. We have applied this method to all 150species of natural enemies that are currently commercially available in north-western Europe and concluded that about 5% of these (exotic) species were considered too risky for release in this region, while information was not sufficient for another 15%. However,the applicant could still try to undergo the comprehensive approach in order to get a permit for release.©CAB

Eretmocerus species (Hym. Aphelinidae) are solitary parasitoids of Bemisia tabaci (Gennadius). Mate finding and mating behavior of two species, E. mundus and E. eremicus, were studied under laboratory conditions. We used three populations of Eretmocerus: typical arrhenotokous populations of E. eremicus ( from USA) and E. mundus ( from Spain), and an atypical thelytokous population of E. mundus ( from Australia). We studied the intra- and interspecific responses of males to volatile and nonvolatile components of the female sex pheromones, mating behavior, and hybridization between populations and species. In both arrhenotokous populations, males reacted to volatile pheromones by walking toward conspecific virgin females. Males also reacted to nonvolatile pheromones by spending more time on and around patches on leaves of poinsettia plants that had been exposed to virgin females. Males of E. eremicus showed the same reaction to the nonvolatile sex pheromone of E. mundus females, but E. mundus males did not show any reaction to the nonvolatile sex pheromone of E. eremicus. There was no response of males of both species to thelytokous females of E. mundus. In both species three phases were distinguished in the mating behavior: premating, mating, and postmating. The duration of the phases differed between the three populations. Successful copulation between the two Eretmocerus species did not occur. In contrast, we recorded some successful copulations between Australian males and Spanish females of E. mundus, but they did not produce any hybrid females.

In the past 30 years, many exotic natural enemies have been imported, mass-reared and released as biological control agents. Negative effects of these releases have not been reported yet. The current popularity of biological control may, however, result in problems, as an increasing number of activities will be executed by persons not trained in the identification, evaluation and release of biocontrol agents. Therefore, protocols for risk assessment are being developed within the European Union (EU)-financed project 'Evaluating Environmental Risks of Biological Control Introductions into Europe' (ERBIC) as a basis for regulation of the import and release of exotic natural enemies. This chapter presents a summary of the situation concerning regulations for the import and release of natural enemies, a general framework for risk-assessment procedures for biological control agents, and a more detailed framework on the methodology for risk assessment of natural enemies. In the methodology for risk assessment, information on the potential of an agent to establish, its abilities to disperse and its direct and indirect effects, including host-specificity testing, is integrated.

A 4-year research project on ‘Evaluating Environmental Risks of Biocontrol Introductions in Europe’ (ERBIC) is described, and early results are presented. The project focuses on arthropod biological control (using both microbial and macrobial agents), and uses literature review, case studies with empirical work and various types of modelling to illuminate risk to non-target organisms. These methods will hopefully lead to the development of usable methodologies and guidelines for risk assessment in arthropod biological control, by the project’s completion in 2002. Reviewing existing published and unpublished data on the classical biological control of insects (a first step in this project) has revealed that for only 1.5% of introductions is there some data regarding the realized field © CAB International 2001. Evaluating Indirect Ecological Effects of Biological Control (eds E. Wajnberg, J.K. Scott and P.C. Quimby) 99 A3935: AMA: Wajnberg: First Revise:30-Oct-00 6 117 Z:\Customer\CABI\A3873 Wajnberg Evaluating Indirect\A3935 Wajnberg Evaluating Indirect #G.vp 30 October 2000 16:30:57 Color profile: Disabled Composite Default screen

The life history of the endoparasitoid, Ceranisus menes (Walker) (Hymenoptera: Eulophidae) was studied in the laboratory on Frankliniella intonsa and western flower thrips (WFT). Parasitoid development and reproductive capacity depended on temperature. Development is synchronized with larval development of the host and is faster on WFT than on F. intonsa. There is a marked variation in pupal duration of C. menes at 20 and 25°C. Average longevity of C. menes did not differ between WFT and F. intonsa at 25°C. Fecundity was 2.5 times as high with WFT as hosts than with F. intonsa. The intrinsic rate of increase (r m ) of C. menes on WFT was higher than that on F. intonsa at both temperatures, but was lower than those of the thrips hosts. It is suggested that multiple releases will be needed to control F. intonsa or WFT outbreaks.