A code of conduct for the import and release of exotic biological control agents for Europe?1

The FAO Code of Conduct for the import and release of exotic biological control agents is concerned with the importation of live, pest-control agents for research and/or field release. The objectives of the Code are to set forth responsibilities and to establish voluntary standards of conduct for all public and private entities engaged in or affecting the distribution and use of biological control agents, particularly where national legislation to regulate their use does not exist or is inadequate. Unfortunately, the Code is more like an instruction to governments to introduce legislation. Furthermore, it does not discriminate between various categories: research purposes, classical biological control and biocontrol products. Consequently, the Code is a document of little practical value and a European Code of Conduct of more substance and of a more realistic nature is called for.     

Prospects for the use of biological control agents against Anoplophora in Europe

This review summarises the literature on the biological control of Anoplophora spp. (Coleoptera: Cerambycidae) and discusses its potential for use in Europe. Entomopathogenic fungi: Beauveria brongniartii Petch (Hypocreales: Cordycipitaceae) has already been developed into a commercial product in Japan, and fungal infection results in high mortality rates. Parasitic nematodes: Steinernema feltiae Filipjev (Rhabditida: Steinernematidae) and Steinernema carpocapsae Weiser have potential for use as biopesticides as an alternative to chemical treatments. Parasitoids: a parasitoid of Anoplophora chinensis Forster, Aprostocetus anoplophorae Delvare (Hymenoptera: Eulophidae), was discovered in Italy in 2002 and has been shown to be capable of parasitising up to 72% of A. chinensis eggs; some native European parasitoid species (e.g. Spathius erythrocephalus) also have potential to be used as biological control agents. Predators: two woodpecker (Piciformis: Picidae) species that are native to Europe, Dendrocopos major Beicki and Picus canus Gmelin, have been shown to be effective at controlling Anoplophora glabripennis Motschulsky in Chinese forests. The removal and destruction of infested and potentially infested trees is the main eradication strategy for Anoplophora spp. in Europe, but biological control agents could be used in the future to complement other management strategies, especially in locations where eradication is no longer possible. © 2014 Crown copyright. Pest Management Science © 2014 Society of Chemical Industry     

Mixed inoculum for the biological control of chestnut blight1

The vegetative compatibility of four hypovirulent isolates of Cryphonectria parasitica was checked with 35 virulent isolates obtained from chestnut samples collected in many regions of Italy. Artificial inoculation tests confirmed the effectiveness of a mixture prepared with hypovirulent isolates. This was packed in squeezing tubes, to simplify the biological control of chestnut blight in practice.     

Progress in biological control of the Colorado beetle (Leptinotarsa decemlineata) in Eastern Europe

Intensive studies conducted in Eastern Europe to introduce and acclimatize two predatory bugs, Perillus bioculatus and Podisus maculiventris , and one fly, Doryphorophaga doryphorae , have not given positive results so far. Seasonal colonization with predators has provided good protection of potato and aubergine crops but the method requires release of high numbers of insects. Two microbial insecticides are produced, registered and used in the USSR for controlling the Colorado beetle, namely Boverin ( Beauveria bassiana ) and Bitoksybacillin ( Bacillus thuringiensis var. thuringiensis 202).     

The European Biological Control Laboratory: an existing infrastructure for biological control of weeds in Europe

The Agricultural Research Service of the United States Department of Agriculture has maintained a continuous European effort in classical biological control of exotic pests in the USA. The European Parasite Laboratory was established in France in 1919, while the European Weed Laboratory began operations in Rome in 1958. The two laboratories were merged in Montpellier in 1991 as the European Biological Control Laboratory (EBCL), becoming the primary overseas biocontrol laboratory of the USDA. The management of weeds, insect pests, and pathogens is an important feature of agricultural research programmes worldwide. These invasive species can lead to vast financial losses for countries engaged in agriculture. The overall goal of research at EBCL is to develop biological control technologies to be used to suppress invading weeds and insect pests. This is done through expeditions to find natural enemies (insects, mites and pathogens), or phytophagous, parasitoid or predator species. These are characterized in careful experimentation in quarantine facilities and eventually developed as biological control agents. Current weed projects include studies on the Centaurea spp., Arundo donax , Vincetoxicum spp., Isatis tinctoria , Taeniatherum sp. and Dipsacus sp. Insect projects research Lygus bugs, the olive fruit fly, the vine mealybug, and the Asian long-horned beetle. The EBCL team is international and interdisciplinary. Entomology, plant and insect pathology, molecular biology and ecology are the main approaches of our biocontrol research. The team cooperates with universities and agencies worldwide.     

A philospohy of pest control —A biological approach to new pesticide developments

The influences on pest control that are external to the pesticide industry are discussed first. The complexity of the interrelationship between the five main parties to the pesticide controversy (the farmer, the public, the pesticide manufacturer, wild life interests and the government) explains in some measure the intensity of the controveersy itself. It is to be hoped that with increasing knowledge all parties will be able to move together along an agreed, optimum course.The responses within pest control in general, and the pesticide industry in particular, to these external influences are then discussed. Existing pest control practices largely utilise control at the level of the individual. Much current research relates to population control procedures. The pesticide industry is concerned with innovations relating to the mode of action of conventional insecticides as well as to new ways of using chemicals to control insect populations. It is suggested the long term success of population control procedures depends as much on the provision of appropriate organisasuccess of population control procedures depends as much on the provision of appropriate organisational requirements as on solving the technical problems.Finally, the likely future couse of pest control is considered. It is suggested that over the next 10 years or more the major burden of pest control will continue to fall on the pesticide industry much as at present. The first innovations, over the period 5–15 years hence, are likely to concern conventional pesticides with novel modes of action. Population control procedures will gradually become established and this process will accelerate over the period 10–20 years hence and beyond. However, full benefit from such procedures will only accrue if organisatonal requirements have been met.     

Systemically induced resistance and microbial competitive exclusion: implications on biological control

The root-knot nematode, Meloidogyne incognita, is among the most damaging agricultural pests, particularly to tomato. The mutualistic endophytes Fusarium oxysporum strain Fo162 (Fo162) and Rhizobium etli strain G12 (G12) have been shown to systemically induce resistance toward M. incognita. By using triple-split-root tomato plants, spatially separated but simultaneous inoculation of both endophytes did not lead to additive reductions in M. incognita infection. More importantly, spatially separated inoculation of Fo162 and G12 led to a reduction in Fo162 root colonization of 35 and 39% when G12 was inoculated on a separate root section of the same plant in two independent experiments. In an additional split-root experiment, spatial separation of Fo162 and G12 resulted in a reduction of Fo162 root colonization of approximately 50% over the water controls in two independent experiments. The results suggested that the suppressive activity of G12 on Fo162 and M. incognita is possibly related to the induction of specific plant defense mechanisms. Thus, although Fo162 and G12 have the ability to systemically repress M. incognita infection in tomato, they can be considered incompatible biocontrol agents when both organisms are present simultaneously on the same root system.     

Studies on the biological control of plant pathogens in Finland1

Studies on biological control of plant pathogens in Finland were started by Pohjakallio in the 1950s, concentrating especially on the microbes parasitizing fungal sclerotia. At the turn of the 70s, Kallio studied the protective effect of Finnish isolates of Phlebia gigantea against the most important forest pathogen Heterobasidion annosum with positive results. The preparation was put on the market. Later in the 1970s, the observation by Tahvonen that Finnish light-coloured peat had an inhibitory effect on the infection of plants by some seed and soil-borne fungal pathogens led to further investigations. Of the microbes isolated from peat, Streptomyces spp. proved the most effective antagonists in both in vitro and in vivo tests. Studies are in progress with S. griseoviridis and several other fungal and bacterial antagonists as potential biocontrol agents against some seed and soil-borne pathogens and storage diseases.     

The regulation of biological control of weeds in Europe – an evolving landscape

After a difficult start, classical biological control of weeds is becoming recognized as an option for management of invasive plants in European Union (EU) Member States with intentional releases in three countries over the past 5 years. Many European countries are benefitting from the presence of Stenopelmus rufinasus, the azolla weevil, which has been accidentally introduced to the region. However, the UK experience with the official release of the psyllid Aphalara itadori against Japanese knotweed (Fallopia japonica) and the subsequent release of the rust Puccinia komarovii var glanduliferae against Impatiens glandulifera showed the regulatory framework that could be followed by EU Member States. This process was followed in advance of the subsequent release of Trichilogaster acaciaelongifoliae, a specific Australian bud‐galling wasp, against the invasive Acacia longifolia in Portugal. Soon the case of Ophraella communa, another accidental introduction that is severely limiting Ambrosia artemisiifolia populations, will influence affected countries, some of which have been uninterested in this technique until now, to consider the advantages and disadvantages of classical biocontrol. The future looks bright for classical weed biocontrol and the EU Regulation on Invasive Species should further aid this situation.     

State of the art regarding carrot fly control in practice and possibilities in the future for Western and Northern Europe1

The carrot fly (Psila rosae) is a major pest of umbelliferous crops, particularly in carrot production. This pest is present in temperate regions of Northern and Western Europe and also in the warm and dry climate of Central and Southern Europe. Currently, control strategies are limited and there may be a bottleneck of pest control solutions in the future. In practice, growers in the Netherlands mainly rely on a commercial, supervised control system which monitors the carrot fly population pressure. Possibilities to control the carrot fly after exceeding an economical threshold are reduced due to a lack of efficient chemical insecticides. Another option is the use of seed treatment to protect the carrots against the larvae developed from the first flight of the carrot flies for 12–14 weeks after sowing. The state of the art of the carrot fly pest and control possibilities are hereby discussed. Bottlenecks in control of carrot flies are highlighted and described.     

Wintering of the biotrophic fungus Puccinia lagenophorae within the annual plant Senecio vulgaris: implications for biological weed control

Epidemics of the obligate biotrophic fungus Puccinia lagenophorae might be used to control populations of the annual plant, groundsel, Senecio vulgaris . Insight into the mechanisms of survival of P. lagenophorae over winter may help to explain the number of inoculum sources, and their strength (assessed by number and size of pustules), present in an S. vulgaris population in spring, indicating the probability and rate of progress of a subsequent epidemic. Results of the study indicated survival of the rust as mycelium within the host over winter. Survival outside the host is unlikely, because aecidiospores lost their capacity to germinate over winter and teliospores have not been reported to be infectious. Survival of S. vulgaris plants over winter was reduced by rust infection in autumn. The mortality of S. vulgaris was 30–100% depending on the date of infection. All plants infected early in autumn died but those infected late in autumn were more likely to survive. In turn, poor survival of the host impacted on the survival of P. lagenophorae over winter. Consequently, the results of the study suggest that no inoculum sources, or only a few weak ones, are present in vulgaris populations in spring. This suggestion was supported by observations of an S. vulgaris population at a ruderal site. Therefore, research on biological weed control should focus on increasing the negative impact of P. lagenophorae on S. vulgaris populations while augmenting the probability of survival of the rust over winter to start new epidemics in spring.     

Advances in biological control of Leptinotarsa decemlineata in Poland1

Results of research, and practical attempts at biological control of Colorado beetle (Leptinotarsa decemlineata), are reviewed. Attempts to introduce parasitic or predatory insects from North America and establish them permanently in Europe were unsuccessful. Studies conducted in Poland and Europe revealed 237 species of indigenous arthropod natural enemies of Colorado beetle (in North America only 61) and over 15 species of microorganisms (mollicutes, fungi, protozoa and nematodes). The combined action of indigenous natural enemies lowers density of Colorado beetle by 30–80%, but this is still above the economic threshold so that chemical control remains necessary. Under a cooperative project (Poland, Czechia, USA), it was demonstrated in Poland that three treatments with the biopesticides Mycotrol or Novodor provided a level of potato protection similar to that of two treatments with a synthetic pyrethroid.     

Concepts and methods in biological control of diseases in apple orchards1

The project ‘Promotion of Biological Methods in Apple Growing’ which started in Switzerland in 1985 concentrates on the control of Venturia inaequalis (scab) and Podosphaera leucotricha (powdery mildew). The project considers the selection of suitable cultivars resistant or only slightly susceptible to fungal diseases and the assessment of tolerable economic loss. It also includes curative treatments with sterol-synthesis-inhibiting fungicides, according to scab infection periods, as well as applications of plant extracts (proposed by the Institute of Biological Husbandry) and suspensions of antagonists or their culture filtrates as plant-protecting agents. Screening experiments on apple seedlings showed that root extracts of Rumex obtusifolium significantly reduced powdery mildew infections under greenhouse conditions. In field experiments treatments with R. obtusifolium extracts at intervals of 7–10 days were less effective. Saponin-containing extracts of different plants gave satisfying control of scab on seedlings in the growth chamber but were not very effective in the field. Applications of spore suspensions and culture filtrates of the phyllosphere fungi Chaetomium spp. reduced scab and mildew infections on apple seedlings to some extent. It was found that in the last 2 years even primary infections of P. leucotricha were severely parasitized by Ampelomyces quisqualis. Preliminary studies showed that the lack of efficacy of this biocontrol system is due to the delayed spread of the hyperparasite.     

Precautions for and experiences with introduction of exotic biological control agents into the former USSR1

The experience of introducing more than 120 species of exotic biological control agents for use against more than 40 species of pests during 70 years in the countries of the former USSR is analysed. The examples of biological protection of citrus orchards and some other programmes using biological control agents are described in more detail. The precautionary measures elaborated for these programmes consist of: (1) the prohibition of use by insufficiently qualified persons or non-State organizations; (2) phytosanitary procedures preventing the spread of quarantine pests; (3) elimination from the biological control material of any hyperparasites, diseases or other accidentally introduced organisms under adequate quarantine conditions; (4) investigations at the place of release of the biological control agent into the environment.     

Top 20 environmental weeds for classical biological control in Europe: a review of opportunities, regulations and other barriers to adoption

Classical biological control remains the only tool available for permanent ecological and economic management of invasive alien species that flourish through absence of their co‐evolved natural enemies. As such, this approach is recognized as a key tool for alien species management by the Convention on Biological Diversity (CBD), the European and Mediterranean Plant Protection Organization (EPPO) and the European Strategy on Invasive Alien Species (ESIAS). Successful classical biological control programmes abound around the world, despite disproportionate attention being given to occasional and predictable non‐target impacts. Despite more than 130 case histories in Europe against insect pests, no exotic classical biological control agent has been released in the EU against an alien invasive weed. This dearth has occurred in the face of increasing numbers of exotic invasive plants being imported and taking over National Parks, forests and amenity areas in this region, as well as a global increase in the use of classical biological control around the world. This paper reviews potential European weed targets for classical biological control from ecological and socioeconomic perspectives using the criteria of historical biological control success, taxonomic isolation from European native flora, likely availability of biological control agents, invasiveness outside Europe and value to primary industry and horticulture (potential for conflicts of interest). We also review why classical biological control of European exotic plants remains untested, considering problems of funding and public perception. Finally, we consider the regulatory framework that surrounds such biological control activities within constituent countries of the EU to suggest how this approach may be adopted in the future for managing invasive exotic weeds in Europe.     

Benefits and risks of introducing exotic macro-biological control agents into Europe1

Biological control of insects — the use of natural enemies to reduce pest numbers — has been applied on a worldwide scale for more than 100 years and its use has considerably increased during the past decades as it offers a sustainable, economical and environmentally attractive alternative to chemical pest control. In biological control, locally occurring natural enemies are used or alien species are imported. Until now, introductions of hundreds of species of insect natural enemies have not led to environmental problems when a procedure of selection, importation and release was carefully applied. In contrast, many intentional and unintentional introductions of plants and phytophagous animals have resulted in very negative effects on the environment. Several early biological control introductions, mostly of generalist, large predators (e.g. vertebrates, birds and toads) and usually not supervised by biological control experts, led to unintended negative effects on native species. For insect biological control executed by experts, examples of unintended, harmful effects are not known. Selected natural enemies are usually specific, mono- or oligophagous species of parasitoids and predators. To prevent making mistakes in the future, pre-introductory evaluation of natural enemies is advocated, including a step where their potential negative effects are studied. Examination of the literature, taxonomic research and host acceptance experiments are used in such studies to estimate negative effects.