Download Sweden

Melanie Josefsson
Swedish Environmental Protection Agency
2015-10-01
Submission of information on Invasive Alien Species Management from Sweden
ii. Experiences of the use of biological control agents against invasive alien species.
Biological control agents released to the environment for control of invasive alien species
Biological control agents for control of invasive alien species are currently being used for controlling the
Spanish slug Arion vulgaris. Phasmarhabditis hermaphrodita, is a nematode is included in commercial
products that are sold to the general public for general use in gardens. P. hermaphrodita is a bacteria
eating nematode that is a lethal parasite of snails and slugs. P. hermaphrodita is also an alien species in
Sweden. It is not specific to Arion vulgaris and thus may also affect snails and slugs in the Milacidae,
Limacidae and Arionidae families.
Phasmarhabditis hermaphrodita was approved for use as a molluscicide in 2008 by the Swedish
Chemicals Inspection. It is widely used in southern and central Sweden where the Spanish slug is a
problem. Experiences show that use of P. hermaphrodita is somewhat successful for controlling juvenile
Spanish slug, but is not effective for adults.
No studies of the effects of the use of P. hermaphrodita on biological diversity in Sweden have been
found in a literature search. It is probable that this biocontrol agent negatively affects populations of
native snails and slugs, but it is difficult to distinguish between the effects of the molluscicide and effects
of Arion vulgaris on native snails and slugs through predation and competition. Arion vulgaris also
causes considerable economic damages to gardens and agriculture. It has a strong negative social
impact on gardeners as considerable efforts are required to deal with Arion vulgaris infestations,
including changing gardening practices and garden design. Infestations of Arion vulgaris may in some
areas even affect property values. When approving P. hermaphrodita as a control agent of Arion
vulgaris, the negative effects of Arion vulgaris on biological diversity and socioeconomic values were
considered more significant than potential negative effects of P. hermaphrodita on biological diversity.
Caution is however urged in spreading P. hermaphrodita.
Biological control agents released to the environment for control of invasive alien species in other
countries in the region
The field trials with releasing the psyllid Aphalara itadori for control of the Japanese knotweed
(Reynoutria japonica) is being followed with interest as the Reynoutria japonica and the Fallopia species
are also a growing problem in Sweden.
Biological control of the invasive alien Spruce bark beetle Dendroctonus micans in Great Britain by the
release of the host-specific predatory beetle, Rhizophagus grandis is considered an interesting and
successful method which reduces the need for pesticides, but has not been done in Sweden.
Biological control agents released for control of pests, which may be invasive alien species
The use of biological control agents is an integral part of an integrated plant protection. More than 20
organisms, including macroorganisms such as nematodes, insects and spiders, have been approved for
use as biological control agents in Sweden, of which most are alien species to Sweden. Many of the
targets pests are also alien species that cause significant economic damage. Biological control agents are
used in greenhouses for pest control and pollination and are particularly important for ecological
cultivation in greenhouses. Most of the target pests are also alien species. It is considered likely that
organisms used in biological control inside greenhouses will spread outside of the greenhouse
environment. However, the risks that these organisms, which are most often native to tropical and
temperate climate zones, will survive the winter and establish and spread outside in the natural
environment are considered small and acceptable. These risks are always assessed in the approval
process.
Biological control agents are used to a small degree in semi-enclosed cultivation tunnels. Nematodes
and predatory mites are most commonly used especially in ecological cultivation. The risk for
establishment and spread in the environment are considerably greater in cultivation tunnels than
greenhouses. The organisms used in biological control in cultivation tunnels must be hardier, the
number of organisms is much greater and access to the natural environment is not restricted; which are
all factors which increase the risk for establishment. Another use of biological control agents outside of
greenhouses is a parasitic Hymenoptera used for controlling flies in stables and barns.
Alien species and populations of bumblebees are imported and spread in the natural environment to
assist in pollination. It is often difficult to identify what species is imported and spread. There are
questions about if the alien bumblebees can hybridize with native bumblebees and what the effect on
biological diversity would be should this occur. Proper marking and identification of the species with
place of origin should be a minimum requirement for obtaining permission to import pollinators and to
enable a research and monitoring on the effects for biological diversity of these introductions and
spread.
Approval process for biological control agents
The use of biological control agents is generally encouraged as the use of pesticides can thereby be
reduced. This enables Sweden to move towards fulfilling the environmental goal “A Non-toxic
environment”. This environmental goal aims to reduce and minimize toxins in the environment, which is
positive for biological diversity. It is however, essential that use of alien species for biological control
does not threaten biological diversity by spreading to the environment and causing damage through
herbivory, predation or competition with indigenous species.
There is no harmonized European Union legislation regulating the use of macroorganisms (nematodes,
insects and spiders) for use in biological control or pollination. However, if the species could be become
a pest, they could be regulated under the EU and national legislation for plant protection. Neither the
EU legislation EG nr 1107/2009 on the placing of plant protection products on the market nor the EU
biocides directive EU nr 528/2012 apply to nematodes, insects or spiders used in biological control. The
European Union’s regulation 1143/2014 on the prevention and management of the introduction and
spread of invasive alien species could in the future apply to specific invasive alien species used for
biological control, should the species be identified as an IAS of union concern. There are no such species
being considered as an IAS of union concern at present. National legislation must thus apply.
The process for approval of macroorganisms for use in biological control in Sweden is concentrated on
determining if a species is alien to Sweden and if it could survive the winter, establish, spread and
become invasive. Health risks for the people producing the agent and those who use the agent are also
considered.
The Swedish legislation on approval of biological control agents is presently being revised to strengthen
the assessments of risks that a biological control agent may have for biological diversity in the approval
process for use.
The approval process has until now been based on the process and regulations for approving chemicals
and carried out by the Swedish Chemicals Agency. A review of the approval process highlighted the need
for a dedicated legislation on use of spiders, insects and nematodes in biological control to strengthen
the approval process to the risks that they may have on biological diversity. A new national regulation
on nematodes, insects and spiders for use as pesticide is presently being considered for adoption.
Responsibility for the approval process would thus be moved to the Swedish Environmental Protection
Agency.
Decision support schemes for approval of organisms used in biological control
In the decision process for approval of organisms to be used in biological control, Sweden relies on
guidance and standards developed by the International Plant Protection Convention (IPPC)1 and the
European Plant Protection Organization (EPPO). The International Standard for Phytosanitary Measures
(ISPM) 11 is particularly helpful in assessing the risks for the environment and biological diversity. EPPO
Standard PM 5/3(4) also gives clear guidance on assessing the risks of organisms used in biological
control.
1
Primarily ISPM 3 Guidelines for the export, shipment, import and release of biological control agents and other
beneficial organisms, but also ISPM 2:2007 and ISPM 11:2004 are helpful for assessing the risks of organisms to be
used in biocontrol .
Availability of information about the species being considered for approval as a biological control agent
is crucial. EPPO’s Panel on Safe Use of Biological Control publishes and annually updates a list of
macroorganisms that are widely used within the regions and for which there are experiences of safe use
for at least 5 years without any negative side effects. This list is a useful support for countries in their
national approval process. A desired future development to further support a country’s approval
process would be to strengthen and further specify the criteria pertaining to risks and potential risks for
biodiversity of the organism used in biological control establishing invasive populations in the
environment outside of human control. CABI’s Invasive Species Compendium is another excellent source
of information to support decision making.