When insect species establish outside of their natural distribution range they are called non-native or exotic.
These non-native insects often remain undetected until populations are well established and become invasive, threatening native species, ecosystems, habitats, human health and many sectors of the economy such as agriculture, forestry and tourism.
One reason why these non-native insects can become invasive is the lack of natural enemies that limit their population growth and spread in the invaded area. Classical biological control, or biocontrol, is the use of living organisms such as insects, mites or fungal pathogens to control pest populations. It levels the playing-field by reintroducing some of the specialist natural enemies that help control the invasive species in its native range. The aim is not to eradicate the invasive insect, but to bring its density below an appropriate ecological or economic threshold.
Biocontrol is an environmentally friendly, cost-effective and sustainable way of managing invasive species and has been used effectively for more than 100 years.
What we offer
CABI has over 60 years’ experience of working on the biological control of invasive insects.
Our team of highly experienced staff works with customers to develop scientifically sound biological control solutions based on thorough research. We advance the science of biological arthropod biological control by carrying out in-depth studies, often in collaboration with universities or other research organisations.
For example, the identification of new biological control agents involves a range of activities including surveys of natural enemies in the pest’s native range, host range studies, and climate simulation models.
Any organism intended for the control of a non-native invasive insect then undergoes an extensive series of tests to determine its environmental safety before considering its release.
In addition, we are investigating the adaptation of native natural enemies of exotic pests in the invaded range and their potential for augmentative biological control (periodical releases of mass reared natural enemies into short-term crops). We are also actively involved in the development of new guidelines on the regulation of biological control.
The team and key contact
The team working at CABI in Switzerland is led by Dr Tim Haye and includes research scientists and temporary research assistants, including students from Canadian universities.
A number of international MSc and PhD students are co-supervised by CABI staff and conduct part of their research at CABI’s Swiss centre. This is an important component of CABI’s work and adds both a breadth and depth to the quality of our scientific research.
We also work closely with the CABI-MoA Joint Laboratory in China, tackling insect pests of Asian origin.
We are currently investigating potential biocontrol agents for seven invasive insects in Canada and Europe. Project highlights include:
- Continuous releases of the biological control agent Diadromus pulchellus, a wasp species, have been made against the invasive leek moth, Acrolepiopsis assectella, in Canada since 2010. First results suggest that immediate parasitism levels of almost 50% can be achieved when sufficient numbers of the biological control agent are released.
- Since 2010, continuous releases of the wasp species, Tetrastichus setifer, have been made against the lily leaf beetle, Lilioceris lilii, across Canada. The parasitoid has established in Ontario and parasitism at release sites is high. Successful releases of the wasp, Peristenus digoneutis, have been made against Lygus plant bugs in Ontario, Canada.
- In spring 2017 a petition for the redistribution of Trichomalus perfectus as a classical biological control agent for cabbage seedpod weevil, Ceutorhynchus obstrictus, in Western Canada was submitted to the Candian Food Inspection Agency (CFIA).
A new invasive pest of particular concern to Switzerland’s orchard industry is the Comstock mealybug, Pseudococcus comstocki. Originating from Asia, the Comstock mealybug was first detected in 2016 in fruit crops of the Swiss canton of Valais. Following its detection, the mealybug has caused significant local economic damage to apricot, pear and apple production, especially during 2018 and 2019. Chemical control is one way of helping to fight the pest but it has produced mixed, and often, insufficient results. Biological control is another method and this project, therefore, aims to develop a sustainable and environmentally friendly, biological control method for the Comstock mealybug.
The spotted lanternfly is an Asian polyphagous pest that feeds on more than 70 plants by sucking the sap out of from leaves, stems and trunks. It was found in Pennsylvania in 2014 and has since expanded its geographical distribution. The damage caused by the pest, its sugary excrement and sooty mold has been devastating for the Pennsylvania wine industry – reportedly causing a 90% grape loss.
A European biological control agent may help control an exotic pest of apple trees in western Canada. Damage from the apple leaf-curling midge in eastern Canada was effectively reduced by introducing a European natural enemy, Platygaster demades, in the 1990s. The pest arrived in British Columbia more recently, where releases of P. demades are now being considered. First, however, the identity of P. demades needs to be confirmed with molecular tools and its host range defined.