Highlighting forests’ vulnerability to invasive species

After habitat destruction, invasive alien species are the second biggest threat to biodiversity worldwide. It has a significant impact on livelihoods and the economy, incurring losses of USD$1.4 trillion a year. Prior to 2012 many South-East Asian countries lacked the policies and information on the presence, distribution and impact of invasive species to properly manage this increasingly urgent threat. Continue reading

The locust invasions devastating Niger

Copyright: Panos

It is the end of December 2016, with clear skies over Niger. But as 2017 draws near prospects are grim for some 500 residents in Bani Kosseye, a village 80km from the capital Niamey. Agricultural production has been poor here, and families’ meagre stocks are expected to run out within a few weeks. People already fear famine. Continue reading

Where to find CABI’s open-access information on fall armyworm


The fall armyworm, Spodoptera frugiperda, is making headlines worldwide for all the wrong reasons. The caterpillar crop pest, native to the Americas, was reported in Africa for the first time last year and is now rapidly marching across the continent. It is a voracious pest of maize and other staple crops and has already destroyed tens of thousands of hectares of farmland. As such, it risks devastating smallholder livelihoods throughout Africa. Given that CABI scientists predict it could reach Europe and Asia in a matter of years, it looks set to quickly become a global problem.

The case for action against fall armyworm is overwhelming. On the ground, CABI will support national extension services to help farmers identify the pest quickly and accurately, contribute to awareness-raising and conduct studies to work out the best ways to control it that are not overly dependent on insecticides. Alongside these efforts, CABI also has a range of freely-available materials to help people understand and manage fall armyworm. Continue reading

Scientists discover new crop-destroying Armyworm is now “spreading rapidly” in Africa

Spodoptera frugiperda larva (fall armyworm) on Maize
Spodoptera frugiperda larva (fall armyworm) on Maize


New research announced today by scientists at CABI confirms that a recently introduced crop-destroying armyworm caterpillar is now spreading rapidly across Mainland Africa and could spread to tropical Asia and the Mediterranean in the next few years, becoming a major threat to agricultural trade worldwide.

Continue reading

New European Union IAS Regulation


Hydrocotyle ranunculoides
Floating pennywort (Hydrocotyle ranunculoides): on the EU species of Union concern list and a target for biocontrol (Credit: Kate Constantine, CABI)

Invasive alien species are a major threat worldwide, impacting upon millions of livelihoods and threatening biodiversity. The situation is worsening, due in no small part to increased global trade and transport. The economic costs of IAS can be vast: worldwide, invasive species are estimated to cost US$1.4 trillion per year – close to 5% of global GDP.

In the European Union alone, invasive alien species (IAS) are estimated to cost €12-20 billion a year.

In response to this threat, the European Union adopted Regulation (EU) No 1143/2014 which makes compulsory the management of key IAS that are of concern to the region. Methods include limitation of spread, eradication of early invasions and active management of established IAS. A list of 37 species to be included under the regulation was approved by EU Member States in December 2015 and has recently come into force (Regulation (EU) 2016/1141). It includes 23 animals and 14 plants whose current and potential impacts across the region will mean that collaborative and concerted action is required across the EU.

This is part of the EU’s biodiversity strategy which aims to halt the loss of biodiversity and ecosystem services in the EU by 2020 and is in line with the Convention on Biological Diversity’s (CBD) Aichi Targets, particularly Target 9:

“By 2020, invasive alien species and pathways are identified and prioritized, priority species are controlled or eradicated, and measures are in place to manage pathways to prevent their introduction and establishment.”

At CABI, we have been working on invasive species at a global scale for decades and are experts in their management using both traditional methods and through biological control. This new legislation is welcome; recognising the serious threats that invasive species pose and imposing compulsory measures to lessen the spread and impacts of IAS in the EU.

A fifth of the world’s plants under threat, as report says 391,000 species now known to science

Dave Simpson – 11 May 2016

A ground-breaking report from the Royal Botanic Gardens, Kew, has produced an estimate of the number of plants known to science. By searching through existing databases, the researchers have estimated that there are now 390,900 known plant species, of which around 369,400 are flowering plants. But this figure is only those species currently documented: new species are being discovered all the time, including over 2000 in 2015 alone. But more worryingly, it is suggested that 21% of plant species are under threat, from a range of pressures including climate change, habitat loss and invasive species. The invasive species component of the report, which draws heavily on CABI’s Invasive Species Compendium, says that nearly 5,000 plant species are documented as invasive, from over 13,000 vascular plant species naturalised outside their native range.

Prof Kathy Willis, director of science at RBG Kew, said: “It’s really important to know how many plant species there are, where they are and the relationship between the groups, because plants are absolutely fundamental to our well-being”

And on invasive species, the head of conservation science at Kew, Dr Colin Clubbe, said that invasive species are one of the biggest challenges for biodiversity. Quantifying the number of species regarded as invasive is a key step towards addressing the problem. “Now that we’ve got this list and this number, it’s certainly a bit like know your enemy,” said Dr Clubbe.


Japanese knotweed, a major invasive
“We know what we are dealing with, we can then look at them, and see what’s similar, what makes a good invasive, and then see how we can use that information to have better management practices in place or recommendations for how you deal with them.”

Trade, plant collecting, and movement of people, has led to at least 13,168 species of vascular plants becoming naturalised outside their native range. The report says that they become classed as invasives once they start to compete with native vegetation and spread to a degree that causes damage to the environment, the human economy or human health. The effects on livelihoods, and on ecosystem services such as agriculture, forestry, water and pollinators, can be staggering: the Kew report cites one study as estimating the total costs from all invasive species as nearly 5% of the world economy, and it also quotes CABI research which estimated the impact on the British economy alone as around £1.7 billion every year. Japanese knotweed, one of the most invasive plants in the UK, costs Great Britain over £165 million annually to control.

The Kew report synthesizes invasive species data from the open-access CABI Invasive Species Compendium, the Global Invasive Species Database (GISD), global reviews of invasive trees and shrubs by Rejmánek and Richardson, and Weber’s Invasive Plant Species of the World: a Reference Guide to Environmental Weeds published by CABI in 2003. CABI’s ISC – flagged in the report as “the most comprehensive web-based resource” – has datasheets for 4,841 of the total of 4979 invasive vascular plants in Kew’s consolidated list.

Identifying other threats to plant biodiversity, the report says that farming is the biggest extinction threat, representing 31% of total risk to plants. Logging and the gathering of plants from the wild is responsible for 21.3% of the risk, followed by construction work with 12.8%. The report said that some 1,771 areas of the world have been identified as “important plant areas” but very few have conservation protection measures in place.

Highlighting just how many plant species are already important to humans, the report says that some 17,810 plant species have a medical use, 5,538 are eaten, 3,649 become animal feed and 1,621 are used for fuels. Over 11,000 plant species are used for materials, for example fibres and timber.

“[Plants] provide us with our food, our fuel, our medicines – even controlling our climate” says Professor Willis.

The report can be downloaded in full, or data from individual sections accessed, at the website stateoftheworldplants.com. A symposium on the report is being held at Kew on 11-12 May. Moving forward, the global assessment will now be carried out annually, allowing scientists to monitor how plants are changing over time.

100 invasive weed factsheets project and my development bursary

Development bursary group pic
Workshop attendees: Invasive weed factsheet development. Nairobi, Kenya. February 2016.


Keen to meet colleagues and external partners in Kenya, and to learn new skills, I applied to CABI’s annual staff Development Bursary in 2015. Successful, I journeyed to Nairobi in February 2016 where I assisted with a workshop focussed on developing factsheets on invasive weed identification, management and control. These factsheets will ultimately help improve the livelihoods of farmers by reducing crop losses.

Who am I?

I am Kate Dey, a Content Editor for CABI’s Invasive Species Compendium (ISC) (kneeling front, right of image above). Sitting in the small compendia office on the second floor at Wallingford HQ, UK, I spend the majority of my time commissioning and editing datasheets. I also update distribution and pest records for the Crop Protection Compendium (CPC) and help manage the @CABI_Invasives Twitter account.

Leading up to my bursary application

In October 2015, I was asked to assist with a project which is part of an initiative known internally as the Invasives Big Push. The aim of this initiative is to stop the world’s worst invasive species undermining the livelihoods of 50 million farming families. To help achieve this aim, the project’s focus was to produce 100 factsheets on invasive weeds for East Africa (Kenya, Tanzania, Ethiopia, Malawi, Rwanda and Uganda) and Southeast Asia (Myanmar, Thailand and Vietnam) with the overarching theme of empowering farmers by providing them with clear and practical information on weed management and control. This exciting project is a collaborative one which involves CABI’s Invasives and Plantwise teams, and external partners, working together.

So I got stuck in, assisting with the prioritisation of species to be covered. They were largely prioritised by taking into account: impact on major crops (mainly maize and rice); number of countries affected by weed; and amount of information CABI already has (largely looking at the ISC and CPC) which could be repurposed and shared more widely.

I proceeded to create the first drafts, editing information from the Compendia so that it was compatible with the factsheet format required by CABI’s Plantwise Knowledge Bank (PWKB) – an online pest information resource on which the factsheets were to be hosted. Making this information available via the PWKB means it will be more readily available to extension workers who can use it to give effective advice to farmers struggling with weed infestations.

More specifically, I helped draft the first few species-specific Pest Management Decision Guides (PMDGs) which hold clear, practical, country-specific advice on pest management and control, and support Integrated Pest Management principles (IPM). These are usually produced by Plantwise but on this occasion their creation was the responsibility of the Invasives Big Push Team because of the focus on invasive weeds. Hence, Plantwise were instrumental in the creation of these factsheets, providing us with useful training and ongoing support.

The second type of factsheets produced was species-specific descriptive factsheets. The creation of these would fulfil the objective to repurpose and disseminate information from weed ID guides, produced by CABI employee Arne Witt. Along with the PMDGs, these were to be developed at two workshops in Kenya and one in Bangkok, making them country-specific in the process. Keen to be part of the development phase and to see what would become of our drafts, I applied for the development bursary in December 2015.

The workshop

I was lucky enough to attend the first four day workshop in Nairobi, Kenya, where the drafted factsheets would be developed. Attendees included specialists in weed ecology and control from a variety of research organisations and universities, and had travelled from Tanzania (2 people), Ethiopia (6 people) and within Kenya itself (6 people).

Day 1

Arne Witt, talking about impacts invasive alien species on crops

Participants were welcomed and introduced, and opening presentations were given, covering: background to the Invasives Big Push and Plantwise initiatives (by Marion Seier); introduction to factsheets and PWKB (by me); impacts of invasive alien species on crop production, and introduction to integrated pest management (IPM) principles (by Arne Witt).

Before beginning factsheet development, we needed to ask each country group what weeds they thought we should focus on. Participants were asked to complete a prioritisation table which would enable them to rank the importance of weeds in their country. It contained criteria such as area affected, crops affected, health impacts and ease of control. Species selected were those ranked 1-10 by at least two countries, luckily resulting in a large cross-over with the countries we had previously prioritised. We then started reviewing the country-specific descriptive factsheets together, asking participants to look over the drafts (some created beforehand and some created during the workshop itself) and confirm the most important common local names for each species.

Day 2

The descriptive factsheets were completed in the morning, before further presentations were given on PMDG writing (by René Eschen) and international pesticide agreements (by Sarah Thomas). We then started discussing how to write the PMDGs. Importantly, the information needed to: promote the use of preventative methods as the first line of defence; provide monitoring guidance so an infestation could be identified early on; and promote the use of the least harmful control methods if an infestation is present (i.e. non-chemical control). If these methods proved ineffective, it was essential to provide information on how to correctly use potentially harmful control methods (i.e. pesticides) safely and effectively.

The first step was to talk through the content of an existing PMDG together, in order to gain an understanding of what should go in the Prevention, Monitoring and Direct Control columns, and what restriction and limitation information was essential to include along with pesticide recommendations. We then reformed into country groups and had a go at creating a PMDG from scratch (for Parthenium hysterophorus, a weed that can not only reduce crop yields by over 90% but also poses a serious health risk to people and livestock).

After completing this task, we joined together again and listened to a representative from each country group present the PMDG they had produced. Content was debated and discussed, helping everyone further their understanding of the information required and providing inspiration by comparing differences and similarities. We then started on PMDGs for the rest of the prioritised species.

Days 3 & 4

Sarah Thomas, assisting with PMDG development

During the final days, PMDG drafts were reviewed, refined and added to. Along with Marion, René, Arne, and Sarah, I sat with the participants, answering their questions on what information was required, where it should be placed and how to make it clear. We assisted with entering the text into the forms and helped look up pesticide information; checking whether they were on Plantwise’s Red List (containing internationally restricted/not to be used pesticides) and on the nationally approved lists.

Some PMDGs were placed on the walls so groups could gain ideas from each other’s factsheets, particularly since many management and control methods would be the same for each country. For this reason also, PMDGs were rotated around the groups, so that as the factsheets were circulated participants added to and edited what a country group before them had written, thereby maximising efficiency. By the final day 18 weed species had been covered, and 33 PMDGs and 30 descriptive factsheets had been produced – a fantastic outcome which was thanks to an engaging, friendly and hard-working group.

What will happen next?

The factsheets will now need to pass through a review process, whereby content will be edited by Plantwise and a weed specialist will validate the information. The final versions will be uploaded the PWKB, a key resource for extension workers, called Plant Doctors, who advise farmers on what action to take when a pest is impacting on their crop. Farmers bring their affected crop along to a local Plant Clinic where the Plant Doctor makes a diagnosis (find out more at www.plantwise.org). The factsheets will provide Plant Doctors with the tools they need to help farmers loose less of what they grow to crop weeds, increasing the amount of food they can sell and eat and ultimately improving their livelihoods.

What did I get out of it?

Firstly, I really enjoyed working with such dedicated and passionate participants, listening to them talk about their research and experience and how much they care about helping farmers. Many of them had farming backgrounds, and/or had close friends and family who were farmers, so they had a good understanding of the challenges they face.

Two particular subjects that we discussed with participants stuck with me; firstly, the presence and growing dominance of women in farming businesses. More and more men are leaving farms to go to the cities and towns to find jobs, which is not surprising when you consider the back-breaking work, high running costs, unpredictable outputs and slim profit margins. 60% of pre-harvest labour in Africa is hand weeding, mostly by women and children (who often have to leave school during peak weeding periods). 100 million women in Africa spend 20 billion hours weeding every year. Secondly, the extent to which pesticides are used unsafely and ineffectively is huge, with many farmers developing health problems from incorrect use, such as not wearing protective clothing or using too high a concentration. More than one participant mentioned that many farmers who use pesticides in Africa don’t eat the crops they spray because even they aren’t sure that they’re safe. Furthermore, there was a story of one farmer not being able to get their beans to market, consequently feeding those beans to their livestock, and their livestock dying from poisoning as a result.

It was also great to make new friendships with CABI staff members who I may not have been able to meet through my usual line of work. It was a really nice experience walking into a CABI office I’d never been to but still feeling welcome and a sense of familiarity. We’re often reminded of the ‘One CABI’ ethos at work but those words mean so much more when you actually experience it. It was not just lovely to meet Kenyan staff, but also to work with Marion, René and Sarah from Egham, UK.


Overall, it was fantastic to be part of a project with the purpose of improving people’s lives. These factsheets will directly help farmers to more effectively manage and control invasive weeds, improving yields and so resulting in more food and income for their families. The workshop experience was a reminder that there is still more work that needs to be done, but that by working together we can really make a difference.