Ebola and IAS

A conversation with Dr Arne Witt

Dr Arne WittThe recent outbreak of Ebola virus disease in West Africa made headline news around the world. During the outbreak this fatal disease, endemic to parts of Central and West Africa, rapidly spread from Guinea, Sierra Leone, and Liberia to other countries in the region such as Nigeria, Mali and Senegal and then further afield to the USA, UK and Spain, mainly through infected health workers. This prompted decisive action from governments around the world and led to the implementation of strict controls at most national points of entry – as a result of this action and increased awareness, the further spread of this disease was effectively halted. No new infections have been reported for a number of months now but the cost has been significant – more than 10,000 people lost their lives, mainly in Guinea, Sierra Leone, and Liberia. However, it is highly probable that without significant interventions the costs could have been far higher. For example, the outbreak of bubonic plague or Black Death in Europe in the 17th century resulted in the death of 34 million people. The accidental introduction of potato blight, a crop disease which affects potatoes, from the Americas to Ireland in the mid-1800s contributed to the starvation of about 1 million people. Rinderpest, a disease affecting livestock was accidentally introduced to Africa from Asia in the late 19th century resulting in the deaths of, it is claimed, a third of the human population of what is now Ethiopia and two-thirds of the Maasai, an ethnic group of pastoralists in East Africa who are totally dependent on livestock. We may ask what Ebola, potato blight and rinderpest have in common – well obviously they have all have had a devastating impact on humanity but what binds them all together is that they are all INVASIVE ALIEN SPECIES (IAS). Fortunately, due to concerted efforts by a range of agencies rinderpest has been eradicated from the planet but as a result of increased trade, travel and tourism more and more species are being moved around the world and many are establishing and are continuing to have devastating impact on livelihoods. Read more of this post

Tuta absoluta on the rampage in Africa

Watch a new video illustrating the devastating impacts that Tuta absoluta is having on tomato yields, and what this means for farmers who rely on these crops for sustenance and income.

Dr Arne Witt, from CABI commented on the implications of Tuta absoluta infestation across Africa

“Tomatoes are one of the most widely cultivated crops in Africa and are grown in the backyards of almost every homestead across sub-Saharan Africa. This important cash crop and source of vitamins is now threatened by the recent arrival of the tomato leafminer, Tuta absoluta.

This Invasive Alien Species is rapidly moving down the African continent, having already decimated crops in Egypt, Ethiopia, Kenya and northern Tanzania. Growers are at their wits end as to how best they can control this pest and many have abandoned tomato growing altogether. The race is on to prevent its spread further south with various interventions planned to mitigate its impact in areas where it is already present.”

For more information on Tuta absoluta visit the Invasive Species Compendium and the Plantwise Knowledge Bank.

New in February 2015 from the ISC

In February 2015 the following datasheets were published on CABI’s Invasive Species Compendium (ISC). You can explore the open-access ISC here: www.cabi.org/isc

February

Furcraea foetida (Mauritius hemp) – native to Central America, this evergreen perennial has been introduced worldwide as an ornamental, for its fibre and for erosion control. However, F. foetida can grow up to three metres across, compete with surrounding vegetation and displace native plants, and as a result has become dominant on many tropical islands and atolls around the world.

Hypostomus plecostomus (suckermouth catfish) – as a popular ornamental fish, H. plecostomus has been introduced to the Americas, Asia and Europe from its native range in northern South America. But this armour-plated, egg-guarding, hypoxia-proof omnivore can quickly monopolise resources and inhibit other aquatic organisms. By building nests in river banks and sediment, the suckermouth catfish contributes to bank erosion and increased turbidity, with associated environmental and socioeconomic impacts.

Bythotrephes longimanus (spiny waterflea) – the invasion of the crustacean B. longimanus in the North America Great Lakes has resulted in a marked decline of both the density and diversity of many copepod zooplankton species, with long-lasting effects in invaded systems. It has also been responsible for a large-scale shift in the zooplankton community and competes directly with planktivorous fish for food.

Other invasive species datasheets recently published include:

Adenostoma fasciculatum (chamise)

Adiantum hispidulum (rosy maidenhair fern)

Belonesox belizanus (pike killifish)

Bromus hordeaceus (soft brome)

Buddleja asiatica (dog tail)

Desmodium incanum (creeping beggerweed)

Euphorbia hypericifolia (graceful spurge)

Hymenachne amplexicaulis (hymenachne)

Lepomis microlophus (redear sunfsh)

Mikania scandens (climbing hempvine)

Polistes dominulus (European paper wasp)

Salvelinus namaycush (lake trout)

Simosyrphus grandicornis (flower fly)

New in January 2015 from the ISC

In January 2015 the following datasheets were published on CABI’s Invasive Species Compendium (ISC). You can explore the open-access ISC here: www.cabi.org/isc.

Clerodendrum thomsoniae Invasive Species Compendium datasheet

Clerodendrum thomsoniae Invasive Species Compendium datasheet

Clerodendrum thomsoniae (bleeding glory bower)native to West Africa, this vine has been widely cultivated in tropics and subtropics worldwide, and is naturalised in many places, including the USA, Australia and the Galapagos Islands. Despite being related to some particularly serious invasives, such as C. chinense and C. quadriloculare, the impacts of bleeding glory bower are so far limited.

Cortaderia jubata (purple pampas grass)familiar to many of us as a garden ornamental, C. jubata is a multipurpose tussock grass native to South America. Surprise surprise, this towering, fast-growing, prolific plant has become a serious invasive in several places around the world, displacing native vegetation and suppressing the growth of young trees. Dense stands of C. jubata can also pose a fire hazard.

Opuntia monacantha (common prickly pear) – another introduced Opuntia, another tale of woe. Opuntia monacantha has been introduced around the world as a fruit and fodder plant since the 1700s. Its ability to regrow from broken and scattered cladodes allows it to quickly form dense, impenetrable thickets. Fortunately, biocontrol of the common prickly pear has proved successful in several countries.

New in November 2014 from the ISC

In November 2014 the following datasheets were published on CABI’s Invasive Species Compendium (ISC). You can explore the open-access ISC here: www.cabi.org/isc

Clerodendrum indicum Invasive Species Compendium datasheet

Clerodendrum indicum Invasive Species Compendium datasheet

Clerodendrum indicum (Turk’s turban) – this small shrub, native to temperate and tropical Asia, has been deliberately introduced principally to the Americas as an ornamental. Having long since escaped from cultivation, it is now established in the neotropics. Rapid growth and the ability to reproduce by seeds, rooted cuttings and suckers have contributed to its spread, although C. indicum does not appear to be as invasive as other species in the Clerodendrum cohort.

Potamopyrgus antipodarum (New Zealand mudsnail) – native to New Zealand, this aquatic snail has been introduced to Europe, North America, Australia and Asia. Females are parthenogenetic, meaning they can reproduce without males. This allows a new population to be founded by a single female – and with an average of 230 offspring per adult per year, P. antipodarum can quickly become very abundant. Its ability to survive desiccation for several days allows this snail to be spread by birds and anglers. It is currently considered invasive in Spain, USA and Australia.

Cosmos caudatus (wild cosmos) – thanks to its prolific seed production wild cosmos can cause chaos in the tropics, where its fast growth and height (up to 2.5 m tall) makes it difficult to control. Thought to be native to southern Mexico, it is now found in Asia, Africa, throughout the Americas, Australia and some Pacific islands. C. caudatus is particularly adept at spreading in disturbed areas, pastures and roadsides.

 

Other invasive species datasheets recently published include:

Cyclosorus parasiticus (parasitic maiden fern)
Vulpia myuros (annual fescue)
Clerodendrum bungei (rose glorybower)

New in October 2014 from the ISC

In October 2014 the following datasheets were published on CABI’s Invasive Species Compendium (ISC). You can explore the open-access ISC here: www.cabi.org/isc

Silybum marianum Invasive Species Compendium datasheet

Silybum marianum Invasive Species Compendium datasheet

Silybum marianum (variegated thistle) – this large, aggressive thistle was already recognised as a serious invasive way back in the 1800s. Native to the Mediterranean and parts of Asia and Russia, S. marianum is now present on every continent except Antarctica. Standing up to two metres tall, and armed with a spiky flowerhead and prickly leaves, the thistle can outcompete native plants, swamp farmland and impede the movement of people and animals. If eaten, S. marinaum can cause potentially fatal nitrate poisoning.

Lumbricus terrestris (lob worm) – after more than 2000 years of human-mediated introductions, the humble earthworm is now found in South Africa, India, Australia, New Zealand, Europe and North America, where it has picked up the exciting name nightcrawler. When introduced to an environment lacking native earthworms, L. terrestris can dramatically alter soil profiles. Thick leaf mats are quickly converted to humus, depriving native invertebrates of a habitat, altering the microbial community and changing the chemistry of the forest floor.

Cestrum nocturnum (night jessamine) – native to Central America, this showy and fragrant but toxic shrub is now widespread throughout the Old and New World tropics, where it forms dense thickets that crowd out native flora. Its small and profuse seed means there is a high risk of further introductions. C. nocturnum is known to be invasive in Hawaii, the Cook Islands, Fiji, French Polynesia, Western Samoa, Tonga, New Caledonia and New Zealand.

Other invasive species datasheets recently published include:

Acacia hockii (white thorn acacia)
Amaranthus dubius (spleen amaranth)
Dipsacus fullonum (common teasel)
Ehrharta erecta (panic veldtgrass)
Erodium botrys (long-beaked stork’s bill)
Erodium cicutarium (common storksbill)
Gaillardia pulchella (Indian blanket)
Glechoma hederacea (ground ivy)
Hypochaeris radicata (cat’s ear)
Juncus planifolius (broadleaf rush)
Lactuca floridana (woodland lettuce)
Lolium perenne (perennial ryegrass)
Lonicera maackii (Amur honeysuckle)
Malva pusilla (round-leaved mallow)
Marrubium vulgare (horehound)
Melilotus albus (honey clover)
Mentha pulegium (pennyroyal)
Nasturtium microphyllum (one-row watercress)
Odontonema callistachyum (purple firespike)
Oryza barthii (African annual wild rice)
Oxalis corniculata (creeping woodsorrel)
Parentucellia viscosa (yellow glandweed)
Paspalidium geminatum (Egyptian paspalidium)
Persicaria punctata (dotted smartweed)
Polycarpon tetraphyllum (fourleaf allseed)
Rosa multiflora (multiflora rose)
Rubus rosifolius (roseleaf raspberry)
Sanchezia parvibracteata (sanchezia)
Silene gallica (common catchfly)
Stenotaphrum secundatum (buffalo grass)
Tibouchina herbacea (cane tibouchina)

Invasive myrtle rust impacts discussed at international forestry congress

CABI has recently published a comprehensive review and update of its ISC datasheet on the globally important pathogen Puccinia psidii, commonly known as myrtle rust or guava rust. This problematic fungus is of worldwide importance and is capable of infecting a wide range of hosts. To date it has over 440 host species; affecting many plants in the Myrtaceae family, including threatened and endangered species (see IUCN Red List of Threatened Species). Severe impacts have been recorded in amenity plantings, commercial plantations and the native environment.

Once established in a new country myrtle rust can spread quickly and this has been the case in many countries including Jamaica, Hawaii, Australia and New Caledonia. Its successful global and local dispersal through urediniospores and human-aided movement of diseased plants, combined with its massive host range make myrtle rust an effective and devastating invasive. It was first identified as an invasive pathogen in the 1930s when it caused extensive damage to allspice (Pimenta dioica) plantations in Jamaica.

Puccinia psidii on Melaleuca quinquenervia in Australia

Effects of the invasive myrtle rust (Puccinia psidii) on the paperbark tree (Melaleuca quinquenervia) in Australia (July, 2011)

Discussions of myrtle rust impacts and a variety of other forestry related issues are currently underway at the 24th IUFRO World Congress, which is being held from the 5th-11th October 2014 in Salt Lake City, USA.

IUFRO is the International Union of Forest Research Organizations – the world’s forest network. The organisation promotes global cooperation on forest-related research and is composed of over 15,000 scientists from 650 member organizations in more than 100 countries.

The Congress is the largest forest research conference worldwide and is held every 5 years. It brings together delegates from varying forestry backgrounds and this year over 3500 scientists, researchers, graduates, decision makers, policy makers and land managers are expected to attend the event, which is focused on “Sustaining Forests, Sustaining People: the Role of Research”. Over the course of the week a number of plenary, sub-plenary, technical and poster sessions will cover themes, such as:

Under the theme of Forest Health in a Changing World, a session dedicated to emerging invasive forest pathogens will see notable speakers discuss the impacts of myrtle rust in the southern hemisphere, including its effects on diversity in both Australia and Hawaii (see p103-104 of the Scientific Program). This session will also focus on ash dieback and the invasive pathogen Hymenoscyphus pseudoalbidus, which causes the disease in ash trees. This pathogen has recently been causing severe impacts across Europe.

For full details of the distributions, impacts, descriptions (and much more!) of both ash dieback and myrtle rust you can access the fully updated and peer reviewed datasheets on CABI’s open access Invasive Species Compendium.

To keep up to date with all the latest news from the 24th IUFRO World Congress, visit the blog here.

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