New in November and December 2015 from the ISC

In November and December 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.

By peganum from Henfield, England (Cotoneaster horizontalis) [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

1. Cotoneaster horizontalis

Cotoneaster horizontalis (wall-spray)

C. horizontalis is a woody, perennial, deciduous or semi-evergreen shrub with horizontally spreading branches, native to parts of China. It is an attractive garden plant with bright red berries which is the main cause for its widespread introduction across the world. In addition to keen gardeners, seeds of this plant are spread easily by birds. Unfortunately, it invades chalk grasslands (such as those of the South Downs in the UK), reducing species richness and diversity.

By Liné1 (Picture taken with my IXUS 800 IS) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

2. Cyperus papyrus

Cyperus papyrus (papyrus)

C. papyrus is a tall (up to 5 m), fast-growing, aquatic perennial sedge native to North Africa, well-known as being a source material for the making of paper (papyrus). Plumes of thread-like stems at the top of the plant make it particularly attractive and have resulted in its use as an ornamental plant and consequently its introduction to other countries. It can anchor itself in water via shallow roots or floats freely in clumps, facilitating its spread. The dense and extensive stands it can form can impede the flow of waterways and displace native species. It can reduce the amount of light that reaches submerged plants and can impact on habitats of wetland bird species.

Myroxylon balsamum (Peru balsam)

M. balsamum is a large tree of tropical America (40-45 m tall and 1 m wide) which produces lots of small whitish flowers and winged seedpods. Providing valuable timber and balsam resin, it has been widely introduced. It can form dense stands and can therefore outcompete native species by shading them. Characteristics which make it such a strong competitor include its large size, capacity for prolific seed production and ability to tolerate a wide range of light conditions. It is particularly problematic in Sri Lanka where native species can tolerate less varied light conditions and where natural enemies, such as diseases and insects, are absent.

By Meneerke bloem (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

3. Persicaria wallichii

Persicaria wallichii (Himalayan knotweed)

P. wallichii is a shrubby perennial herb that originates from the temperate western regions of Asia and the Indian subcontinent. It is reported as invasive in its native range of India and its non-native range of Belgium and the UK. In the USA, it can promote the erosion of river banks where it pushes out native stabilizing species, colonizes large areas, but then dies back in the winter. Furthermore, the dense mats of leaf litter it produces can prevent the germination of native species. It can compete for resources with trees and reduce shade along rivers and streams by displacing native woody species.

Roystonea oleracea

4. Roystonea oleracea

Roystonea oleracea (Caribbean royal palm)

R. oleracea is a palm that grows up to 40 m tall, with a distinctive, solitary, light grey, erect, cylindrical trunk. It is native to the Lesser Antilles, northern South America and Guatemala. This invasive species has been widely introduced for ornamental and landscaping purposes. It tends to be invasive in or near wetlands and can reduce diversity in areas where it becomes dominant. The dropping of large leaves and reproductive parts, which alter light intensity and humidity, have been proposed as possible reasons for these impacts. It is reported to be invasive in the swamps of the Guiana shield countries, in Panama and in the Atlantic forests of southern Brazil.

By Frank Vincentz (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons

5. Urtica dioica

Urtica dioica (stinging nettle)

U. diocia is a weedy species which, as many people know from experience, has hairs which can cause an itchy sting when touched. It occurs in pastures and grasslands in monospecific clumps which can take up considerable space and thus reduce hay yields and the amount of grass available. It is normally avoided by livestock, therefore restricting their free movement. In some circumstances it can be very hard to eradicate because of its large root mass which allows it to spread vegetatively once it has established.

Other new datasheets published in November and December include:

Acacia glauca (wild dividivi)
Argemone ochroleuca (Mexican poppy)
Canine distemper virus
Centella asiatica (asiatic pennywort)
Deroceras invadens (tramp slug)
Flacourtia indica (governor’s plum)
Portulaca quadrifida (chickenweed)
Solanum capsicoides (cockroach berry)
Tephrosia candida (white tephrosia)
Xyris complanata (yellow-eyed grass)

Figure references:

  1. Cotoneaster horizontalis by peganum from Henfield, England (Cotoneaster horizontalis) [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
  2. Cyperus papyrus by By Liné1 (Picture taken with my IXUS 800 IS) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
  3. Persicaria wallichii by By Meneerke bloem (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
  4. Roystonea oleracea by By Krzysztof Ziarnek, Kenraiz (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons
  5. Urtica dioica by By Meneerke bloem (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

 

New in October 2015 from the ISC

In October 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

Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

1. Mysore raspberry

Rubus niveus (Mysore raspberry)

Rubus niveus is an invasive blackberry which is threatening the endemic wildlife of the Galapagos Islands. More specifically, it is a threat to the unusual daisy tree forests (of the Scalesia genus). R. niveus now covers around 30,000 ha of the islands and can grow up to 3 m tall. CABI scientists are searching for potential biocontrol agents from the Asian native range of the blackberry to introduce here. Find about more about this project.

Christian Fischer [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

2. Common knotweed

Polygonum arenastrum (common knotweed)

This species is considered to be one of the world’s most economically important weeds. It is a host of various pathogens which damage crops such as alfalfa, potato and parsnip. Phytotoxic chemicals are produced by the plant that can inhibit the establishment of black medic (Medicago lupulina) and other plant species. It can also affect rhizome bacteria which are important for legume species such as peas and beans. The weed is very resilient as it possesses a long taproot which helps it survive drought.

Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

3. Love-vine

Cassytha filiformis (love-vine)

Invasive in its broad native range (Asia, Africa, America, Oceania), Cassytha filiformis is a parasitic vine that is primarily found in coastal areas. In the Chagos archipelago (Indian Ocean) it is seriously reducing populations of beach cabbage (Scaevola taccada) and increasing the risk of erosion. C. filiformis extracts plant sap from its host and covers it with a dense mat of stems. The sheer weight of its stems can break branches – this is particularly problematic when its host is a crop, such as a citrus tree.

 

Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

4. Portia tree

Thespesia populnea (portia tree)

Thespesia populnea is an Old World, tropical, coastal species that is often found in and around mangroves. Its buoyant and hardy seeds can survive even after a year in seawater. It produces dark, red-brown, strong and hard ‘milo’ wood that is highly valued on Pacific islands. However, it can form dense thickets and reproduces profusely. It is listed as an invasive species in the Bahamas, Florida and Puerto Rico.

Hypogeococcus pungens (cactus mealybug)

Hypogeococcus pungens is a mealybug, native to South America, which was used as a biological control agent of invasive cacti in the subfamily Cactoideae in Queensland, Australia, and in South Africa. Since then, it has become an invasive species itself. It is a threat to native cacti in Florida and Hawaii (USA), Barbados and other Caribbean islands. In addition to cacti, its wide range of hosts includes species within the ornamental plant families Portulacaceae, Apocynaceae and Amaranthaceae.

Other new datasheets published in October include:

Baccharis pilularis (coyote brush)
Cuphea carthagenensis (Colombian waxweed)
Cyrtomium falcatum (Japanese holly fern)
Epilobium ciliatum (northern willowherb)
Maliarpha separatella (African white rice borer)

Figure references

  1. Mysore raspberry by Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)%5D, via Wikimedia Commons
  2. Common knotweed by Christian Fischer [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons
  3. Love-vine by Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)%5D, via Wikimedia Commons
  4. Portia tree by Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)%5D, via Wikimedia Commons

New in September 2015 from the ISC

In September 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

Common mullein by Fritz Geller-Grimm (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0), CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0), GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

1. Common mullein

Verbascum thapsus (common mullein)

A biennial herb which has naturalized in most temperate regions of the world. It grows vigorously, threatening native plants in meadows and forest gaps. Eradication is extremely difficult since each individual can produce 100,000-175,000 seeds that can remain viable for more than 100 years.

Fibropapillomatosis of sea turtles by Peter Bennett & Ursula Keuper-Bennett (Original photograph) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

2. Fibropapillomatosis

Fibropapillomatosis of sea turtles

A disease which most commonly affects the endangered green turtle. It causes internal and external tumours which can obstruct crucial functions such as swimming and feeding. First reported in the 1930s in Florida, it is now a pandemic.

Grey snake-bark maple by KENPEI (KENPEI's photo) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY-SA 2.1 jp (http://creativecommons.org/licenses/by-sa/2.1/jp/deed.en)], via Wikimedia Commons Mnemiopsis leidyi (sea walnut) http://www.cabi.org/isc/datasheet/75102

3. Grey snake-bark maple

Acer rufinerve (grey snake-bark maple)

With striped grey-green bark this tree is aptly named. It produces dense thickets and has been reported as an aggressive coloniser in acidic forests in Belgium. It has been introduced around the world as an ornamental plant, like so many other invasive species.

Sea walnut by No machine-readable author provided. Bastique assumed (based on copyright claims). [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY-SA 2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons

4. Sea walnut

Mnemiopsis leidyi (sea walnut)

Being a comb jelly, this marine species has rows of ‘combs’ (groups of cilia) which it uses for swimming. It is an ‘ecosystem engineer’ which can change water transparency and water nutrient content. It has the impressive ability to regenerate from fragments larger than one-quarter of an individual.

 

Ficus microcarpa (Indian laurel tree)

A high-risk, aggressively invasive, strangling fig which is an agricultural weed and “garden thug” – how much worse could it be!? Reportedly invasive to some places where its specialist pollinator wasp has also been introduced. It starts life as an epiphyte, growing on a tree’s surface, before sending its aerial roots down to the ground. The roots end up forming a lattice around the trunk of the host tree which remains after the host tree dies.

Figure references

  1. Common mullein by Fritz Geller-Grimm (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0), CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0), GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons
  2. Fibropapillomatosis of green turtle by Peter Bennett & Ursula Keuper-Bennett (Original photograph) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)%5D, via Wikimedia Commons
  3. Grey snake-bark maple by KENPEI (KENPEI’s photo) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY-SA 2.1 jp (http://creativecommons.org/licenses/by-sa/2.1/jp/deed.en)%5D, via Wikimedia Commons
  4. Sea walnut by ‘No machine-readable author provided’. Bastique assumed (based on copyright claims). [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY-SA 2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)%5D, via Wikimedia Commons

New in August 2015 from the ISC

In August 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


August

Bidens frondosa (beggarticks) – native to North America, this herbaceous annual has a range of medicinal, herbal and decorative uses and been introduced throughout Europe as well as New Zealand and parts of Asia. The seeds can easily attach to fur and clothes, helping spread the plant to new areas.

Opuntia elatior (red-flower prickly pear) – the prickly pears are proving a prickly problem, with many Opuntia species invasive outside of their native range. O. elatior is less widespread than some, but has still been introduced to India, Southeast Asia, South Africa and Queensland. Biological control has had some success with this species.

Stictococcus vayssierei (cassava root mealybug) – found in Equatorial Africa, S. vayssieri feeds on the root system of the cassava plant, causing leaf-fall, wilting, tip dieback and occasionally death. Although it has only been reported in Cameroon and the Democratic Republic of Congo, the cassava root mealybug can cause yield losses of up to 100% and could pose a major threat to cassava production in Central Africa.

New in July 2015 from the ISC

In July 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

July invasivesAkebia quinata (five-leaf akebia) – a highly invasive, aggressive vine native to East Asia, A. quinata has been introduced as an ornamental to Canada, Europe, Oceania and the USA. It can outcompete native understory plants and young trees, and its dense growth can block sunlight and prevent the germination of native plants.

Geophagus brasiliensis (pearl cichlid) – an ornamental freshwater fish native to southeast Brazil, G. brasiliensis has been introduced to Australia, Florida, the Philippines and Taiwan. Its fast growth, opportunistic diet and broad environmental tolerances have allowed it to colonize new waterways, particularly artificial and disturbed habitats.

Rudbeckia laciniata (thimbleweed)R. laciniata is an ornamental perennial plant that has been introduced to China, Japan, New Zealand and Europe. Native to eastern North America, thimbleweed grows best in bright, humid areas, such as wetlands, forest edges and roadsides. By producing lots of seeds and spreading from rhizome fragments, it can form dense monocultures which outcompete native plants.

Other invasive species datasheets recently published include:

Brugmansia suaveolens (white angel’s trumpet)
Chrysemys picta (painted turtle)
Macaranga tanarius (parasol leaf tree)
Paederia foetida (skunkvine)
Umbra pygmaea (eastern mudminnow)

Investigating the impacts of the invasive species Prosopis in Baringo, Kenya

The Baringo district northwest of Nairobi is one of the regions in Kenya where a number of mesquite species, Prosopis spp., were introduced some 40 years ago as part of poverty alleviation efforts. The trees were intended to provide, among other benefits, additional income.

Today Baringo is one of the most heavily invaded regions in eastern Africa, with severe consequences for the rural communities. As part of the kick-off meeting of the recently launched, Swiss government funded R4D (research for development) project called “Woody Weeds”, the project team visited the district, one of the case study areas in the project.

During this two-day visit, two communities were visited which suffered from high Prosopis invasion levels. These communities gave an interesting first insight into the dilemmas that have arisen due to Prosopis invasion. The first community we visited utilizes Prosopis for charcoal production and hopes to benefit in the future also from selling Prosopis wood to a local power plant; by utilizing this invasive species the community members gain some financial benefits and at the same time reduce the impacts of this plant on their land.

Irrespective of how the local communities deal with this invasive species, one of the main challenges in management is to find ways to slow down or reduce the spread of Prosopis and mitigate its negative impacts in Baringo (and elsewhere). While the government of Kenya supports local communities in utilizing Prosopis, there is, so far, little scientific evidence that utilization indeed slows down or even stops the spread of this aggressive invader.

One of the key tasks of the “Woody Weeds” project will therefore be the evaluation of the impacts on the environment and rural livelihoods of the various management options against Prosopis and other woody invasive species, such as management by utilization, physical, chemical or biological control, or doing nothing, and to inform decision-makers about the key findings.

Urs Schaffner, CABI

New in June 2015 from the ISC

It’s been a bumper month for the ISC, with 42 new datasheets published and the total number of full datasheets topping 2000. You can explore the open-access ISC here: www.cabi.org/isc


A selection of new datasheets published to the ISC in June 2015.

A selection of new datasheets published to the ISC in June 2015.

Bothriocephalus acheilognathi (Asian fish tapeworm) – in the past few decades this tapeworm has spread from its native East Asia to all continents except Antarctica, largely thanks to the aquaculture and pet trade. A parasite of over 200 fish species, infections of B. acheilognathi negatively impact the aquaculture industry and have been responsible for 90% mortality rate in grass carp in the past. Environmental impacts are still largely unknown, but the Asian fish tapeworm is thought to be adversely affecting some endangered species.

Deparia petersenii subsp. petersenii (Petersen’s lady fern) – an aggressive, fast-growing perennial fern that can form thick ground cover and outcompete native plants. Native to Asia, New Guinea and Polynesia, Petersen’s lady fern has been introduced as an ornamental and is now invasive in Madeira, the Azores, southeastern USA, southeastern Brazil and Hawaii.

Trioceros jacksonii (Jackson’s chameleon) – native to Kenya and Tanzania, this chameleon has been introduced via the pet trade to California and Hawaii. It may pose a threat to native Hawaiian insects and snails that it preys on.

Read more of this post

Follow

Get every new post delivered to your Inbox.

Join 232 other followers