November 2, 2015 Leave a comment
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/iscRubus 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.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.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.
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 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)
- Mysore raspberry by Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)%5D, via Wikimedia Commons
- Common knotweed by Christian Fischer [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons
- Love-vine by Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)%5D, via Wikimedia Commons
- Portia tree by Forest & Kim Starr [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)%5D, via Wikimedia Commons