Presentation on theme: "Invasive species threatening Zimbabwe Water Hyacinth (Eichhornia crassipes Martius) is amonocotyledonous freshwater aquatic plant, belonging to the family."— Presentation transcript:
Invasive species threatening Zimbabwe Water Hyacinth (Eichhornia crassipes Martius) is amonocotyledonous freshwater aquatic plant, belonging to the family Pontederiaceae, related to the lily family (Liliaceae)and is a native of Brazil and Equador region. It grows from a few inches to about a met er in height. The stem and leaves contain air filled sacs, which help them to stay afloat in water. Water hyacinth is considered as anoxious weed in many parts of the world as it grows very fast and depletes nutrient and oxygen rapidly from water bodies, adversely affecting flora and fauna Water Hyacinth in Zimbabwe is a threat in rivers along the Manyame Catchment and Zambezi river basin
Invasive species threatening Zimbabwe Lantana camara is a small perennial shrub which can grow to around 2m in height and forms dense thickets in a variety of environments. Due to extensive selective breeding throughout the 17th and 18th Century for use as an ornamental plant there are now many different forms of L. camara present throughout the world. The fruit of L. camara is berry-like and turns a deep purple colour when mature. Both vegetative (asexual) and seed reproduction occur. Up to 12,000 fruits can be produced by each plant which are then eaten by birds and other animals which can spread the seeds over large distances, facilitating the spread of L. camara.
Invasive species threatening Zimbabwe Australian red claw crayfish (Cherax quadricarinatus) in Lake Kariba and the Zambezi river basin Omnivore, mainly detritus feeder, but also alleged to feed on eggs of other fish species and other aquatic species that form the base of the trophic triangle in the lake ecosystem (needs verification) Burrower and therefore threatens the structural integrity of hydro- electric installations
Invasive species threatening Zimbabwe The jumping cholla (Cylindropuntia fulgida) mainly found in Matebeleland South Province with the severely affected districts being Gwanda and Beitbridge. Rapidly spreading to other arid districts and threatening livestock and human settlements
Invasive species threatening Zimbabwe The weed spreads vegetatively and rarely through seed The thony plant segments are adapted to be spread by animal, bird and human traffic. Its ecology is largely unknown in the arid environments of Zimbabwe Current management strategies include cutting and burning (EMA) but the most sustainable management method is to release the biological control agent for Cylindropuntia fulgida, the cholla biotype of the cochineal insect Dactylopius tomentosus The jumping cholla (Opuntia fulgida) segments attached to a goat
Invasive species threatening Zimbabwe The black wattle, Acacia mearnsii De Wild. (Syn. A. mollissima Willd.; Acacia decurrens var. mollis Lindl.) is a major invasive species in the Eastern Highlands of Zimbabwe. Potentially over 200 000 ha is affected, most of it in the mist belt of the eastern highlands (1500- 1900 m altitude)
Invasive species threatening Zimbabwe The larger grain borer (Prostephanus trancatus) has already invaded Zimbabwe from Tanzania and will be a major threat to maize and other cereal grain stores in Zimbabwe.
Invasive species threatening Zimbabwe Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), also known as the bronze bug, is sap sucking Eucalyptus pest from Australia that has invaded Zimbabwe from South Africa
Invasive species threatening Zimbabwe Native to Queensland, Australia, Leptocybe invasa is currently spreading through out Zimbabwe from South Africa Adult wasps spread by flight and wind and introductions can be from nursery stock Severe gall formation and damage especially to Eucalyptus nursery stock Damaged trees show leaf fall, gnarled appearance, loss of growth and vigour, dieback and eventual tree death (Mendel et al., 2004)
Invasive species threatening Zimbabwe The red gum lerp psyllid (RGLP) (Glycaspis brimblecombei) is a foliar pest on red gum eucalyptus trees (Eucalyptus camaldulensis) from Australia that has invaded Zimbabwe from South Africa. International transport of nursery stock is the main method of spread. Adults are strong fliers
Invasive species threatening Zimbabwe The African invader (or Asian) fruit fly Bactrocera invadens, has recently invaded Africa from Sri Lanka. It had spread to more than 10 countries in Africa, including Mozambique, Zimbabwe, South Africa and Namibia. This fruit fly is highly invasive with a high reproductive potential, and has a long list of host plants, including citrus, mango, cashew, papaya, guava, pepper, and several wild host plants. The main pathway for fruit flies to spread from one country to another is through the international movement of infested fruits. Its base colour is blue-black with yellow patches in the mid- section, and a couple of paler stripes on the abdomen. Eyes are blue-black, and wings are clear with prominent, dark leading edges.