Depuis son introduction en 1996 à la Réunion, la bactérie Xanthomonas axonopodis pv. dieffenbachiae (Xad), agent du dépérissement de l’anthurium, fait l’objet d’une attention toute particulière. Cette bactérie provoque des dégâts importants sur le feuillage et les fleurs et conduit à un dépérissement irréversible des plants.
A new aphid pest of cypress, CInara cuppressivora was detected locally in January 1999. The pest has spread rapidly over the whole island during the months of winter and attacks cypress trees mainly Juniperus bermudiana which covers about 20 ha of forest land. In Mauritius, cypress plants have no economic value but are of great aesthetic importance locally. Six species of cypress are present, all of them being exotic. They are mainly planted as a decorative plant in gardens, public areas and private yards. Presently, a biological control programme is being implemented which seems to be an important and promising option for long term management of this pest as compared to chemical control measures.
Cutworms are caterpillars of moths that attack leaves and stems of leguminous crops, cereals, vegetable crops among which potatoes, etc… The young caterpillars feed on leaves that they perforate in an irregular way. The older caterpillars provoke more important damage. Being unable to go up the plants, these larvae hide in the superficial layers of the ground and feed at the base of the young plants at ground level. This provokes withering and drying of the attacked plants.
Les symptômes associés à ce virus sont très variables en fonction des espèces végétales et même parfois au sein d'une même espèce.
This little fly has a large range of host-plants. In Mauritius, it has been identified on several cultivated host-plants such as tomatoes, pepper, water melon, onion, potato and garden peas. The larva digs galleries in the leaves and spends there the three larva stages of its cycle. A the end of its growth, it makes an opening in the superior epidermis, gets away and becomes pupa in the ground. The length and the number of galleries vary according to the number of eggs deposited on the leaf as well as the duration of the attack. The damages can go up to complete defoliation of the attacked plant.
The spiralling whitefly is a small insect of white colour that owes its name to the spiral pattern of its egg laying. It provokes direct weakness of the plant by the nutrition of the larvae and the adults and indirect damages due to the secretions of the insect (honey dew) that make the leaves sticky and favour the development of sooty mould.
|
 |
|
 |
|
 |
 |
 |
 |
 |
 |
