Host range: The number of host range is over 400 kind plants. Meanwhile attacks olive, carob, citrus, mulberry, acacia, oleander, cissus, plum and other various trees.
Occurrence and importance:
This is because of piercing and sucking insect that has as result the weakness of the tree, leaf fall, drying of shoots and the deformation of fruits. This is very serious for the quality of table olives.
Small spots on the fruit olives and honeydew on the shoots and leaves
are the most common symptoms.
Description of pest:
This insect has three phases during its life, egg, nymph and adult. At the beginning, eggs are laid under the protection of female where they develop and hatch. They have yellow colour. The next phase after hatching is the nymphal phase with legs. In this phase the insects are called crawlers and they can remain under maternal protection many hours until the climate conditions outside are prosperous. When they are free from the cover they wander and finally they cause damage on the leaves or/and begin to secrete their internal future nympls. Newly nymphs piercing into the tree, sucking mouthparts into tree tissue and start feeding on sap.
Adult female has
size 1,8 to 2,2 mm in diameter and its colour is brown to more dark
and matt. On the other side male is smaller (1mm long) with yellow colour
and is egg-shaped.
Aspidiotus nerii has three generations per year. We have the appearance of young nymphs in March - April, then in July and in October again. However the period from April until October, on the tree there is possibility to be found the all phases of the insect.
Insect prefers to stay under the leaves of the olive tree and female laid eggs for 5-12 days and produce approximately 150 eggs. Reproduction is parthenogenetic and the appropriate duration for nymphs is 40-50 days. The first generation starts from March-April and develops in 8-9 weeks, as the second generation also needs the same time. Finally the third generation starts from September - October for six months during the winter period.
There are parasites that attack Aspidiotus nerii. The most common are Aphytis chrysomphalis, Aphytis chilensis, Aphytis melinus, Aspidiotiphagus citrinus, Chilocorus bipustulatus, Rhyzobius lophanthae, Scymnus subvillosus, Exochomus quadripustulatus and Chrysoptera carnea.
Effective mechanical control is to scrap and scrub in order to be removed Aspidiotus nerii from plants.
Apart from the above methods there is also a possibility of chemical control.
Useful insecticides are in the following table: oleander.doc