Description, Biology, Life Cycle, Damage, Common Names, Images
- Host plants: a large number of shrubby species such as apple, pear, plum, cherry, olive, pomegranate (Punica granatum), quince, black currant, currant, Citrus, vine, oak (Quercus), ash (Fagus), willow (Salix), lime (Tilia), plane (Platanus), beech (Fagus), poplar (Populus), maple (Acer), tamarisk (Tamarix), etc.
- Adult: it does not feed and its lifespan is extremely brief, from 8 to 10 days. The female mates soon after it has emerged.
- Fecundity: about 1,000 eggs deposited in clusters on trees, preferably in places where the female can insert her ovipositor (crack, old larval gallery); she can occasionally lay in the ground.
- Egg: embryonic development lasts 7 to 23 days.
- Larva: the caterpillars at first remain clustered in a silken cocoon from which they eventually disperse at dawn or at dusk. They then bore into the tips of branches and shoots, then move downwards to attack the young parts of the tree (twigs, spurs, pouches, central veins and leaf peduncles on certain shrubby species).
The caterpillars generally move about to penetrate lower in the twigs and branches. After several migrations, the larvae attack the larger branches and the trunk, in which they form ascending galleries under the bark, then in the wood. The entry holes of the larvae are marked by small heaps of saw-dust and frass (in the shape of small cylinders) accompanied by sap outflows, particularly visible on the large branches, typically at a stage where the damage is already very advanced (*) .
- Annual cycle in the French meridional regions. The cycle lasts two years in septentrional regions.
- The adults appear from the beginning of June to August. The young caterpillars can be carried by the wind, attached to a silk thread. This mode of infestation is often predominant in young orchards; it also occurs on trees situated close to hedges and thickets. In spring, the larva continues boring its gallery only in the wood and often in the centre of the branch. Pupation occurs from April to July (*) .
The leopard moth is one of the most important pests of apple and pear orchards in Mediterranean regions (*) (and, in certain countries, of olive). The seriousness of the attacks varies according to the age of the plantations:.
- On young trees: 1 caterpillar is enough to kill a tree; 3-year-old trees can lose part of their structure. The attacked trees become extremely vulnerable to wind damage and the central axis system is permanently affected.
- Old trees are sverely damaged, particularly in dry years and on dry ground.
- Healthy trees resist attacks better (favourable influence of irrigation and of a balanced mineral supply).
- Trees weakened by leopard moth attacks are frequently subject to other xylophagous pests: hornet clearwing moth (Synanthedon myopaeformis), goat moth (Cossus cossus), bark beetles.
Furthemore, the old larval galleries serve as a refuge to the woolly aphid (Eriosoma lanigerum), which thus partially escapes from chemical treatments.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.