Description, Biology, Life Cycle, Damage, Common Names, Images
- The host is pear. Most attacked cultivars are, in Portugal, Passe Crassane, Comice, Douillard and Rocha. Other varieties are also attacked but less seriously. Williams and Guyot suffer little damage.
- The complete life-cycle is as follows: virginiparous females hatch from winter eggs giving rise to several generations of identical types of female. Sexuparae appear in September. These lay male and female eggs from which, in the autumn, the sexuales emerge. After mating these lay the winter eggs.
- In Portugal it is not known if the complete life-cycle, as described, occurs every year. No winter eggs have been found in certain areas. The overwintering form being then the parthenogenetic female (*) .
- In August sexuparae take shelter in the apical growth (*) especially on those of late varieties where this area does not close completely. The feeding activity of these females produces large black areas known by the French authors as "Cul noir" (*) , a symptom similar to an early Botrytis cinerea attack.
- These black areas will appear, sometimes on other parts of the fruit, for instance where a leaf or fruit touches another fruit. Occasionally the black lesions will occur in the peduncular groove.
- The commercial value of the damaged fruits will be severely reduced, often by 50% to 60%.
- The damage may occur:.
a) During the maturation period, on the tree.
b) During the cold storage together with the lesions caused by storage rots.
This insect is endemic in the main pear-producing districts of Portugal, where humid and temperate summers and mild winters prevail.
DE: Birnenzwerglaus ES: Tiña del peral FR: Phylloxéra du poirier IT: Fillossera del pero PT: Filoxera da pereira GB: Pear phylloxera, Pear bark aphid
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.