Analyse des Pontes de la Spongieuse, Lymantria dispar L. (Lepidoptera, Lymantriidae) sur Chêne Liège (Blida-Algérie)

In the last infestation of Gypsy moth, counting and egg mass biometrics were conducted in Bouarfa cork oak forest. The comparison of means showed a high significance between eggs mass quantified during the years 2007 and 2008 with respective averages of 135 and 29 per tree. At the second year, eggs mass measurements and quantification of eggs laid have found significant reduction surface of 40% and the 65% average number of eggs. Frequency analysis of surfaces and the number of eggs have revealed five classes for the two generations considered. The data confirm the typical pattern of a gradation of Lymantria dispar.