マツノハマルカイガラムシ

The pine needle Hemiberlesian scale Hemiberlesia pitysophila Takagi, an important pest of pine trees, is distributed in Okinawa and Sakishima Islands as well as Taiwan. It was accidentally introduced into China during the 1980's. A preliminary life table of the scale for a generation was developed from four population tables which were constructed for each sampling date from mid September to early October in 1989 at a census site in Ishigaki Island. Survival rate from the crawler to the ovipositing female was estimated as 8.41%. The highest stage-specific mortality was attained during the preovipositing adult stage, of which 30.6% was caused by parasitism. Among the parasitoids, an aphelinid Coccobius azumai Tachikawa was the dominant one, which was parasitizing in the scale at the stage from early adult to ovipositing female. Some biological and behavioural characteristics of the parasitoid C. azumai were investigated. The mean number of eggs deposited per female was 5.7, and the mean longevity of the ovipositing females was 9.3 days. One oviposition took 47 to 203 sec. Host-feeding behaviour was frequently observed, and took 203 to 346 sec. When the host was not given, the mean longevity of adults feeding on honey solution was 21.6 days in females and 16.2 days in males, while it was extremely decreased when the parasitoid was provided only water or without food. Both the longevity and the fecundity of C. azumai were remarkably smaller than those of the congeneric C. fulvus (Compere et Annecke), a parasitoid of Unaspis yanonensis (Kuwana) imported from China.