Life history of Aulacaspis marina Takagi and Williams (Hom., Coccoidea), anew pest of mangrove plantations in Indonesia, and its damage to mangrove seedlings

Scale insects of a newly described species, Aulacaspis marina Takagi and Wi lliams, have killed a large number of mangrove (Rhizophora mucronata Lamk.) saplings planted in abandoned shrimp ponds on Ball island, Indonesia. The mean fecundity of A. marina was 141 eggs. The generation time of this speci es was between 34 and 42 days, based on four generations, suggesting that t he species has nine to 10 generations a year on Ball island where the tempe ratures are seasonally constant. When crawlers of A. marina were transferre d to potted seedlings of R. mucronata, they settled on all leaves of the se edlings. Newly expanded leaves were not infested by the first generation cr awlers but were attacked by the following generations. The insect attack in duced browning of the leaves and finally caused leaf fall; the leaves fell 25-159 days after the crawler transfer. Consequently, the seedlings died on average 128 (range 82-159) days after infestation. This suggests that once a large number of crawlers attack R. mucronata seedlings, A. marina call k ill them within several months. When crawlers were transferred to potted se edlings of three mangrove species (R. mucronata, Rhizophora apiculata Bl, a nd Bruguiera gymnorrhiza L.), which were the main species planted at the st udy site, the numbers that developed into adult females did not differ sign ificantly among these species. This suggests that these mangrove species ar e almost equally susceptible to A. marina.