PERKEMBANGAN POPULASI KUTU PERISAI AULACASPIS TEGALENSIS ZEHNTNER (HOMOPTERA: DIASPIDIDAE) DAN PENGARUH TINGKAT SERANGANNYA TERHADAP PENURUNAN HASIL TEBU DI PT GUNUNG MADU PLANTATIONS, LAMPUNG TENGAH

Population development of a scale insect Aulacaspis tegalensis Zehntner (Homoptera: Diaspididae)  and  effect of its infestation  on sugarcane  yield loss  in  PT  Gunung Madu Plantations, Central Lampung.   Sugarcane scale insect, Aulacaspis tegalensis,  is a new major pest of sugarcane in PT Gunung Madu Plantations (GMP).  A survey  was conducted at the experimental station of  the Research and Development Division of  PT  GMP to investigate the  population growth of  the pest and  effects of their infestation on sugarcane production.  The first study indicated  that the population of the pest started to grow when the host plants were at the age of  8 months and  reached a  peak (300 individuals/stem) on mature sugarcane plants (11 month old).  A low population of the pest at younger sugarcane plants  might be due to the fact that during  their first seven months of  growth, sugarcane plants had no stem or even if they had, the leaf sheaths were still closedly intact to the stem,  while the scale insects could  live and  survive optimally at the internodes under the leaf sheaths.   The second study showed that the first  pest outbreak occurred in 2000 which covered  162.27 ha of  sugarcane fields.  In the year of  2001, the infested area increased significantly (up to 1157.93 ha). In addition, the effect of the scale insect  infestation  caused an enormous yield loss. The losses could be  expressed as the reductions in: stem weight, pol (polarisation, sucrose  content), brix (total soluble solids), and sugar contents.