Occurrence and control of coconut scale (Aspidiotus Destructor Signoret) in bananas

• Main Author: Chou, Ming-Yi
• Other Authors: Mau, Ronald F L
• Published: University of Hawaii at Manoa 2009
• Online Access: http://hdl.handle.net/10125/6972

Field studies were conducted to determine the distribution of Coconut scale, Aspidiotus destructor Sign. in banana orchard. Populations with different densities were found year-round in the six surveyed orchards on the island of Oʻahu and Hawaiʻi. Significant reduction of infestation was found after two orchards adopted pruning culture practice. The spatial distribution within banana mat was investigated at sprayed and unsprayed orchard via Taylor's power law. Aggregative distribution (b=1.31) was found in the unsprayed field with highest infestation level among surveyed orchards. The sprayed orchard had a nearly uniform scale distribution (b=1.01) within banana cluster. Laboratory studies were conducted to evaluate insecticide compounds (diazinon, imidacloprid, pyriproxyfen and thiamethoxam) and hot water treatment as field control and quarantine control tactics. Complete control of nymphs was found in treatments of pyriproxyfen and thiamethoxam. Adults had various responses to the tested insecticides. Hot water treatments at 47 and 49°C were found successful for scale disinfestation. The minimum time requirement was 15 and 10 min for 47 and 49°C, respectively === viii, 78 leaves