BIOLOGY OF BAMBOO APHID (Pseudoregma sp.)

Abstract

Study on the bamboo aphid, Pseudoregma sp., was done in four provinces, Kanchanaburi, Ratchaburi, Chanthaburi and Bangkok throughout the year of 1989. The aphid belongs to the family Pemphigidae. It is a social insect and comprises of many classes. The special class is the sterile soldier, called Pseudoscorpion-like soldier, to protect the colony from predators and does not moult from 1^st instar larva. Bamboo serves as secondary host and styrax is primary host. From May to February, parthenogenesis was occured on secondary host and produced only morphs and soldier, but on November to February some morphs changed to alate and moved to the primary host. Sexual reproduction take place in the primary host for 2-3 generations. Aphid moved to the bamboo shoot again on May until July, aphid also feed on sap of young branches. The bamboo species that found affected by this aphid were Thyrsostachys siamensis Gamble, Dendrocalamus strictus Nees, Bambusa nana Roxb., B. arundinacea, B. ventricosa and B. flexuosa. Spraying of 2. 5% liquid soap solution can control this aphid in 12 hours. The national enemies were coccinelid beetle (Synonycha grandis Thunberg) and pyralid moth (Dipha aphidivora ( Meyrick)).