Degree of Insect Damages on Four Specles of Indian Mahogany

บทคัดย่อ

Insect pests are major problems that hinder the growth and the development of the Indian Mahogany. Selecting for resistant species is one way to tackle the problems. Survey of damages caused by the shoot borer, Hypsipyla robusta Moore, and the root collar borer, Pagiophloeus longiclavis Marshall, was done in Toona ciliata M. J. Roem, Toona sureni (Blume) Merrill, Cedrela odorata L. and Cedrela augustifolia Sesse & Moc. It was found that H. robusta caused higher damage to T. ciliata than C. odorata On the other hand P. longiclavis showed more infestation on C. odorata than 5? ciliata. Damages from both insects in T. sureni and C. augustifolia were recorded but have not yet compared to other species due to t,he low survival percentage of the seedling resulted in small number of trees remaining.