2022 Volume 12 Issue 1 Pages 22-28
Assessment of associated insects and leaf damage caused by insects is essential concerning decisions to contribute to developing suitable rehabilitation techniques. Few studies have been done to identify the insect species associated with dipterocarp species and determine the damage caused by insects and their growth performance. Six species of dipterocarps, namely: Dipterocarpus alatus (hairy leaf apitong), Hopea philippinensis (gisok-gisok), Shorea malibato (malibato), Shorea assamica (manggasinoro), Shorea polita (malaanonang), and Shorea almon, were studied. This study was conducted to determine the insect-associated fauna using the visual and handpicking method of insect collection, leaf damage assessment using the Bioleaf app, and the morphological traits (i.e., basal diameter and plant height) on the growth performance of dipterocarps. There were eight orders of insects associated with the dipterocarps: Coleoptera, Diptera, Hemiptera, Heteroptera, Hymenoptera, Lepidoptera, Odonata, and Orthoptera. There was a significant difference (p ≤ 0.05) in the leaf damage among the six dipterocarps species after 25 months from planting. Shorea assamica had the highest leaf damage (8.68% ± 0.09), and Shorea almon had the least leaf damage (2.57% ± 0.09). In terms of basal diameter, the species with the highest significant increment (p ≤ 0.05) was Shorea polita (2.49 ± 0.67 mm), while Shorea almon had the least growth increment (0.98 ± 0.67 mm) 25 months after planting. Dipterocarpus alatus grows faster for the plant height than other species with a significant increment (p ≤ 0.05) of 32.90 ± 0.19 cm, while Shorea assamica had the least increment of (4.95 ± 0.19) cm. The study indicated eight orders of insects associated with the dipterocarps showing significant damage on the S. assamica. Despite the insect association, the plants grow significantly with the rapid increase observed on D. alatus.
