Pengaruh Provenan Sengon Terhadap Perkembangan Larva Boktor (Xystrocera Festiva Thoms) Dalam Makanan Buatan (Artificial Diet)

Abstract

Problem which is most commonly encountered in the management of sengon plantation forest, at present was the attack by stem borer insect Xystrocera festiva Thoms, a pest which is more often referred to as boktor, uter-uter, wowolan, and engkes-engkes. Up to now, the effective and efficient specific control for boktor pest, has not been discovered yet. One method which had ever been practiced was slicing the sengon bark and discarding the boktor larvae existing inside the tree. However, this practice will damage the physiological process of sengon trees, and this will in turn reduce the quality and price of sengon wood. One of the cause which makes the control of boktor has not been fully successful is the lack of knowledge concerning this insect, particularly in its larval stadium (the damaging phase), when this insect larvae live under the bark, which makes the study of biology and physiology of the insect difficult. For overcoming this phenomenon, a laboratory research was conducted where the boktor insects were reproduced and observed while being raised using artificial diet. This research was useful for obtaining information on the behavior and life cycle of boktor. The objectives of this research were learning the effects of provenance, tree health condition (sick or healthy condition of trees) and artificial diet on the growth of boktor larvae, and seeking the appropriate composition of artificial diet for boktor larvae. Materials used in this research were sengon wood powder from Kediri and Subang provenance with two kinds of tree condition (sick and healthy trees) while each of them had undergone freeze drying process, yeast extract, streptomycin, sucrose, agar, aquadest, vitamin C, vitamin B, benzoate, NaCl, dolomite, olive oil, and small sized boktor larvae (1.4 – 2.4 cm). The parameters observed and measured were larvae weight, weight of consumed food by the boktor larvae, larvae length, and diameter of boktor larvae head. Observation and measurements were conducted each week for 8 weeks, while conducting also food change. Results of analysis of variance showed that the provenance factor exhibited the greatest and significant effect on larvae growth (larvae length, diameter of larvae head) and amount of food consumed by the boktor larvae. On the other hand, factor of tree condition did not create significant effect on all parameters for 7 weeks. Factor of tree condition was seen to have effect on week 8. Patterns of average growth of larvae weight and length, for all treatments showed significant decrease in week-5 and 6. This phenomenon occurred because at week 5 and 6, many larvae underwent ecdysis (molting). Results of Duncan test showed that Subang provenance gave the best effect. The best growth of boktor larvae, namely those of Subang provenance had larvae length increment of 2.53 mm and larvae head diameter increment of 0.166 mm. Feeding behavior of boktor larvae during the laboratory research, using artificial diet, was similar with that in the field. Keywords: sengon, artificial diet, boktor