PENETUAN ALE DAN AE LARVA LEPIDIOTA STIGMA F PADA TANAMAN TEBU

Abstract

This research was conducted to determine the value of Economic Injury Level (EIL) and Economic Threshold (ET) for the larvae of Lepidiota stigma instar 1, 2 and 3 in three different locations. The amount of larvae population and plant per m² in the field, and the weight proportion of the vanished root or to-be-eaten by a larva were needed to determine the loss of result per m² data on the maximum harvest outcome and the harvest outcome in the field per m². The highest proportion value of the outcome loss per m² based on the Walker Model, which has been modified on biological control with Nematode Entomo Patogen (NEP) Steinernema spp. combined with light trap, was in Tempel Sari, i.e. larvae instar 1 (0.0108), instar 2 (0.0174), and instar 3 (0.0221). The lowest value was in Grenjeng, i.e. larvae instar 1 (0.0048), instar 2 (0.0078), and instar 3 (0.0099). There were significant differences among the three instars, where the consumption greediness of instar 3 is higher than instar 1 and 2, so the proportion value of the outcome loss per m² of larvae instar 3 in the respective locations was higher than that of the two other instars. Determination of EIL value based on the Bode & Calvin Models gave the highest EIL value in Grenjengwith larvae instar 1 in the amount of 15.50 with ET value 12.40, instar 2 in the amount of 9.59 with ET value 7.67, and instar 3 in the amount of 7.54 with ET value 6.03. On the other hand, the lowest EIL value was found in Tempel Sari, with larvae instar 1 in the amount of 6.97 with ET value 5.58, instar 2 in the amount of 4.31 with ET value 3.45, and instar 3 in the amount of 3.39 with ET value 2.71.