Vulnerability Climate Changes Index to Primary Productivity in the Java Sea

Source: SEAMEO BIOTROP's Research Grant | 2016


An experiment on the calassical biological control of C.odorata using its bioagent, C. connexa was carried out at BIOTROP, West Java, in a confined area under the shade of oil palm trees from March to November 2016.  The experimental design was factorial, the first factor was  C. odorata shoot tips density consisting of 3 levels, i.e. , 5, 10 and 20  shoot/ cage, and the second factor was with release and without release of 5 pairs of C.connexa imago to the caged C.odorata. There were 6 treatment combinations,  replicated 4x., and randomised completely. In March 2016,  24 plastic pots of 5 lt capacity were filled with  local soil fertilized with composted goat manure at 1:1 ratio, and planted with 3 cut stem of C.odorata . In June,  the potted C.odorata were selected and trimmed to have the required density and put in a cage measuring  50 x 50 cm with the height of 150 cm . The cages were made of wooden frame with plastic net of1 x 1 mm mess covering the whole sides to prevent parasites from entering the cage, and there were a total of 24 cages. In June 4, 5 pairs of C.connexa imago were released to the  apropriate cages. The release of C.connexa imago induced the production of higher vegetative shoot tips on higher initial shoot tip density. The release also induced the production of galls,however the reselase reduced the production of flower heads, especially after the second generation of C.connexa. The release of C.connexa require 2,5 months to generate the second generation. In that period a considerable new vegetative shoot tips were produced. It was suggested to release the imago at the ratio of 20: 5 or higher every 2-3 weeks for the first 2,5 months.

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