Judul: Bioaktivitas Ekstrak Kulit Batang Beberapa Jenis Tumbuhan Simaroubaceae dan Daun Tephrosia vogelii terhadap Larva Crocidolomia pavonana (F.) (Lepidoptera: Crambidae).
Abstrak: This study was conducted to evaluate the bioactivity of methanol stem bark extracts of some Simaroubaceae plants and ethyl acetate leaf extract of Tephrosia vogelii, either separately or in mixtures against-second instar larvae Crocidolomia pavonana, and phytotoxicity of the extracts on chinese cabbage. Bioassays with each active extract and their mixtures were done at six concentration levels with five replications, by a leaf dip feeding method. T. vogelii extract was 7.8 and 8.8 times more active than Quassia amara and Q. indica extracts, respectively, at LC50 level against C. pavonana larvae. T. vogelii extract at 0.25% inhibited feeding by C. pavonana larvae as high as 99.3% and caused 100% larval mortality. The mixture of T. vogelii and Q. amara extract was 3.6 and 3.8 times more toxic than T. vogelii and Q. indica mixture and had synergistic joint action both at LC50 and LC95 level. The treatments with all active extracts delayed the development of C. pavonana larvae from second to forth instar by 1.2-5.0 days compared with control. T. vogelii and Q. amara extracts and their mixture were not phytotoxic to chinese cabbage, and thus, they are potential to be used for controlling C. pavonana.
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Judul: Kesesuaian Ekstrak Piper spp. (Piperaceae) untuk Meningkatkan Toksisitas Ekstrak Tephrosia vogelii terhadap Ulat Krop Kubis, Crocidolomia pavonana
Abstrak: Crocidolomia pavonana is one of major pests of Brassica vegetable crops. One of the viable control alternatives against this pest is the use of botanical insecticides. This study was conducted to determine the suitability of extracts of Piper spp. (P. aduncum, P. betle, P. cubeba, P. retrofractum, and P. sarmentosum) to increase the toxicity of Tephrosia vogelii leaf extract against C. pavonana larvae. Plant materials were extracted separately with ethyl acetate and the resulting extracts were tested against second instar larvae C. pavonana using a leaf-dip feeding method. Extract-treated cabbage leaves were provided to the test larvae for 48 hours then the larvae were fed untreated leaves for the following 48 hours. The number of dead larvae was counted daily until day 4 then larval mortality data were subjected to probit analysis. At 96 hours after treatment (HAT), LC50 of T. vogelii, P. aduncum, and P. retrofractum extracts was 0.046%, 0.105%, and 0.125% respectively. The treatment with extracts of P. betle 1%, P. cubeba 0.6%, and P. sarmentosum 1% caused low larval mortality at 72 HAT, i.e. 16.7%, 10%, and 34.4%, respectively. LC50 and LC95 of mixtures of T. vogelii extract with P. aduncum and P. retrofractum extracts were smaller than those of each extract tested separately and the mixtures had synergistic joint action against C. pavonana larvae. Addition of P. sarmentosum extract 0.2% or boiled P. betle aqueous extract 10% somewhat increased the toxicity of T. vogelii extract. Thus, P. aduncum and P. retrofractum extracts are potential to be used in mixtures to increase the toxicity of T. vogelii extract, especially for controlling C. pavonana.
Keyword: Tephrosia vogelii., Piperaceae, synergistic joint action, botanical insecticide mixtures, Crocidolomia pavonana

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh.
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. ,,,
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular.