Judul: Biological Activities of Extract Mixtures of Tephrosia vogelii (Leguminosae) and Annona squamosa (Annonaceae) against Crocidolomia pavonana.
Abstrak: The use of botanical insecticides is one of pest control tactics that has several advantages, such us easily biodegradable in the environment, slow development of insect resistance, synergism of extract components so that they are more effective, short persistence, and generally safe to non-target organisms. Insecticidal properties of Tephrosia vogelii leaf and Annona squamosa seed extracts have been well established, but the evaluation of toxicity, effect on fecundity, and effect on oviposition of T. vogelii and A. squamosa extract mixture against Crocidolomia pavonana has not been done. The objectives of this study were to evaluate the toxicity, effect on fecundity, and effect on oviposition of T. vogelii leaf extract and A. squamosa seed extract and their mixtures against C. pavonana. In the toxicity test, ethyl acetate extract of T. vogelii leaves and methanol extract of A. squamosa seeds and their mixtures were tested by a leaf-dipping method against second-instar larvae of C. pavonana. Each test extract was tested at six concentration levels in the range of 0.025%-0.190% and 0.004%-0.020% for T. vogelii and A. squamosa extracts, respectively. The extract mixture was tested at three concentration ratios, i.e. 1:1, 9:1, and 1:9, with concentrations ranges of 0.0050%-0.0400%, 0.025%-0.200%, and 0.004%-0.020%, respectively. Each treatment and control were replicated five times. Observation was conducted from 24 to 96 hours after treatment (HAT). The number of dead larvae was recorded. Larval mortality data was analyzed by probit method using POLO-PC. The fecundity test was conducted using T. vogelii and A. squamosa extract and their mixture which has the highest toxicity at LC25 and LC50 levels. Treated leaves were fed to second, third, and fourth instar C. pavonana larvae by a leaf-dipping method for 48 hours. The emerging adults were paired to obtain 15 pairs for each test concentration and control. The number of eggs laid each day was collected and counted. The adults were maintained until death. The total egg production and the fecundity per day were analyzed using analysis of variance followed by Duncan's multiple range test (α = 0.05). The tests on antioviposition effect was conducted using T. vogelii and A. squamosa extract and their mixture with a concentration ratio of 1:9 at LC99 and 2 x LC99 levels. The test extracts were prepared in the same way as in the toxicity test. Broccoli plants used were 1 month old (possessing 5 leaves) and 2 month old (possessing 8 leaves). Broccoli plants were sprayed with extract preparations until run-off. Four broccoli plants consisting of 2 treated broccoli plants and 2 control plants were placed alternatingly in a plastic cage. Two pairs of 3 day old adults of C. pavonana were introduced into the cage and allowed to oviposit for 2 days. The number of eggs laid on treated plants and control plants were compared with paired t-test. viii The results show that the mortality of C. pavonana larvae as a result of the treatment with T. vogelii extracts and A. squamosa extracts and their mixtures increased with the increase in extract concentration and observation time. T. vogelii extract is highly toxic and A. squamosa
Keyword: Botanical insecticides, joint action, fecundity reduction, oviposition

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. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular