Judul: Biology and host range of gall fly, Cecidochares connexa (Macquart) (Diptera: Tephritidae) as a biological control agent of siam weed
Abstrak: Gall fly, Cecidochares connexa (Macquart) (Diptera: Tephritidae) is an important natural enemy of siam weed Chromolaena odorata (L.) King & Robinson (Asteraceae), that was introduced to Indonesia from Colombia in 1993. After being release in 1995, the biological aspects of the fly have not been evaluated yet. This research was conducted to study: 1) the biology of C. connexa in the field, 2) the development and number of larval instars, and 3) the host range of the gall fly. Biological parameters observed were larval development, life cycle, longevity of adults and fecundity of the females. Larval instars were determined by observing morphological characters of mandible, sclerite hypopharyng and larval size (volume). The fly host range was evaluated by observing fly infestation and oviposition, larval development and survival, as well as gall formation on three different plant species that were closely related to siam weed (Asteraceae). Results of the study indicated that the eggs were laid in clusters in tissue of terminal or axillary bud. After hatching, larvae bored deeper into the bud and lived inside the gall that was formed on the infested bud until pupation. Gall were visible about two week after oviposition. One gall contained 1 to 13 larvae. There was no correlation between the gall size and number of larvae living in the gall. The gall fly pupate inside the gall. The adults emerged from the pupae and leaved the gall through out gall windows that were prepared and made by the last instar larvae before pupation. The life cycle of the gall fly was completed in 56-77 days. In the study was found that the highest mortality occurred when the fly was in the larval stage, and the natural enemies, especially predators, were the most important mortality factors. Longevity of the fly was about 8-17 days and 7-11 days for female and male, respectively. The fecundity of the fly was 140-329 eggs/female. Based on the size of the mandible and sclerite hypopharyng, there was indication that C. connexa larva had four instars to complete its development. The characters of mandible and hypopharyng were good indicators to determine larval development stage of C. connexa, but not the larval volume. Mandible character was found to be the best indicator to determine the development stage of C. connexa. The shape and size of mandible was different among different instars of C. connexa larvae. Form the host range test, it was known that C. connexa laid eggs on all species of tested plants. However, larvae could survive on the tested plants for no longer than two weeks. On babadotan, the fly infestations were able to stimulate gall formation but the larvae were fail to complete their development. It can be concluded that C. connexa is a host specific species that can develop and complete its life cycle only on siam weed.
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Judul: New Assossiation between Gall-forming Insect Cecidochares connexa (M.) with Local Parasitoids in Polewali Mandar West Sulawesi
Abstrak: Chromoloaena odorata merupakan salah satu spesies gulma invasif yang masuk ke Indonesia dan menjadi gulma pada tanaman perkebunan. Salah satu teknik pengendalian yang telah dilakukan untuk mengendalikan gulma tersebut di Indonesia adalah dengan menggunakan serangga penyebab puru Cecidochares connexa (M) yang diintroduksi dari Colombia, Amerika Selatan pada tahun 1993. C. connexa telah dilepaskan di beberapa daerah di Indonesia termasuk Sulawesi pada tahun 1995-2000,. Walaupun introduksi C. connexa pernah dilakukan di Kecamatan Bantimurung, Kabupaten Maros, Sulawesi Selatan pada tahun 1999 akan tetapi informasi mengenai keberadaan dan kemapanan dari C. connexa di Sulawesi masih sangat minim. Penelitian ini bertujuan meneliti keberadaan C. connexa pada dua habitat berbeda dan asosiasi barunya dengan parasitoid lokal di Polewali Mandar, Sulawesi Barat. Penelitian dilakukan pada dua habitat yaitu lahan terbuka dan perkebunan kakao, pada empat desa berbeda, di Kecamatan Binuang, Kabupaten Polewali Mandar, Sulawesi Barat. Pemilihan tumbuhan sampel dilakukan secara purposive sampling, dengan mengumpulkan C. odorata yang memiliki puru. Tiga puluh C. odorata berpuru dikoleksi pada tiga lokasi berbeda setiap habitatnya. Pengamatan puru dimulai dengan mengkategorisasikan puru menjadi dua kelompok, yaitu puru yang tidak berlubang dan puru yang berlubang. Setiap puru dimasukkan ke dalam plastik zip-lock berukuran 8 cm x 12 cm. Pengukuran lubang puru dilakukan terhadap sampel puru dari lapang yang sudah berlubang. Puru yang tidak berlubang dipelihara sampai keluar serangga dan diidentifikasi di Laboratorium Pengendalian Hayati, Departemen Proteksi Tanaman, Institut Pertanian Bogor. Hasil penelitian menunjukkan adanya dua jenis serangga yang ditemukan berasosiasi dengan puru pada C. odorata, yaitu C. connexa (Diptera: Tephritidae) dan serangga famili Sciaridae (Diptera). C. connexa dapat ditemukan pada habitat lahan terbuka dan perkebunan kakao dan telah menyebar sampai di Polewali Mandar, Sulawesi Barat. Berdasarkan pengamatan, jumlah puru yang dapat ditemukan pada satu tumbuhan C. odorata berkisar antara 1-137 puru per C. odorata. Mayoritas tumbuhan C. odorata memiliki 1-10 puru per tumbuhan. Setiap puru dapat dihuni 1-5 individu C. connexa dan paling banyak ditemukan berkisar antara 1-2 individu per puru. Hasil penelitian menunjukkan adanya serangan parasitoid pada serangga puru C. connexa. Total ditemukan enam morfo-spesies parasitoid yang menyerang C. connexa. Parasitoid dominan adalah Aprostocetus sp.1 dengan tingkat parasitasi 13,57% pada lahan terbuka dan 10,63% di perkebunan kakao. Hasil penelitian ini menunjukkan bahwa telah terbentuk asosiasi baru antara seranga puru dengan serangga parasitoid lokal., Chromoloaena odorata (L) R.M. King & H. Rob is an invasive weed species that accidentally entered Indonesia and became a weed in plantation crops. One of the methods used to control the invasive weed C. odorata in Indonesia is Cecidochares connexa (M) which was introduced from Colombia, South America in 1993. C. connexa released in several areas of Indonesia, including Sulawesi In 1995-2000. Although the introduction of C. connexa was conducted in Bantimung sub-district, Maros Regency, South Sulawesi, in 1999, information about the presence and establishment of C. connexa in Sulawesi is still scarce. This study aims to determine the success of classic biological control on C. odorata and its new association with local parasitoids in Polewali Mandar, West Sulawesi. The research was conducted in two types of habitats, namely open fields and cocoa plantations, in four different villages within
Keyword: Interaksi baru, pengendalian biologi klasik, parasitoid, serangga puru, Classical biological control, gall insect, new interactions, parasitoids

Judul: Sintesis BaTiO3 dari Campuran Ba(OH)2 dan TiO2 dengan Tambahan PbO
Abstrak: Piezoelectric material can generate electric field in response to applied mechanical stress. Conversely, they can stretch and contract in response to an electric field. This material can be used for many applications such as transducer, microphone, ultrasound, and pressure gauge. Barium titanate is a ferroelectric material with piezoelectric properties that can be synthesized easily. The aim of this study is to synthesis barium titanate from mixture of Ba(OH)2 and TiO2, also observe its optimum temperature and the effect of PbO addition. The method of synthesis was solid-state reaction and sol-gel method, then the products were characterized with x-ray diffraction (XRD). Based on XRD analysis, the optimum temperature for both methods was 800°C. Addition of PbO to BaTiO3 in the solid-state reaction formed a compound with formula of Ba1-xPbxTiO3. The addition has changed diffraction pattern peak at 2θ and strengthened its tetragonal structure. The best result was obtained at x of 0.5 which will form a compound of Ba0.5Pb0.5TiO3.
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