Judul: Perkembangan Ulat Sutra Samia cynthia ricini (Lepidoptera: Saturniidae) pada Suhu dan Lama  Penyimpanan Pupa Berbeda
Abstrak: Samia cynthia ricini merupakan spesies ulat sutra liar yang bersifat multivoltine yaitu mampu menghasilkan 5-6 generasi setiap tahunnya. Dalam budidaya ulat sutra yang dilakukan di Indonesia tidak ada masa diapause sehingga siklus berjalan terus sepanjang tahun. Pengaturan waktu budidaya dapat dilakukan dengan memberikan perlakuan suhu dan lama penyimpanan pada pupa ulat sutra. Penelitian ini bertujuan menganalisis pengaruh suhu dan lama penyimpanan pupa terhadap perkembangan S. ricini. Pupa disimpan pada tiga suhu penyimpanan berbeda yaitu suhu ruang, suhu refrigerator, dan suhu freezer. Durasi penyimpanan pupa adalah 2, 4, dan 8 hari sehingga total terdapat sembilan perlakuan. Beberapa parameter yang diamati adalah karakteristik kokon, durasi perkembangan pupa, persentase keluarnya imago, karakteristik imago, dan produksi telur. Hasil penelitian menunjukkan terjadi penurunan bobot dan ukuran kokon setelah masa penyimpanan pada setiap perlakuan. Durasi perkembangan pupa semakin lama dan persentase keluarnya imago semakin rendah pada pupa yang disimpan dalam refrigerator. Pupa yang disimpan dalam freezer seluruhnya mati. Kondisi sayap imago akan lebih banyak yang mengkerut ketika pupa disimpan di refrigerator. Produksi telur yang dihasilkan semakin rendah pada perlakuan refrigerator dengan durasi penyimpanan yang lama. Penurunan suhu simpan dan lamanya waktu penyimpanan dalam refrigerator meningkatkan penghambatan perkembangan S. ricini., Samia Cynthia ricini is a wild silkworm species that is multivoltine and can produce 5-6 generations each year. In the cultivation of silkworms carried out in Indonesia, there is no period of diapause so the cycle will continue throughout the year. It is necessary to adjust the timing of silkworm cultivation according to the availability of feed. This study aimed to analyze the effect of temperature and pupae storage time on the development of S. ricini. Pupae were stored at three different storage temperatures, i.e. room temperature, refrigerator temperature, and freezer temperature. The pupae storage duration were 2, 4, and 8 days so there were nine treatments in total. Several parameters observed were characteristics of the cocoon, duration of pupal development, percentage of imago emerged, imago characteristics, and egg production. The results showed a decrease in the weight and size of the cocoon after the storage period in each treatment. The duration of pupae development was longer and the percentage of imago emerged was lower in the pupae stored in the refrigerator and freezer. The pupae stored in the freezer are completely dead. The condition of the imago wings will shrink more when the pupae was stored in the refrigerator. The egg production was lower in the refrigerator treatment with long storage duration. The decrease in storage temperature and the length of storage duration on refrigerator increased the inhibition of the development of S. ricini.
Keyword: Cultivation, diapause, freezer, multivoltine, refrigerator

Judul: Development of Silkworm (Samia cynthia ricini) at Different Temperatures and Egg Storage Time
Abstrak: Samia cynthia ricini (Lepidoptera: Saturniidae) berasal dari India yang kini sudah banyak dibudidayakan. Samia cynthia ricini bersifat multivoltine, yaitu dalam satu tahun dapat bereproduksi menghasilkan banyak generasi. Oleh karena itu, ketersediaan pakan menjadi sangat penting. Salah satu cara untuk mengontrol ketersediaan pakan adalah dengan melakukan pengontrolan pada penetasan. Penundaan penetasan telur S. c. ricini dapat dilakukan dengan cara menyimpan di suhu rendah. Penelitian ini bertujuan menganalisis pengaruh suhu dan lama penyimpanan telur terhadap perkembangan ulat sutra S. c. ricini. Perlakuan yang digunakan adalah lama penyimpanan (2, 4, dan 8 hari) dan suhu (kontrol, refrigerator, dan freezer) dengan menggunakan sampel masing-masing 100 telur dengan tiga kali pengulangan. Pengambilan data meliputi suhu dan kelembapan lingkungan penelitian, durasi penetasan telur, penetasan telur, perkembangan larva, dan perkembangan embrio S. c. ricini. Hasil penelitian menunjukkan penyimpanan dengan refrigerator dalam waktu dua hari menghasilkan persentase penetasan dan kelangsungan hidup yang lebih tinggi dan pada perlakuan freezer semua telur mati. Mortalitas paling tinggi terjadi pada instar 1 dan 2. Penyimpanan telur pada suhu rendah (6,3oC dan -21,7oC) menyebabkan pertumbuhan larva tidak normal., Samia cynthia ricini (Lepidoptera: Saturniidae) originated from India which is now widely cultivated. Samia cynthia ricini is multivoltine, that is, in one year it can reproduce many generations. Therefore, the availability of feed becomes very important. One of the ways to control the availability of feed is to control the hatchery. Delayed hatching of S. c. ricini eggs can be done by storing at low temperatures. This study aimed to analyze the effect of temperature and egg storage time on the development of S. c. ricini silkworms. The treatments used were storage duration (2, 4, and 8 days) and temperature (control, refrigerator, and freezer) by using 100 eggs each treatment with three repetitions. Data collection included air and humidity, duration of hatching eggs, the number of hatching eggs, larval development, and embryonic development of S. c. ricini. The results showed that storage with a refrigerator within two days resulted in a higher percentage of hatching and survival and in the freezer treatment result all of eggs died. The highest mortality occurred in instars 1 and 2. Storage of eggs at low temperatures (6,3oC dan -21,7oC) caused abnormal larval growth.
Keyword: Penetasan, Perkembangan embrio, Samia cynthia ricini, Suhu, Telur, Eggs, Hatching, Samia cynthia ricini, Temperature, Embryo development

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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