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: Egg Hatching of Silkworm Samia cynthia ricini  (Lepidoptera: Saturniidae) at Different Storage Duration in Refrigerator
Abstrak: Ulat sutra Samia cynthia ricini (Lepidoptera: Saturniidae) merupakan salah satu jenis ulat sutra yang banyak dibudidayakan di Indonesia. Ulat sutra S. c. ricini bersifat multivoltine, artinya dalam satu tahun menghasilkan banyak generasi dan tidak memiliki masa diapause. Hal tersebut menjadi permasalahan bagi peternak ulat sutra karena larva yang berlebih tanpa diimbangi dengan ketersediaan pakan yang cukup dapat mengurangi produktivitas ulat sutra. Tujuan dari penelitian ini menganalisis pengaruh lama penyimpanan telur di suhu refrigerator terhadap penetasan. Penelitian dilakukan dengan tiga perlakuan penyimpanan telur, yaitu 7, 10, dan 14 hari di refrigerator dan kontrol di suhu ruang. Pengamatan meliputi persentase telur menetas, durasi penetasan, kelangsungan hidup larva, bobot larva, dan perkembangan embrio. Hasil menunjukkan semakin lama penyimpanan telur S. c. ricini di refrigerator menyebabkan persentase jumlah telur makin rendah, waktu penetasan makin lama, kelangsungan hidup makin pendek, dan bobot larva semakin kecil. Penyimpanan di refrigerator dapat menyebabkan perkembangan abnormal embrio S. c. ricini., Silkworm Samia cynthia ricini (Lepidoptera: Saturniidae) is one species of silkworm that is widely cultivated in Indonesia. The species of silkworm is multivoltine, i.e., in one year produces many generations and has no dormancy period. The high produce of larvae caused a problem for farmers to provide the availability of sufficient feed. The insufficient food can reduce silkworm productivity. The purpose of this study was to analyse the effect of storage duration of S. c. ricini eggs at refrigerator on hatching of S. c. ricini silkworms. The study was conducted with three egg storage treatments, namely 7, 10, and 14 days in the refrigerator and control at room temperature. Observations included percentage of eggs hatched, hatching duration, larval survival, larval weight, and embryo development. The results showed that the longer eggs storage of S. c. ricini in the refrigerator, the lower the percentage of eggs hatched, the longer the hatching duration, the shorter the survival time, and the smaller the larval weight. The development of S. c. ricini embryos in the storage treatment in the refrigerator can caused abnormal embryo.
Keyword: storage., Samia cynthia ricini, silkworms, diapause, eggs

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
Keyword: