Pola Sebaran Kelompok Telur Ostrinia furnacalis Guenée (Lepidoptera: Crambidae) pada Beberapa Fase Pertumbuhan Tanaman Jagung (Zea mays L.)

Abstract

A field study was conducted to determine the distribution of egg masses of Ostrinia furnacalis on corn leaves and within corn field. The corn field was divided into three regions: the inner edge closed to other crops and outer edge closed to main road and the middle region. The numbers of egg masses laid were recorded entirely in all corn plants existed (census method). Egg laying period lasted for 34 days, with 11 days from initiation of egg laying to the peak of oviposition and 23 days from the peak to termination of egg laying. The egg masses laid on corn leaves were distributed in aggregation pattern. During eight-opened-leaf to twelve-opened-leaf stages, there were 847 egg masses found, and 80.9% was laid on the sixth-to-ninth leaves. From tasseling to blister stages there were 491 egg masses found of which approximately 80.7% was laid on the seventh-to-11 32.8, and 29.8% of those were found in the inner edge, middle, and outer edge of corn field, respectively. leaves. Egg masses laid within corn field varied, in which 37.4, 32.8, and 29.8% of those were found in the inner edge, middle, and outer edge of corn field, respectively.

Kajian lapang dilaksanakan untuk mengetahui pola sebaran peletakan kelompok telur ngengat Ostrinia furnacalis pada daun tanaman jagung dan penyebarannya pada lahan pertanaman jagung. Lahan penelitian dibagi menjadi tiga kelompok yaitu lahan pinggir dalam berdekatan dengan pertanaman lain, bagian tengah lahan, dan lahan pinggir luar berdekatan dengan jalan raya. Pengamatan kelompok telur dilakukan pada seluruh tanaman jagung (sensus). Periode peletakan telur berlangsung selama 34 hari, dengan periode inisiasi hingga puncak 11 hari dan periode setelah puncak hingga akhir peletakan telur 23 hari. Peletakan telur O. furnacalis pada daun tanaman jagung menyebar secara berkelompok. Pada fase 8 hingga 10 daun telah terbuka sempurna ditemukan sebanyak 847 kelompok telur, 80,9% diantaranya  ditemukan pada daun ke 6–9. Pada fase VT (bunga jantan) hingga fase R2 (bunga betina telah kering) ditemukan sebanyak 491 kelompok telur, 80,7% diantaranya ditemukan pada daun 7–11. Penyebaran kelompok telur pada bagian lahan terjadi secara berkelompok. Jumlah kelompok telur tertinggi berturut-turut dari bagian lahan pinggir dalam, bagian tengah lahan, dan bagian lahan pinggir luar masing-masing 37,4; 32,8; dan 29,8%.