Analisis Hubungan Kondisi Iklim Dengan Ledakan Ulat Bulu: Studi Kasus di Kabupaten Probolinggo, Jawa Timur

Abstract

An outbreak of caterpillars Arctornis submarginata Wlk.(Lep.: Lymantriidae) occured in nine subdistrict of Probolinggo during March-April 2011. The caterpillar caused heavy defoliation on mangoes, with a total of 14.813 trees affected. Pest populations are commonly strongly influenced by the dynamics of climatic factors. The research aimed to evaluate and analyze the relationship between climatic conditions and the outbreaks of caterpillars. We used a qualitative-descriptive method to analyze rainfall variation for 10 years in the area, regression analysis of climatic factors and pest severity, and climex software to analyze potential pest distribution. Our analysis showed a strong relationship between outbreak of caterpillars and a high rainfall in the study area. The monthly average of rainfall for January to April was higher than monthly rainfall for 10 years. Based on regression analysis, the strongest influence of the whole climatic factors was found on the larval stages of which the value of R2 is 28.9%. Analysis using software climex showed the value of EI (Ecoclimatic Index) is 92, 87 and 46 in compare location, indicating that the study area was more suitable for the caterpillars. Climate is one of the factors affecting caterpillar outbreaks, in addition to biotic factors such as natural enemies.