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Indonesia is the third largest cocoa producer in the world with annual export value of more than 1.2 million USD. However, cacao production in Indonesia has decreased by approximately 50% in the last decade due to socioeconomic issues and the high prevalence of pests and diseases. Cacao mosaic disease caused by cacao mild mosaic virus (Badnavirus teselotheobromae, CMMV) is currently emerging in Indonesia. This study aims to map the distribution of CMMV in cacao‐growing areas in Indonesia. Samples were collected in 2021–2023 in Java, Sumatera, Bali, and Sulawesi, which represent major cacao‐growing areas in Indonesia. We successfully detected CMMV from all samples, indicating CMMV is already distributed widely in Indonesia. Sequencing data suggests the Indonesian isolates have a common ancestor with American isolates. These findings provide new information for the quarantine board, government, and industry to arrange the policy to control the emerging CMMV. [ABSTRACT FROM AUTHOR]

Genetically modified MON 89034 corn (Zea mays L.) expressing Bacillus thuringiensis (Bt) insecticidal proteins, viz. Cry1A.105 and Cry2Ab2, is a biotechnological option being considered for the management of the major corn pest in Indonesia, the Asian corn borer (Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae)). As a part of a proactive resistance-management program for MON 89034 corn in Indonesia, we assessed the baseline susceptibility of field-collected populations of O. furnacalis to Cry1A.105 and Cry2Ab2 proteins. Dose–response bioassays using the diet-dipping method indicated that the lethal concentration (LC50) values of Cry1A.105 and Cry2Ab2 in 24 different field populations of O. furnacalis ranged from 0.006 to 0.401 µg/mL and from 0.044 to 4.490 µg/mL, respectively, while the LC95 values ranged from 0.069 to 15.233 µg/mL for Cry1A.105 and from 3.320 to 277.584 µg/mL for Cry2Ab2. The relative resistance ratios comparing the most tolerant field populations and an unselected laboratory population were 6.0 for Cry1A.105 and 2.0 for Cry2Ab2 based on their LC50 values. Some field populations were more susceptible to both proteins than the unselected laboratory population. The LC99 and its 95% fiducial limits across the field populations were calculated and proposed as candidate diagnostic concentrations. These data provide a basis for resistance monitoring in Bt Corn and further support building resistance-management strategies in Indonesia. [ABSTRACT FROM AUTHOR]

The beet armyworm, Spodoptera exigua (Hübner), is a major insect pest in shallot in Java, Indonesia. To control this insect, farmers rely on the use of a narrow spectrum of insecticides leading to resistance development. The objective of this study was to determine the level of resistance of S. exigua populations from different areas of Java to the most widely used insecticides, chlorfenapyr, methomyl, and emamectin benzoate, as well as to cyantraniliprole which was recently introduced in Indonesia. Spodoptera exigua populations were collected from three major shallot production areas in Java, the Districts of Brebes, Nganjuk, and Bantul. Based on the LC50 values, resistance ratios of S. exigua populations compared to the most susceptible population from the sub-district Pundong in Bantul varied from very low to very high: 1.1- to 113.8-fold for chlorfenapyr, 16.4- to 223.6-fold for methomyl, and 1.5- to 51.7-fold for emamectin benzoate. Spodoptera exigua populations from the same location were more susceptible to cyantraniliprole, with a resistance ratio of 4.0- to 12.1-fold. These findings indicate that the field populations of S. exigua collected from major shallot areas in Java were resistant to chlorfenapyr and methomyl and less resistant to emamectin benzoate, whereas they were still susceptible to cyantraniliprole. The populations from Brebes and Nganjuk were more resistant to chlorfenapyr, methomyl, and emamectin benzoate than those collected from Bantul. To prevent the further increase of resistant of S. exigua populations, IPM principles need to be applied including the alternate use of insecticides with different modes of action. [ABSTRACT FROM AUTHOR]

The brown planthopper, Nilaparvata lugens Stål. is a major insect pest causing serious damage to the rice crop in many rice-producing countries. The aim of the study was to determine the inheritance characteristics and realized heritability of resistance to imidacloprid in N. lugens from Banyumas, Central Java Province, Indonesia. The five generations of selection increased the resistance ratio (RR) from 46.20-fold at generation 45 (G45) to 150.39-fold (G49) compared with the laboratory-susceptible population. The LC50 values of imidacloprid for the progeny of reciprocal crosses, F1 and F1', showed no significant differences, indicating that imidacloprid resistance was inherited autosomally in N. lugens. The degree of dominance (D) values for F1 and F1' were 0.65 and 0.64, respectively, suggesting that imidacloprid resistance in N. lugens was expressed as an incompletely dominant trait. Chi-square analysis based on the monogenic hypothesis indicated that imidacloprid resistance in N. lugens was polygenic. Furthermore, the estimation realized heritability value (h 2) was 0.0893. These results would be useful to determine an effective resistance management strategies in N. lugens. [ABSTRACT FROM AUTHOR]

Keywords: Badnavirus; Theobroma cacao EN Badnavirus Theobroma cacao 1 2 2 06/29/22 20220401 NES 220401 Cocoa is one of the most important exports from Indonesia with an annual value of up to US$1.3 billion. Cacao mosaic disease is caused by badnaviruses and represents a risk for the cultivation of cacao ( I Theobroma cacao i ) (Marelli et al., 2019). [Extracted from the article]