Composition of three zingiberaceae essential oils and their efficacy against the survivability of cocoa pod borer, Conopomorpha cramerella (Snellen) eggs

Authors: BAKAR, SARIPAH - Malaysian Cocoa Board; HAIJAR MD LATIP, SITI NOOR - Universiti Teknologi Mara (UITM); AWANG, ALIAS - Malaysian Cocoa Board; Zhang, Aijun

Submitted to: Journal of Bangladesh Agricultural University
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2021
Publication Date: 3/30/2021
Citation: Bakar, S., Haijar Md Latip, S., Awang, A., Zhang, A. 2021. Composition of three zingiberaceae essential oils and their efficacy against the survivability of cocoa pod borer, Conopomorpha cramerella (Snellen) eggs. Journal of Bangladesh Agricultural University. https://doi.org/10.5455/JBAU.36604.
DOI: https://doi.org/10.5455/JBAU.36604

Interpretive Summary: The cocoa pod borer (CPB) is a tiny moth that has become one of the most serious insect pests to cocoa growing countries in the South-East Asia region. The severe infestation may lead up to 100% yield loss if left untreated. Implementation of chemical control is the most common technique in managing CPB infestation and currently adopted by local growers. However, it has caused great environmental, pesticide resistance, and human health concerns. The alternative strategy is urgently needed. Zingiberaceae plants were widely planted in South-East Asia. The essential oils (EOs) from these species have been previously studied and our results indicated that EOs have great potential to be used in CPB control. In this study, we found that all three EOs were more effective than controls to inhibit CPB egg hatchability but EO of A. galanga exhibited the most efficient ovicidal activity as compared with the other two EOs. Because EOs from zingiberaceae species are considered as environmentally friendly, they have great potential to be used by growers as alternative tools to synthetic pesticides for CPB control in cocoa production. This information will be used by scientists and commercial industry interested in safe pest control.

Technical Abstract: The use of botanical extracts derived from potential plants is promising due to their target-specific, biodegradable, and can be implemented in insect management programs. This study was conducted to observe the potential of three zingiberaceae essential oils (EOs): lesser galanga Alpinia galanga, Turmeric Curcuma longa, and ginger Zingiber officinale against the cocoa pod borer, Conopomorpha cramerella (Lepidoptera: Gracillariidae) - the most devastating pest of cocoa in the Southeast Asia region. Bioassay on the C. cramerella eggs were performed using four different concentrations of EOs at 100, 200, 400, and 800 ppm. It is found that the A. galanga performed as the best EOs that can disrupt egg hatchability (0.025b ± 0.158), where only 0.03 eggs hatched and significantly different (p < 0.05) with control (2.367a ± 0.928), where 2.37 eggs were successfully hatched. The concentration of EOs at 800 ppm was able to influence the penetration rate of pre-larva on the cocoa pod. During large cage observation, the mean of C. cramerella eggs were the highest at control (0.900a ± 1.029) and significantly different (p < 0.05) with C. longa (0.150b ± 0.483), A. galanga (0.050 b ± 0.221) and Z. officinale (0.025 b ± 0.158). Higher concentrations (400 and 800 ppm) were able to hinder C. cramerella from depositing eggs after cocoa pods were treated with treatments. The effect of Zingiberaceae EOs towards the egg hatchability may provide a foundation for their potential in managing C. cramerella in the future.