The major control of pest stored Lasioderma serricorne for using synthetic pesticides, look like phosphine. Although quite effective, synthetic pesticides have a negative effect on the environment, such as pest resistance, deadly natural enemies, residues that are harmful to the environment and human health. The use of botanical pesticides as an alternative control be the focus this study. Botanical pesticides are selective to the target, safe for non-target insects and the environment. This research studies the repellent and fumigant activity of the leaf extract of Citrus hystrix against all L. serricorne life stage. The results of GC-MS analysis of leaf crude extracts of C. hystrix with N-hexane solvent showed the highest percentage in the citronellal compound (86.43%). C. hystrix leaf extract showed stronger fumigant against pupae and eggs, compared adults, and larvae. The toxicity of the leaf extract of C. hystrix increased with increasing concentration. At a concentration of 60 ppm, fumigant activity showed the toxicity of 98.75% (pupae), 93.75% (eggs), 86.25% (adults) and 76.25% (larvae). Sequentially the LC50 value of fumigant activity from the highest to the lowest as follows; larvae 47.56 ppm, adults 43.42 ppm, eggs 31.61 and pupae 29.63 ppm. Extract of leaves of C. hystrix, have character repellent against L. serricorne. At a concentration of 60 ppm the IR value of 66% including repellent class IV, which means strong repellent level. Based on the results of the research, extracts of leaves of C. hystrix has a fumigant activity and repellent for controlling L. serricorne.

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Abstract. Ikawati S, Himawan T, Abadi AL, Tarno H. 2020. Thermostability, photostability, and toxicity of clove oil nanoparticles against Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae). Biodiversitas 21: 4764-4771. Problems related to the essential oils as insecticides are their volatility, poor solubility in water and environmental degradation (such as caused by high temperatures and UV light) which can adversely affect the application. An ideal botanical insecticide formulation would maintain the level of the main compounds adequate for pest control. This study was to evaluate the stability of polyethylene glycol (PEG) coated nanoparticles loaded with clove (Syzygium aromaticum) essential oil to high temperature and UV light also their toxicity to C. ferrugineus. There is a reduction in nanoparticle size after heating from 257 to 173 nm and there is no difference in size distribution. After heating and UV-light treatment, eugenol content in free clove oil decreased significantly, while on nanoparticles there were not significantly changed, that indicated greater stability on the nanoformulation. The median lethal concentration (LC50) of CO-NPs to C. ferrugineus adults value for 72 and 120 hours was 0.734 and 0.676%.

Abstract. Ikawati S, Himawan T, Abadi AL, Tarno H. 2020. Fumigant and feeding deterrent activity of essential oils against Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae). Biodiversitas 21: 4301-4308. This study aimed to determine the fumigant and antifeedant activity of some plant essential oils against Cryptolestes ferrugineus. Essential oils were extracted from cinnamon (Cinnamomum verum), kaffir lime (Citrus hystrix), citronella grass (Cymbopogon nardus), zodea (Euodia suaveolens), and clove (Syzygium aromaticum). The extraction used the maceration method with n-Hexane as a solvent. The results of the experiments showed that all essential oils have fumigant toxicity. Fumigant toxicity of kaffir lime, citronella grass, zodea, and clove oil; eggs and pupae were more susceptible than adults and larvae, while for cinnamon, pupae and adults were more susceptible than eggs and larvae. Median Lethal Concentration (LC50) of all essential oils for eggs larvae, pupae, and adults respectively, for cinnamon were 17, 24, 9, and 12 ppm, for kaffir lime were 12, 17, 8 and 15 ppm, however, on citronella grass were 11, 22, 8, and 14 ppm, for zodea were 16, 22, 10 and 20 ppm, for clove were 11, 24, 7 and 14 ppm. The fifth essential oils showed antifeedant activity in a no-choice test against C. ferrugineus adults. Also, the fifth essential oils significantly reduced the relative growth rate (RGR), relative consumption rate (RCR), and food utilization (ECI) of C. ferrugineus adults. It shows that the essential oils have great potential as one of the storage pest control components.

The application of essential oils to storage pest control requires an appropriate formulation formed by biodegradable compounds. This formulation should protect essential oils from degradation and evaporation while simultaneously allowing sustained release. This study aims to characterize nanoparticles loaded by clove essential oil-based polymer polyethylene glycol (PEG) and to investigate their insecticidal activity. In this study, clove oil solid dispersion was prepared using the fusion or melting-dispersion method with polyethylene glycol 6000 (PEG 6000) to form a binary solid dispersion system. The ratio of 10% of clove oil to PEG was optimal and had low PDI, small size, and the highest clove oil loading efficiency. Their size changed from 179 to 197 nm after 24 weeks of storage and the loading efficiency decreased for about 36%. Clove oil formulation in nanoparticles could not enhance the toxicity of clove oil but yet still showed high contact toxicity to C. ferrugineus. These formulations also have the slow and persistent release of the bioactive.