Insecticidal Activity of Essential Oils Leaves of Cinnamomum spp. (Lauraceae) against Crocidolomia pavonana and Their Phytotoxicity on Broccoli Seedlings

Abstract

Essential oils from leaves of 13 species of Cinnamomum were tested for their insecticidal activity on the cabbage head caterpillar Crocidolomia pavonana with leaf immerse method. The results showed that the treatment with 1% (w/v) essential oils leaves of C. celebicum, C. multiflorum, C. sintoc, and C. verum caused 21.45, 93.65, 60.30, and 76.10% mortality, respectively. Based on the results of phytotoxicity and insecticidal activity tests, C. multiflorum oil was further tested at 6 concentration levels. In all treatments, larval mortality has occurred at 24 hours after treatment (HAT) and increased at 48 HAT. LC50 of C. multiflorum oil at 24 and 48 HAT was 0.504 and 0.396%, respectively. The treatment with C. multiflorum oil at ≤0.31% did not inhibit the development of C. pavonana larvae. Determination of the chemical constituents of Cinnamomum oils were carried out by gas chromatography-mass spectrometry (GCMS). Totally, 345 compounds were identified. Methyleugenol constituted the main component (49.4%) of leaf essential oil of C. multiflorum and was assumed to be responsible for the insecticidal activity of the oil against C. pavonana larvae. LC50 of pure methyleugenol obtained at 0.365% (48 HAT) and 0.363% (72 HAT). The results showed that C. multiflorum was more effective with LC50 value equivalent to methyleugenol content of 0.32% (24 HAT) and 0.24% (48 HAT).

Aktivitas insektisida minyak atsiri daun 13 spesies Cinnamomum terhadap ulat krop kubis Crocidolomia pavonana diuji dengan metode celup daun. Hasil pengujian menunjukkan bahwa perlakuan dengan minyak atsiri daun C. celebicum, C. multiflorum, C. sintoc, dan C. verum pada konsentrasi 1% (b/v) mengakibatkan mortalitas berturut-turut 21.45, 93.65, 60.30, dan 76.10%. Berdasarkan hasil uji fitotoksisitas dan aktivitas insektisida, dilakukan uji lanjutan terhadap C. multiflorum dalam 6 taraf konsentrasi. Pada semua perlakuan, mortalitas larva sudah terjadi pada 24 jam setelah perlakuan (JSP) dan meningkat pada 48 JSP. LC50 minyak atsiri C. multiflorum pada 24 dan 48 JSP masingmasing 0.504 dan 0.396%. Perlakuan dengan minyak atsiri C. multiflorum pada konsentrasi ≤0.31% tidak menghambat perkembangan larva C. pavonana. Identifikasi komponen minyak atsiri 13 spesies Cinnamomum dilakukan dengan GCMS. Total komponen yang teridentifikasi mencapai 345 senyawa. Metileugenol merupakan senyawa yang paling banyak ditemukan dalam minyak atsiri C. multiflorum dan diduga sebagai senyawa aktif yang memiliki aktivitas insektisida terhadap ulat C. pavonana. LC50 metileugenol murni diperoleh pada 0.365% (48 JSP) dan 0.363% (72 JSP). Hasil pengujian menunjukkan bahwa C. multiflorum lebih efektif dengan nilai LC50 ekuivalen dengan kandungan metileugenol sebesar 0.32% (24 JSP) dan 0.24% (48 JSP).