Adulticidal, larvicidal and biochemical properties of essential oils against Culex pipiens L

Hossam El-Din M. Zahran,Hamdy K. Abou-Taleb,Samir A.M. Abdelgaleil 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.1

In this study, the insecticidal properties of sixteen essential oils isolated from Egyptian plants were evaluated against the fourth instar larvae and adults of Culex pipiens L. The inhibitory effects of most active essential oils on the activity of acetylcholinesterase (AChE) and adenosine triphosphatases (ATPases) were also tested. In larvicidal assay against Cx. pipiens, the oils of Artemisiamonosperma, S. terebinthifolius and Origanumvulgare showed the highest insecticidal activity with LC50 values of 7.73, 8.14 and 8.40 mg/l after 24 h of treatment and 2.63, 3.46 and 6.74mg/l after 48 h of treatment.On the contrary, the oils of Schinusmolle and Rosmarinus officinalis were the less effective. The results of fumigant toxicity assay against the adults of Cx. pipiens revealed that the tested oils had remarkable toxicity based on their LC50 valueswhich ranged between 0.06 and 12.84 mg/l. The oil of Artemisia judaicawas the most activewith an estimated LC50 value of 0.06mg/l air after 24 h of treatment, while the oil of Citrus paradisi was less active. The essential oils of A. monosperma, O. vulgare, S. terebinthifolius and C. paradisi elicitedmarked enzymatic inhibition towards AChE and ATPases isolated fromCx. pipiens larvae. These results indicated that the essential oils have potential for the development of natural larvicides and fumigants for Cx. pipiens control.

Chemical composition, aphicidal and antiacetylcholinesterase activities of essential oils against Aphis nerii Boyer de Fonscolombe (Hemiptera: Aphididae)

Hussein Hanaa S.,Tawfeek Mohamed E.,Abdelgaleil Samir A.M. 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.2

Aphids are important sucking insects that attack many crops and cause huge economic loss. Essential oils have been proposed to be appropriate alternative to synthetic insecticides due to their low impact on environment and human health. In this work, the chemical compositions of eight essential oils extracted from plants growing in Egypt were determined by gas chromatography/mass spectrometry (GC–MS). The aphicidal activities of the isolated oils were examined against the adults of oleander aphid, Aphis nerii by a leaf-dipping assay. The inhibitory effect of essential oils on acetylcholinesterase (AChE) activity was also tested in vitro. Chemical an alyses showed the essential oils consisted mainly of monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons and oxygenated sesquiterpenes except the oil of Artemisia monosperma which con tained high content of benzenes. The results of toxicity assay showed that the oils of A. monosperma and Citrus sinensis were the most potent toxicants displaying LC 50 value of 0.06 mg/L. The oils of Callistemon viminals, Schinus terebinthifolius and Schinus molle were also highly effective against aphid as their LC 50 values were lower than 1 mg/L. In addition, the highest inhibitory effect on AChE was recorded by 0.5 mg/L C. sinensis with in hibition of 49.33%, while 0.1 mg/L Citrus lemon oil recorded the lowest inhibitory effect with inhibition of 0.4%. In general, six of tested essential oils showed high toxicity against A. nerii and they might be applied in the IPM programs for this insect.

Comparative toxicity, growth inhibitory and biochemical effects of terpenes and phenylpropenes on Spodoptera littoralis (Boisd.)

Nagwa M.A. Al-Nagar,Hamdy K. Abou-Taleb,Mohamed S. Shawir,Samir A.M. Abdelgaleil 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.1

Eleven monoterpenes, phenylpropenes and sesquiterpenes were evaluated for their insecticidal and growth inhibitory activities against the second and fourth larval instars of Spodoptera littoralis. Among the tested compounds, 1,8-cineole revealed the highest fumigant toxicity against the 2nd and 4th larval instars with LC 50 values of 2.32 and 3.13 mg/L air, respectively. The monoterpenes, p-cymene, α-terpinene, (−)α-pinene and (−)-carvone were highly toxic to both larval stages as their LC 50 values ranged between 7.35 and 13.79 mg/L air against 2nd larval instar and between 14.66 and 32.02 mg/L air against 4th larval instar. In topical application assay against the 4th larval instar, (−)-carvone (LD 50 = 0.15 mg/larva) and cuminaldehyde (LD 50 = 0.27 mg/larva) were the most potent contact toxicants. In residual film assay, trans-cinnamaldehyde, (−)-citronellal and pcymene showed the highest insecticidal activity against the 2nd larval instar, while α-terpinene and (−)-carvone were most effective compounds against the 4th larval instar. Moreover, the tested compounds caused strong growth reduction of both larval stages with growth inhibition higher than 80% in the 2nd larval instar and higher than 70% in the 4th larval instar. On the other hand, (−)-carvone, cuminaldehyde and (Z,E)-nerolidol showed pronounced inhibitory effects on acetylcholinesterase (AChE) and adenosine triphosphatases (ATPases) activity of S. littoralis larvae. Cuminaldehyde (IC 50 = 1.04 mM) and (Z,E)-nerolidol (IC 50 = 0.02 mM) caused the highest inhibition of AChE and ATPases, respectively. Taken together, the results indicate that monoterpenes, phenylpropenes and phenylpropenes could be used to develop new botanical insecticides for S. littoralis management.

Effectiveness of monoterpenes and phenylpropenes on Sitophilus oryzae L. (Coleoptera: Curculionidae) in stored wheat

Mona M.G. Saad,Samir A.M. Abdelgaleil 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.4

Six monoterpenes, ((−)-citronellal, p-cymene, (−)-menthone, α-pinene, α-terpinene and (−)-terpinen-4-ol) and two phenylpropenes, (trans-cinnamaldehyde and eugenol) were tested for their insecticidal activity against the rice weevil, Sitophilus oryzae under laboratory conditions. The bioassays were carried out on wheat at the concentrations of 0.5, 1.0 and 5.0 g/kg. Adult mortality was assessed after 14 days of exposure. After this interval, the treated wheat was retained for an additional period of 90 days, in order to evaluate progeny production and wheat loss. At the concentrations of 0.5 and 1.0 g/kg, trans-cinnamaldehyde and eugenol achieved highest adult mortality. At 5.0 g/kg, all compounds except for p-cymene and α-pinene caused complete (100%) adult mortality. Generally, trans-cinnamaldehyde was the most potent compound causing complete inhibition of progeny at the three concentrations. Similarly, no progeny were observed in the wheat treated with (−)-citronellal, eugenol, p-cymene, (−)-menthone, and (−)-terpinen-4-ol at 5.0 g/kg after 45 and 90 days. Similar trends were noted for wheat weight loss and damage as the treatment with monoterpenes and phenylpropenes at the highest rate preserved the wheat intact and free from damage by S. oryzae for 90 days. Our findings suggest the tested compounds except p-cymene and α-pinene could be recommended for use as part of an integrated pest management program for S. oryzae control in stored wheat.

Insecticidal and developmental inhibitory properties of monoterpenes on Culex pipiens L. (Diptera: Culicidae)

Hossam El-Din M. Zahran,Samir A.M. Abdelgaleil 한국응용곤충학회 2011 Journal of Asia-Pacific Entomology Vol.14 No.1

Twelve monoterpenes were evaluated for larvicidal and adulticidal activities towards Culex pipiens. Geraniol and cuminaldehyde were the most toxic monoterpenes to larvae, with LC_50 values of 38.6 and 38.9 mg/l after 24 h of treatment, respectively, whereas cuminaldehyde was the most potent compound after 48 h of treatment, followed by geraniol and thymol. In fumigant toxicity experiments, (R)-carvone and geraniol were the most toxic monoterpenes against the adults at all three tested concentrations and after both 24 and 48 h. When tested at sublethal concentrations (0.5 LC_50), (R)-carvone, (S)-limonene and cuminaldehyde decreased hatchability, pupation and adult emergence and induced high larval mortality. Our results suggest that geraniol, cuminaldehyde and (R)-carvone are promising toxicants against Culex pipiens and could be useful in the search for new natural insecticides.