Toxicity Azadirachta indica and Piper Sarmentosum extract mixture formulations against Nilaparvata lugens (Hemiptera: Delphacidae) in paddy field

Infestation of Nilaparvata lugens on rice in Malaysia is not as heavy compared to other Asian countries, but still lower the rice yield production. Nilaparvata lugens is developing resistance against chemical pesticide, therefore an alternative approach such as the application of botanical pesticide is potential to control the N. lugens. The aims of this research were to determine the synergistic activity in combination of Azadirachta indica and Piper sarmentosum emulsion formulations extract against Nilaparvata lugens. Three formulations were developed were coded as F1, F2, and F3. The F1 was selected as the best formulation because it in range of good zeta potential value (-48.3 mV) and viscosity value (100.1 mPa/s), the lowest particle size (202.5 nm), remained homogenous for centrifugation and stability test, polydispersity index (PDI) value indicated it is in ideal monodisperse phase (0.359), low surface tension (31.3 mN/m) and low pH (3.65). The lethal concentration, LC50 and sub lethal, LC10 and LC25 were determined from nymph mortality bioassay test on third instar N. lugens nymphs. Mortality rate of F1 and F2 were 0.011 mg/l and F3 was 0.031 mg/l. The value of lethal and sublethal concentration were used in a test against female N. lugens to determine the effect of formulations on fecundity of N. lugens. There were significant differences between formulations on the number of eggs produced after treatments. The lowest egg produced from F1 with 128.11 number of eggs. It can be concluded that all formulations showed promising result in controlling N. lugens

Toxicity of Malaysian Medicinal Plant Extracts Against Sitophilus oryzae and Rhyzopertha dominica

The insecticidal activities of extracts from 22 Malaysian medicinal plant extracts from 8 botanical families were tested against rice weevil: Sitophilus oryzae (L.) and lesser grain borer: Rhyzopertha dominica (F.). The extracts were obtained using hexane, methanol, and dichloromethane to extract potential biopesticides from dried leaves. The toxicity levels were examined periodically based on antifeedant activity and contact toxicity assays using treated grain assay. Hexane extracts of Alpinia conchigera, Alpinia scabra, Curcuma mangga, Curcuma purpurascens, Goniothalamus tapisoides, Piper sarmentosum , and methanol extracts of Curcuma aeruginosa, C. mangga , and Mitragyna speciosa were the most potent extracts against S. oryzae and R. dominica with lethal concentration (LC50) values of ≤ 0.42 mg/mL and ≤ 0.49 mg/mL, respectively. The contact toxicity test results showed that methanol extracts of C. aeruginosa and C. mangga , dichloromethane extracts of Cryptocarya nigra , and hexane extracts of C. mangga, and C. purpurascens resulted in 100% mortality of both pests within 28 days exposure of 5 mg/cm2 concentration

Ketoksikan cypermethrin dan cyfllithrin terhadap kumbang badak dewasa

"Kajian ketoksikan Cypennethrin dan Cyfluthrin terhadap kumbang badak dewasa telah dijalankan di Makmal Umum 5, Fakulti Pertanian Lestari, Universiti Malaysia Sabah Kampus Sandakan. Kajian ini telah dilaksanakan selama 2 bulan (Julai 2015 hingga bulan Ogos 2015). Kajian ini telah melibatkan empat peringkat eksperimen iaitu pengumpulan sampel, penjagaan kumbang, penyediaan stok larutan pestisid dan ujian bioasai. Sampel kumbang badak dewasa telah diambil dari dua buah ladang kelapa sawit persendirian di sekitar SUngai Satang, Sandakan yang ditangkap menggunakan perangkap feromon selama 12 hari berturut-turut. Kajian ini telah menggunakan lima rawatan (satu rawatan kawalan) dengan masing-masing sebanyak lima replikasi untuk kedua-dua bahan aktif. LCso bagi mortaliti kumbang telah dianalisis menggunakan perisian Probit PoloPluS© (LeOra Software 2(02) dan perbezaan masa mortaliti bagi kedua-dua jenis insektisid telah dianalisis menggunakan Microsoft Excel 2013. Ujian lRe menerima hipotesis null; garisan regresi bagi Cypermethrin dan Cyfluthrin adalah selari (chi square = 0.96, df = 2, P>0.05). Ujian lRp menerima hipotesis null; garis kecerunan (slope) dan garis (memintas) adalah sarna (chi square = 0.42, df = 1, P>O.OS). Keadaan ini menunjukkan bahawa kedua-dua insektisid tersebut memberi respon relatif kimia yang sama terhadap mortaliti kumbang badak dewasa.

Synergism activity between Moringa oleifera and Azadirachta indica crude extract against Nilaparvata lugens (Hemiptera: Delphacidae)

Extract seeds of Moringa oleifera and Azadirachta indica were tested separately and in mixture (1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1) in the laboratory for their insecticidal activity against Nilaparvata lugens (Hemiptera: Delphacidae). Moringa oleifera and A. indica plant materials were extracted with hexane using maceration technique. Insecticidal bioassays were done by leaf-dip bioassays method. Second to fourth instar nymph of N. lugens were fed extract treated paddy seedling and were observed for 24, 48 and 72 hours. The data were analyzed using PoloPlus V.2 program, analysis of variance (ANOVA) and CompuSyn software. The results showed that the yield of extraction for M. oleifera was 26.7%, while for A. indica was 3.0%. Based on LC50 value, mixture extract (3:7) of M. oleifera and A. indica (LC50=52.24 mg/L) were more toxic compared to other mixture ratios and single crude of M. oleifera (98.03mg/L) and A. indica (87.45mg/L). Based on mortality percentages at 72 hours, 0.05% mixture of M. oleifera and A. indica showed good efficacy against nymph of N. lugens with 74.81% compared to 0.025% and 0.01% mixture of M. oleifera and A. indica at 68.15% and 49.63%, respectively. Based on the combination index (CI), all mixtures have synergistic joint action against N. lugens nymph except ratio 8:2 (C1=0). For ratio 1:9, 2:8, 3:7, 4:6, 5:5 6:4, 7:3 and 9:1 the CI were 0.0048, 0.0086, 0.0091, 0.019, 0.0133, 0.047, 0.0163 and 0.0379 respectively