Efficiency And Performance Of Certain Formulations Botanical Pesticides Against Some Insect Pests:

Mohamed Radwan Mahmoud?

The present investigation aimed to throw light on the emulsifiable concentration (EC) formulations of preparation of certain plant extracts in different organic solvents. The insecticidal activities of certain crude plant extracts and their prepared EC formulations on the larvae of the cotton leafworm, S.littoralis (Boisd) and Culex pipiens mosquitoes were also studied. Also, the TLC separation and bioassay evaluation against the mosquito larvae were also considered. At the end, the active TLC bands as shown from bioassay tests were subjected to GC-MS identification.The obtained results could be summarized in the following:1.Preliminary bioassay tests showed the superior larvicidal activity of chloroform and ethanol extracts of Withania somnifera plant against 3rd instar Culex pipiens compared with the other extracts of Pinus halepensis and Carpobrotus edulis. Chloroform extract proved much more efficiency than ethanol extract.2.Data indicate the great insecticidal activities of prepared EC formulation of Withania somnifera plant in chloroform or ethanol against 3rd instar larvae of C.pipiens compared with their crude extracts in the same organic solvents.3.The obtained results indicated the higher insecticidal activities of chloroform crude extract of W.somniferaagainst both 2nd and 4th instar larvae of the cotton leafworm than ethanol crude extract.4. Data indicated the superior larvicidal activity of EC formulation prepared from chloroform extract against cotton leafworrn larvae than the crude extract of the same solvent only. The LC50’s were 93.8 and 1594.4 ppm (2nd instar) and 455.7 and 1973.1 ppm (4th instar) in case of EC and crude extracts, respectively. Extracts and EC formulation from chloroform proved more potencies on both instars of leafworm larvae than those from ethanol. Larvae of 2nd instar showed more succeptibility to the tested crude extracts and EC formulation.5.thin layer chromatography technique resulted in the separation of 13 bands with sequencial RF values from Wsomnifera extract. Bands with RF ’s from ethanolic extract of 0.76, 0.80, 0.08, 0.04 and 0.24 showed satisfactory larvicidal activities against 3rd instar larvae of C.pipiens. Data also indicate that the band with RF 0.83 of chloroform extract was the only one with larvicidal activity against 3rd instar larvae of C.pipiens (60.0% mortality).6.GC/MS identification of the most active components of TLC separated bands of W.somnifera ethanol extracts and chloroform extracts showed the following compounds as library searched (D : databaseWilley 275.L.) (Figs. 12to 27).Talbotine (GAS) SS TALBOTIN SS indolo [3,2,1-W pyrano [3,4-b] [1,5] naphthyridine-12 a (12 H) —carboxylic acid 9-e thylidene —5,6,7, 7a, 8, 8a,.•8-Amino-3- (carbomethoxy) —1- methyl —5- (3,4,5- trimethoxyl phenyl) —1H-pyrimido [4,5-c1-1,2-diazepin —6- (7H) —one.•Methyl (23E) —3. beta. —acetoxy-12, 21-dioxo-23- phenylth-5. beta., 21E-cholan-24-oate SS Cholan-24- oic acid, acetyloxy) 12, 21-dioxo-2.•4-Dibenzothienyl —2- (4,4-dimethyl —2- oxazolin —2- yl) phenylmethanol SS 4-Dibenzothiophenemethanol, alpha, -[2-(4,5-dihydro-4, 4-dimethyl.•26, 27-Dinorergoata-5, 22-dien-3-ol, (3, beta, 22E) —(CAS) SS 24-NOR —CHOLESTA-5, 22 (TRANS) — DIEN —3, BETA —OL SS No rcholestadienol SS 26, 27.•t-Butyl 5-Iodo-4- (2-methoxycarbonylethyl) —3- methoxy-carbonylmethyl pyrrole-2- carboxylate SS 1H-Pyrrole-3- propanoic acid, 5- [(1,1-dimet)].•Isocephalotaxinone.•N-(Methylsulfonyl)-O-(trimethylsilyl) hydroxylamine.•1-Methylspiro [5,5] unec-2-ene-4, 7-dione SS Spiro [5.5] u ndec-9-ene-1, 8-dione, 11-methyl-.•Thymol acetate.•Alpha, -Tumerone.•Phenanthrene, tetradecahydro- (CAS) SS perhyDROPhe-nant hrene SS TetradecahyDROPhenanthrene.•9,10—Anthracenedione, 1,8-bis (1,3- dihydro-1,3- dioxo (2h) isoindol -2-y1).•DI-H-Agnosteryl Acetate SS Lanosta-7,9 (11)-dien-3- ol, acetate, (3,beta)- (CAS) SS 3-Beta, -Acetoxy-5- Alpha, -Lanosta-7,9 (11)-Diene S.•Gradirubrine (CAS) SS 9H-Azuleno [1, 2, 3-ij] isoquinolin-9- one, 10-hydroxy-4, 5, 6-trimethoxy.•Dichlorofuroxan.