Veena Prajapati

Repellency and toxicity of oil from Artemisia annua to certain stored-product beetles.

Abstract The essential oil of Artemisia annua L. was tested for its toxic repellent and development inhibitory activities against 2 economically important stored product insects: Tribolium castaneum (Herbst) and Callosobruchus maculatus (L.). Adult beetles of T. castaneum were repelled significantly by oil of A. annua at 1% concentration (vol:vol) and above in filter paper arena test. Dose–response relationship of A. annua oil revealed a significant negative correlation between larval survival; pupal survival and adult emergence of T. castaneum (i.e., increase in dose caused decrease in survival and adult emergence). Effective concentration (EC50) to reduce F1 progeny by 50% was calculated to be 2.6 and 4.1 μl/ml solvent against both the insect species, C. maculatus and T. castaneum, respectively. The relationship between bioactivity of oil from A. annua and responses of T. castaneum and C. maculatus is discussed. We found that oil from A. annua was largely responsible for both repellent (behavioral) and toxic (physiological) actions on 2 species of insect tested.

Bioactivities of the Leaf Essential Oil of Curcuma Longa (Var. Ch-66) On Three Species of Stored-Product Beetles (Coleoptera)

Abstract Essential oil extracted from the leaves of turmeric, Curcuma longa L., was investigated for contact and fumigant toxicity and its effect on progeny production in three stored-product beetles, Rhyzopertha dominica F. (lesser grain borer), Sitophilus oryzae L. (rice weevil), and Tribolium castaneum Herbst (red flour beetle). Oviposition-deterrent and ovicidal actions of C. longa leaf oil were also evaluated against T. castaneum. The oil was insecticidal in both contact and fumigant toxicity assays. The adults of R. dominica were highly susceptible to contact action of C. longa leaf oil, with LD50 value of 36.71 μg/mg weight of insect, whereas in the fumigant assay, adults of S. oryzae were highly susceptible with LC50 value of 11.36 mg/liter air. Further, in T. castaneum, the C. longa oil reduced oviposition and egg hatching by 72 and 80%, respectively at the concentration of 5.2 mg/cm2. At the concentration of 40.5 mg/g food, the oil totally suppressed progeny production of all the three test insects. Nutritional indices indicate >81% antifeedant action of the oil against R. dominica, S. oryzae and T. castaneum at the highest concentration tested.

Toxicity, feeding deterrence, and effect of activity of 1,8-Cineole from Artemisia annua on progeny production of Tribolium castanaeum (Coleoptera : Tenebrionidae)

Abstract 1,8-Cineole isolated from Artemisia annua was tested against Tribolium castaneum (Herbst) for contact toxicity, fumigant toxicity, and antifeedant activity. The adults of T. castaneum were more susceptible than larvae to both contact and fumigant toxicity of 1,8-cineole, and LD50 and LC50 values of 108.4 μg/mg body weight of adult insect and 1.52 mg/liter air were found, respectively. Furthermore, 14-d-old T. castaneum larvae were more tolerant than 16- and 18-d-old larvae and adults to the contact toxicity of 1,8-cineole, but the 16- and 18-d-old larvae have similar susceptibility. In contrast, all the larvae (14–18 d old) of T. castaneum were much more tolerant than the adults to the fumigant action, but larvae of different ages had similar susceptibility. The compound 1,8-ciineole applied to filter paper at a concentration of 3.22–16.10 mg/cm2 significantly (P < 0.05) reduced the hatching of T. castaneum eggs and the subsequent survival rate of the larvae. Adult emergence was also reduced by 1,8-cineole. Feeding deterrence of 81.9% was achieved in T. castaneum adults by using a concentration of 121.9 mg/g food, whereas larvae showed 68.8% at the same concentration.

Piperitenone Oxide as Toxic, Repellent, and Reproduction Retardant Toward Malarial Vector Anopheles stephensi (Diptera: Anophelinae)

Abstract Anopheles stephensi (Liston) is a well-known vector of malarial parasite in tropical countries. The developing trend of resistance in mosquitoes toward synthetic mosquitocidal agents makes their management extremely difficult. Effectiveness of essential oils with aroma therapeutic values seems to be an emerging tool to combat this vector. Piperitenone oxide isolated from essential oil of a new genotype, Mentha spicata L. variety viridis, has been evaluated for larvicidal, ovicidal, oviposition-deterrent, developmental toxicity, and repellent properties against various stages of A. stephensi. The results indicated the higher efficacy of piperitenone oxide than the crude essential oil of M. spicata variety viridis in all the bioassay experiments. The lethal response of piperitenone oxide and the oil toward fourth instar larvae showed LD50 values of 61.64 and 82.95 μg/ml, respectively. Female adults of A. stephensi exposed to the oil laid ≈42 times less number of eggs at the dose of 60.0 μg/ml as compared with control, whereas exposure of piperitenone oxide at the same dose completely inhibited the oviposition. Furthermore, piperitenone oxide also completely inhibited egg hatching at the dose of 75.0 μg/ml in ovicidal assay. Developmental toxicity studies showed the significant developmental inhibition potential of the compound and oil. Additionally, piperitenone oxide was found to be highly toxic and repellent toward adults of A. stephensi as compared with oil.

Toxicity of 1,8-cineole towards three species of stored product coleopterans

Abstract1,8-cineole, one of the components of the essential oil of Artemisia annwa, was evaluated for repellency and toxicity against three stored product coleopterans—Callosobruchiis maculatus F. (Coleoptera: Bruchidae), Rhyzopertha dominica F. (Coleoptera: Bostrychidae) and Sitopliilus oryzae L. (Coleoptera: Curculionidae). It was found to be moderately repellent to all three species, with a mean repellency in the range of 65–74% at the highest dose tested (4.0 μl/ml) within 1h. A contact toxicity assay revealed that direct topical application was more effective than using impregnated filter paper. The compound was more effective as a fumigant and gave 93–100% mortality against all the three pest species at the dose of 1.0 μl/l air under empty jar conditions as compared to treatment of jars filled with grain (11–26% mortality). The lethal dose and lethal concentration required to kill 50% of the beetles (LD50 and LC50 respectively) varied with the toxicity assay method. LD50 values of 0.03, 0.04 and 0.04 μl/insect against C. maculatus, R. dominica and S. oryzae respectively were found in the topical application assay while the LC50 in the fumigant assay was 0.28, 0.33 and 0.46 μl/l against C. maculatus, R. dominica and S. oryzae respectively.RésuméL’un des composés de l’huile essentielle d’Artemisia annua, le 1,8-cineole, a été évalué pour sa répulsion et sa toxicité vis à vis de trois coléoptères des denrées stockées, Callosobrnchus maculatus F. (Coleoptera: Bruchidae), Rhyzoperta dominica F. (Coleoptera: Bostrychidae) et Sitopliilus orizae L. (Coleoptera: Curculionidae). Il s’est avéré être modérément répulsif pour les 3 espèces, avec une répulsion moyenne de 65–74% à la plus forte dose testée (4.0 ml/ml) pendant 1 heure. Un essai de toxicité de contact indique qu’une application locale directe est plus efficace que l’utilisation d’un papier filtre imprégné. Le composé est plus efficace en fumigation et provoque 93–100% de mortalité chez les trois espèces de ravageurs à la dose de 1.0 ml/l d’air dans un pot vide par rapport à un pot rempli de grains (11–26% de mortalité). La dose létale et la concentration létale requises pour tuer 50% des scarabées (LD50 et LC50 respectivement) varient avec le type d’essai de toxicité. Des valeurs de LD50 de 0.03, 0.04 et 0.04 ml/insecte pour C. maculatus, R. dominica et S. oryzae respectivement ont été trouvées dans l’essai avec une application locale alors que la LC50 dans l’essai de fumigation était respectivement de 0.28, 0.33 et 0.46ml/l pour C. maculatus, R. dominica et S. oryzae.

Anti-insect Screening of Medicinal Plants from Kukrail Forest, Lucknow, India

Ten medicinal plants were evaluated at a dose of 10mg/ml for insecticidal, ovicidal, feeding-deterrence, growth inhibition and morphogenetic effects against various life stages of a noxious lepidopteran insect-pest, Spilarctia obliqua Walker. The acetone extract of Ageratum conyzoides, methanol extract of Justicia adhatoda, and chloroform extract of Plumbago zeylanica showed strong feeding-deterrence, growth inhibition and ovicidal effects against eggs and larvae of S. obliqua. In addition, the chloroform extract of P. zeylanica also created strong morphogenetic disorders in treated pupae of S. obliqua. The methanol extracts of Chenopodium ambrosioides and Ailanthus excelsa showed only feeding-deterrence and growth inhibitory effects but no ovicidal effect, whereas all the five extracts (hexane, chloroform, acetone, methanol and water) of Catharanthus roseus exhibited strong growth inhibition towards larvae of S. obliqua. The acetone extract of Vitex negundo was found to exhibit all the activities tested against S. obliqua. Other plants tested, Ajuga remota, Andrographis paniculata and Clerodendrum inermre, were found to have low to moderate effects towards S. obliqua.

Toxicity of l -menthol and its derivatives against four storage insects

Abstractl-menthol isolated from the essential oil of Mentha arvensis and seven of its acyl derivatives were tested for contact and vapour toxicity, and ovicidal and repellent activity against the storage pests Callosobruchus maculatus F., Rhyzopertha dominica F., Sitophilus oryzae L. and Tribolium castaneum Herbst. Menthyl propionate and l-menthol were highly toxic in contact assays and vapour toxicity assays respectively. l-menthol was also found to be strongly repellent (82–100% at 0.353 μg/cm2 dose) against all the insects, while menthyl acetate was highly ovicidal against T. castaneum.RésuméLe l-menthol isolé de l’huile essentielle de Mentha arvensis et sept de ses dérivés acétylés ont été testés pour leur toxicité de contact et fumigène et leur activité ovicide et répulsive vis à vis des ravageurs des stocks Callosobruchus maculatus F., Rhyzopertha dominica F., Sitophilus oryzae L. et Tribolium castaneum Herbst. Le propionate de menthyl et le l-menthol ont été hautement toxiques lors des essais par contact et par fumigation. Le l-menthol a été également fortement répulsif (82–100% à la dose de 0,353 mg/cm2) contre tous les insectes, alors que l’acétate de menthyl a été hautement ovicide contre T. castaneum.

Characterization of an ursane triterpenoid from centella asiatica with growth inhibitory activity against spilarctia obliqua.

A new triterpenoid glycoside 3-O-[a-L-arabinopyranosyl] 2 a, 3 ß , 6 ß , 23-a tetrahydroxyurs-12-ene-28-oic acid ( 1 ) accompanied by 6ß-hydroxyasiatic acid and asiatic acid were isolated from Centella asiatica . The structure of 1 was established by physicochemical data. Compound 1 exhibited dose-dependent growth inhibitory activity against larvae of Spilarctia obliqua but was not as active as azadirachtin.

Potential toxicity of new genotypes of Tagetes (Asteraceae) species against stored grain insect pests

Essential oils of three genotypes of Tagetes minuta, six of Tagetes patula and 15 of Tagetes erecta were screened for potential fumigant and contact toxicity against three stored product beetle species, Callosobruchus maculatus (Fabricius), Sitophilus oryzae (Linnaeus) and Tribolium castaneum (Herbst). Genotype 1 of T. minuta (TM-1), genotype 2 of T patula (TP-2) and genotype 13 of T erecta (TE-13) were the most toxic. These three genotypes were then evaluated for adult toxicity, oviposition deterrence, and ovicidal and population reduction activities. Essential oils of genotypes TM-1 and TP-2 induced 100% adult mortality for all three insect species at dosages of 50,000 ppm and 500 μgg/insect in fumigant and contact toxicity bioassays, respectively. Adults of C. maculatus and S. oryzae were highly susceptible to the essential oils of the three genotypes in both fumigant and contact toxicity bioassays. The essential oil of genotype TM-1 deterred oviposition in T. castaneum by 81% and suppressed its egg hatchability by 91% when applied at a dosage of 70,000 ppm on filter paper.RésuméDes huiles essentielles extraites des trois génotypes de Tagetes minuta, six de Tagetes patula et quinze de Tagetes erecta ont été évaluée pour leur toxicité par fumigation ou contact, envers les bruches Callosobruchus maculatus (Fabricius), Sitophilus oryzae (Linnaeus) et Tribolium castaneum (Herbst). Les génotypes TM-1 de T. minuta, TP-2 de T. patula et TE-13 de T. erecta étaient les plus toxiques. Les trois génotypes ont été ensuite évalués pour leur toxicité envers les adultes, leurs effets sur l’oviposition et le pouvoir ovicide, et la réduction de la population chez T. castaneum. Les huiles essentielles des génotypes TM-1 et TP-2 ont provoqué une mortalité totale chez les adultes des trois insectes, à la dose de 50,000 ppm dans des essais de fumigation et à la dose de 500 μg/insecte dans les tests de toxicité par contact. Les adultes de C. maculatus et S. oryzae étaient les plus sensibles à l’effet des huiles essentielles des trois génotypes, à la fois dans les essais de fumigation et de toxicité par contact. Les huiles essentielles de TM-1 ont réduit de 81% l’oviposition et de 91% le taux d’éclosion à la dose de 70,000 ppm appliquée sur du papier-filtre.

Sesamin a potent antifeedant principle from Piper mullesua

Sesamin, a major lignan of Piper mullesua of Manipur origin, exhibited significant antifeedant activity and moderate growth inhibition towards 4th instar larvae of Spilarctia obliqua. No larval toxicity of sesamin could be established in topical bioassay experiments. Its effective dose for 50% feeding deterrence (ED50) and growth inhibition (GI50) were found to be 3856 and 6212 ppm, respectively. Copyright