Acaricidal properties of extracts of some medicinal and culinary plants against Tetranychus urticae Koch.

Abstract

Pavela R. (2016): Acaricidal properties of extracts of some medicinal and culinary plants against Tetranychus urticae Koch. Plant Protect. Sci., 52: 54-63.The acaricidal activity of aqueous extracts obtained from 28 plant species was tested against Tetranychus urticae. The extract efficacy on the incidence of individual development stages of T. urticae on the treated plants was determined, compared to untreated plants. Of the 28 extracts, 24 showed an efficacy higher than 50%; of these, 16 extracts caused a reduction in the count of adults on the plants by more than 90% compared to the control. The counts of nymphs and eggs showed significant differences depending on the extract used. Only 13 extracts showed an efficacy higher than 50%, and only 2 extracts (obtained from ammi visnaga and Saponaria officinalis) had more than 90% efficacy. Twenty extracts resulted in eggs reduction of more than 50% compared to the control; of these, 6 extracts (from a. visnaga, G. glabra, J. palmata, l. carthamoides, O. majorana, S. officinalis) exhibited an efficacy higher than 90%. Extracts with the highest efficacy were tested for their acute toxicity for T. urticae adults, and LD 50(90) values were estimated. By comparing the confidence intervals (CI 95 ) for individual LD 50 values, extracts obtained from Saponaria officinalis roots and ammi visnaga seeds were found to provide the significantly highest efficacies, and lethal doses (LD 50 ) of 10.3 and 12.5 g/l, respectively, were estimated for them. However, wanting to compare LD 90 values as well, we chose 5 extracts (a. visnaga, C. annum, M. × piperita, O. majorana, and S. officinalis) whose CI 95 intervals overlapped (P ≤ 0.05). Based on our tests, aqueous extracts from S. officinalis roots can be recommended for the development of products which reduce the incidence of T. urticae on plants.

Effect of the extract and compound from Solanum nigrum Linn on Tetranychus cinnabarinus

“…In addition, according to Chen and Dai (), Cinnamomum camphora crude extracts showed a similar acaricidal efficacy as S. nigrum crude extract in the same bioassays. Moreover, similar results were observed by Pavela (), who published the efficacy of aqueous extracts obtained from 28 plant species, and extracts obtained from Saponaria officinalis roots and Ammi visnaga seeds were found to provide the significantly highest efficacies with LC 50 of 10.3 and 12.5 g/l, respectively, which are still much higher than S. nigrum crude extract, even though they were tested against Tetranychus urticae Koch, whereas the methanol extract of A. visnaga seeds showed a more remarkable persistence than the extract we tested in this study, for which LC 90 was estimated as lower than 5.0 g/l against adult T. urticae after 10 days of treatment (Pavela ). Furthermore, many other plant extracts from different families found by various authors are considered acaricides under in vitro laboratory conditions, including Eucalyptus camaldulensis (Mansour et al.…”

Activité Acaricide Des Huiles Essentielles Du Mentha Pulegium, Origanum Compactum Et Thymus Capitatus Sur L’acarien Phytophage Tetranychus Urticae Koch (Acari : Tetranychidae)

“…D'autres constituants ont aussi été détectés dans l'huile de cette menthe mais à des concentrations peu importantes i.e., eucarvone (13,8%), menthone (2,16%), limonène (1,62%) et p-mentha, 8 en3-one (1,52%). Dans la littérature, de nombreux travaux ont aussi trouvé que l'huile essentielle de la menthe pouliot contient le pulégone comme principal constituant, avec un pourcentage variant de 25 à 92% (e.g., Rodrigues, 2013) (Pavela, 2016) ; selon cet auteur, l'incidence de l'infestation des plantes est nulle lorsqu'elles sont traitées avec l'origan.…”

URSOLIC ACID AND CIS-TILIROSIDE PRODUCED BY Merremia tomentosa AFFECT OVIPOSITION OF Leucoptera coffeella ON COFFEE PLANTS

“…Thus, an effort to discover natural products affecting the oviposition of insects has been pursued in recent years. 5,48 Such an approach resulted in the selection of M. tomentosa among several plant species studied as part of a project aiming to identify the biological activities of metabolites produced by native plants in Minas Gerais State, Brazil (Table 1S). Only the extract from leaves of this plant reduced the oviposition of the insect to values statistically equal to those obtained with the commercial insecticide chlorpyrifos, which was used as the positive control in the present work because no product that affects the oviposition of L. coffeella without killing the adults has been described in the literature (Table 1).…”

“…4 To circumvent such a problem, plants appear to be promising sources of new products to control insects, since many research groups have demonstrated the ability of several plant species to produce substances active against insects. 5 Consequently, to contribute to the development of new methods to control the coffee leaf miner, this work initially aimed to select plants able to produce substances that could affect the oviposition of L. coffeella on coffee plants. Then, the most active extract against L. coffeella was submitted to successive fractionation steps to achieve the isolation and identification of the major substances of the extract, so that they could be tested against the insect.…”