Tetranychus truncatus is a phytophagous spider mite that is one of the economic pests of agricultural and economic crops. Its control has been and still is based mainly on the use of chemical controls. Since pesticides compatibility with natural enemies is a main concern for IPM programs, the aim of this study was carried out to explore the toxicity, repellency, oviposition deterrent and eggs hatching inhibition of crude ethyl acetate extract of Moelleriella raciborskii and their secondary metabolites against adults and eggs of T. truncatus. The results indicated that M. raciborskii crude extract at 5% (w/v) had high contact toxicity (89% mortality) on adult females of T. truncatus. The LC50 value was 1.476%, 1.026 and 0.732% after 24, 48 and 72 h posttreatment. Among the two steroidal and two hopane triterpenes separated from the ethyl acetate extract, 3β-acetoxy-15α,22-dihydroxyhopane was identified as the most active compound with LC50 values of 0.232% (w/v), followed by ergosterol, ergosterol 5, 8-endoperoxide with LC50 values of 0.235% and 0.318% at 72 h posttreatment, respectively. In addition, 3β-acetoxy-15α,22-dihydroxyhopane showed strong repellency (70.19%) and ergosterol and ergosterol 5, 8-endoperoxide decreased egg production of T. truncatus by 70.35 and 67.98%, respectively. Strong oviposition deterrent (ODI=100) was noted when 0.5% (w/v) crude extract was applied on half of the leaf disc. The crude ethyl acetate extract of M. raciborskii could have potential for the development of novel acaricides to control T. truncatus for use in an integrated pest management program.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 27 • No. 6