This study involved both greenhouse and laboratory experiments evaluating the effect of an essential oil product (QRD 400) derived from Chenopodium ambrosioides variety nr. Ambrosioides L. (Chenopodiaceae) on greenhouse insect pests that feed on different plant parts: citrus mealybug, Planococcus citri (Risso); longtailed mealybug, Pseudococcus longispinus (Targioni Tozzetti); western flower thrips, Frankliniella occidentalis (Pergande), and fungus gnats (Bradysia spp.). Treatments were applied to coleus, Solenostemon scutellarioides plants; transvaal daisy, Gerbera jamesonii flowers; or growing medium, depending on the insect pest. The essential oil was most effective, based on adult emergence, on both the second and third instars of the fungus gnat Bradysia sp. nr. coprophila when applied as a drench to growing medium. In addition, there was a significant rate response for QRD 400 on fungus gnats. The QRD 400 treatment had the highest percentage of mortality on longtailed mealybug (55%) compared with the other treatments. However, the essential oil was less effective against citrus mealybug (3% mortality) and western flower thrips adults (18–34% mortality) compared with standard insecticides, such as acetamiprid (TriStar) and spinosad (Conserve), which are typically used by greenhouse producers. This lack of efficacy may be associated with volatility and short residual properties of the essential oil or with the essential oil taking longer to kill insect pests. Other insecticides and miticides evaluated, including sesame oil, garlic, paraffinic oil, and Bacillus thuringiensis subsp. israelensis, provided minimal control of the designated insect pests. In addition, adult rove beetle Atheta coriaria Kraatz adults were not effective in controlling the larval instars of fungus gnats when applied at a rate of five adults per container.
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. 100 • No. 2