Screening of Dialkoxybenzenes and Disubstituted Cyclopentene Derivatives against the Cabbage Looper, Trichoplusia ni, for the Discovery of New Feeding and Oviposition Deterrents

Abstract

The antifeedant, oviposition deterrent, and toxic effects of dialkoxybenzene minilibraries and of disubstituted cyclopentene minilibraries (i.e., consisting of four to five compounds) along with their pure constituent compounds were assessed against third instar larvae and adults of the cabbage looper, Trichoplusia ni, in laboratory bioassays in a search for new insect control agents. These compounds mimic naturally occurring bioactive odorants and tastants and are relatively easily prepared from commodity chemicals. Most of these libraries strongly deterred larval feeding, with some exhibiting strong toxic and oviposition deterrent effects as well. Our results suggest some structure-function relationships within these libraries. Replacement of a methyl group with larger alkyl substituents increased the feeding deterrent effects in most cases. The presence of a free hydroxyl group, irrespective of the carbon framework or alkyl substituent, served to reduce feeding deterrent effects in all series of compounds. Further, exceeding a certain group size also generally had a detrimental effect. This information will be useful in designing new insect control agents for agriculture. Some of these libraries and compounds may have potential for development as commercial insecticides.

Can We Disrupt the Sensing of Honey Bees by the Bee Parasite Varroa destructor?

“…We tested two classes of compounds: dialkoxybenzenes and 5-2′hydroxyethyl-2-cyclopenten-1-ol ether derivatives (“cy” compounds). In particular, we have compared the effect of four dialkoxybenzenes that showed activity against insects [19],[30],[31], and six “cy” compounds on the ability of the Varroa olfactory organ to detect stimuli consisting of nurse honey bee volatiles. We utilized the headspace of nurse bees as a positive stimulus.…”

Semisynthesis and Antifeedant Activity of New Derivatives of a Dihydro-β-Agarofuran from Parnassia wightiana

“…Next, compound 1 and derivatives ( 2 – 6 ) was evaluated for their antifeedant activity against M. separata using a leaf disk choice bioassay [22]. The results are presented in Table 3.…”

“…Third instar larvae of M. separata Walker (armyworm), provided by the Institute of Pesticides, Northwest A & F University, were used as test insect for evaluation of antifeedant activity using a leaf disk choice bioassay [22]. M. separata was continuously maintained on a Petri dish (Ø 10 cm) in a growth chamber in our laboratory at a temperature of 27 ºC and 60% relative humidity under a 16L:8D photoperiod.…”

Primula spectabilis Tratt. aerial parts: Morphology, volatile compounds and flavonoids

“…The elevated production of benzenoids with a different structure (alkoxybenzenes) with respect to those synthesized by the flower is noteworthy. They may be involved in the chemical defence of leaves, both as repellent against herbivorous and as attractant for parasitoids, as well as allelopathic agents (Akhtar et al, 2007;Paduraru et al, 2008;Pettersson and Boland, 2003).…”