title: Assessment of species specificity of moulting accelerating compounds in Lepidoptera: comparison of activity between Bombyx mori and Spodoptera littoralis by in vitro reporter and in vivo toxicity assays.
abstract: BACKGROUND
  Dibenzoylhydrazine analogues have been developed successfully as a new group of insect growth regulators, called ecdysone agonists or moulting accelerating compounds. A notable feature is their high activity against lepidopteran insects, raising the question as to whether species-specific analogues can be isolated. In this study, the specificity of ecdysone agonists was addressed through a comparative analysis in two important lepidopterans, the silkworm Bombyx mori L. and the cotton leafworm Spodoptera littoralis (Boisd.).
  
  
  RESULTS
  When collections of non-steroidal ecdysone agonists containing different mother structures (dibenzoylhydrazine, acylaminoketone, tetrahydroquinoline) were tested, in vitro reporter assays showed minor differences using cell lines derived from both species. However, when compounds with high ecdysone agonist activity were examined in toxicity assays, larvicidal activity differed considerably. Of note was the identification of three dibenzoylhydrazine analogues with > 100-fold higher activity against Bombyx than against Spodoptera larvae.
  
  
  CONCLUSIONS
  The present study demonstrated that species-specific ecdysone-agonist-based insecticides can be developed, but their species specificity is not based on differences in the activation of the ecdysone receptor but rather on unidentified in vivo parameters such as permeability of the cuticle, uptake/excretion by the gut or metabolic detoxification.
authors.affiliation: Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Soin
authors.forename: Ellen
authors.initials: E
authors.lastname: De Geyter
authors.forename: Hadi
authors.initials: H
authors.lastname: Mosallanejad
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Iga
authors.forename: David
authors.initials: D
authors.lastname: Martín
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Ozaki
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kitsuda
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Harada
authors.forename: Hisashi
authors.initials: H
authors.lastname: Miyagawa
authors.forename: Dimitra
authors.initials: D
authors.lastname: Stefanou
authors.forename: Georgia
authors.initials: G
authors.lastname: Kotzia
authors.forename: Rodica
authors.initials: R
authors.lastname: Efrose
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Labropoulou
authors.forename: Danny
authors.initials: D
authors.lastname: Geelen
authors.forename: Kostas
authors.initials: K
authors.lastname: Iatrou
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Colin R
authors.initials: CR
authors.lastname: Janssen
authors.forename: Guy
authors.initials: G
authors.lastname: Smagghe
authors.forename: Luc
authors.initials: L
authors.lastname: Swevers
mesh_terms: D000818:Animals; D012831:Bombyx / Q000187:drug effects* / Q000378:metabolism; D002460:Cell Line; D004440:Ecdysone / Q000819:agonists / Q000037:antagonists & inhibitors; D017930:Genes, Reporter / Q000235:genetics*; D006834:Hydrazines / Q000633:toxicity; D007605:Juvenile Hormones / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D018978:Molting / Q000187:drug effects*; D011987:Receptors, Steroid / Q000378:metabolism; D013045:Species Specificity; D018411:Spodoptera / Q000187:drug effects* / Q000378:metabolism; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D006834:Hydrazines; D007605:Juvenile Hormones; D011987:Receptors, Steroid; C055469:ecdysone receptor; D004440:Ecdysone; C082026:tebufenozide