Four ecdysone agonists, RH-5849, RH-5992, RH-0345, and RH-2485, were tested for toxicity against fifth-instar larvae of Choristoneura fumiferana. RH-2485 was the most toxic (LD50 = 1.05 ng/larva) followed by RH-5992 (LD50 = 8.8 ng/larva), RH-0345 (LD50 = 41.0 ng/larva), and RH-5849 (LD50 = 236.9 ng/larva). The relative potencies of these compounds to induce the transcription factor Choristoneura hormone receptor 3 (CHR3) was studied. Detectable levels of CHR3 mRNA were induced by RH-2485 at a concentration as low as 1.5 ng/larva, but similar inductions required concentrations as high as 7.5 ng of RH-5992/larva, 37.5 of RH-0345/larva, and 187.5 of RH-5849/larva. The order of potency of these four ecdysone agonists for inducing CHR3 mRNA is the same as their larval toxicity.
|Number of pages||8|
|Journal||Pesticide Biochemistry and Physiology|
|State||Published - Dec 1998|
Bibliographical noteFunding Information:
We thank Rohm and Haas company scientists for supplying compounds, Dr. Sardar S. Sohi for critical comments on the manuscript, Ms. K. Jamieson for editorial help. This research was supported by a Canadian Forest Service/Natural Sciences and Engineering Research Council Research Partnership Program Award CRD No. 0192158, with Rohm and Haas Company.
- Hormone receptor 3
- Pest control
- Spruce budworm
- Transcription factor
ASJC Scopus subject areas
- Agronomy and Crop Science
- Health, Toxicology and Mutagenesis