Abstract
Mortality (%) of the 1st instar larvae of the cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), treated with different concentrations of the wild plant Conyza dioscoridis extracts was recorded. The two tested extracts; hexane and acetone, exhibited insecticidal activity against the 1st instar larvae of P. gossypiella. Hexane extract was more toxic than acetone extract. LC50 values were 2.32 and 6.58 (g extract/ 100g diet) for hexane and acetone extracts, respectively. GC-MS analysis of C. dioscoridis hexane extract revealed the presence of precocene (22.85%), berkheyaradulen (15.04%), a-Guaiene (5.65%), Junipene (5.02%), c-Cadinene (5:17%), Epiglobulol (6.96%), A-Cadinol (4.86%), (-)-a-Selinene (4.95%). The present findings may encourage more research aiming to find out new biopesticides based on botanical resources and more purification and identification of active compounds from C. dioscoridis.