Intraspecific Chemical Variability of Essential Oil of Hoslundia opposita
Chemical investigation on leaves oil of Hoslundia opposita, aromatic plant used 
in traditional medicine, harvested from 20 localities of C?te d’Ivoire 
was realized by GC and GC/MS. In total, 101 compounds were identified 
accounting to 92% - 99%, aromatic compounds such benzyl benzoate and sesquiterpenes 
namely germacrene D, β-caryophyllene and α-humulene hydroxyl were found as the major constituents. As regard, 
the chemical profiles of our samples, it was found a great chemical variability 
suggesting a high polymorphism degree. In order to study this chemical 
variability, the results were submitted to the principal components and cluster 
analysis which allowed distinguishing two main groups of essential oils with 
respect to sampling site. The cluster I was dominated by benzyl benzoate (15%) 
and thymol (7.4%) comprising 6 localities, cluster II was characterized by 
phytol (8.5%) and α-humulene (7%) and constituted by 14 localities.
Insectifugal and insecticidal potentials of two tropical botanical essential oils against cowpea seed bruchid
Essential oils (EO) obtained from Xylopia parviflora root bark and Hoslundia opposita leaf via hydro distillation were analysed by GC-MS and evaluated for their insectifugal (repellent) and insecticidal activities against cowpea seed bruchid (Callosbruchus maculatus Fabricius), a cosmopolitan pest of cowpea seeds. X. parviflora was predominated by sesquiterpenes (59.57%), with the main compounds being β-himachalene (22.68%), 1,7,7,Trimethylbicyclo[2.2.1]hept-5-en-2-ol (19.68%), β-elemene (14.41%), 5(1H)-Azulenone, 2,4,6,7,8,8a–hexahydro-3,8-dimethyl-4-(1-methylethylidene)-(85-cis)- (12.38%) and (−)-α-parasinsen (8.34%). The predominant compounds in H. opposita EO were 1,8-cineole (61.15%), followed by α-terpineol (16.81%) and β-phellandrene (13.25%). Percentage repellence at application rates of 0.66–1.32 μl/cm2 (46.93–73.07%) was significantly (p < 0.05) higher than that of control (17.73%). RD50 (repellence dose for 50% of treated adults) for H. opposita (0.43 μl/cm2) was not significantly different from the value for X. parviflora (0.60 μl/cm2). Although higher percentage of male mortality than female mortality was observed due to topical application of the EOs, the disparity was not significant. The results of correlation of the chemical groups of the EOs with the insectifugal activity indicate that the observed bioactivity was due to the synergistic effects of the chemical groups. The two EOs are therefore recommended for incorporation into bruchid protection schemes in the tropics.
AN INTRODUCTION T O THE SOILS OF THE SOUTH-EASTERN PORTION OF THE AUSTRALIAN ARID ZONE
Summary 
 
Seven soil regions, each of which is dominated by soils belonging to one or two great soil groups, are defined and mapped. The outstanding feature is the presence of a variety of soils with widely differing characteristics. The soils are deeper, have more profile differentiation and are finer-extured than those in most-arid regions and are frequently overlain by currently-forming deposits of wind-transported materials. Because the vegetative cover is better developed and there are only small areas of rocky hills and bare rock pediments, water erosion and deposition are not as prominent as in other arid areas.