Relative Components of Neem Berry and Biocidal Effects of Kernel Extracts Against The Adult of Agonoscelis Pubescens (Thunb.)

Neem (Azadirachta indica) seed extracts proved potent insecticidal effects against various pests in Sudan. In the course of studyingneem products as rich sources of natural insecticides, this research was undertaken to quantify the relative components of neem berries that might help in estimating the portions needed in preparation of natural products, and to study the insecticidal effects of different kernel extracts against the adult sorghum bug (Agonoscelis pubescens). Three extracts (water, hexane and methanol) were bio assayed at different doses in comparison with a standard insecticide (Malathion 57% EC). The results revealed that seeds kernels, the richest neem part in active compounds, represent 20.1% and 43.4% of corticated seeds and fruit berries, respectively. Accordingly, a sack (100kg) of neem berries can provide an amount of kernels almost equivalent to one fifth of its weight. The kernels yielded 46.3% oil (hexane extracted) as the highest extract obtained. Such oil also revealed higher insecticidal effects against the adult sorghum bug than water and methanol extracts. In all extracts, the mortality rates generally increased in response to concentration and exposure time. Neem oil at 8% concentration exerted significantly the highest mortality effects as compared with the other treatments. It showed significantly comparable effect with malathion after three days post application, and scored 100% mortality after a week. Hence, neem oil is advocated for further studies to be assessed under field situations as a component of sorghum bug management program.